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Interleukin-7 (IL-7) in Colorectal Cancer: IL-7 is Produced by Tissues from Colorectal Cancer and Promotes Preferential Expansion of Tumour Infiltrating Lymphocytes
Abstract
Despite increasing survival rates for patients with colorectal cancer, additional treatment options are required, including active or passive immunotherapy for patients with metastatic disease. Freshly harvested colorectal cancer specimens and in vitro cultured colorectal cancer cell lines were examined for IL-7 protein secretion in order to examine the potential role of this cytokine in the interaction between tumour cells and the host immune system. Freshly harvested colorectal cancer specimens (21/21), or normal adjacent mucosa (3/3), as well as long-term established colorectal cancer cell lines (3/4) exhibited IL-7 mRNA expression as detected by RT-PCR and confirmed by Southern Blot analysis. Freshly harvested colorectal cancer tissue (16/18), or long-term established colorectal cancer cell lines (2/4) secreted in vitro IL-7 as detected by ELISA. In contrast, breast, pancreatic, or lung cancer cell lines, as well as several haematopoietic cancer cells lines, tested negative for IL-7 mRNA and protein. The authors tested different cytokines (IL-1β, IL-2, IL-7, or a combination of IL-1β/IL-7) in vitro for the ability to expand tumour-infiltrating T lymphocytes (TIL) from individual patients (n = 9) with colorectal cancer. TIL populations were tested at day 14 after in vitro propagation for phenotypic analysis by FACS and for reactivity directed against NK and LAK sensitive target cells and autologous cancer cells as measured by cytotoxicity and cytokine release. TIL obtained from colorectal cancer lesions can be efficiently expanded in the presence of IL-7, some (3/9) of which appear to exhibit autologous tumour recognition as measured by cytolytic effector functions and by detection of IFNγ and TNFα release. Detection of IL-7 mRNA expression in colorectal cancer, in normal mucosa adjacent to tumour, as well as the ability of colorectal cancer tissue to secrete IL-7, raises new questions about the biology of the host/tumour interactions in colorectal cancer.
... Concerning colon cancer, IL-7 was evaluated in single-cell suspensions derived from patients [31], in human colon carcinoma xenografts [32], and mouse models of peritoneal and lung metastasis [33]. Maeurer et al. [31] demonstrated that tumor cells obtained from CRC patients synthesize and secrete IL-7, and that mRNA for IL-7 is present in both tumor and tumor-adjacent tissue. ...
... Concerning colon cancer, IL-7 was evaluated in single-cell suspensions derived from patients [31], in human colon carcinoma xenografts [32], and mouse models of peritoneal and lung metastasis [33]. Maeurer et al. [31] demonstrated that tumor cells obtained from CRC patients synthesize and secrete IL-7, and that mRNA for IL-7 is present in both tumor and tumor-adjacent tissue. We, in turn, showed that these results translate into protein, as IL-7 was detectable in both tumors and macroscopically normal tissue adjacent to the tumors. ...
... Studies on the IL-7 effect on colon-cancer cells yielded consistent results, showing that IL-7 alone had neither a positive nor a negative effect on tumors. Unlike in breast and lung cancers, IL-7 did not stimulate proliferation of colon-cancer cells [31,33]. Of note, the lack of mitogenic activity toward keratinocytes was recently also observed [34]. ...
Background and objectives:
Interleukin-7 (IL-7) is exploited in cancer immunotherapies although its status in solid tumors is largely unknown. We aimed to determine its systemic and local concentrations in esophageal (EC), gastric (GC), and colorectal (CRC) cancers.
Materials and methods:
IL-7 was immunoenzymatically measured in paired surgical specimens of tumors and tumor-adjacent tissue (n = 48), and in the sera of 170 individuals (54 controls and 116 cancer patients). Results: IL-7 was higher in tumors as compared to noncancerous tissue in all cancers (mean difference: 29.5 pg/g). The expression ratio (tumor to normal) was 4.4-fold in GC, 2.2-fold in EC, and 1.7-fold in CRC. However, when absolute concentrations were compared, the highest IL-7 concentrations were in CRC, both when tumor and noncancerous tissue were analyzed. In CRC tumors, IL-7 was 2 and 1.5 times higher than in EC and GC tumors. In noncancerous CRC tissue, IL-7 was 2.3- and 2.8-fold higher than in EC and GC. IL-7 overexpression was more pronounced in Stage 3/4 and N1 cancers as a result of decreased cytokine expression in noncancerous tissue. Tumor location was a key factor in determining both local and systemic IL-7 concentrations. Serum IL-7 in CRC and EC was higher than in controls, GC, and patients with adenocarcinoma of gastric cardia (CC), but no significant correlation with the disease advancement could be observed. Conclusions: IL-7 protein is overexpressed in EC, GC, and CRC, but concentrations differ both in tumor and tumor-adjacent tissue with respect to tumor location. More advanced cancers have lower IL-7 concentrations in the immediate environment of the tumor. At the systemic level, IL-7 is elevated in CRC and EC, but not CC or GC. IL-7 dependence on the location of the primary tumor should be taken into account in future IL-7-based immunotherapies. Functional studies explaining a role of IL-7 in gastrointestinal cancers are needed.
... Human IL-7 which has initially been characterized in a hepatocarcinoma cell line (12) is expressed and secreted from colorectal cancer cells (13). In contrast to IL-7, there is widespread IL-15 mRNA expression in a number of tissues and cells, such as placenta, kidney, some epithelial cells and activated macrophages (1,13). ...
... Human IL-7 which has initially been characterized in a hepatocarcinoma cell line (12) is expressed and secreted from colorectal cancer cells (13). In contrast to IL-7, there is widespread IL-15 mRNA expression in a number of tissues and cells, such as placenta, kidney, some epithelial cells and activated macrophages (1,13). However, biologically meaningful IL-15 protein secretion has exclusively been demonstrated in macrophages after stimulation with LPS or after infection with intracellular bacteria or parasites (14,15). ...
... IL-7 has been reported to be produced by human and murine keratinocytes (41,42), by human interdigitating dendritic cells (24) and serves as a major growth factor for dendritic epidermal T-cells (DTEC) expressing the yô TCR (41,43). Like IL-2, IL-7 promotes the preferential expansion of tumor-infiltrating lymphocytes obtained from patients with colorectal cancer (6,13). Longterm /'/; vitro culture with IL-7 of human intestinal intra epithelial lymphocytes (ilEL) harvested from patients with colorectal cancer results in preferential outgrowth of yô + Tcells (Völ + ) (6) which recognize colorectal cancer cells, renal cell cancer, and pancreatic cancer cell lines. ...
Although not structurally related, the pleiotropic cytokines interleukin-7 (IL-7) and interleukin-15 (IL-15) share a variety of biological functions including stimulation and maintenance of cellular immune responses. Cytokines, such as IL-7 or IL-15, elaborated by cells in situ, e.g. cancer cells, may be involved in shaping the quality of anti-tumor directed immune responses. We have analysed the constitutive and IFN-gamma-inducible expression of IL-15 or IL-7 mRNA, protein expression, and protein secretion in human tumor cell lines of distinct origin. IL-15 mRNA expression was detected in renal cell carcinoma (RCC), small cell lung carcinoma (SCLC), glioblastoma, neuroblastoma, mesothelioma cells and in EBV-transformed B-lymphocytes. IL-7-specific transcripts could be detected in colorectal cancer and in renal cell cancer cell lines. Immunohistochemical analysis demonstrated cytosolic IL-15 protein expression in renal cell cancer cells without apparent IL-15 protein secretion in vitro. Time kinetic analyses revealed that IFN-gamma mediated increase of IL-15 mRNA expression was transcriptionally regulated and dependent on de novo protein synthesis. However, enhanced IL-15 mRNA expression did not lead to effective protein secretion. In contrast, IL-7 mRNA expression in renal cell cancer or in colorectal cancer was associated with effective protein secretion which could be augmented by IFNgamma-treatment. These data suggest that both IL-7 and IL-15 mRNA are expressed in renal cell cancer, but exclusively IL-7 may be elaborated by tumor cells in situ. IL-15 regulation appears to be tightly controlled both at the transciptional and post-transcriptional level. Appropriate stimuli leading to effective IL-15 secretion from tumor cells may aid in modulating cellular immune responses directed against cancer.
... However, there is an increasing number of reports showing IL-7 to be overexpressed by solid tumors [11,[16][17][18][19] and being elevated in sera of the cancer patients [20][21][22][23][24]. Although functional data are still scanty, available evidence seems to link IL-7 overexpression with tumor aggressiveness, metastasis, and unfavorable prognosis [11,19]. ...
... There is paucity of data concerning IL-7 in CRC and conditions predisposing to the disease. IL-7 expression was found in tumor biopsies obtained from CRC patients [16], and it was reported by Crucitti et al. ...
Interleukin (IL)-7 is a cytokine essential for protective immunity, and it is considered as a promising agent for cancer immunotherapy. Recent studies, however, appear to associate IL-7 with aggressiveness of solid tumors. The IL-7 has been less studied in colorectal cancer (CRC) and conditions associated with increased risk of CRC development. To explore IL-7 status in bowel diseases, it was measured immunofluorometrically in 431 individuals (110 with CRC) by using Luminex platform. A level of IL-7 in CRC patients was significantly higher than in controls, did not differ from those with adenomas, but was lower than in both active and inactive inflammatory bowel disease (IBD) cases. In CRC, IL-7 was higher in patients with lymph node and distant metastases and with tumors located in right colon. In adenomas, IL-7 elevation was associated exclusively with villous growth pattern, while in IBD, circulating IL-7 reflected clinical activity of Crohn’s disease and ulcerative colitis. Systemic TNFα, IL-10, and PDGF-BB were independent predictors of circulating IL-7. In summary, our study is the first to demonstrate IL-7 elevation in CRC in association with metastatic disease and tumor location. Both associations should be considered when designing IL-7-based immunotherapies for CRC. Further studies on IL-7 functionality in CRC are necessary.
... FLT1, also known as VEGFR-1, a high-affinity receptor for VEGF, is expressed on CRC cells and its activation is related to tumor progression and metastasis [60]. IL7 is expressed in CRC and promotes the outgrowth of cancer-derived TIL [61]. KDM3A is an independent unfavorable prognostic factor in CRC patients and it acts as an oncogene to regulate the migration and invasion of cancer cells by regulating EMT and MMPs [62]. ...
Accumulated evidence highlights the biological significance of diverse protein post-translational modifications (PTMs) in tumorigenicity and progression of colorectal cancer (CRC). In this study, ten PTM patterns (ubiquitination, methylation, phosphorylation, glycosylation, acetylation, SUMOylation, citrullination, neddylation, palmitoylation, and ADP-ribosylation) were analyzed for model construction. A post-translational modification index (PTMI) with a 14-gene signature was established. CRC patients with high PTMI had a worse prognosis after validating in nine independent datasets. By incorporating PTMI with clinical features, a nomogram with excellent predictive performance was constructed. Two molecular subtypes of CRC with obvious difference in survival time were identified by unsupervised clustering. Furthermore, PTMI was related to known immunoregulators and key tumor microenvironment components. Low-PTMI patients responded better to fluorouracil-based chemotherapy and immune checkpoint blockade therapy compared to high-PTMI patients, which was validated in multiple independent datasets. However, patients with high PTMI might be sensitive to bevacizumab. In short, we established a novel PTMI model by comprehensively analyzing diverse post-translational modification patterns, which can accurately predict clinical prognosis and treatment response of CRC patients.
... Greater than 70% of the patients with T-ALL have IL7R-positive blast cells, and disease status is closely associated with IL7Ra expression. In previous studies, IL-7, IL-4, and IL-2 were confirmed to be growth factors in pediatric T-ALL [13][14][15] ; however, other studies have demonstrated that upregulation of BCL-2 expression after IL7 binding to the IL7R is an efficient inhibitor of spontaneous apoptosis in T-ALL cells 44,45 . ...
Objective:
Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant gastrointestinal cancer with a 5-year survival rate of only 9%. Of PDAC patients, 15%-20% are eligible for radical surgery. Gemcitabine is an important chemotherapeutic agent for patients with PDAC; however, the efficacy of gemcitabine is limited due to resistance. Therefore, reducing gemcitabine resistance is essential for improving survival of patients with PDAC. Identifying the key target that determines gemcitabine resistance in PDAC and reversing gemcitabine resistance using target inhibitors in combination with gemcitabine are crucial steps in the quest to improve survival prognosis in patients with PDAC.
Methods:
We constructed a human genome-wide CRISPRa/dCas 9 overexpression library in PDAC cell lines to screen key targets of drug resistance based on sgRNA abundance and enrichment. Then, co-IP, ChIP, ChIP-seq, transcriptome sequencing, and qPCR were used to determine the specific mechanism by which phospholipase D1 (PLD1) confers resistance to gemcitabine.
Results:
PLD1 combines with nucleophosmin 1 (NPM1) and triggers NPM1 nuclear translocation, where NPM1 acts as a transcription factor to upregulate interleukin 7 receptor (IL7R) expression. Upon interleukin 7 (IL-7) binding, IL7R activates the JAK1/STAT5 signaling pathway to increase the expression of the anti-apoptotic protein, BCL-2, and induce gemcitabine resistance. The PLD1 inhibitor, Vu0155069, targets PLD1 to induce apoptosis in gemcitabine-resistant PDAC cells.
Conclusions:
PLD1 is an enzyme that has a critical role in PDAC-associated gemcitabine resistance through a non-enzymatic interaction with NPM1, further promoting the downstream JAK1/STAT5/Bcl-2 pathway. Inhibiting any of the participants of this pathway can increase gemcitabine sensitivity.
... IL-7, encoded by the IL7 gene, is a 25 kDa secreted soluble protein, which was initially discovered by Hunt et al. in 1987 when they explored the latent role of bone marrow stromal cells in the development of the pre-B cell subset (12,13). Subsequently, increasing evidence proved that except for thymocytes and stromal non-hematopoietic cells (14), IL-7 is also secreted by lymphoid organs, non-lymphoid tissues, and even cancers (15)(16)(17)(18)(19)(20) (Figure 1). The receptor of IL-7 is a heterodimer complex that comprises an IL-7Ra chain (CD127, encoded by the IL7R gene) and a common g chain (CD132, encoded by the IL2RG gene) shared with receptors for IL-2, IL-4, IL-7, IL-9, IL-15 and IL-21 (21, 22). ...
Cancer vaccines exhibit specificity, effectiveness, and safety as an alternative immunotherapeutic strategy to struggle against malignant diseases, especially with the rapid development of mRNA cancer vaccines in recent years. However, how to maintain long-term immune memory after vaccination, especially T cells memory, to fulfill lasting surveillance against cancers, is still a challenging issue for researchers all over the world. IL-7 is critical for the development, maintenance, and proliferation of T lymphocytes, highlighting its potential role as an adjuvant in the development of cancer vaccines. Here, we summarized the IL-7/IL-7 receptor signaling in the development of T lymphocytes, the biological function of IL-7 in the maintenance and survival of T lymphocytes, the performance of IL-7 in pre-clinical and clinical trials of cancer vaccines, and the rationale to apply IL-7 as an adjuvant in cancer vaccine-based therapeutic strategy.
... In PEs, the association of high IL-7 levels with lower survival of patients could be related to the tumor development. Since MPM cells can secrete IL-7, as shown for some other malignant cells [24][25][26], the higher IL-7 levels in PE may reflect higher tumor burden and serve as a prognostic biomarker of tumor development. Moreover, several publications have described an autocrine action of the IL-7/IL-7R pathway on tumor cells to promote cell proliferation [19]. ...
Malignant pleural mesothelioma (MPM) is an aggressive cancer mainly related to asbestos exposure. Despite recent therapeutic advances, notably immunotherapies, the benefit remains limited and restricted to a small percentage of patients. Thus, a better understanding of the disease is needed to identify new therapeutic strategies. Recently, interleukin 7 receptor (IL‐7R) has been described as being expressed by MPM cells and associated with poorer patient survival. Thus, the aim of this work was to study the IL‐7R/IL‐7 pathway in MPM using patient samples. We found that, although more than 40% of MPM cells expressed IL‐7R, IL‐7 had no effect on their intracellular signalling. Accordingly, the addition of IL‐7 to the culture medium did not affect MPM cell growth. Using The Cancer Genome Atlas (TCGA) database, we showed that high IL7 gene expression in MPM tumours was associated with a higher overall patient survival and an induction of genes involved in the immune response. In pleural effusions (PEs), we found that IL‐7 concentration was not a good diagnostic biomarker. However, we observed that high IL‐7 levels in PEs were associated with shorter survival of MPM patients, but not of lung cancer patients. The prognostic value of IL‐7 was also conserved when only patients with epithelioid mesothelioma, the most common histological type of MPM, were analyzed. Taken together, our study suggests that, although the IL‐7R/IL‐7 signalling pathway is not functional in MPM cells, IL‐7 expression in PEs may have prognostic value in MPM patients.
... This cytokine was officially named interleukin-7 (IL-7) at the 6th International Lymphokine Conference, France (2). Subsequently, it has been confirmed that IL-7 is mainly produced by thymus and bone marrow stromal cells (3), but can also be secreted by lymphoid organs (spleen, tonsil), non-lymphoid tissues (liver, lung, intestine, and skin), and tumors (colorectal cancer, prostate cancer) (4)(5)(6)(7)(8)(9)(10)(11). B and T lymphocytes develop from hematopoietic stem cells (HSCs) and play critical roles in regulating immune responses. ...
Interleukin-7 (IL-7) is produced by stromal cells, keratinocytes, and epithelial cells in host tissues or tumors and exerts a wide range of immune effects mediated by the IL-7 receptor (IL-7R). IL-7 is primarily involved in regulating the development of B cells, T cells, natural killer cells, and dendritic cells via the JAK-STAT, PI3K-Akt, and MAPK pathways. This cytokine participates in the early generation of lymphocyte subsets and maintain the survival of all lymphocyte subsets; in particular, IL-7 is essential for orchestrating the rearrangement of immunoglobulin genes and T-cell receptor genes in precursor B and T cells, respectively. In addition, IL-7 can aid the activation of immune cells in anti-virus and anti-tumor immunity and plays important roles in the restoration of immune function. These biological functions of IL-7 make it an important molecular adjuvant to improve vaccine efficacy as it can promote and extend systemic immune responses against pathogens by prolonging lymphocyte survival, enhancing effector cell activity, and increasing antigen-specific memory cell production. This review focuses on the biological function and mechanism of IL-7 and summarizes its contribution towards improved vaccine efficacy. We hope to provide a thorough overview of this cytokine and provide strategies for the development of the future vaccines.
... To better visualize the data, we created a summary heatmap that grouped cytokines, chemokines, and growth factors into two categories: (1) analytes that are correlated with immunosuppression or unfavorable prognosis [6,[9][10][11][12][13][14][15][16][17][18] or (2) analytes that are correlated with immunostimulation or favorable prognosis in the context of CRC, specifically [19][20][21][22][23][24][25][26] (Figure 3). When designing these two groups, we focused on the implications of a particular analyte when colon cancer cell-derived. ...
Inflammatory cytokines, chemokines, and growth factors are molecular messengers that circulate and have the capability to modify the tumor microenvironment and impact therapeutic response. The characterization of soluble mediators as biomarkers for diagnosis and prognosis is of interest in oncology. We utilize the cytokinome to characterize the response of colorectal tumor cell lines to selected small-molecules in oncology as a proof-of-concept dataset with immunomodulatory analyte heat map rankings for drug and cell line combinations. We observed overall trends in drug class effects with MEK-, BRAF-, PARP-inhibitors, and Imipridones in cytokine, chemokine, and growth factor responses that may help guide therapy selection. MEK-inhibitor treatment downregulated analytes VEGF, CXCL9/MIG, and IL-8/CXCL8 and upregulated CXCL14/BRAK, Prolactin, and CCL5/RANTES. BRAF-inhibitor treatment downregulated VEGF and IL-8/CXCL8, while increasing soluble TRAIL-R2. Treatment with PARP-inhibitors decreased CXCL9/MIG, IL-8/CXCL8, CCL3/MIP-1 alpha, VEGF, and CXCL14/BRAK, while treatment increased soluble TRAIL-R2 and prolactin. Treatment with Imipridones decreased CCL3/MIP-1 alpha, VEGF, CXCL14/BRAK, IL-8/CXCL8, and Prolactin and increased CXCL5/ENA-78. We also observed differential responses to therapeutics depending on the mutational profile of the cell line. In the future, a similar but larger dataset may be utilized in the clinic to aid in the prediction of patient response to immunomodulatory therapies based on tumor genotype.
... . The involvement of IL-7 and IL-7R in colon chronic inflammation agrees with the observation that patients with metastatic colorectal cancer display high IL-7 levels42 and that the cancer tissue itself can secrete IL-7100 . Notably, high IL-7 and IL-7R expression in tumor tissues of breast and lung cancer patients correlates positively with LN metastasis and poorer survival95,96,101,102 . ...
The cytokine IL-7 and its receptor, IL-7R, are critical for T cell and, in the mouse, B cell development, as well as differentiation and survival of naive T cells, and generation and maintenance of memory T cells. They are also required for innate lymphoid cell (ILC) development and maintenance, and consequently for generation of lymphoid structures and barrier defense. Here we discuss the central role of IL-7 and IL-7R in the lymphoid system and highlight the impact of their deregulation, placing a particular emphasis on their ‘dark side’ as promoters of cancer development. We also explore therapeutic implications and opportunities associated with either positive or negative modulation of the IL-7–IL-7R signaling axis. The cytokine IL-7 plays essential roles in lymphocyte development. In their Review, Barata, Durum and Seddon describe IL-7’s key homeostatic functions and how its dysregulation can lead to autoinflammatory disease and cancer.
... Adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TIL) is a personalized cancer treatment based on the infusion of autologous CD4þ and CD8þ T lymphocytes expanded from tumors in the presence of interleukin-2 (IL-2) [1] alone, or in combination with IL-7, IL-15, and/or IL-21 [2][3][4]. CD8þ T cells have historically been considered the primary T-cell mediators driving tumor rejection, although CD4þ T cells have also shown tumor killing potential [5,6]. TILs are polyclonal populations enriched for lymphocytes recognizing tumor-specific antigens, including shared tumor-associated antigens as well as private tumor neoantigens. ...
Background:
Adoptive cell therapy (ACT) using autologous tumor-infiltrating lymphocytes (TIL) has been tested in advanced melanoma patients at various centers. We conducted a systematic review and meta-analysis to assess its efficacy on previously treated advanced metastatic cutaneous melanoma.
Design:
The PubMed electronic database was searched from inception to 17 December 2018 to identify studies administering TIL-ACT and recombinant interleukin-2 (IL-2) following non-myeloablative chemotherapy in previously treated metastatic melanoma patients. Objective response rate (ORR) was the primary endpoint. Secondary endpoints were: complete response rate (CRR), overall survival (OS), duration of response (DOR) and toxicity. Pooled estimates were derived from fixed or random effect models, depending on the amount of heterogeneity detected. Analysis was performed separately for high-dose (HD) and low-dose (LD) IL-2. Sensitivity analyses were performed.
Results:
Among 1,211 records screened, 13 studies (published 1988-2016) were eligible for meta-analysis. Among 410 heavily pretreated patients (some with brain metastasis), 332 received HD-IL-2 and 78 LD-IL-2. The pooled overall ORR estimate was 41% (95% CI: [35-48%]), and the overall CRR was 12% (95% CI: [7-16%]). For the HD-IL-2 group, the ORR was 43% (95% CI: [36-50%]), while for the LD-IL-2 it was 35% (95% CI: [25-45%]). Corresponding pooled estimates for CRR were: 14% (95% CI: [7-20%]) and 7% (95%CI: [1-12%]). The majority of HD-IL-2 complete responders (27/28) remained in remission during the extent of follow-up after CR (median: 40 months). Sensitivity analyses yielded similar results. Higher number of infused cells was associated with a favorable response. The ORR for HD-IL-2 compared favorably to the nivolumab/ipilimumab combination following anti-PD-1 failure.
Conclusion:
TIL-ACT therapy, especially when combined with HD-IL-2, achieves durable clinical benefit and warrants further investigation. We discuss the current position of TIL-ACT in the therapy of advanced melanoma, particularly in the era of immune checkpoint blockade therapy, and review future opportunities for improvement of this approach.
... Bars represent mean values and n = 3 for both groups has been implicated. These include B-ALL [34] and nonhematopoietic malignancies such as non-small cell lung cancer [35], breast [36], colorectal [37], renal [38], esophageal [39], and central nervous system cancers [40]. In addition to treatment with unmodified MAbs, they could be coupled to drugs or toxins or used in combination with other chemotherapeutics or biologics. ...
Pediatric T cell acute lymphoblastic leukemia (T-ALL) cells frequently contain mutations in the interleukin-7 (IL-7) receptor pathway or respond to IL-7 itself. To target the IL-7 receptor on T-ALL cells, murine monoclonal antibodies (MAbs) were developed against the human IL-7Rα chain and chimerized with human IgG1 constant regions. Crystal structures demonstrate that the two MAbs bound different IL-7Rα epitopes. The MAbs mediated antibody-dependent cell-mediated cytotoxicity (ADCC) against patient-derived xenograft (PDX) T-ALL cells, which was improved by combining two MAbs. In vivo, the MAbs showed therapeutic efficacy via ADCC-dependent and independent mechanisms in minimal residual and established disease. PDX T-ALL cells that relapsed following a course of chemotherapy displayed elevated IL-7Rα, and MAb treatment is effective against relapsing disease, suggesting the use of anti-IL7Rα MAbs in relapsed T-ALL patients or patients that do not respond to chemotherapy.
... IL-7 is a monomeric cytokine that is expressed by stromal cells [27], such as epithelial and endothelial cells. It can also be secreted by certain tumor cells [28]. The receptor for IL-7 consists of the γ c and IL-7Rα (CD127). ...
Purpose of Review
In this article, recent advances in the application of cytokine therapeutics in cancer, as single agents or in combination with other immunotherapies, are reviewed. Additionally, critical characteristics that govern cytokine exposure-response properties are discussed.
Recent Findings
Immunotherapy has revolutionized the traditional approach to treating cancer. Targeted therapies, via modulation of the host immune responses, have elevated the expectations for a beneficial impact on patients’ lives. Novel drugs that modulate various steps in the cancer-immunity cycle are now available with an impact on both the magnitude and duration of effect relative to traditional chemotherapeutic approaches. Due to cancer heterogeneity, induction of effective anti-tumor immunity requires the orchestration of several critical events, and hence, combination approaches are being explored. Combination immunotherapy is anticipated to enhance the durability and efficacy profiles of otherwise single agents that can benefit from the “synergistic” effects from the engagement of two or more pathways, simultaneously. As cytokines regulate many aspects of innate and adaptive immunity, application of cytokines in cancer immunotherapy has attracted considerable attention.
Summary
Application of cytokines in the treatment of cancer is limited by their pleiotropic effects, toxicity at required clinical doses, and unfavorable pharmacokinetic properties. Recent advances in protein engineering have now made it possible to improve the undesirable properties of these biologics. Additionally, the recent breakthroughs in the treatment of cancer, using immunotherapies, have renewed interest in evaluating cytokines and their variants in combination regiments to improve immunity against malignant cells.
... Although IL-7 is secreted mainly by stromal cells in the thymus and bone marrow 9 , IL-7 is also dysregulated at the transcriptional level in renal and colorectal cancer cells and is concentrated in the cancer cells, plasma, and tissues of ovarian cancer patients [10][11][12][13] . Patients with prostate cancer are more likely to express IL-7 than are those with benign prostatic hyperplasia 14 . ...
Precise mechanisms underlying interleukin-7 (IL-7)-mediated tumor invasion remain unclear. Thus, we investigated the role of IL-7 in tumor invasiveness using metastatic prostate cancer PC-3 cell line derivatives, and assessed the potential of IL-7 as a clinical target using a Janus kinase (JAK) inhibitor and an IL-7-blocking antibody. We found that IL-7 stimulated wound-healing migration and invasion of PC-3 cells, increased phosphorylation of signal transducer and activator of transcription 5, Akt, and extracellular signal-regulated kinase. On the other hand, a JAK inhibitor and an IL-7-blocking antibody decreased the invasiveness of PC-3 cells. IL-7 increased tumor sphere formation and expression of epithelial–mesenchymal transition (EMT) markers. Importantly, lentiviral delivery of IL-7Rα to PC-3 cells significantly increased bone metastasis in an experimental murine metastasis model compared to controls. The gene expression profile of human prostate cancer cells from The Cancer Genome Atlas revealed that EMT pathways are strongly associated with prostate cancers that highly express both IL-7 and IL-7Rα. Collectively, these data suggest that IL-7 and/or IL-7Rα are promising targets of inhibiting tumor metastasis.
... 39 Early evidence showed that IL-7 was able to stimulate the proliferation of CD4 + TILs that were extracted from colorectal cancer biopsies. 40 In normal breast tissues, low levels of IL-7 transcripts have been found, while IL-7 transcripts are generally absent in BC cell lines. In contrast, IL-7 receptor (IL7R) transcripts have been found in both BC cell lines and in normal breast tissue. ...
The tumor microenvironment is composed of many immune cell subpopulations and is an important factor in the malignant progression of neoplasms, particularly breast cancer (BC). However, the cytokine networks that coordinate various regulatory events within the BC interstitium remain largely uncharacterized. Moreover, the data obtained regarding the origin of cytokine secretions, the levels of secretion associated with tumor development, and the possible clinical relevance of cytokines remain controversial. Therefore, we profiled 27 cytokines in 78 breast tumor interstitial fluid (TIF) samples, 43 normal interstitial fluid (NIF) samples, and 25 matched serum samples obtained from BC patients with Luminex xMAP multiplex technology. Eleven cytokines exhibited significantly higher levels in the TIF samples compared with the NIF samples: interleukin (IL)-7, IL-10, fibroblast growth factor-2, IL-13, interferon (IFN)γ-inducible protein (IP-10), IL-1 receptor antagonist (IL-1RA), platelet-derived growth factor (PDGF)-β, IL-1β, chemokine ligand 5 (RANTES), vascular endothelial growth factor, and IL-12. An immunohistochemical analysis further demonstrated that IL-1RA, IP-10, IL-10, PDGF-β, RANTES, and VEGF are widely expressed by both cancer cells and tumor-infiltrating lymphocytes (TILs), whereas IP-10 and RANTES were preferentially abundant in triple-negative breast cancers (TNBCs) compared to Luminal A subtype cancers. The latter observation corresponds with the high level of TILs in the TNBC samples. IL-1β, IL-7, IL-10, and PDGFβ also exhibited a correlation between the TIF samples and matched sera. In a survival analysis, high levels of IL-5, a hallmark TH2 cytokine, in the TIF samples were associated with a worse prognosis. These findings have important implications for BC immunotherapy research.
... Despite these promising findings, it is still to investigate the impact of the sequential extraction procedure on the possible loss of low molecular weight secreted factors, such as chemokines, growth factors, and cytokines. For instance, among the detected proteins the lack of interleukin-7, which is known to be secreted by CRC cells to promote the expansion of tumor infiltrating lymphocytes (Maeurer et al., 1997), could be ascribed to the aggressiveness of the sequential extraction procedure. ...
Colorectal cancer (CRC) whit more than a million of new cases per year is one of the most common registered cancers worldwide with few treatment options especially for advanced and metastatic patients. The tumor microenvironment is composed by extracellular matrix (ECM), cells and interstitial fluids. Among all these constituents, in the last years an increased interest around the ECM and its potential role in cancer tumorigenesis is arisen. During cancer progression the ECM structure and composition became disorganized, allowing cellular transformation and metastasis. Up to now, the focus has mainly been on the characterization of CRC microenvironment analyzing separately structural ECM components or cell secretome modifications. A more extensive view that interconnects these aspects should be addressed. In this review, biochemical (secretome) and biomechanical (structure and architecture) changes of tumor microenvironment will be discussed, giving suggestions on how these changes can affect cancer cell behavior. This article is protected by copyright. All rights reserved.
... IL-7 mRNA has also been identified in numerous solid organ tumours, including Warthin's tumour of the parotid gland (45), head and neck squamous cell carcinomas (46), renal cell carcinoma (47), oesophageal carcinoma (48), colorectal carcinoma (49) and breast carcinoma (19). The exact role of IL-7 in these tumours is not fully understood, however it is thought to affect lymphocytes (49); for instance, in cutaneous T-cell lymphoma, IL-7 has been shown to support the growth of malignant T-cells in the skin (21). Increased IL-7 expression in breast cancer is associated with a higher tumour grade and poorer prognostic outcome (19). ...
Methods of identifying chronic wounds that will heal in a timely, coordinated fashion and those that will not, together with novel therapeutic strategies, are vital for progression in the field of wound healing. Interleukin (IL)-7 has been associated with various biological and pathological processes. The present study explored the potential role of IL-7 in wound healing. IL-7 expression levels were examined in a clinical cohort of chronic wounds using reverse transcription-quantitative polymerase chain reaction and immunohistochemical staining analysis. The impact of recombinant human IL-7 (rhIL-7) on the growth and migrational rates of HaCaT keratinocyte cells was subsequently examined using in vitro growth and electric cell-substrate impedance sensing functional assays. The mRNA expression levels of IL-7 were increased in the healed chronic wound tissue samples, compared with non-healed chronic wound tissue samples, although the difference was not statistically significant. Similarly, immunohistochemical analysis revealed a greater staining intensity of IL-7 in the healed chronic wound tissue sections compared with the non-healed tissue sections. Treatment with rhIL-7 did not affect HaCaT cell growth rates, but was shown to enhance cell migration, an effect that could be further enhanced through the addition of inhibitors of neuronal Wiskott-Aldrich syndrome protein and protein kinase B. The data of the present study suggest that the expression levels of IL-7 may be increased in healing chronic wounds, and thus IL-7 may have a role in this process, potentially through its effects on the cellular migration of keratinocytes.
... T cells do not produce IL-7, but it is produced by non-immune stromal cells such as lymphatic endothelial and epithelial cells, bone marrow epithelial, a subpopulation of epithelial cells in the intestines [41]. IL-7 and its receptor are expressed by tumor cells such as colorectal [42], hematopoietic, lung, and brain cancers [43]. Unlike IL-2R, the IL-7R is a heterodimer consisting of IL-7R? and ?C that may lead to activation of Src kinases [44], PI3K [45]; and similarly to IL-2, Jak1, Jak3 and STAT5 [46]. ...
Common γ chain (γC) cytokines, namely IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21 are important for the proliferation, differentiation, and survival of lymphocytes that display antitumor activity, thus stimulating considerable interest for the use of cytokines in cancer immunotherapy. In this review, we will focus on the γC cytokines that demonstrate the greatest potential for immunotherapy, IL-2, IL-7, IL-15, and IL-21. We will briefly cover their biological function, potential applications in cancer therapy, and update on their use in combinatorial immune strategies for eradicating tumors and hematopoietic malignancies.
... Oncogenesis IL-7 was found to be secreted in vitro by cultured colorectal cancer cell lines (2/4) and primary samples (16/18) (Maeurer et al., 1997). Mutations in the exon 6 of the IL7R (0.5%) were found in a cohort of primary samples (Kim et al., 2013). ...
... IL-7 values have been associated with bone metastatic disease and hematological malignancies [8][9][10]. Different levels of IL-7 have been measured in renal [11], neuroblastoma [12], glioma [13], colorectal [14], central nervous system, and lung cancers [15], however; until now no clear conclusions had been drawn in regards to how these values influence tumor progres-Ivyspring International Publisher sion. It has also been observed that IL-7 is responsible for osteoclastogenesis through fusion with macrophage colony stimulating factor (M-CSF), binding with tumor necrosis factor-α (TNF-α) and receptor activator of nuclear factor-α (RANKL) [16][17][18]. ...
Interleukin 7 and 15 are considered powerful pro-inflammatory cytokines, they have the ability to destabilize chromosomes and induce tumorigenesis. Additionally, they can control malignancy proliferation by influencing the tumor microenvironment and immune system. Immunotherapy has been proposed as a treatment modality for malignancy for over a decade; the exact mechanisms of action and pathways are still under investigation. Interleukin 7 and 15 have been extensively investigated in hematological malignancies since their mode of action influences the stimulation of the immune system in a more direct way than other malignancies such as lung, melanoma, and breast, renal and colorectal cancer.
... Thus, the IL-7/IL-7R axis appears to be a 'double-edged sword': The IL-7R may mediate growth promoting effects in transformed cells and contribute therefore to tumor development. In contrast, IL-7 represents a central T-cell survival factor (Maeurer, Walter et al. 1997;Al-Rawi, Rmali et al. 2004;Cattaruzza, Gloghini et al. 2009). IL-7R expression on immune effector cells (Fry and Mackall 2002;Abraham, Ma et al. 2005) aid to establish and to maintain long-term anti-EBV cellular immune responses that may be able to kill off or contain EBV+ B-cells. ...
... Vd1+ T cells are activated by stress-induced self-antigens such as MIC-A/B and UL-16 binding proteins through the T cell receptor and NKG2D [19][20][21] and recognize glycolipids presented by CD1c on the surface of immature dendritic cells and can induce DC to mature and produce IL-12 [22,23]. This population comprises cells that are highly cytotoxic to a wide variety of malignancies [24][25][26][27][28][29], and long-term persistence of Vd1+ T cells in bone marrow transplant patients has been associated with long-term disease free survival [30,31]. Vd1-expressing T cells can also exhibit immunosuppressive and regulatory properties in addition to effector function [32,33], a finding of particular importance in determining the interaction of cd T cells and malignancy. ...
Vδ2(neg) γδ T cells, of which Vδ1+ γδ T cells are by far the largest subset, are important effectors against CMV infection. Malignant gliomas often contain CMV genetic material and proteins, and evidence exists that CMV infection may be associated with initiation and/or progression of glioblastoma multiforme (GBM). We sought to determine if Vδ1+ γδ T cells were cytotoxic to GBM and the extent to which their cytotoxicity was CMV dependent. We examined the cytotoxic effect of ex vivo expanded/activated Vδ1+ γδ T cells from healthy CMV seropositive and CMV seronegative donors on unmanipulated and CMV-infected established GBM cell lines and cell lines developed from short- term culture of primary tumors. Expanded/activated Vδ1+ T cells killed CMV-negative U251, U87, and U373 GBM cell lines and two primary tumor explants regardless of the serologic status of the donor. Experimental CMV infection did not increase Vδ1+ T cell - mediated cytotoxicity and in some cases the cell lines were more resistant to lysis when infected with CMV. Flow cytometry analysis of CMV-infected cell lines revealed down-regulation of the NKG2D ligands ULBP-2, and ULBP-3 as well as MICA/B in CMV-infected cells. These studies show that ex vivo expanded/activated Vδ1+ γδ T cells readily recognize and kill established GBM cell lines and primary tumor-derived GBM cells regardless of whether CMV infection is present, however, CMV may enhance the resistance GBM cell lines to innate recognition possibly contributing to the poor immunogenicity of GBM.
... Vd1+ T cells are activated by stress-induced self-antigens such as MIC-A/B and UL-16 binding proteins through the T cell receptor and NKG2D192021 and recognize glycolipids presented by CD1c on the surface of immature dendritic cells and can induce DC to mature and produce IL-12 [22,23]. This population comprises cells that are highly cytotoxic to a wide variety of malignancies242526272829, and long-term persistence of Vd1+ T cells in bone marrow transplant patients has been associated with long-term disease free survival [30,31] . Vd1-expressing T cells can also exhibit immunosuppressive and regulatory properties in addition to effector function [32,33], a finding of particular importance in determining the interaction of cd T cells and malignancy. ...
Vd2 neg gd T cells, of which Vd1+ gd T cells are by far the largest subset, are important effectors against CMV infection. Malignant gliomas often contain CMV genetic material and proteins, and evidence exists that CMV infection may be associated with initiation and/or progression of glioblastoma multiforme (GBM). We sought to determine if Vd1+ cd T cells were cytotoxic to GBM and the extent to which their cytotoxicity was CMV dependent. We examined the cytotoxic effect of ex vivo expanded/activated Vd1+ cd T cells from healthy CMV seropositive and CMV seronegative donors on unmanipulated and CMV-infected established GBM cell lines and cell lines developed from short-term culture of primary tumors. Expanded/ activated Vd1+ T cells killed CMV-negative U251, U87, and U373 GBM cell lines and two primary tumor explants regardless of the serologic status of the donor. Experimental CMV infection did not increase Vd1+ T cell -mediated cytotoxicity and in some cases the cell lines were more resistant to lysis when infected with CMV. Flow cytometry analysis of CMV-infected cell lines revealed down-regulation of the NKG2D ligands ULBP-2, and ULBP-3 as well as MICA/B in CMV-infected cells. These studies show that ex vivo expanded/activated Vd1+ cd T cells readily recognize and kill established GBM cell lines and primary tumor-derived GBM cells regardless of whether CMV infection is present, however, CMV may enhance the resistance GBM cell lines to innate recognition possibly contributing to the poor immunogenicity of GBM.
... Reportedly, some types of leukemia and of solid tumor cells can produce TGF- (40 -44) or IL-7 (45). However, in our system, leukemic cells did not seem to play a role in bringing about the mRNA changes because a similar cytokine profile appeared when leukemia injection was omitted. ...
Background. We have previously shown that allogeneic bone marrow CBRl) chimeras preconditioned with total lymphoid irradiation and low-dose total body irradiation (TLI/TBI) develop a stronger graft-versus leukemia (GVL) effect than chimeras preconditioned with high-dose total body irradiation only (TBI). Here, we report on the possible role of cytokines in the mechanism underlying this GVL effect. Methods. Splenic mRNA levels of the cytokines interleukin (IL)-1, IL-2, IL-4, IL-6, IL-7, IL-10, IL-12, IL-15, interferon-gamma, tumor necrosis factor-alpha, and transforming growth factor-beta (TGF-beta), and of inducible nitric oxide synthetase were determined by reverse transcription-poly merase chain reaction in TLI/TBI- or TBI-conditioned C3H/AKR BM chimeras challenged with AKR-type BW5147.3 leukemia cells. Ex vivo TGF-beta protein production by splenocytes was determined using ELISA. The possibility that cytokines influence the GVL effect by modulating the activity of IL-2-activated lymphocytes (LAK cells) was investigated by in vitro assays on donor-type BM cells. Results. Of all cytokine mRNA levels studied, those of TGF-beta and IL-7 were different between groups; both were significantly more elevated in TBI- than in TLI/ TBI-conditioned or normal mice. Differences were apparent after conditioning and were not influenced by additionally injected BM or leukemia cells. Cultured splenocytes of TBI-conditioned animals produced significantly more TGF-beta protein than those of TLI/TBI-conditioned ones or normal controls. r-TGF-beta but not r-IL-7 suppressed in vitro LAK activity of donor-type BM cells against BW5147.3 cells in a dose-dependent way. Conclusions. High-dose TBI-induced, host-derived splenic TGF-beta may inhibit generation of LAR cells from subsequently transplanted donor BN cells, suppressing their capacity to generate cytotoxicity upon injection of leukemia cells. The cytokine profile, induced by irradiation in host hematopoietic organs, can significantly modify posttransplant immunological processes such as the GVL,effect and graft-versus-host disease (GVHD).
... Significance of detection calls: * ≤ 0.05, * * ≤ 0.005, and * * * ≤ 0.0005. in lymphoblastic leukemia [10], prostate cancer [11], breast cancer [12], and colorectal cancer [13]. IL7 is expressed in CS 2 but not in CS 1 , again suggesting that CS 2 may be a more conducive microenvironment for tumor growth than CS 1 . ...
Although stromal cell signaling has been shown to play a significant role in the progression of many cancers, relatively little is known about its importance in modulating ovarian cancer development. The purpose of this study was to investigate the process of stroma activation in human ovarian cancer by molecular analysis of matched sets of cancer and surrounding stroma tissues. RNA microarray profiling of 45 tissue samples was carried out using the Affymetrix (U133 Plus 2.0) gene expression platform. Laser capture microdissection (LCM) was employed to isolate cancer cells from the tumors of ovarian cancer patients (Cepi) and matched sets of surrounding cancer stroma (CS). For controls, ovarian surface epithelial cells (OSE) were isolated from the normal (noncancerous) ovaries and normal stroma (NS). Hierarchical clustering of the microarray data resulted in clear separations between the OSE, Cepi, NS, and CS samples. Expression patterns of genes encoding signaling molecules and compatible receptors in the CS and Cepi samples indicate the existence of two subgroups of cancer stroma (CS) with different propensities to support tumor growth. Our results indicate that functionally significant variability exists among ovarian cancer patients in the ability of the microenvironment to modulate cancer development.
... The current information on the IL-7 level in breast cancer do not correspond. In one study IL-7 mRNA and protein could not be detected in breast cancer (Maeurer et al., 1997). In another study, however, the levels of IL-7, IL-7R, and its signalling intermediates were shown to be overexpressed in the aggressive breast tumors (Al-Rawi et al., 2004). ...
Introduction:
Breast cancer cells and tumor stroma produce different cytokines and soluble factors. Cytokines, while playing crucial roles in immune responses to tumors, also favour tumor growth and progression. IL-7 and G-CSF are two cytokines that may exert influences on the pathophysiology of breast cancer.
Materials and methods:
Sera were collected from 136 females with breast cancer before receiving chemotherapy or radiotherapy. The control group comprised of 60 healthy age-matched females without any acute or chronic diseases with no family history of breast cancer. Serum levels of IL-7 and G-CSF were measured by commercial enzyme linked immunosorbent assay.
Results:
While there was no significant difference in the level of G-CSF between patients (92.81 ± 594.54 pg/ml) and controls (0.00 pg/ml), G-CSF level in sera of patients with advanced stages of breast cancer was elevated compared to early stages (p=0.0001). Moreover, the highest level of G-CSF was seen in patients with N3 phase tumors (p=0.0001). IL-7 was slightly but not significantly higher in the control group (0.04 ± 0.11 pg/ml) in comparison with patients (0.02 ± 0.10 pg/ml). Interestingly, a significant increase in the level of IL-7 in patients with skin involvement was observed (p=0.001).
Conclusion:
Our results showed an elevation of G-CSF in sera of patients with advanced stages of tumor, while IL-7 elevation correlated with skin involvement of breast cancer. IL-7 can be produced by keratinocytes in skin tissue and may be involved in the pathologic establishment of metastatic tumor cells in skin.
... Notably, however, elevated IL-7 serum levels have been detected in Hodgkin disease and in ovarian cancers26272829 . Furthermore, IL-7 has been shown to be produced by breast and colorectal cancer cells[30,31]. IL-15 has also been shown to be produced by colon cancer cells and specific gene expression has been shown to be associated with distant metastases [32] . Moreover, elevated IL-15 serum levels were detected in multiple mye- loma[33]. ...
Chronic inflammation has been suggested to favour prostate cancer (PCA) development. Interleukins (IL) represent essential inflammation mediators. IL-2, IL-7, IL-15 and IL-21, sharing a common receptor γ chain (c-γ), control T lymphocyte homeostasis and proliferation and play major roles in regulating cancer-immune system interactions. We evaluated local IL-2, IL-7, IL-15 and IL-21 gene expression in prostate tissues from patients with early stage PCA or benign prostatic hyperplasia (BPH). As control, we used IL-6 gene, encoding an IL involved in PCA progression. IL-6, IL-7 and IL-15 titres were also measured in patients' sera.
Eighty patients with BPH and 79 with early (1 to 2c) stage PCA were enrolled. Gene expression in prostate tissues was analyzed by quantitative real-time PCR (qRT-PCR). Serum IL concentrations and acute phase protein titres were evaluated by ELISA. Mann-Whitney, Wilcoxon and χ(2) tests were used to compare IL gene expression and serum titers in the two groups of patients. Receiver operating characteristic (ROC) curves were constructed to evaluate the possibility to distinguish sera from different groups of patients based on IL titers.
IL-2 and IL-21 gene expression was comparably detectable, with low frequency and at low extents, in PCA and BPH tissues. In contrast, IL-6, IL-7 and IL-15 genes were expressed more frequently (p < 0.0001, p = 0.0047 and p = 0.0085, respectively) and to significantly higher extents (p = 0.0051, p = 0.0310 and p = 0.0205, respectively) in early stage PCA than in BPH tissues. Corresponding proteins could be detected to significantly higher amounts in sera from patients with localized PCA, than in those from patients with BPH (p = 0.0153, p = 0.0174 and p = 0.0064, respectively). Analysis of ROC curves indicates that IL-7 (p = 0.0039), but not IL-6 (p = 0.2938) or IL-15 (p = 0.1804) titres were able to distinguish sera from patients with malignancy from those from patients with benign disease. Serum titres of C reactive (CRP), high mobility group B1 (HMGB1) and serum amyloid A (SAA) acute phase proteins were similar in both groups of patients.
Expression IL-7 and IL-15 genes in prostate tissues and corresponding serum titres are significantly increased in patients with early stage PCA as compared with patients with BPH.
... Previously, we found that the higher expression IL-7/IL-7 receptor (IL-7R) was correlated well with clinical stages, the lymph node metastasis, and short survival in human non-small cell lung cancer (NSCLC) patients [8]. Moreover, IL-7/IL-7R mRNA is detected in different tumors, such as colorectal [9], renal [10], and central nervous system cancers [11]. Following the binding of IL-7R to its ligand, a series of intracellular phosphorylation events occurred, such as the activation of the Janus kinases (JAK-1 and JAK-3), phosphoinositide 3 kinase (PI3K), and the signal transducers and activators of transcription (STAT-5) [12]. ...
Interleukin-7 is a potent regulator of lymphocyte proliferation, but it inducing growth of solid tumors is few known. We study the relationship between Interleukin-7 and the regulator of the cell cycle, cyclin D1 and the mechanism of Interleukin-7 regulating cell growth in human lung cancer. We detected expression of cyclin D1 and its impact on the prognosis of lung cancer patients. Using Western blot, reverse transcriptase-PCR, Co-Immunoprecipitation, and Chromatin Immunoprecipitation, we investigated how Interleukin-7 regulated cyclin D1 in vitro and in nude mice. We found that, in lung cancer cell lines and in nude mice, Interleukin-7/Interleukin-7 receptor increased the expression of cyclin D1 and phosphorylation of c-Fos/c-Jun, induce c-Fos and c-Jun heterodimer formation, and enhanced c-Fos/c-Jun DNA-binding activity to regulate cyclin D1. In addition, lymph node metastasis, tumor stage, and cyclin D1 were the strongest predictors of survival in 100 human non-small cell lung cancer specimens analyzed. Taken together, our results provided evidence that Interleukin-7/Interleukin-7 receptor induced cyclin D1 up-regulation via c-Fos/c-Jun pathway to promote proliferation of cells in lung cancer.
... IL-10 and TGFβ have been implicated in tumor-induced immunosuppression in CRC patients, whereas mitogen-stimulated peripheral blood mononuclear cells (PBMCs) from CRC patients have been reported to produce low levels of IFNα , IFN-γ, ΙL-1, IL-2 and IL-12, when compared to healthy volunteers141516. More recent studies have demonstrated abnormal gene expression of immuno-modulatory cytokines TGF-β, IL-10, IL-6, IL-8, and IL-7 in colon carcinoma cell lines or in tumor cells in situ17181920. Nevertheless, the role of pro-and anti-inflammatory cytokines in promoting or impairing cell-mediated immune responses, such as the autologous mixed lymphocyte reaction (auto-MLR) and ex vivo cytotoxicity specific for colorectal tumor cell epitopes, has not been systematically explored in patients with CRC. ...
Background:
Bevacizumab, a monoclonal antibody (mAb) targeting vascular endothelial growth factor (VEGF), has produced promising results when combined with chemotherapy in the treatment of advanced colorectal cancer (CRC). The aim of the present study was to define the immunological profile of metastatic CRC patients at baseline and following chemotherapy with either irinotecan/5-fluorouracil/leucovorin (IFL) alone or IFL in combination with.bevacizumab (B-IFL).
Methods:
Peripheral blood mononuclear cells (PBMCs) obtained from healthy donors (HD) (n = 20) and patients (n = 40) were tested for T-cell proliferation in the autologous mixed lymphocyte reaction (auto-MLR), and cytokine production following stimulation with anti-CD3 mAb.
Results:
PBMCs obtained from CRC patients prior to treatment exhibited lower auto-MLR responses and low production of IL-2, IFN-γ, IL-12 and IL-18 cytokines, whereas IL-4 and IL-10 cytokines were increased as compared to HD (p < 0.001, for all parameters) following in vitro stimulation with anti-CD3 mAb. During treatment, and in particular in week 12 of evaluation, IL-2 (p < 0.001 for both IFL and B-IFL groups), IFN-γ (p < 0.001 for IFL and p = 0.001 for B-IFL), IL-12 (p < 0.001 for both IFL and B-IFL) and IL-18 (p < 0.001 for both IFL and B-IFL) production, as well as auto-MLR responses increased (p < 0.001 for both IFL and B-IFL), whereas IL-4 (p < 0.001 for IFL and p = 0.001 for B-IFL) and IL-10 [p < 0.001 for IFL and p = 0.067 (non-significant) for B-IFL] production decreased over baseline in the two treatment groups, yet their respective values never reached those of HD. Moreover, IL-2, IFN-γ production, and auto-MLR were higher in the B-IFL over the IFL treatment group (p < 0.001, p < 0.04, p < 0.001, respectively).
Conclusion:
Our study demonstrates that the abnormal immune parameters observed in metastatic CRC patients at presentation can substantially improve during treatment with either IFL or B-IFL. The immune parameters examined can provide a sensitive and valuable tool for monitoring immune function in CRC patients, and could be applied as surrogate markers predicting treatment-related outcome.
... In the bone marrow, CD8 T cells expressing CD69 have been found (Zhang et al., 2006), and in the gut, intestinal epithelial cells (IELs) retain CD69 expression long after antigen has been cleared (Masopust et al., 2006). It follows that both the bone marrow and gut are anatomic sites where IL-7 production has been observed (Maeurer et al., 1997;Pillai et al., 2004). ...
Interleukin-7 (IL-7) increases lymphocyte numbers, a critical feature of immune reconstitution, through mechanisms that are still poorly understood. Part of the problem is that IL-7 is produced in limited amounts by non-lymphoid cells, making in vivo studies of the cytokine's activity a challenge. To overcome this, we developed an in vitro system by which lymphocytes from secondary immune organs could be cultured to produce IL-7 responsive cells. Using this method, we showed that CD8(hi)CD44(hi) T cells accumulate in culture with IL-7 from a population of lymph node or splenic cells. These results were validated when a similar lymphocyte subset was found in mice expressing a constitutively active form of STAT5b, a key transducer of IL-7 signals. Interestingly, IL-7-expanded cells also up regulated the activation marker, CD69. The IL-7-derived CD44(hi)CD69(hi) cells were not generated from naïve cells, but expanded from an existing population, since culture in IL-7 of naïve lymphocytes from OT-1/Rag1(-/-) mice did not produce CD44(hi)CD69(hi) cells. Using the in vitro culture system to study lymphocytes from mice deficient in the apoptotic protein, BIM, we were able to attribute the expansion of CD8(hi)CD44(hi)CD69(hi) T cells to the proliferative and not survival activity of IL-7. The in vitro culture system provides an important new methodology to examine the activities of this essential as well as immunotherapeutic cytokine.
... [2][3][4][5][6][7][8][9][10][11][12][13][14] However, little was known about its involvement in solid tumours, including lung cancer. Some malignant cells, such as chronic lymphoblastic leukaemia cells, 8 Burkitt's lymphoma cells 9 and colonic cancer cells 15 were also capable of producing IL-7. Other solid tumours could express the IL-7 gene, including oesophageal, 16 renal, 17 head and neck squamous cell carcinoma, 18 and Warthin's tumour of the parotid gland. ...
Interleukin 7 (IL-7) is known to promote lymphangiogenesis. To study the relationship between IL-7 and the lymphangiogenic factor, vascular endothelial growth factor (VEGF)-D, in human lung cancer cells and its impact on the prognosis of lung cancer patients, we investigated how IL-7 regulates VEGF-D. We found that, in lung cancer cell lines, IL-7/IL-7 receptor (IL-7R) increase the expression of VEGF-D and phosphorylation of c-Fos/c-Jun, induce c-Fos and c-Jun heterodimer formation, and enhance c-Fos/c-Jun DNA binding activity to regulate VEGF-D. In addition, the expression levels of IL-7 and IL-7R correlated well with that of VEGF-D, lymphatic vessels density (LVD), clinical stages, lymph node metastasis, and poor prognosis in 100 human non-small cell lung cancer (NSCLC) specimens analysed. Taken together, our results provide evidence that IL-7/IL-7R induce VEGF-D up-regulation and promote lymphangiogenesis via c-Fos/c-Jun pathway in lung cancer.
... 36 Recent evidence, however, has shown that colorectal tumour cells secrete IL-7, a cytokine that can cause TIL to proliferate, secrete tumour necrosis factor (TNF) and lyse autologous tumour cells. 37 The absence of costimulation (e.g. by helper cytokines or B7 binding) during recognition of tumour cells by T cells results in anergy of tumour specific T cells, 38 rendering them ineVective. Such anergy may need to be reversed in immunotherapy. ...
Gene therapy, in particular the transfer of genes encoding immunostimulatory molecules (cytokines and costimulatory molecules) as well as selectively cytotoxic enzymes and DNA vaccination, has the potential of enhancing cell mediated immune responses against tumours including those of colorectal origin. Genes can be transferred using viral vectors either to cultured tumour cells in vitro that can be returned to the patient as a "cancer vaccine", or directly to tumour cells in vivo. Vaccination with DNA constructs expressing specific tumour antigens characteristic of colorectal neoplasia can trigger immune recognition and destruction of tumour cells. The aim is to tip the balance from protumour to antitumour mechanisms by generating a local immune response and systemic antitumour immune memory to destroy metastases. Studies in murine models, combined with human studies, show that such approaches could become an adjunct to current treatments for human colorectal cancer in the near future.
... Reportedly, some types of leukemia and of solid tumor cells can produce TGF- (40 -44) or IL-7 (45). However, in our system, leukemic cells did not seem to play a role in bringing about the mRNA changes because a similar cytokine profile appeared when leukemia injection was omitted. ...
We have previously shown that allogeneic bone marrow (BM) chimeras preconditioned with total lymphoid irradiation and low-dose total body irradiation (TLI/TBI) develop a stronger graft-versus-leukemia (GVL) effect than chimeras preconditioned with high-dose total body irradiation only (TBI). Here, we report on the possible role of cytokines in the mechanism underlying this GVL effect.
Splenic mRNA levels of the cytokines interleukin (IL)-1, IL-2, IL-4, IL-6, IL-7, IL-10, IL-12, IL-15, interferon-gamma, tumor necrosis factor-alpha, and transforming growth factor-beta (TGF-beta), and of inducible nitric oxide synthetase were determined by reverse transcription-polymerase chain reaction in TLI/TBI- or TBI-conditioned C3H/AKR BM chimeras challenged with AKR-type BW5147.3 leukemia cells. Ex vivo TGF-beta protein production by splenocytes was determined using ELISA. The possibility that cytokines influence the GVL effect by modulating the activity of IL-2-activated lymphocytes (LAK cells) was investigated by in vitro assays on donor-type BM cells.
Of all cytokine mRNA levels studied, those of TGF-beta and IL-7 were different between groups; both were significantly more elevated in TBI- than in TLI/ TBI-conditioned or normal mice. Differences were apparent after conditioning and were not influenced by additionally injected BM or leukemia cells. Cultured splenocytes of TBI-conditioned animals produced significantly more TGF-beta protein than those of TLI/TBI-conditioned ones or normal controls. r-TGF-beta but not r-IL-7 suppressed in vitro LAK activity of donor-type BM cells against BW5147.3 cells in a dose-dependent way.
High-dose TBI-induced, host-derived splenic TGF-beta may inhibit generation of LAK cells from subsequently transplanted donor BM cells, suppressing their capacity to generate cytotoxicity upon injection of leukemia cells. The cytokine profile, induced by irradiation in host hematopoietic organs, can significantly modify posttransplant immunological processes such as the GVL effect and graft-versus-host disease (GVHD).
... Reportedly, some types of leukemia and of solid tumor cells can produce TGF- (40 -44) or IL-7 (45). However, in our system, leukemic cells did not seem to play a role in bringing about the mRNA changes because a similar cytokine profile appeared when leukemia injection was omitted. ...
Overview
IL-7 is a member of the family of cytokines with four anti-parallel α helixes that bind Type I cytokine receptors. It is produced by stromal cells and is required for development and homeostatic survival of lymphoid cells.
Genomic architecture
Interleukin 7 (IL7) human IL7: gene ID: 3574 on ch 8; murine Il7 gene ID: 16,196 on ch 3.
Protein
Precursor contains a signal sequence, mature human IL-7 peptide 152aa, predicted 17.4kd peptide, glycosylated resulting in 25kd. Crystal structure: http://www.rcsb.org/structure/3DI2.
Regulation of IL-7 production
Major producers are stromal cells in thymus, bone marrow and lymphoid organs but also reported in other tissues. Production is primarily constitutive but reported to be affected by IFNγ and other factors.
IL-7 receptors
Two chains IL-7Rα (IL-7R) and γc (IL-2RG). Human IL-7R: gene ID 3575 on ch 5; human IL2RG: gene ID 3561 on ch X; mouse IL-7R: gene ID 16,197 on ch 15; murine Il2rg gene ID 16,186 on ch X. Member of γc family of receptors for cytokines IL-2, −4, −9, −15, and −21. Primarily expressed on lymphocytes but reports of other cell types. Expression in T-cells downregulated by IL-7. Low expression on Tregs, no expression on mature B-cells. Crystal structure: http://www.rcsb.org/structure/3DI2.
IL-7 receptor signal transduction pathways
Major signals through JAK1, JAK3 to STAT5 and through non-canonical STAT3, STAT1, PI3K/AKT and MEK/ERK pathways.
Biological activity of IL-7
Required for survival of immature thymocytes, naïve T-cells, memory T-cells, pro-B-cells and innate lymphocytes. Pharmacological treatment with IL-7 induces expansion of naïve and memory T-cells and pro-B-cells.
Abnormalities of the IL-7 pathway in disease
Deficiencies in the IL-7 pathway in humans and mice result in severe combined immunodeficiency due to lymphopenia. Excessive signaling of the pathway in mice drives autoimmune diseases and in humans is associated with autoimmune syndromes including multiple sclerosis, type 1 diabetes, rheumatoid arthritis, sarcoidosis, atopic dermatitis and asthma. Mutations in the IL-7 receptor pathway drive acute lymphoblastic leukemia.
Clinical applications
IL-7 has been evaluated in patients with cancer and shown to expand lymphocytes. It accelerated lymphocyte recovery after hematopoietic stem cell transfer, and increased lymphocyte counts in AIDS patients and sepsis patients. Monoclonal antibodies blocking the IL-7 receptor are being evaluated in autoimmune diseases. Cytotoxic monoclonals are being evaluated in acute lymphoblastic leukemia. Drugs blocking the signal transduction pathway are being tested in autoimmunity and acute lymphoblastic leukemia.
Interleukin (IL)-7 plays an important immunoregulatory role in different types of cells. Therefore, it attracts researcher's attention, but despite the fact, many aspects of its modulatory action, as well as other functionalities, are still poorly understood. The review summarizes current knowledge on the interleukin-7 and its signaling cascade in context of cancer development. Moreover, it provides a cancer-type focused description of the involvement of IL-7 in solid tumors, as well as hematological malignancies.The interleukin has been discovered as a growth factor crucial for the early lymphocyte development and supporting the growth of malignant cells in certain leukemias and lymphomas. Therefore, its targeting has been explored as a treatment modality in hematological malignancies, while the unique ability to expand lymphocyte populations selectively and without hyperinflammation has been used in experimental immunotherapies in patients with lymphopenia. Ever since the early research demonstrated a reduced growth of solid tumors in the presence of IL-7, the interleukin application in boosting up the anticancer immunity has been investigated. However, a growing body of evidence indicative of IL-7 upregulation in carcinomas, facilitating tumor growth and metastasis and aiding drug-resistance, is accumulating. It therefore becomes increasingly apparent that the response to the IL-7 stimulus strongly depends on cell type, their developmental stage, and microenvironmental context. The interleukin exerts its regulatory action mainly through phosphorylation events in JAK/STAT and PI3K/Akt pathways, while the significance of MAPK pathway seems to be limited to solid tumors. Given the unwavering interest in IL-7 application in immunotherapy, a better understanding of interleukin role, source in tumor microenvironment, and signaling pathways, as well as the identification of cells that are likely to respond should be a research priority.
Interleukin 7 (IL-7) is a stromal cell derived cytokine that stands out as being the only cytokine identified to date on which development of B and T lymphocytes is absolutely dependent. IL-7 functions primarily as a growth and anti-apoptosis factor for B- and T cell (alpha beta and gamma delta TCR+ cells) precursors, and is essential for differentiation of gamma delta TCR+ cells. IL-7 can function as a cofactor during myelopoiesis, and is capable of activating monocytes/macrophages and natural killer (NK) cells. Its receptor (IL-7R) is a heterodimer of an alpha chain that specifically binds IL-7 and the common gamma chain gamma(c) that is also a component of the receptors for IL-2, IL-4, IL-9 and IL-15. The functions of IL-7 in normal lymphocyte development and activation have led to the demonstration of the ability of IL-7 to stimulate lymphopoiesis in lymphopenic mice, suggesting a possible clinical application of IL-7 in accelerating lymphoid reconstitution in lymphopenic patients. There have also been a number of preclinical studies pointing to the possible utility of IL-7 in antitumor clinical applications, and clinical trials involving IL-7 gene therapy of metastatic disease are underway. IL-7 has also been shown to promote engraftment of stem cells in mice receiving bone marrow transplants, pointing to a possible use of IL-7 in patients receiving bone marrow or peripheral blood stem cell transplants. Areas of IL-7 biology that are essentially unexplored include the mechanisms of regulation of the expression of IL-7 and IL-7R alpha, as well as the mechanisms by which IL-7 is a growth and differentiation factor for gamma delta T cells but a growth factor only for alpha beta T cells.
Fas and Fas ligand (FasL) are implicated in programmed cell death or apoptosis. In the immunological field, they are particularly important in auto-immunity, graft rejection and anti-tumoral response. Fas ligand expression on thymocytes, activated T lymphocytes, and in sites of immune privilege, suggests the importance of Fas/FasL interactions in negative control of the immune response. The recent description of FasL expression by tumoral cells, represents a new mechanism of immune escape for different cancer, and has been well studied in colon adenocarcinoma.
Alternative splicing evolved as a very efficient way to generate proteome diversity from a limited number of genes, while at the same time modulating posttranscriptional events of gene expression-such as stability, turnover, subcellular localization, binding properties, and general activity of both mRNAs and proteins. Since the vast majority of human genes undergo alternative splicing, it comes to no surprise that interleukin genes also show extensive alternative splicing. In fact, there is a growing body of evidence indicating that alternative splicing plays a central role in modulating the pleiotropic functions of cytokines, and aberrant expression of alternatively spliced interleukin mRNAs has been linked to disease. However, while several interleukin splice variants have been described, their function is still poorly understood. This is particularly relevant, since alternatively spliced cytokine isoforms can act both as disease biomarkers and as candidate entry points for therapeutic intervention. In this chapter we describe a protocol that uses radiolabeled semi-quantitative RT-PCR to efficiently detect, analyze, and quantify alternative splicing patterns of cytokine genes.
Our previous study has confirmed that IL-7δ5 (an IL-7 variant lacking exon 5) promotes breast cancer growth. However, whether IL-7δ5 is involved in tumor cell EMT and metastasis remains unclear. In this study, we investigated the preclinical effects and molecular mechanisms of IL-7δ5 on EMT and metastasis in human MCF-7 and BT-20 breast cancer cells in vitro and in vivo. The results showed that IL-7δ5 induced EMT and invasion in tumor cells, associated with up-regulation of N-cadherin and the down-regulation of E-cadherin. Furthermore, we found that IL-7δ5 induced the activation of Akt. Inhibition of PI3K/Akt pathway by LY294002 reversed the EMT transition in breast cancer cell lines MCF-7 and BT-20 induced by IL-7δ5. In addition, IL-7δ5 enhanced cancer metastasis and shortened survival time, with increased level changes of activated Akt in nude mice with breast cancer. In conclusion, our findings demonstrate that IL-7δ5 induces human breast cancer cell lines EMT and metastasis via activation of PI3K/Akt pathway. Thus, IL-7δ5 may be a potential target against human breast cancer.
Objectives: To investigate the epithelial ovarian carcinoma (EOC) secretion of interleukin-7 (IL-7). Methods: Levels of IL-7 were assayed by enzyme-linked immunoadsorbent assay and IL-7 mRNA, and protein expression in tissues and cell lines were detected by RT-PCR and immunohistochemistry. Results: The median serum IL-7 level in patients with EOC (32 cases; 32.49 pg/ml) was significantly higher than that of patients with benign tumors (16 cases; 7.59 pg/ml) and healthy women (16 cases; 10.64 pg/ml) (P<0.05). The median peritoneal fluid IL-7 level in patients with EOC (17.39 pg/ml) was slightly higher than that of patients with benign tumors (14.09 pg/ml), but not significantly so (P>0.05). There were positive correlations between the serum and peritoneal fluid IL-7 levels in both ovarian cancer and benign group (P<0.05, both). Only two EOC specimens expressed IL-7 mRNA, and no IL-7 protein positive was found in any specimens. Conclusions: Epithelial ovarian carcinoma cells rarely express IL-7, and IL-7 levels are decreased in the ascitic fluid of patients with EOC.
Inframe insertion and deletion/insertion (delins) mutations of the IL7R gene in exon 6 have recently been reported in childhood T-cell acute lymphoblastic leukemia (T-ALL). The recurrent nature of the IL7R mutations in the same region strongly suggests that the IL7R mutations may play an important role in the pathogenesis of childhood T-ALL. The aim of this study was to address whether IL7R exon 6 mutation occurs in other human tumors besides childhood T-ALL. For this, we analyzed 1792 tumor tissues from various origins, including 432 hematologic and 1360 nonhematopoietic tumors by single-strand conformation polymorphism analysis to detect the exon 6 mutations. Overall, we found 10 IL7R exon 6 mutations in seven hematologic malignancies (three childhood T-ALL [12%], one adult T-ALL [7%], two childhood precursor B-cell acute lymphoblastic leukemia (B-ALL) [2%] and one adult acute myelogenous leukemia (AML) [1%]) and three nonhematopoietic malignancies (one lung cancer [0.6%] and two colorectal cancer [0.5%]), but none in other tumors. IL7R mutations detected in hematologic tumors were exclusively inframe insertion and delins mutations, whereas those detected in non-hematologic tumors were missense and frameshift mutations. Our data indicate that IL7R exon 6 inframe mutations occur not only in childhood T-ALL but also other acute leukemias at slightly lower frequencies. Our data suggest that the IL7R mutations may contribute to the development of diverse types of acute leukemias, and that possible therapies targeting the IL7R exon 6 mutation should include not only childhood T-ALL but also T-ALL, childhood precursor B-ALL, and adult AML.
Various tumor cells express interleukin 7 (IL-7) and IL-7 variants. IL-7 has been confirmed to stimulate solid tumor cell proliferation. However, the effect of IL-7 variants on tumor cell proliferation remains unclear. In this study, we evaluated the role of IL-7δ5 (an IL-7 variant lacking exon 5) on proliferation and cell cycle progression of human MDA-MB-231 and MCF-7 breast cancer cells. The results showed that IL-7δ5 promoted cell proliferation and cell cycle progression from G1 phase to G2/M phase, associated with upregulation of cyclin D1 expression and the downregulation of p27(kip1) expression. Mechanistically, we found that IL-7δ5 induced the activation of Akt. Inhibition of PI3K/Akt pathway by LY294002 reversed the proliferation and cell cycle progression of MDA-MB-231 and MCF-7 cells induced by IL-7δ5. In conclusion, our findings demonstrate that IL-7δ5 variant induces human breast cancer cell proliferation and cell cycle progression via activation of PI3K/Akt pathway. Thus, IL-7δ5 may be a potential target for human breast cancer therapeutics intervention.
Cisplatin is one of the most commonly used chemotherapeutic agents for glioma patients. In this study, array comparative genomic hybridization (aCGH) was used to identify genes associated with cisplatin resistance in a human glioma cell line. The cisplatin-resistant U251/CP2 cell line was derived by stepwise selection using cisplatin. The genetic aberrations of the U251 parental cell line and the U251/CP2 cells were analyzed using aCGH. RT-PCR was used to detect the expression of the altered genes revealed by aCGH. The sensitivity of glioma cells to cisplatin was determined by using the MTT assay. Apoptosis was detected using flow cytometry and western blot analysis. The IC 50 value of cisplatin in U251/CP2 cells was five times higher than its IC 50 in U251 cells. The U251 cells lost at least one copy each of the CFHR1 and CFHR3 genes, and both CFHR1 and CFHR3 were homozygously deleted in U251/CP2 cells. The U251/CP2 cells gained two to three copies of C8orf70 and IL-7 genes. IL-7 mRNA expression was studied in 12 glioma cell lines, and expression was positively correlated with the IC 50 of cisplatin. Furthermore, IL-7 mRNA expression was also positively correlated with the IC 50 of cisplatin in 91 clinical glioma specimens. Additionally, treatment with recombinant human IL-7 (rhIL-7) enhanced cisplatin resistance and increased the relative growth rate of the glioma cells. Moreover, the apoptosis induced by cisplatin could be inhibited by IL-7. In conclusion, our results suggest that IL-7 may play an important role in cisplatin resistance in glioma.
Interleukin-7 (IL-7) is produced by both immune and non-immune cells including stromal cell lines, B-cells, monocytes/macrophages, follicular dendritic cells, keratinocytes, and gut epithelial cells. The development of IL-7 knockout mice aided to elucidate the role of this multifaceted cytokine in lymphopoiesis. Additionally, IL-7 gene-deleted mice may represent an excellent model in order to define the functional role of locally secreted IL-7 in organ-specific immunity and in anti-microbial responses as well. For instance, analysis of IL-7 gene-deleted mice revealed reduced numbers of total T-lymphocytes with preservation of the CD4/CD8 ratio and increased ratio of alpha beta + T-cells compared to gamma delta + T-cells. Transition of pro-T-cells to pre-T-cells was impaired. Cell marker analysis of thymocytes in IL-7 -/- mice suggested that IL-7 may induce expression of as yet unidentified cytokine receptors, and that IL-7 may also be critically involved in T-cell differentiation. However, there are clear differences in the requirements of alpha beta or gamma delta T-cells for IL-7. In general, IL-7 appears to serve as the major growth and differentiation factor for gamma delta T-cells. IL-7 -/- mice are characterized by a block of maturation of V gamma 3low, CD24+ T-cells to V gamma 3high, CD24low T-cells. Thus, IL-7 does not only represent a 'maintenance factor', but rather a cytokine required for successful thymic and extrathymic development and maturation of gamma delta T-cells. gamma delta + intestinal intraepithelial lymphocytes (iIEL) are absent in IL-7 -/- animals. In contrast, alpha beta + iIEL can be detected in IL-7 gene-deleted animals, but not in gamma c, or in JAK-3 deficient mice suggesting that alternative cytokines may be involved in development of iIEL alpha beta + T-cells, but not necessarily for gamma delta T-cells. To this end, IL-7 has predominantly been studied in the context of B- and T-cell development. With the availability of IL-7 gene-deleted mice, the paracrine effects of IL-7, which may be secreted in vivo by non-immune cells including keratinocytes or gut epithelial cells, can now be critically examined.
it has been proven that lymph node metastasis was closely related to prognosis of lung cancer. Interleukin-7 (IL-7) and interleukin-7 receptor (IL-7R) could promote lymph node metastasis through vascular endothelial growth factor-D (VEGF-D). The aim of this study is to explore the expressions of IL-7 and IL-7R in lung cancer and the relationship between them with lymph node metastasis and prognosis in non-small cell lung cancer (NSCLC).
the expressions of IL-7 and IL-7R in 95 cases of NSCLC were detected with immunohistochemistry method and the relationship between IL-7 and IL-7R and their impact on lung cancer patients' outcomes were analyzed.
in 95 cases of NSCLC, the high expression rates of IL-7, IL-7R and VEGF-D were 63.16%, 61.05% and 58.95%. The expressions of IL-7 and IL-7R were correlated closely with clinic stage and lymph node metastasis, but had no relationship with age, gender, histological type and differentiation degree. The lymphatic vessel density (LVD) mean of the group with high expressions of IL-7 and IL-7R was higher than that with low or negative expressions of IL-7 and IL-7R, and they were significant different in statistics. Log-rank analysis showed that the postoperative survival period was significantly shorter in high expression groups IL-7, IL-7R and VEGF-D comparing with that in low or negative groups.
the high expression of IL-7 and IL-7R is highly positie correlated with clinic stage, lymph node metastasis, VEGF-D, LVD and poor prognosis in Non-small cell lung cancer.
Alternative splicing of pre-mRNA increases proteomic diversity, a crucial mechanism in defining tissue identity. We demonstrate differentially spliced interleukin (IL)-7 in distinct anatomic areas in the adult, in developing human brains and in normal human neuronal progenitor (NHNP) cells. IL-7c (c, the canonical form spanning all six exons) or its variants IL-7 delta 5, delta 4 or delta 4/5 were cloned and expressed as recombinant proteins. IL-7 and splice variants were able to shift the differentiation of NHNP cells as compared with the diluent control (P<0.01) defined by anti-beta (III)-tubulin and glial fibrillary acidic protein expression, with different degrees (IL-7c>delta 4/5>IL-7 delta 5); IL-7 delta 4 exhibited a significantly weaker potency. Differentiation was confirmed by transcriptome analysis of IL-7c-stimulated neural NHNP cells, resulting in 58 differentially expressed genes; some of these are involved in neural differentiation, for example, the developmentally regulated transcription factor krüppel-like factor 12, musashi 2, a translational regulator of cell fate or the sonic hedgehog receptor patch 1. This suggests that IL-7 influences neural development at a molecular level by participating in human brain architecture through glia cell formation: a paradigm that alternative splicing in cytokines, for example, for IL-7, has a physiological role in human organ development and progenitor cell differentiation.
Alternative splicing results in multiple protein isoforms derived from a single gene. The magnitude of this process ranges from a complete loss of function to gain of new function. We examined, as a paradigm, alternative splicing of the non-redundant human cytokine, interleukin-7 (IL-7). We show that extensive IL-7 splicing in human tissues of different histology, including MTB+ granuloma lesions, transformed tissue and tumor cell lines. IL-7 splice variants were expressed as recombinant proteins. A differentially spliced IL-7 isoform, lacking exon 5, leads to STAT-5 phosphorylation in CD4+ and CD8+ T cells, promotes thymocyte maturation and T-cell survival. Human tumor lesions show aberrant IL-7 isoform expression, as compared with the autologous, non-transformed tissue. Alternatively spliced cytokines, such as IL-7, represent candidates for diagnostics and therapeutic interventions.
Interleukin 15 (IL-15 mRNA expression was detected in human colorectal cancer cells (Colo320, WiDr, TCO and DLD1) by the reverse transcriptase-polymerase chain reaction (RT-PCR). Only Colo320 and WiDr cells secreted IL-15 culture medium. With IL-15 treatment, all cell lines grew at a rate of 120-180% of that of nontreated cells. A binding assay with (125)I-labeled IL-15 showed binding activity to IL-15 in Colo320 (K(d): 0.098 nM) cells. IL-15 also reversed the growth inhibition caused by serum starvation in Colo320 cells. IL-15-induced cell growth in regular and serum-free media was abrogated by anti-IL-15 antibody treatment in Colo320 cells. Moreover, IL-15 treatment reduced doxorubicin-induced cytostasis and cytolysis in Colo320 cells by 50%. The invasion capacity of IL-15-treated Colo320 cells was 5.3 times that of untreated cells. Immunoblotting showed that IL-15-treated Colo320 cells exhibited downregulation of p21Waf1 and Bax, and upregulation of Bcl-2, phospho-AKT, MMP9/MMP2, and VEGF. Finally, immunostaining of human colon cancer revealed that 33 (70%) of 47 Dukes' C cases showed IL-15 expression in cancer cells, whereas only 16% of Dukes' B cases did (p < 0.0001). IL-15 may play important roles in cell proliferation, invasion, and metastasis of human colorectal cancer.
The high-affinity human interleukin-7 (IL-7)R is a heterodimeric complex consisting of the IL-7Ralpha and common interleukin-2 receptor gamma (IL-2Rgamma(c)) chains. Activation of the IL-7R complex is associated with tyrosine and serine residue phosphorylation of a number of intracellular substrates leading to proliferation and induction of various cellular differentiation processes. In this study, we demonstrate, by S1 nuclease protection assay, immunoprecipitation and in vitro kinase assay that functional human (h) IL-7R is expressed in haematopoietic and nonhaematopoietic cell lines. The National Cancer Institute (NCI) tumour panel of 60 cell lines (NCI60) was screened for the expression of IL-7R mRNA by S1 nuclease protection assay, and IL-7R mRNA was detected in 9 of 12 leukemia, 3 of 7 lung, 4 of 6 CNS, 2 of 7 melanoma, 2 of 7 renal, 1 of 6 colon and 1 of 6 breast cancer cell lines. Immunoblot analysis of haematopoietic, lung cancer and brain tumour cell lines demonstrated expression of IL-7R, IL-2Rgamma(c) and p59 fyn, suggesting that the components of an IL-7R signalling network are present in nonhaematopoietic neoplastic cells. Immunoprecipitation of IL-7Ralpha followed by an in vitro kinase assay demonstrated functional receptor phosphorylation events in the lung cancer cells but not in the brain tumour cell lines. The expression of functional IL-7R on epithelial tumour cells may represent a potential target for receptor-directed therapy.
Two human melanoma cell lines were transduced with the human interleukin (IL)-7 and IL-2 genes using retroviral-mediated gene transfer. Stable, high-level cytokine expression was achieved. The in vitro growth of transduced tumors was unaltered. Neither of the IL-2- transduced melanoma cell lines grew in athymic mice, whereas one IL-7- transduced melanoma line showed retarded in vivo growth. This is consistent with animal studies suggesting a predominantly T-cell response to IL-7-transduced tumors and a more nonspecific response to IL-2-transduced tumors. Both IL-7- and IL-2-transduced melanoma cell lines could induce cytotoxic lymphocytes in mixed lymphocyte-tumor cultures. The expression of putative melanoma antigens (MAGE)-1 and MAGE-3 was unaltered by cytokine transduction. In one cell line, IL-7 transduction resulted in a marked inhibition of the immunosuppressive peptide transforming growth factor (TGF)beta 1. The results allow a comparison of immunobiologic properties of IL-7- and IL-2-transduced human melanoma cell lines in consideration of their use in genetically engineered tumor vaccines. IL-7 transduction results in stable cytokine expression and phenotypic alterations that appear to be favorable for enhanced immunogenicity and it deserves clinical testing.
A new method of total RNA isolation by a single extraction with an acid guanidinium thiocyanate-phenol-chloroform mixture is described. The method provides a pure preparation of undegraded RNA in high yield and can be completed within 4 h. It is particularly useful for processing large numbers of samples and for isolation of RNA from minute quantities of cells or tissue samples.
Vaccination of colon cancer patients with X-irradiated autologous tumor cells and Bacillus Calmette-Guérin results in a significant reduction in tumor recurrence. A study was undertaken to determine whether the expression of tumor-associated antigens, expression of major histocompatibility complex molecules, or the cellular composition of the vaccine cells correlates with vaccine efficacy. A significant increase in the percentage of histocompatibility leukocyte antigen (HLA) class II molecule-expressing tumor cells was the only marker with a positive correlation. Because HLA class II molecule expression is not a prognostic marker in control patients, it was hypothesized that HLA class II molecules are involved in the induction of tumor immunity in patients treated with the autologous colon tumor vaccine. Enhancement of HLA class II molecule-expressing cells could be induced in X-irradiated colon tumor cells injected into the skin of mice when the cells were mixed with gamma-interferon. Therefore, addition of gamma-interferon to the colon tumor vaccine, resulting in increased numbers of HLA class II molecule-expressing cells, could potentiate the generation of tumor immunity.
P21ras proteins are thought to play an important role in cell proliferation and differentiation. Single nucleotide mutations in the encoding cellular proto-oncogenes often result in p21ras proteins with transforming activity. Such activated ras oncogenes have been demonstrated in a variety of human malignancies and also in preneoplastic changes. Using a synthetic peptide corresponding to amino acids 5-16 of mutated p21ras proteins with an exchange of the normal glycine at position 12 by valine, it is shown here that human CD4+ T cells specifically recognize the mutated protein sequence and can be generated as antigen-specific T lymphocyte lines. The fact that these T lines did not crossreact to the sequence of normal p21ras proteins offers new perspectives for specific immunotherapy of human malignancies and even precancerous lesions.
Peripheral blood monocytes can be induced by stimuli such as bacterial lipopolysaccharide (LPS) to secrete an array of cytokines. We have studied the effects of interleukin 7 (IL-7) on human peripheral blood mononuclear cells (PBMC) and found that IL-7 is a relatively potent inducer of IL-6 secretion IL-6 protein levels were determined either by the B9 hybridoma growth factor assay or by enzyme-linked immunosorbent assay, and mRNA for IL-6 was analyzed by Northern hybridization. Detailed examination revealed that, among PBMC, monocytes, rather than lymphocytes, were secreting IL-6 in response to IL-7. In contrast to the low concentrations of IL-7 required to stimulate T cell growth and differentiation (as low as 0.1 ng/ml), relatively high concentrations of IL-7 were necessary to induce IL-6 secretion by monocytes (at least 10 ng/ml). An optimal concentration of IL-7 (100 ng/ml) induced monocytes to secrete 10-fold more IL-6 than an optimal concentration of IL-1 beta (10 ng/ml), and almost as much as LPS. However, significantly more IL-7 than IL-1 beta was required to induce detectable levels of IL-6. The kinetics of IL-6 secretion by monocytes were identical in response to IL-7, IL-1 beta, or LPS, with IL-6 protein detectable in culture supernatants as early as 2 h after the initiation of culture. IL-4 was found to markedly inhibit the ability of IL-7 or LPS to induce IL-6 mRNA and IL-6 secretion. In addition to promoting IL-6 production, IL-7 induced the secretion of immunoreactive IL-1 alpha, IL-1 beta, and tumor necrosis factor alpha (TNF-alpha) by monocytes. IL-7 also induced monocyte/macrophage tumoricidal activity against a human melanoma cell target, an activity that may be related to the secretion of IL-1 alpha, IL-1 beta, and TNF-alpha. Finally, we used a whole blood culture system as a bridge to in vivo analysis to demonstrate that IL-7 induces cytokine secretion in the absence of culture medium, fetal calf serum, and adherence to plastic. Our data suggest that IL-7, in addition to regulating lymphocyte growth and differentiation, has potent effects on cells of the monocytic lineage. Thus, IL-7 may be an important mediator in inflammation and in the macrophage immune response to tumors.
The effects of purified recombinant interleukin 7 (IL-7) on the generation of cytolytic T lymphocytes (CTL) in mixed lymphocyte culture (MLC) and on the induction of lymphokine-activated killer (LAK) cells in autologous cultures of human peripheral blood mononuclear cells were investigated. IL-7 was found to induce the generation of both CTL and LAK cells in bulk cultures. The appearance of peak CTL activity in MLC established with exogenous IL-7 was delayed in comparison with replicate cultures containing exogenous IL-2, but both cytokines stimulated quantitatively similar levels of antigen-specific lytic activity. An IL-2-neutralizing antiserum inhibited substantially, but not completely, the effect of IL-7 on CTL generation, implying the existence of both an indirect component of IL-7 activity via IL-2 utilization, as well as an IL-2-independent component. Cell surface phenotypic analysis of IL-2- or IL-7-generated CTL effector cells revealed that CD8+ cells were responsible for the vast majority of lytic activity. Limiting dilution analysis (LDA) revealed that essentially identical frequencies of CTL precursors (CTL-P) were capable of clonal expansion and/or differentiation in the presence of exogenous IL-2, IL-4, or IL-7, supporting the concept that all three of these cytokines are capable of exerting a major influence on T cell growth and differentiation. Approximately half of the CTL-P that responded in IL-7-supplemented LDA cultures did so in an IL-2-independent manner. IL-7 stimulated the development of LAK cells in autologous bulk cultures, but only weakly in comparison with IL-2. In contrast to its effects on CTL generation, the induction of LAK cells by IL-7 was virtually independent of IL-2. LAK cells induced by IL-7, like those induced by IL-2, were phenotypically heterogeneous and included CD8+, CD56+, and gamma/delta+ cells. Limiting dilution analysis indicated that IL-2 stimulated fivefold more LAK-P than IL-7 and 220-fold more than IL-4. Collectively, these data suggest that IL-7 has potent regulatory effects on human cytolytic cell populations and, either alone or in combination with other cytokines, could be important for the in vitro expansion of cells for adoptive immunotherapy.
A new method of total RNA isolation by a single extraction with an acid guanidinium thiocyanate-phenol-chloroform mixture is described. The method provides a pure preparation of undegraded RNA in high yield and can be completed within 4 h. It is particularly useful for processing large numbers of samples and for isolation of RNA from minute quantities of cells or tissue samples.
A cDNA encoding biologically active human interleukin 7 was isolated by hybridization with the homologous murine clone. Nucleotide sequence analysis indicated that this cDNA was capable of encoding a protein of 177 amino acids with a signal sequence of 25 amino acids and a calculated mass of 17.4 kDa for the mature protein. Recombinant human interleukin 7 stimulated the proliferation of murine pre-B cells and was active on cells harvested from human bone marrow that are enriched for B-lineage progenitor cells. Analysis of RNA by blot hybridization demonstrated the presence of two size classes of interleukin 7 mRNA in human splenic and thymic tissue.
In order to assess the potential of interleukin 7 (IL-7) as an immunotherapeutic agent in human melanoma, we have evaluated the in vitro activity of IL-7-induced lymphokine-activated killer (LAK) cells from patients with advanced melanoma against allogeneic and autologous melanoma cells. Peripheral blood lymphocytes (PBLs) from 14 patients with stage III melanoma were isolated and incubated in the presence of 1,000 U ml-1 IL-7 and 100 U ml-1 IL-2 for comparison. LAK-cell activity was determined by a 24 h cytotoxicity assay using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]. The activity of IL-7-induced LAK cells against two allogeneic melanoma cell lines was 32.7% (+/- 17.9) against SK-Mel-37 and 38.1% (+/- 12.5) against SK-Mel-23 at an effector-to-target (E/T) ratio of 20:1. The activity of IL-2-induced LAK cells was significantly higher against SK-Mel-37 (78 +/- 24.6%) and against SK-Mel-23 (73.5 +/- 19.7%). IL-7 and suboptimal doses of IL-2 (10 U ml-1) were found to have a co-stimulatory on lymphocyte proliferation as well as on LAK activity. Against autologous melanoma cells, the activity of IL-7- and IL-2-induced LAK cells did not differ significantly (55.8 +/- 25.6% versus 68.7 +/- 21.7% respectively). In two patients, IL-7-induced LAK-cell activity against autologous melanoma cells exceeded even that of IL-2 significantly (67% vs 35% and 95% vs 82%). Levels of tumour necrosis factor alpha (TNF-alpha) in the supernatants of LAK-cell cultures generated by IL-7 were lower than those of IL-2-generated LAK-cell cultures. These results suggest that IL-7 is a potential alternative to immunotherapy with IL-2 in terms of efficacy and possible side-effects and encourages pilot studies with IL-7 in melanoma patients.
We analyzed the phenotype and V beta-T cell receptor (TCR) repertoire, together with interleukin 7 receptor (IL-7R) expression in unfractionated thymocytes stimulated in vitro with IL-7. This culture system results in a specific proliferation of mature thymocytes belonging to the CD3+CD4-, CD4+8-, and CD4-8+ subsets. IL-7 induced a preferential expansion of V beta 8.2+CD4-8- and V beta 8.2+CD4-8- thymocytes. This phenomenon is not observed in beta 2-microglobulin-deficient mice, showing that a fraction of CD4+8- thymocytes, enriched in V beta 8.2+ cells, is selected by class I molecules in normal mice, as are a large proportion of CD4-8- alpha beta TCR+ thymocytes. Our findings also establish that IL-7 plays a major role in the expansion of rare thymocyte subsets, which could exert important functions in inflammatory and immune responses.
This study investigated the phenotype of freshly isolated human tumour infiltrating lymphocytes (TIL) from 14 patients with colorectal tumours, and compared them with lymphocytes derived from the lamina propria of the unaffected mucosa and with lymphocytes derived from peripheral blood of the same patients. It was found that TIL expressed the activation markers CD25 and HLA-DR to a higher extent than the peripheral blood lymphocytes (p = 0.01), and that both lamina propria lymphocytes and TIL preferentially expressed the CD45RO + phenotype, associated with memory cells, in contrast with peripheral blood lymphocytes [corrected]. Both lamina propria lymphocytes and TIL contained few natural killer (NK) cells (CD3-CD56+) compared with peripheral blood lymphocytes (p = 0.001), and this was reflected in the cytotoxicity assays. After 1 to 2 weeks in culture with interleukin-2 100 U/ml, lymphocytes from all three compartments had a high cytolytic activity against all targets tested, consistent with the lymphokine activated killer cell phenomenon. No increase in the number of NK cells was noted after culture, but 20-30% of the T cells now coexpressed the CD56 molecule. This was most prominent in the CD8+ subset, but lymphokine activated killer cell activity was found in both CD4+ and CD8+ subsets. Possible tumour escape mechanisms are discussed.
The presence of T lymphocytes in solid tumours may reflect an ongoing immune response against the transformed cells. We have used polymerase chain reaction (PCR) technology to investigate the T-cell receptor variable-region gene (V-gene) usage in freshly isolated tumour-infiltrating lymphocytes (TILs) to look for a possible oligoclonality of T cells in the tumour area. We used 19 different V beta-family-specific primers. Peripheral blood lymphocytes and lamina propria lymphocytes from the same patients were also tested by PCR. Our results demonstrate a limited heterogeneity in the V-gene usage of TILs from seven patients with colorectal cancers, suggesting a local antigen-driven immune response at the tumour site.
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We previously reported that culture of murine fetal liver (FL) cells with interleukin 7 (IL-7) results in expression of high levels of T cell receptor (TCR) gamma transcripts by a population of cells expressing Thy-1 and Pgp-1, suggesting that IL-7 promotes the growth and/or differentiation of pre-T cells. We demonstrate herein that culture of FL cells for 7 d with IL-7 caused the rearrangement and expression of TCR gamma variable (V) region genes V gamma 4 and V gamma 6, but not V gamma 5 or V gamma 7. Since this effect was not blocked by hydroxyurea, it appeared to represent induction of expression of these genes by IL-7 rather than expansion of a preexisting positive population. We also show that IL-7 induced RAG-1 and RAG-2 mRNA expression by FL cells. These data provide evidence that specific TCR gamma/delta V region genes can be rearranged and expressed by T lineage cells before their migration to the thymus, in response to IL-7.
Two human melanoma cell lines were transduced with the human interleukin (IL)-7 and IL-2 genes using retroviral-mediated gene transfer. Stable, high-level cytokine expression was achieved. The in vitro growth of transduced tumors was unaltered. Neither of the IL-2-transduced melanoma cell lines grew in athymic mice, whereas one IL-7-transduced melanoma line showed retarded in vivo growth. This is consistent with animal studies suggesting a predominantly T-cell response to IL-7-transduced tumors and a more nonspecific response to IL-2-transduced tumors. Both IL-7- and IL-2-transduced melanoma cell lines could induce cytotoxic lymphocytes in mixed lymphocyte-tumor cultures. The expression of putative melanoma antigens (MAGE)-1 and MAGE-3 was unaltered by cytokine transduction. In one cell line, IL-7 transduction resulted in a marked inhibition of the immunosuppressive peptide transforming growth factor (TGF)beta 1. The results allow a comparison of immunobiologic properties of IL-7- and IL-2-transduced human melanoma cell lines in consideration of their use in genetically engineered tumor vaccines. IL-7 transduction results in stable cytokine expression and phenotypic alterations that appear to be favorable for enhanced immunogenicity and it deserves clinical testing.
A major obstacle to the effective use of adoptive immunotherapeutic treatment of cancer is the difficulty of obtaining tumor-reactive lymphocytes in either sufficient numbers or with appropriate in vivo function to make such an approach feasible. Previous studies have shown that antitumor cytotoxic T lymphocytes (CTL) with in vivo efficacy can be generated in vitro from lymphoid cells obtained from lymph nodes that drain the anatomical site of a tumor. Results presented here demonstrate that inclusion of interleukin 7 (IL-7) into the medium in which such CTL are cultured can support their growth in vitro for prolonged periods of time in the absence of repeated stimulation with either tumor stimulator cells or tumor antigen. More importantly, antitumor CTL propagated in medium containing IL-7 have retained both their antigenic specificity and their ability to reject tumors in vivo subsequent to intravenous injection. Parallel cultures of antitumor CTL similarly cultured in medium containing only IL-2 could only be maintained for 5-6 wk, after which the number and proportion of viable cells that were recoverable from such cultures progressively decreased. Phenotypic analysis of CTL maintained after extended culture (i.e., 22 mo) in medium containing IL-7 demonstrated them to be CD3+4-8+ T cells. These cells were also found to express lymphocyte function associated 1, intercellular adhesion molecule 1, and Mel-14 cell interaction molecules. The data also demonstrate that these CTL do not require the presence of antigen-presenting cell populations to mount a proliferative response to tumor stimulator cells. Cells in these cultures were also demonstrated to produce IL-2 after stimulation with irradiated tumor cells, thereby indicating that these CTL have become independent of the requirement for CD4+ helper cells to survive and function either in vitro or in vivo. Collectively, the findings that IL-7 can beneficially augment the generation, and propagate the long-term growth, of antitumor CTL from lymph nodes draining a tumor site may have profound implications for promoting the immunotherapeutic treatment of cancer in humans.
One hundred large bowel carcinomas operated on between 1978 and 1982 were studied immunohistochemically with regard to expression of HLA-DR antigens. Three sections from each tumour were investigated by a semiquantitative scoring system, and a mean score for each patient established. Based on this scoring system, the tumours were divided into three groups: 0; 0.1-1.0; and > 1.0. All patients were followed until death (n = 68) or until June 1, 1992, and all cancer-specific deaths (n = 56) have been recorded. Analysis of survival in the whole patient group showed significant difference between the three levels of tumour HLA-DR expression (P = 0.006); patients who had tumours with strong HLA-DR expression showing the best survival. In a stratified analysis after Dukes' stages there was still a significant difference (P > 0.001) between the three levels of HLA-DR staining intensity. After a multiple regression analysis (Cox) with correction for different variables, the HLA-DR expression maintained its significance as a risk factor. To our knowledge this is the first time a relationship between intensity of tumour DR expression and survival has been shown in large bowel carcinoma.
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Figure 1
The proliferation of epithelial cells lining the small intestinal mucosa may be regulated by microenvironmental signals leading to differentiation of precursor cells in the small intestinal crypts. Proliferation of hematopoietic cells within the hematopoietic microenvironment is known to be regulated by a growing number of glycoprotein growth factors in a hierarchial fashion. We studied the effects of administration of the microenvironment-derived hematopoietic growth factor interleukin-11 (IL-11) on mice given combination radiation/chemotherapy. Treatment of such mice with IL-11 led to significantly increased survival and evidence of rapid recovery of the small intestinal mucosa, which is severely damaged by these cytoxic agents. This recovery was associated with an increase in the mitotic index of crypt cells and an increased frequency of staining of these cells with a monoclonal antibody to proliferating cell nuclear antigen, a member of the cyclin family of nuclear antigens.
HLA expression is frequently altered in tumours compared to the tissue from which they originate. Given the central role of MHC products in the restriction of T-cell recognition, regulation of tumour HLA expression might be a strategy for the evasion of immune surveillance by the malignant cells. Federico Garrido, Peter Stern and colleagues present data from a variety of tumour types, suggesting that HLA class I alterations may occur at a particular step between the development of an in situ lesion and an invasive carcinoma.
In contrast to CD8+ T cells. it has been difficult to establish consistently satisfactory conditions for the bulk culture of antitumor CD4+ T cells in either mice or humans. This difficulty is not limited to tumor antigen, since similar problems are encountered growing CD4+ T cells that recognize alloantigen, tetanus, or candida. Four basic findings are reviewed in this article, stemming from work with identical results in both human and mouse. (a) Although CD4+ T cells initially proliferate after exposure to appropriate antigen-presenting cells (APCs), such proliferation is not sustained; however, expansion of CD4- T cells can be achieved with the addition of recombinant interleukin-2 (rIL2) or rIL-7. (b) Specific CD4+ responses to antigens are often better sustained with exogenous IL-7 than with exogenous IL-2. (c) Adding rIL-7 or rIL-2 permits sustained CD4+ T-cell proliferation, but subsequent culture restimulation is complicated by high background reactivity to APCs whether APCs are antigen pulsed or not; this problem can be overcome by addition of exogenous interferon-gamma (IFN-gamma) to the CD4+ cultures. (d) In certain instances proliferation is paradoxically impaired by reexposure to specific antigen, possibly reflecting apoptosis; this problem is also overcome by addition of rINF-gamma to culture. We conclude that combinations of exogenous IL-7, IL-2, and IFN-gamma with APC restimulation can be used to sustain antigen-specific CD4+ T cells in culture. Using these techniques, antitumor CD4+ T cells were propagated from the peripheral blood of two tumor-bearing patients.
Virus-specific cytotoxic T lymphocytes (CTLs), which kill virus-infected cells, are thought to be a major host defense against viral infections. The addition of interleukin 7 (IL-7) at the onset of mitogen-stimulated cultures resulted in a marked (up to threefold) augmentation of env-specific cytotoxicity in human immunodeficiency virus type 1 (HIV-1)-infected individuals (p < 0.001). Addition of IL-7 on day 3 or 5 produced a significant but lesser augmentation of CTL response as compared to day 0. The IL-7-induced proliferative response and augmentation of cytotoxic activity was time and dose dependent, with an optimal IL-7 concentration of 1000 U/ml. Cell surface phenotypic analysis of CTL effector cells indicates that IL-7 primarily affects the proliferation of CD8(+) T cells. Anti-IL-2 monoclonal antibody (MAb) substantially inhibited the proliferative effect of IL-2, but did not affect the proliferative effect of IL-7. Endogenous IL-2-induced generation of cytotoxic T cells was blocked by MAbs to IL-2 or IL-2R. The addition of IL-7 restored the process of conversion of precursor CTLs (pCTLs) to mature CTLs (mCTLs) and significantly enhanced specific cytolytic activity. It appears that IL-7 is a potent regulatory cytokine capable of acting independently of IL-2 in mitogen-specific activation of pCTLs to mCTLs. These data suggest that IL-7 should be considered as a potential therapeutic approach in AIDS and other infectious diseases in which CTL response declines.
Adoptive immunotherapy with lymphokine-activated killer (LAK) cells has shown some promise in the treatment of certain cancers that are unresponsive to conventional treatment approaches. However, colon adenocarcinomas tend to respond poorly to LAK therapy, possibly as a result of tumor-induced immunosupprression. Recently, in vivo administration of anti-CD3 antibody has been shown to induce mouse T lymphocytes to mediate major-histocompatibility-complex(MHC)-unrestricted tumoricidal activity which is distinet from natural-killer-cell-derived LAK activity. It has therfore been suggested that anti-CD3 therapy may find application in tumor immunotherapy in humans. However, the effectiveness of anti-CD3-activated killer cell induction within the environment found in the vicinity of colon adenocarcinoma cells has not been evaluated. The present report demonstrates that colon cancer cells of human (HT-29) and mouse (MCA-38) origin markedly inhibit the generation of activated killer cells in murine spleen cell cultures. DNA synthesis and interleukin-2 production by spleen cells following stimulation with anti-CD3 antibody are also profoundly depressed in the presence of MCA-38 and HT-29 adenocarcinoma cells. MCA-38- and HT-29-mediated inhibition of activated killer cell development is exerted through the production of a tumor-associated soluble factor that is distinct from transforming growth factor or prostaglandins. Local immunosupression associated with sites of tumor growth may therefore represent a major obstacle to successful anti-CD3 immunotherapy of certain colon adenocarcinomas.
Experience with the administration of high doses of interleukin 2 (IL-2) alone is described herein. Ten patients with a variety of malignant disorders unresponsive to conventional treatments were treated with at least 30,000 U/kg of IL-2 by bolus administration three times a day. Patients were treated intravenously or intraperitoneally from four to 21 days in a single course, usually interrupted by a week of recovery. Three of six patients with melanoma experienced an objective regression (greater than 50% decrease in volume); there was no response to treatment in patients with colorectal (0/3) or ovarian (0/1) cancer. Two patients with initial objective regressions who subsequently developed progression were re-treated and one sustained a second partial response. Responses lasted 1, 3, and 7 months without additional treatment. Responses in the three patients with melanoma were in visceral sites (lung, liver, and spleen), as well as cutaneous sites in one patient. Progressive shrinkage of tumors for three to six months after the conclusion of therapy has been noted in two patients. Marked lymphocytic infiltrate was noted in a patient with lesions accessible to repeated biopsies. This study demonstrates that the administration of IL-2 can mediate the regression of established cancer in some patients.
Melanoma represents the single best example of a human tumor that has been shown to elicit specific T-cell reactivity. The responsiveness of some patients with metastatic melanoma to treatment with the prototypic T-cell growth factor (TCGF), interleukin-2 (IL-2), indicates that T cells play a role in antitumor immunity. Interleukin-4 (IL-4), another TCGF that has been administered clinically to humans, was not associated with tumor response in our trials conducted at the Surgery Branch of the National Cancer Institute. Combination trials of IL-2 with IL-4 have shown no increase in responsiveness of melanoma or other tumors when compared to IL-2 alone. However, enhanced expansion of tumor-infiltrating lymphocytes (TILs) in vitro has been observed with combinations of low-dose IL-2 and IL-4. We have begun a study evaluating the trafficking of such expanded lymphocytes following their adoptive transfer in association with systemic administration of IL-2 and IL-4. We have established several TIL cultures from fresh tumor samples, maintained them in long-term culture, and marked them with the neomycin phosphotransferase gene using the LNL6 retroviral vector. Such TILs appear to demonstrate no notable alterations in phenotype or cytolytic activity when compared to their nontransduced counterparts. In addition to IL-2 and IL-4, there are a variety of other novel TCGFs that are now available for evaluation in preclinical and clinical trials. IL-7 induces proliferation and lymphokine-activated killer (LAK) cell activity from human peripheral blood mononuclear cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Epidermal cells (EC) are a rich source of cytokines that can regulate the function of cells in skin and in other tissues. To organize the array of data pertaining to cytokine expression by EC subpopulations, we have tabulated such data according to cell source, state of cell activation, and type of assay employed. This information forms a background for our own studies, in which reverse transcriptase-polymerase chain reaction (RT-PCR) was used to show that Langerhans cells (LC) are the principal source of mRNA for interleukin 1 beta and macrophage inflammatory protein-1 alpha (MIP-1 alpha) among unstimulated mouse EC.
Peptides derived from mutated human proto-oncogenes bound to HLA may represent a novel type of tumor-specific antigen. Mutated ras genes are the oncogenes most frequently identified in human cancer. The transforming genes carry a mutation in codons 12, 13, or 61. We have investigated whether the T-cell repertoire of healthy individuals contains T cells capable of recognizing and responding to oncogene-derived peptides. Synthetic peptides derived from mutated p21 ras proto-oncogenes, covering mutations at codons 12 or 13 were selected. It was feasible to elicit T-cell responses and isolate several new T-cell clones (TCC) with specificity for a number of different mutated ras peptides after repeated in vitro immunization. Four TCC were characterized with respect to fine specificity and HLA restriction. TCC B and I were restricted by HLA-DR molecules, and recognized the mutated p21 ras-derived peptide carrying Arg and Lys at residue 12, respectively. TCC E and F were restricted by HLA-DQ molecules, the former being specific for a mutated p21 ras-derived peptide with Val in position 13 and the latter more broadly reactive. Peptide competition experiments with a panel of ten peptides derived from p21 ras indicated that all could bind to HLA-DQ molecules of the T-cell donor, while several were also able to bind his HLA-DR molecules. These results show that several p21 ras mutations resulting in aa substitutions at residues 12 or 13 could be recognized by T cells derived from precursor T cells of relatively low frequency present in the normal repertoire of a single donor.
Induction of lymphokine-activated killer (LAK) activity by IL-2 has been described and characterized as broadly cytolytic activity against both fresh and cultured tumors. rIL-7 in the absence of IL-2 also induces LAK activity in human cells. This activity is unique for IL-7, because it is not shared by other cytokines including IL-1, IL-4, IL-6, and TNF-alpha. IL-7 also induces either de novo or increased expression of the surface markers CD25 (Tac, IL-2R alpha-chain), CD54 (ICAM-1), Mic beta 1 (IL-2R beta-chain) and CD69 (early T cell activation Ag). IL-7-induced LAK activity is independent of IL-2 secretion, because it is not abrogated by IL-2 antisera. The LAK precursor responding to IL-7 stimulation is enriched in the null cell fraction as has been demonstrated for IL-2-induced LAK cells. TGF-beta and IL-4 interfere with generation of LAK activity by IL-7. Anti-IL-4 antiserum enhances IL-7-induced LAK activity and augments induction of surface marker expression by IL-7. This may be indirect evidence that IL-7 stimulation leads to induction of IL-4 activity. Our results describe the activation of mature lymphoid cells by IL-7. This and the previously described role of IL-7 in lymphohemopoiesis makes it a cytokine of potential therapeutic value for treatment of immunodeficiency states and possibly the immunotherapy of cancer.
To study in vivo the contribution of different thymic epithelial cells to T-lymphocyte differentiation, we have established several nontransformed thymic epithelial cell lines and developed an in vivo assay, not involving exposure to drugs or radiation, that permitted us to study the capacity of these epithelial lines to support T-cell differentiation. We found that cell lines EA2 and ET, which express markers of cortical epithelial cells, produce interleukin 7 mRNA and after being injected into the spleens of young athymic nude mice support in vivo generation of CD4+CD8- T-cell receptor alpha beta+ T lymphocytes (ET line) or both CD4+CD8- and CD4-CD8+ T-cell receptor alpha beta+ T cells (EA2 line). Both cell lines also supported generation of T-cell receptor gamma delta+ T cells but appear not to support development of double-positive (CD4+CD8+) cells. One cell line, EB3, which expresses markers of medullary epithelial cells, produces interleukin 1 alpha RNA transcripts but does not support T-lymphocyte differentiation. The results provide direct evidence for functional heterogeneity of thymic epithelial cells in vivo and show the involvement of different cortical epithelial cells in the differentiation of T-cell progenitors into distinct thymocyte subsets.
We have developed and established mouse transgenic lines in which the mouse interleukin 7 gene was targeted for expression in the lymphoid cell compartment. Northern blot analysis indicate that the transgene is expressed in bone marrow (BM), spleen and thymus, but not in kidney, liver, brain or heart. Both the frequency and absolute numbers of B cell precursors and mature B lymphocytes are increased in the BM and spleen of the transgenic mice. Although there is no expansion of the pro-T lymphocyte population in the BM, the number of all major subsets of thymocytes and peripheral T lymphocytes is increased in the majority of the transgenic mice analyzed. The B and T cell lymphocytes in the transgenic mice are functionally competent. In contrast, the number of granulocytes and macrophages in the BM of transgenic mice is similar to that in control non-transgenic littermates. Our results indicate that interleukin 7 plays an important role in vivo in the development of B and T lymphocytes.
CD3+ T cells mediate relatively promiscuous patterns of major histocompatibility complex (MHC)-unrestricted target cell lysis following activation. Cell-cell contact between target and effector cells is essential in this form of cytotoxicity. Although the T-cell receptor (TCR)-CD3 molecular complex can transmit signals that initiate MHC unrestricted T-cell killing, recognition of targets by the TCR is not essential for this form of cytotoxicity. In this review by Dwain Thiele and Peter Lipsky, a model of the triggering of T cells to effect MHC-unrestricted cytotoxicity is proposed.
The events involved in the commitment and development of lymphoid lineage cells are poorly understood. We have used a recently described long-term culture system to establish a bioassay that can detect a novel growth factor capable of stimulating the proliferation of lymphoid progenitors. Using direct expression in mammalian cells we have isolated a complementary DNA clone encoding this novel haematopoietic growth factor, designated interleukin-7.
Lymphocytes extracted from freshly resected melanomas can be expanded in vitro and can often mediate specific lysis of autologous tumor cells but not allogeneic tumor or autologous normal cells. We treated 20 patients with metastatic melanoma by means of adoptive transfer of these tumor-infiltrating lymphocytes and interleukin-2, after the patients had received a single intravenous dose of cyclophosphamide. Objective regression of the cancer was observed in 9 of 15 patients (60 percent) who had not previously been treated with interleukin-2 and in 2 of 5 patients (40 percent) in whom previous therapy with interleukin-2 had failed. Regression of cancer occurred in the lungs, liver, bone, skin, and subcutaneous sites and lasted from 2 to more than 13 months. Toxic effects of interleukin-2 occurred, although the treatment course was short (five days); these side effects were reversible. It appears that in patients with metastatic melanoma, this experimental treatment regimen can produce higher response rates than those achieved with interleukin-2 administered alone or with lymphokine-activated killer cells. It is too early to determine whether this new form of immunotherapy can improve survival, but further trials seem warranted.
The authors have observed a previously unexpected heterogeneity in the lytic reactivity of CTL clones established in vitro. Many CTL clones, in addition to their predicted specificity when measured on LPS target cell blasts, kill a spectrum of NK-susceptible tumor target cells. Additionally, removal of antigenic stimulation from established CTL clones, accompanied by a change in the growth conditions (to high concentrations of growth factors) led to a 'differentiation' process, in which morphologic changes were seen to accompany a change in lytic reactivity. Such functional changes, which included a loss of antigen-specific recognition, were also reflected in membrane-macromolecule display on CTL clones. Discrete changes in the glycolipid and glycoprotein profiles were discernible when CTL grown under antigen-dependent and antigen-independent conditions were compared. The relationship between such membrane alterations and the functional changes in lytic activity are not yet clearly defined, but promise to provide important insights into the molecular events associated with CTL-antigen interactions.
The principles and procedures of active specific immunotherapy developed from studies with the inbred guinea pig hepatocarcinoma model were used as the basis of a randomized, controlled prospective trial of active specific immunotherapy of colorectal cancer patients. The goal was to determine whether colorectal cancer patients treated with vaccines made of autologous tumor cells plus Bacillus Calmette-Guérin as adjuvant would have an increased reaction to their autologous tumor cells as measured by delayed-type cutaneous hypersensitivity (DCH) responses. Our results demonstrate that the active specific immunotherapy significantly increased the DCH responses to autologous tumor cells in 16 of 24 patients (67%). The DCH response of immunized patients to autologous normal mucosa, used as a normal tissue control, did not increase significantly. Furthermore, no significant DCH responses against autologous tumor or mucosa cells were detected in a group of nonimmunized control patients. The induced DCH responses were not correlated with other factors, such as the presence of bacteria in the cell preparation or the protein concentration of the cell preparations. The qualitative and quantitative differences in DCH responses to tumor cells and to normal mucosa cells suggest that the immunizations are targeted mainly to tumor-associated antigens with tissue-associated antigens playing a secondary role.
In contrast to CD8+ T cells, it has been difficult to establish consistently satisfactory conditions for the bulk culture of antitumor CD4+ T cells in either mice or humans. This difficulty is not limited to tumor antigen, since similar problems are encountered growing CD4+ T cells that recognize alloantigen, tetanus, or candida. Four basic findings are reviewed in this article, stemming from work with identical results in both human and mouse. (a) Although CD4+ T cells initially proliferate after exposure to appropriate antigen-presenting cells (APCs), such proliferation is not sustained; however, expansion of CD4+ T cells can be achieved with the addition of recombinant interleukin-2 (rIL2) or rIL-7. (b) Specific CD4+ responses to antigens are often better sustained with exogenous IL-7 than with exogenous IL-2. (c) Adding rIL-7 or rIL-2 permits sustained CD4+ T-cell proliferation, but subsequent culture restimulation is complicated by high background reactivity to APCs whether APCs are antigen pulsed or not; this problem can be overcome by addition of exogenous interferon-gamma (IFN-gamma) to the CD4+ cultures. (d) In certain instances proliferation is paradoxically impaired by reexposure to specific antigen, possibly reflecting apoptosis; this problem is also overcome by addition of rIFN-gamma to culture. We conclude that combinations of exogenous IL-7, IL-2, and IFN-gamma with APC restimulation can be used to sustain antigen-specific CD4+ T cells in culture. Using these techniques, antitumor CD4+ T cells were propagated from the peripheral blood of two tumor-bearing patients.
Virus-specific cytotoxic T lymphocytes (CTLs), which kill virus-infected cells, are thought to be a major host defense against viral infections. The addition of interleukin 7 (IL-7) at the onset of mitogen-stimulated cultures resulted in a marked (up to threefold) augmentation of env-specific cytotoxicity in human immunodeficiency virus type 1 (HIV-1)-infected individuals (p < 0.001). Addition of IL-7 on day 3 or 5 produced a significant but lesser augmentation of CTL response as compared to day 0. The IL-7-induced proliferative response and augmentation of cytotoxic activity was time and dose dependent, with an optimal IL-7 concentration of 1000 U/ml. Cell surface phenotypic analysis of CTL effector cells indicates that IL-7 primarily affects the proliferation of CD8+ T cells. Anti-IL-2 monoclonal antibody (MAb) substantially inhibited the proliferative effect of IL-2, but did not affect the proliferative effect of IL-7. Endogenous IL-2-induced generation of cytotoxic T cells was blocked by MAbs to IL-2 or IL-2R. The addition of IL-7 restored the process of conversion of precursor CTLs (pCTLs) to mature CTLs (mCTLs) and significantly enhanced specific cytolytic activity. It appears that IL-7 is a potent regulatory cytokine capable of acting independently of IL-2 in mitogen-specific activation of pCTLs to mCTLs. These data suggest that IL-7 should be considered as a potential therapeutic approach in AIDS and other infectious diseases in which CTL response declines.
IL-7 plays a central role in regulating the growth and differentiation of T cells. We have reported previously that epidermal keratinocytes produce biologically relevant amounts of IL-7, thereby supporting the growth of epidermal gamma delta T cells. In this report, we report that IL-7 gene expression is regulated in keratinocytes by IFN-gamma. Treatment of Pam 212 keratinocytes with IFN-gamma induced a preferential expression of 2.6- and 1.5-kb IL-7 mRNAs, in addition to the 2.9- and 1.7-kb mRNAs that are expressed constitutively. The 2.6- and 1.5-kb mRNAs are produced through the use of alternative transcription initiation sites; these mRNAs are transcribed within 250 bp from the coding sequence, whereas 2.9- and 1.7-kb mRNAs contain > 400 bases in the 5'-untranslated region. IFN-gamma appears to promote this conversion through the IFN-stimulated response element (ISRE), which is located 270 bp upstream from the coding sequence. ISRE is followed by the initiator, a non-TATA-type transcription control element. Functional relevance of the ISRE/initiator complex was suggested by the observations that IFN-gamma-dependent transcription was initiated from immediately downstream of this complex, and that its deletion resulted in an abrogated IFN-gamma responsiveness in transcriptional regulation. These results document a novel mechanism by which IL-7 gene expression is regulated in keratinocytes by a cytokine produced by T cells (IFN-gamma).
The goal of the present study was to investigate the role of IL-7 in regulating immune responses to infection. Leprosy provides a model for understanding human immune responses to infection; the disease presents as a spectrum in which the clinical manifestations correlate with the levels of cell-mediated immunity to the pathogen, Mycobacterium leprae. To determine whether IL-7 is produced at the site of infection in leprosy, we used the PCR to measure IL-7 and IL-7R mRNA in skin lesions. IL-7 mRNA was more strongly expressed in the tuberculoid form of the disease, in which the infection is limited (mean cpm = 48 +/- 8; n = 11), as compared with the progressive lepromatous form (17 +/- 2; n = 11). IL-7R mRNA, both membrane-bound and soluble forms, were also more strongly expressed in tuberculoid lesions, although these differences were not as striking as those for IL-7. The cellular source of IL-7 included Ag-stimulated monocytes and IFN-gamma-induced keratinocytes. M. leprae-induced PBMC responses in tuberculoid patients involved up-regulation of IL-7 and IL-7R mRNA and was IL-7 dependent. In contrast, M. leprae did not induce IL-7 mRNA in lepromatous patients, and their T cell responses were weakly augmented by rIL-7. These data suggest that IL-7, produced at the site of disease, contributes to the cell-mediated immune response to human pathogens.
Peptides derived from mutated ras are immunogenic in mice and humans, and represent a group of specific tumor antigens that are potential targets for immunotherapy. T-cell responses against mutant p21 ras can be initiated in vitro by repeated stimulation of peripheral-blood mononuclear cells with mutant ras-derived peptides. Patients with tumors commonly harbouring ras mutations may therefore show evidence of in vivo reactivity against such mutations. Peripheral-blood mononuclear cells from 10 patients with colorectal adenocarcinoma were screened for reactivity against synthetic ras-derived peptides corresponding to the most commonly found mutations in this type of cancer. In one patient, T-cell reactivity against the 1-25,13Gly-->Asp peptide was detected. From this patient, both CD4+ and CD8+ T-cell clones specific for the 1-25,13Gly-->Asp mutation could be raised. We were not, however, able to detect the corresponding mutation in the cancer. The 13Gly-->Asp mutation in the ras oncogene is frequent and constitutes 9 to 27% of all K ras mutations found in biopsies from patients with colorectal carcinomas. Our study demonstrates a mutant ras-specific T-cell response of both the CD4+ and the CD8+ phenotype in a cancer patient. We speculate that in this patient a specific T-cell response resulted in eradication of tumor cells harboring the 13Gly-->Asp mutation.
The presence of intestinal intra-epithelial lymphocytes (IEL) has been appreciated for over 100 years. However, until recently, the IEL were thought to be simply another specialized component of the gut-associated lymphoid tissue (GALT), sharing the same origin as lymphocytes found in other GALT compartments such as the lamina propria, the Peyer's patches, and the mesenteric lymph nodes. While the IEL remain functionally enigmatic, over the last ten years increasing evidence, originally based on the phenotypic complexity of IEL, has led to the conclusion that the intestinal epithelium comprises a distinct and unique lymphoid compartment within the organism. The recent discovery that the intestinal epithelium is a primary T lymphopoietic organ provides obvious potential explanations for the phenotypic peculiarities of IEL. The following discussion reviews the experiments that established that the intestinal epithelium is a site of T cell development and selection, and the discussion correlates phenotypic and functional heterogeneity of IEL within this context.
IL-7 was originally reported as a cytokine produced by stromal cells which supports pre-B cell proliferation in vitro. To determine whether human B cells secrete IL-7 and express IL-7R we studied a wide panel of B cell lines (CLS). In Northern blot analysis we detected 2.4 kb IL-7 mRNA and by quantitative PCR we demonstrated IL-7 expression in 5 of 6 B CLS derived from patients with AIDS-associated Burkitt's lymphoma (AABCL), 3 of 3 CLS derived from patients with American Burkitt's lymphoma and 5 of 6 normal lymphoblastoid CLS. Only 1 of 5 African Burkitt's lymphoma CLS and 2 of 7 EBV- CLS expressed IL-7. A total of 484-bp amplicons was cloned and sequenced and found to correspond to the original IL-7 sequence. Constitutive IL-7 secretion was detected in 5 of 6 AABCL and in 6 of 7 normal lymphoblastoid CLS but in none of the 7 EBV- CLS. IL-7R expression was demonstrated in 8 of 26 CLS, none of which secreted IL-7. Our data suggest that 1) IL-7 mRNA is expressed in malignant B cell phenotypes, which correspond to a narrow window in the B cell differentiation pathway (pre-B, early B, intermediate B), as well as in normal lymphoblastoid B CLS. 2) IL-7 mRNA is expressed in both EBV+ and EBV- CLS, but only the EBV+ CLS secrete IL-7. 3) B cells activated by both EBV and HIV-1 (AABCL) secrete the greatest amount of IL-7. 4) IL-7 autocrine loops are not evident since IL-7R were detected on on CLS, which do not secrete IL-7. Our data provide the first direct evidence of IL-7 secretion by human cells and it is yet to be determined whether IL-7 is secreted by other cell types.
A cytokine was identified that stimulated the proliferation of T lymphocytes, and a complementary DNA clone encoding this
new T cell growth factor was isolated. The cytokine, designated interleukin-15 (IL-15), is produced by a wide variety of cells
and tissues and shares many biological properties with IL-2. Monoclonal antibodies to the beta chain of the IL-2 receptor
inhibited the biological activity of IL-15, and IL-15 competed for binding with IL-2, indicating that IL-15 uses components
of the IL-2 receptor.
Dendritic epidermal T cells (DETC) are CD3+, CD45+, CD4-, CD8-, TCR-V gamma 3/V delta 1+ T lymphocytes that reside in symbiosis with keratinocytes in mouse epidermis. To address mechanisms by which these cells survive and proliferate within the epidermal environment, we have tested the hypothesis that cytokines secreted by neighboring keratinocytes play relevant roles. The present study was conducted to determine whether keratinocytes produce biologically relevant amounts of IL-7, and, if so, to study its effects on DETC. The long term cultured DETC line, 7-17, and freshly isolated DETC exhibited dose- and time-dependent proliferative responses to rIL-7. These responses were blocked completely by anti-IL-7 antibodies, whereas anti-IL-2 had no effect, indicating that DETC respond to IL-7 by an IL-2-independent mechanism. Proliferative responses depended on the state of cell activation; DETC stimulated 2 to 5 days earlier with Con A proliferated optimally to added IL-7, whereas cells stimulated 10 days earlier did not proliferate. DETC that failed to proliferate responded to IL-7 by showing prolonged survival; cells maintained for 7 days with IL-7 alone retained their capacity to proliferate in response to Con A. Mouse epidermal cells and Pam 212 keratinocyte line both expressed IL-7 mRNA constitutively, as demonstrated by reverse transcription-polymerase chain reaction analyses. The production of IL-7 by mouse keratinocytes was also confirmed; Pam 212 culture supernatants supported DETC proliferation, and this activity was diminished by 50% with added anti-IL-7 antibodies. These results indicate that keratinocytes produce IL-7 in biologically relevant amounts, which, in turn, serve to promote the survival and growth of DETC. IL-7-mediated communication between epithelial cells and gamma delta T cells may represent one mechanism to sustain the indefinite residence of gamma delta T cells in epithelial tissues of mice.
HLA expression is frequently altered in tumours compared to the tissue from which they originate. Given the central role of MHC products in the restriction of T-cell recognition, regulation of tumour HLA expression might be a strategy for the evasion of immune surveillance by the malignant cells. Federico Garrido, Peter Stern and colleagues present data from a variety of tumour types, suggesting that HLA class I alterations may occur at a particular step between the development of an in situ lesion and an invasive carcinoma.
The proliferation of epithelial cells lining the small intestinal mucosa may be regulated by microenvironmental signals leading to differentiation of precursor cells in the small intestinal crypts. Proliferation of hematopoietic cells within the hematopoietic microenvironment is known to be regulated by a growing number of glycoprotein growth factors in a hierarchial fashion. We studied the effects of administration of the microenvironment-derived hematopoietic growth factor interleukin-11 (IL-11) on mice given combination radiation/chemotherapy. Treatment of such mice with IL-11 led to significantly increased survival and evidence of rapid recovery of the small intestinal mucosa, which is severely damaged by these cytoxic agents. This recovery was associated with an increase in the mitotic index of crypt cells and an increased frequency of staining of these cells with a monoclonal antibody to proliferating cell nuclear antigen, a member of the cyclin family of nuclear antigens.
Unlabelled:
Little is known about the nature of the mucosa-associated immune system within the normal colon, or about the immune response to colon carcinoma. In this study inflammatory cells (ICs) in 14 normal colons and 14 carcinomas were characterized. Overall inflammation, lymphocytes, plasma cells, neutrophils, and eosinophils were graded in routine H & E sections. Frozen sections were stained by an immunoperoxidase technique using antibodies to the T cell associated antigens CD2, CD7, CD4, CD8, and T cell receptors alpha beta and gamma delta. B cells were identified with CD20, macrophages with CD68, and Class II antigen with anti-HLA DR. Each cell type was semiquantitatively graded in 10 high power fields (HPFs) in the lumenal half (LH) or basal half (BH) of the normal mucosae, and in epithelium or stroma of the carcinomas. In normal colons, ICs were more frequent in LH than in BH. Plasma cells, lymphocytes and monocytes predominated. Subtyping of lymphocytes showed that CD4+ TCR alpha beta + T lymphocytes were most numerous in the lamina propria. Lymphocytes within the epithelium were CD8+ T cells. Around carcinomas the overall grade of ICs was 1+ in the majority of cases. Plasma cells, CD4+ and CD8+ cells with the TCR alpha beta receptor, and macrophages were most frequent. Lymphoid aggregates of both T and B cells were frequent.
Conclusions:
1. Normal colon contains a diffuse luminally oriented population of TCR alpha beta+ CD4+ T cells, plasma cells, macrophages and class II antigen-expressing cells in the lamina propria.(ABSTRACT TRUNCATED AT 250 WORDS)
Tumor immunity developing as a response to an autologous colon-tumor/bacillus Calmette-Guérin (BCG) vaccine appears to be associated with induction of CD4+ helper T cells, implied by the observation that vaccine efficacy is associated with major histocompatibility complex class-II molecule expression on the vaccine tumor cells. Therefore, in an attempt to identify colon-tumor-associated antigens responsible for conferring immunity, we examined and compared the proliferative responses of peripheral-blood lymphocytes (PBL) from patients immunized with the autologous tumor/BCG vaccine to T-cell lines cloned expanded from colon-tumor-infiltrating lymphocytes to 5 antigens isolated on the basis of their reactivity by colon-tumor-reactive human monoclonal antibodies. Enzymatically dissociated colon tumors provided a source for establishment of cloned T-cell lines, tumor cell lines propagated in vitro or in vivo as nude-mouse xenografts and EBV-transformed B-cell lines used as antigen-presenting cells. Of 104 different T-cell lines tested, only 3 proliferated in response to CTAA 28A32-46K, and I to the CTAA28A32-32K antigen. In contrast, PBL from 64% of patients immunized with the autologous colon-tumor/BCG vaccine responded to the CTAA 28A32-32K antigen. This antigen is related to a family of calcium- and phospholipid-binding placental proteins termed annexins. Since proliferative responses developed to this antigen after vaccination in 64% of individuals, this antigen may be an important common colon-tumor-associated rejection antigen.