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Turnover of Vγ2⁺ thymocytes in G8 TCR-γ/δ transgenic mice. STx TCR-γ/δ transgenic mice were given BrdU for 2 (▪) or 21 ( ) d and Vγ2⁺ thymocytes were analyzed. (A) Total Vγ2⁺ thymocytes. (B) Vγ2⁺ CD45RB thymocyte subsets. (C) Vγ2⁺ HSA thymocyte subsets. (D) Vγ2⁺ CD44 thymocyte subsets. (E) Vγ2⁺ CD62L thymocyte subsets. Data represent mean values ± SD for two to three mice per point.
Source publication
Information on the turnover and lifespan of murine γ/δ cells was obtained by administering the DNA precursor, bromodeoxyuridine (BrdU), in the drinking water and staining lymphoid cells for BrdU incorporation. For TCR-γ/δ (Vγ2) transgenic mice, nearly all γ/δ thymocytes became BrdU+ within 2 d and were released rapidly into the peripheral lymphoid...
Citations
... Similar to NK cells, the short lifespan of γδ T cells is both an advantage for avoiding T-cell aplasia and a disadvantage for lacking persistence. Due to the short lifespan of γδ T cells [158], multiple doses may be required to attain the desired effect, and there is currently limited research on how to improve the persistence of γδ T cells to achieve long-term efficacy. While γδ T cells have not been shown to cause GvHD, there is limited research on the risk of immune rejection, which is a factor worth considering for developing γδ T cells as an allogeneic off-the-shelf product, especially when repeated injections are required. ...
Simple Summary
Patients with relapsed and refractory T-cell malignancies have poor outlook and limited treatment options. Recently, adoptive cell therapy has emerged as a promising therapy for patients with T-cell malignancies. In this review, we examine the current progress on adoptive cell therapy for T-cell malignancies and discuss the potential future directions.
Abstract
T-cell malignancies are often aggressive and associated with poor prognoses. Adoptive cell therapy has recently shown promise as a new line of therapy for patients with hematological malignancies. However, there are currently challenges in applying adoptive cell therapy to T-cell malignancies. Various approaches have been examined in preclinical and clinical studies to overcome these obstacles. This review aims to provide an overview of the recent progress on adoptive cell therapy for T-cell malignancies. The benefits and drawbacks of different types of adoptive cell therapy are discussed. The potential advantages and current applications of innate immune cell-based adoptive cell therapy for T cell malignancies are emphasized.
... 22 Healthy donor-derived γδ T cell expansions are a potentially superior "off-the-shelf" source as they are likely more potent and offer the opportunity for serial dosing to overcome any issues with persistence. 23 We have recently adapted our ex vivo expansion protocol to include depletion of αβ T cells from allogeneic γδ T cell expansions. This modification yields a final αβ T lymphocyte contamination of <1% to minimize the risk for graft verses host disease. ...
T lymphocytes represent an emerging class of cellular immunotherapy with preclinical promise to treat cancer, notably neuroblastoma. The innate-like immune cell subset demonstrates inherent cytoxicity toward tumor cells independent of MHC recognition, enabling allogeneic administration of healthy donor-derived γδ T cell therapies. A current limitation is the substantial interindividual γδ T cell expansion variation among leukocyte collections. Overcoming this limitation will enable realization of the full potential of allogeneic γδ T-based cellular therapy. Here, we characterize γδ T cell expansions from healthy adult donors and observe that highly potent natural killer (NK) lymphocytes expand with γδ T cells under zoledronate and IL-2 stimulation. The presence of NK cells correlates with both the expansion potential of γδ T cells and the overall potency of the γδ T cell therapy. However, the potency of the cell therapy in combination with an antibody-based immunotherapeutic, dinutuximab, appears to be independent of γδ T/NK cell content both in vitro and in vivo, which minimizes the implication of interindividual expansion differences toward efficacy. Collectively, these studies highlight the utility of maintaining the NK cell population within expanded γδ T cell therapies and suggest a synergistic action of combined innate cell immunotherapy toward neuroblastoma.
... The higher secretion was associated with a higher proportion of IFN-γ producing γδ T cells, specifically the Vδ2 + subset, in multigravid women compared to primigravid women. Recent studies suggest that γδ T cells are essential for non-specific targeting of P. falciparum [49] and can show a "memory/recall" phenotype [50][51][52]. With increased exposure to CSA-binding IE over successive pregnancies, women are presumed to develop increased pregnancy-malaria specific IFN-γ responses. ...
Background
Malaria in pregnancy causes maternal, fetal and neonatal morbidity and mortality, and maternal innate immune responses are implicated in pathogenesis of these complications. The effects of malaria exposure and obstetric and demographic factors on the early maternal immune response are poorly understood.
Methods
Peripheral blood mononuclear cell responses to Plasmodium falciparum-infected erythrocytes and phytohemagglutinin were compared between pregnant women from Papua New Guinea (malaria-exposed) with and without current malaria infection and from Australia (unexposed). Elicited levels of inflammatory cytokines at 48 h and 24 h (interferon γ, IFN-γ only) and the cellular sources of IFN-γ were analysed.
Results
Among Papua New Guinean women, microscopic malaria at enrolment did not alter peripheral blood mononuclear cell responses. Compared to samples from Australia, cells from Papua New Guinean women secreted more inflammatory cytokines tumor necrosis factor-α, interleukin 1β, interleukin 6 and IFN-γ; p<0.001 for all assays, and more natural killer cells produced IFN-γ in response to infected erythrocytes and phytohemagglutinin. In both populations, cytokine responses were not affected by gravidity, except that in the Papua New Guinean cohort multigravid women had higher IFN-γ secretion at 24 h (p = 0.029) and an increased proportion of IFN-γ⁺ Vδ2 γδ T cells (p = 0.003). Cytokine levels elicited by a pregnancy malaria-specific CSA binding parasite line, CS2, were broadly similar to those elicited by CD36-binding line P6A1.
Conclusions
Geographic location and, to some extent, gravidity influence maternal innate immunity to malaria.
... Concurrent with their accumulation, after FTY720 treatment the C and E populations displayed downregulated CD24 levels comparable to mature γδ T cells in the periphery ( Fig. 5c and Supplementary Fig. 5c). While most peripheral γδ T cells express low levels of CD24, a large proportion of the γδ T cell recent thymic emigrants (γδRTEs) are CD24 high when they reach their target organs, upon which they downregulate their CD24 expression 39 . The presence of CD24 low cells within the C and E populations, solely when thymic export was blocked, suggested that at homoeostasis these populations are exported while still expressing high levels of CD24. ...
... Due to the lack of development markers and a focus on the foetal system, most previous studies have focused solely on CD24 low cells as the thymic end point of γδ T cell development 32,42,43 . This is despite strong and long-standing evidence of CD24 expression within the majority of γδ T cell recent thymic emigrants (γδRTEs) in adult mice 39,44 . These CD24 high γδRTEs have been shown to constitute approximately half of the total γδ T cell populations in peripheral lymphoid organs and to be continuously replenished 39 . ...
... This is despite strong and long-standing evidence of CD24 expression within the majority of γδ T cell recent thymic emigrants (γδRTEs) in adult mice 39,44 . These CD24 high γδRTEs have been shown to constitute approximately half of the total γδ T cell populations in peripheral lymphoid organs and to be continuously replenished 39 . In this study, we identified two populations of CD24 high γδ thymocytes, stages C and E, which Untreated d10 FTY720 d10 Fig. 5 γδ T cells emigrate from the thymus at the C, E and G stages a, b TCRδ + thymocyte distributions within population A to G after treatment with FTY720 for 5 (5d) or 10 days (10d) visualised using a t-SNE maps and b stacked bar plots of cell numbers within TCRδ + , Vγ1.1 + and Vγ2 + subsets. ...
Murine γδ T cells include subsets that are programmed for distinct effector functions during their development in the thymus. Under pathological conditions, different γδ T cell subsets can be protective or can exacerbate a disease. Here we show that CD117, CD200 and CD371, together with other markers, identify seven developmental stages of γδ T cells. These seven stages can be divided into three distinct developmental pathways that are enriched for different TCRδ repertoires and exhibit characteristic expression patterns associated with adaptive (γδTn), IFN-γ-producing (γδT1) and IFN-γ/IL-4-co-producing γδ T cells (γδNKT). Developmental progression towards both IFN-γ-producing subsets can be induced by TCR signalling, and each pathway results in thymic emigration at a different stage. Finally, we show that γδT1 cells are the predominating IFN-γ-producing subset developing in the adult thymus. Thus, this study maps out three distinct development pathways that result in the programming of γδTn, γδT1 and γδNKT cells.
... BrdU is a nucleoside analogue that is incorporated instead of thymidine into the DNA of cells that divide. BrdU has been used for decades in mice [209,210], and more recently in monkeys [162]. Because of potential problems with toxicity it has been used infrequently in humans [58,132,133,138,202], and only over short periods. ...
Peripheral T cell populations are maintained by production of naive T cells in the thymus, clonal expansion of activated cells, cellular self-renewal (or homeostatic proliferation), and density dependent cell life spans. A variety of experimental techniques have been employed to quantify the relative contributions of these processes. In modern studies lymphocytes are typically labeled with 5-bromo-2'-deoxyuridine (BrdU), deuterium, or the fluorescent dye carboxy-fluorescein diacetate succinimidyl ester (CFSE), their division history has been studied by monitoring telomere shortening and the dilution of T cell receptor excision circles (TRECs) or the dye CFSE, and clonal expansion has been documented by recording changes in the population densities of antigen specific cells. Proper interpretation of such data in terms of the underlying rates of T cell production, division, and death has proven to be notoriously difficult and involves mathematical modeling. We review the various models that have been developed for each of these techniques, discuss which models seem most appropriate for what type of data, reveal open problems that require better models, and pinpoint how the assumptions underlying a mathematical model may influence the interpretation of data. Elaborating various successful cases where modeling has delivered new insights in T cell population dynamics, this review provides quantitative estimates of several processes involved in the maintenance of naive and memory, CD4(+) and CD8(+) T cell pools in mice and men.
... BrdU has been used for decades in mice [11,12], and more recently in monkeys [13][14][15]. Because of potential problems with toxicity, it has been used infrequently in humans [16][17][18][19][20], and only over short-term periods. ...
Bromodeoxyuridine (BrdU) is widely used in immunology to detect cell division, and several mathematical models have been proposed to estimate proliferation and death rates of lymphocytes from BrdU labelling and de-labelling curves. One problem in interpreting BrdU data is explaining the de-labelling curves. Because shortly after label withdrawal, BrdU(+) cells are expected to divide into BrdU(+) daughter cells, one would expect a flat down-slope. As for many cell types, the fraction of BrdU(+) cells decreases during de-labelling, previous mathematical models had to make debatable assumptions to be able to account for the data. We develop a mechanistic model tracking the number of divisions that each cell has undergone in the presence and absence of BrdU, and allow cells to accumulate and dilute their BrdU content. From the same mechanistic model, one can naturally derive expressions for the mean BrdU content (MBC) of all cells, or the MBC of the BrdU(+) subset, which is related to the mean fluorescence intensity of BrdU that can be measured in experiments. The model is extended to include subpopulations with different rates of division and death (i.e. kinetic heterogeneity). We fit the extended model to previously published BrdU data from memory T lymphocytes in simian immunodeficiency virus-infected and uninfected macaques, and find that the model describes the data with at least the same quality as previous models. Because the same model predicts a modest decline in the MBC of BrdU(+) cells, which is consistent with experimental observations, BrdU dilution seems a natural explanation for the observed down-slopes in self-renewing populations.
... Differing from those of ab T cells, these T cells have a phenotype of spontaneous activation and release large quantities of cytokines upon activation (2,6,7). On the basis of these features, gd T cells are also called "innate-like lymphocytes" and can bridge the innate and adaptive immune responses (3,6). ...
It has been demonstrated that the two main subsets of peripheral γδ T cells, Vγ1 and Vγ4, have divergent functions in many diseases models. Recently, we reported that Vγ4 γδ T cells played a protective role in tumor immunity through eomesodermin-controlled mechanisms. However, the precise roles of Vγ1 γδ T cells in tumor immunity, especially whether Vγ1 γδ T cells have any interaction with Vγ4 γδ T cells, remain unknown. We demonstrated in this paper that Vγ1 γδ T cells suppressed Vγ4 γδ T cell-mediated antitumor function both in vitro and in vivo, and this suppression was cell contact independent. Using neutralizing anti-IL-4 Ab or IL-4(-/-) mice, we determined the suppressive factor derived from Vγ1 γδ T cells was IL-4. Indeed, treatment of Vγ4 γδ T cells with rIL-4 significantly reduced expression levels of NKG2D, perforin, and IFN-γ. Finally, Vγ1 γδ T cells produced more IL-4 and expressed significantly higher level of GATA-3 upon Th2 priming in comparison with Vγ4 γδ T cells. Therefore, to our knowledge, our results established for the first time a negative regulatory role of Vγ1 γδ T cells in Vγ4 γδ T cell-mediated antitumor immunity through cell contact-independent and IL-4-mediated mechanisms. Selective depletion of this suppressive subset of γδ T cells may be beneficial for tumor immune therapy.
... The efficacy of adoptive cell transferbased tumor immunotherapy can be improved by the removal of the host immune system; several mechanisms might underlie the augmented efficacy of tumor-reactive T cells in the lymphopaenic environment. These factors include the elimination of regulatory T cells which have the capability to inhibit phosphoantigen-activation of Vc9Vd2 [65], the depletion of endogenous cells that compete for activating cytokines and the increased function and availability of APC [66]. Preclinical and clinical studies have identified multiple mechanisms contributing to successful adoptive immunotherapies, including hostrelated factors, as well as the phenotypic and functional characteristics of the tumor-reactive T cells used for transfer. ...
The potent anti-tumor activities of γδ T cells, their ability to produce pro-inflammatory cytokines, and their strong cytolytic
activity have prompted the development of protocols in which γδ agonists or ex vivo-expanded γδ cells are administered to
tumor patients. γδ T cells can be selectively activated by either synthetic phosphoantigens or by drugs that enhance their
accumulation into stressed cells as aminobisphosphonates, thus offering new avenues for the development of γδ T cell-based
immunotherapies. The recent development of small drugs selectively activating Vγ9Vδ2 T lymphocytes, which upregulate the endogenous
phosphoantigens, has enabled the investigators to design the experimental approaches of cancer immunotherapies; several ongoing
phase I and II clinical trials are focused on the role of the direct bioactivity of drugs and of adoptive cell therapies involving
phosphoantigen- or aminobisphosphonate-activated Vγ9Vδ2 T lymphocytes in humans. In this review, we focus on the recent advances
in the activation/expansion of γδ T cells in vitro and in vivo that may represent a promising target for the design of novel
and highly innovative immunotherapy in patients with hematologic malignancies.
KeywordsVγ9Vδ2 T cells-Hematologic malignancies-Immunotherapy-Cytokines-Cytotoxicity
... To determine if diminished skin γδ T cell proliferation in BKS db/db mice accounts for the reduction in epidermal T cell numbers, we first had to investigate the rate of γδ T cell proliferation in vivo. Although long-lived, memory-like Vγ2+ T cells in the periphery have been shown to have very slow turnover [28], the rate of Vγ3+ T cell proliferation and homeostatic maintenance in the epidermis has yet to be defined. Unlike the rapid turnover of epithelial keratinocytes [29], [30], [31], LC turnover is much slower, between 5 and 10% of cells proliferating per week [32], [33]. ...
Epithelial cells provide an initial line of defense against damage and pathogens in barrier tissues such as the skin; however this balance is disrupted in obesity and metabolic disease. Skin gammadelta T cells recognize epithelial damage, and release cytokines and growth factors that facilitate wound repair. We report here that hyperglycemia results in impaired skin gammadelta T cell proliferation due to altered STAT5 signaling, ultimately resulting in half the number of gammadelta T cells populating the epidermis. Skin gammadelta T cells that overcome this hyperglycemic state are unresponsive to epithelial cell damage due to chronic inflammatory mediators, including TNFalpha. Cytokine and growth factor production at the site of tissue damage was partially restored by administering neutralizing TNFalpha antibodies in vivo. Thus, metabolic disease negatively impacts homeostasis and functionality of skin gammadelta T cells, rendering host defense mechanisms vulnerable to injury and infection.
... Regarding the latter possibility, it remains unclear whether peripheral gd cells are descended mostly from mature or immature thymic precursors. In vivo labelling studies indicate that the majority of gd thymocytes that have recently entered the periphery (recent thymic emigrants or RTEs) exhibit a CD24 þ phenotype, and undergo CD24 downmodulation only after arriving in the periphery (Kelly et al, 1993; Tough and Sprent, 1998), in contrast to ab RTEs, which are mostly CD24À (Kelly and Scollay, 1990). Further, it has been argued that the rate of production of CD24À gd thymocytes is too low to account for the appearance of new gd cells in the periphery (Zorbas and Scollay, 1993). ...
... Further, it has been argued that the rate of production of CD24À gd thymocytes is too low to account for the appearance of new gd cells in the periphery (Zorbas and Scollay, 1993). Nevertheless, as gd RTEs are not uniformly CD24 þ and, in fact, contain a substantial CD24À/lo fraction (Kelly et al, 1993; Zorbas and Scollay, 1993), and as a high proportion of CD24 þ RTEs seem to die off soon after reaching the periphery (Tough and Sprent, 1998), the relative contribution of CD24 þ and CD24À RTEs to the long-lived peripheral gd pool remains difficult to estimate. Regardless, of the precise developmental route by which peripheral gd cells arise, they exhibit significant differences in subset distribution in ThPOK-deficient mice, consistent with an important function for ThPOK in development of these cells as well. ...
T lymphocytes develop into two major lineages characterized by expression of the αβ and γ δ T cell receptor (TCR) heterodimers. Within each major lineage, further specialization occurs, resulting in distinct subsets that differ in TCR specificity, phenotype and functional attributes. Thus, in the murine thymus, two distinct subsets of mature (CD24-) γ δ cells have been identified, that is NK1.1+ cells, which are enriched for VÎ 31.1 usage and selectively produce IFNÎ 3 on stimulation, and CCR6+ cells, which are enriched for VÎ 32 usage produce IL17. The upstream signals and transcriptional pathways that promote development of these distinct γ δ subsets remain relatively poorly understood. Here, we show that the Zn-finger transcription factor ThPOK has a critical function in the development of γ δ thymocytes. Thus, lack of functional ThPOK causes a marked reduction in the percentage and absolute number of mature γ δ thymocytes, and a particularly severe reduction of NK1.1+ cells. Conversely, constitutive ThPOK expression leads to a striking increase in mature NK1.1+ γ δ thymocytes. Further, we show that ThPOK induction in γ δ thymocytes is induced by strong TCR signals mediated by engagement with antibody or high-affinity endogenous ligands, and that an important ThPOK cis-acting element, the distal regulatory element (DRE), is sufficient for this TCR-dependent induction. These results show that ThPOK expression in γ δ thymocytes is regulated in part by the strength of TCR signalling, identify ThPOK as an important mediator of γ δ T cell development/maturation, and lend strong support to the view that development of a significant fraction of γ δ T cells depends on TCR engagement/signalling. © 2010 European Molecular Biology Organization - All Rights Reserved.
