Honglin Jin's research while affiliated with Huazhong University of Science and Technology and other places

Dendritic cell (DC) migration to the lymph node is a key component of DC-based immunotherapy. However, the DC homing rate to the lymphoid tissues is poor, thus hindering the DC-mediated activation of antigen-specific T cells. Here, we developed a system using fluorescent magnetic nanoparticles (α-AP-fmNPs; loaded with antigen peptide, iron oxide nanoparticles, and indocyanine green) in combination with magnetic pull force (MPF) to successfully manipulate DC migration in vitro and in vivo. α-AP-fmNPs endowed DCs with MPF-responsiveness, antigen presentation, and simultaneous optical and magnetic resonance imaging detectability. We showed for the first time that α-AP-fmNP-loaded DCs were sensitive to MPF, and their migration efficiency could be dramatically improved both in vitro and in vivo through MPF treatment. Due to the enhanced migration of DCs, MPF treatment significantly augmented antitumor efficacy of the nanoparticle-loaded DCs. Therefore, we have developed a biocompatible approach with which to improve the homing efficiency of DCs and subsequent anti-tumor efficacy, and track their migration by multi-modality imaging, with great potential applications for DC-based cancer immunotherapy.

Integrins, over-expressed in a broad range of cancer diseases, are widely utilized as a tumor biomarker. Metabolism investigation also plays important roles in tumor theranostics. Developing simple integrin-targetting probe and monitoring tumor metabolism will give opportunities to find ways for cancer treatment, however, the investigation of tumor metabolism with integrin receptor based probes has been rarely reported so far. Here, we developed an octavalent fluorescent probe Octa-RGD by convenient genetic method, based on one tetrameric far-red fluorescent protein (fRFP) linked with RGD peptides. We validated its intergin targeting by confocal imaging in vitro. Then we screened a variety of tumor cells, and differentiated their binding affinity based on the fluorescence of the probe via flow cytometry. Among these cells, CNE-2 cells had the highest uptake of the probe, while B16 cells had the lowest, corresponding with their intergin expression levels. Next, the fluorescent and metabolic imaging was performed in HT1080 (intergin postive) tumor, where nicotinamide adenine dinucleotide hydrogen (NADH), flavoprotein (Fp) and fRFP fluorescent signals were collected. The tumor from mice intravenously injected with Octa-RGD probe displayed obviously higher NADH redox ratio NADH/ (Fp+NADH) and fRFP signal, than those with fRFP protein. It suggested that integrin targeting may have influence on the target cell metabolism, and further demonstrated Octa-RGD probe facilitated its uptake in the targeted tumor in vivo. This paper developed a useful probe, which can bind integrins specifically and efficiently in tumor cells, and together with tumor metabolic information, it may provide new insight for RGD targeting-based cancer therapeutics.

Integrins, over-expressed in a broad range of cancer diseases, are widely utilized as a tumor biomarker. Metabolism investigation also plays important roles in tumor theranostics. Developing simple integrin-targetting probe and monitoring tumor metabolism will give opportunities to find ways for cancer treatment, however, the investigation of tumor metabolism with integrin receptor based probes has been rarely reported so far. Here, we developed an octavalent fluorescent probe Octa-RGD by convenient genetic method, based on one tetrameric far-red fluorescent protein (fRFP) linked with RGD peptides. We validated its intergin targeting by confocal imaging in vitro. Then we screened a variety of tumor cells, and differentiated their binding affinity based on the fluorescence of the probe via flow cytometry. Among these cells, CNE-2 cells had the highest uptake of the probe, while B16 cells had the lowest, corresponding with their intergin expression levels. Next, the fluorescent and metabolic imaging was performed in HT1080 (intergin postive) tumor, where nicotinamide adenine dinucleotide hydrogen (NADH), flavoprotein (Fp) and fRFP fluorescent signals were collected. The tumor from mice intravenously injected with Octa-RGD probe displayed obviously higher NADH redox ratio NADH/(Fp+NADH) and fRFP signal, than those with fRFP protein. It suggested that integrin targeting may have influence on the target cell metabolism, and further demonstrated Octa-RGD probe facilitated its uptake in the targeted tumor in vivo. This paper developed a useful probe, which can bind integrins specifically and efficiently in tumor cells, and together with tumor metabolic information, it may provide new insight for RGD targeting-based cancer therapeutics.

Photodynamic therapy (PDT) gains wide attention as a useful therapeutic method for cancer. It is mediated by the oxygen and photosensitizer under the specific light irradiation to produce the reactive oxygen species (ROS), which induce cellular toxicity and regulate the redox potential in tumor cells. Nowadays, genetic photosensitizers of low toxicity and easy production are required to be developed. KillerRed, a unique red fluorescent protein exhibiting excellent phototoxic properties, has the potential to act as a photosensitizer in the application of tumor PDT. Meantime, the course of tumor redox metabolism during this treatment was rarely investigated so far. Thus here, we investigated the effects of KillerRed-based PDT on tumor growth in vivo and examined the subsequent tumor metabolic states including the changes of nicotinamide adenine dinucleotide hydrogen (NADH) and flavoprotein (Fp), two important metabolic coenzymes of tumor cells. Results showed the tumor growth had been significantly inhibited by KillerRed-based PDT treatment compared to control groups. A home-made cryo-imaging redox scanner was used to measure intrinsic fluorescence and exogenous KillerRed fluorescence signals in tumors. The Fp signal was elevated by nearly 4.5-fold, while the NADH signal decreased by 66% after light irradiation, indicating that Fp and NADH were oxidized in the course of KillerRed-based PDT. Furthermore, we also observed correlation between the fluorescence distribution of KillerRed and NADH. It suggests that the KillerRed protein based PDT might provide a new approach for tumor therapy accompanied by altering tumor metabolism.

Immune responses are based on the coordinated searching behaviors of immunocytes that are aimed at tracking down specific targets. The search efficiency of immunocytes significantly affects the speed of initiation and development of immune responses. Previous studies have shown that not only the intermittent walk but also the zigzag turning preference of immunocytes contributes to the search efficiency. However, among existing models describing immunocytes' search strategy, none has captured both features. Here we propose a zigzag generalized Lévy walk model to describe the search strategy of immunocytes more accurately and comprehensively by considering both the intermittent and the zigzag-turning walk features. Based on the analysis of the searching behaviors of typical immune cell types, dendritic cells and leukocytes, in their native physiological environment, we demonstrate that the model can describe the in vivo search strategy of immunocytes well. Furthermore, by analyzing the search efficiency, we find that this type of search strategy enables immunocytes to capture rare targets in approximately half the time than the previously proposed generalized Lévy walk. This study sheds new light on the fundamental mechanisms that drive the efficient initiation and development of immune responses and in turn may lead to the development of novel therapeutic approaches for diseases ranging from infection to cancer.

Methods, Fig.S1 - S3.

Nasopharyngeal carcinoma (NPC) is a very regional malignant head and neck cancer that has attracted widespread attention for its unique etiology, epidemiology and therapeutic options. To achieve high cure rates in NPC patients, theranostic approaches are actively being pursued and improved efforts remain desirable in identifying novel biomarkers and establishing effective therapeutic approaches with low long-term toxicities. Here, we discovered that the scavenger receptor class B type I (SR-B1) was overexpressed in all investigated NPC cell lines and 75% of NPC biopsies, demonstrating that SR-B1 is a potential biomarker of NPC. Additional functional analysis showed that SR-B1 has great effect on cell motility while showing no significant impact on cell proliferation. As high-density lipoproteins (HDL) exhibit strong binding affinities to SR-B1 and HDL mimetic peptides are reportedly capable of inhibiting tumor growth, we further examined the SR-B1 targeting ability of a highly biocompatible HDL-mimicking peptide-phospholipid scaffold (HPPS) nanocarrier and investigated its therapeutic effect on NPC. Results show that NPC cells with higher SR-B1 expression have superior ability in taking up the core constituents of HPPS. Moreover, HPPS inhibited the motility and colony formation of 5-8F cells, and significantly suppressed the NPC cell growth in nude mice without inducing tumor cell necrosis or apoptosis. These results indicate that HPPS is not only a NPC-targeting nanocarrier but also an effective anti-NPC drug. Together, the identification of SR-B1 as a potential biomarker and the use of HPPS as an effective anti-NPC agent may shed new light on the diagnosis and therapeutics of NPC.

The cytolytic peptide melittin is a potential anticancer candidate that may be able to overcome tumor drug resistance due to its lytic properties. However, in vivo applications of melittin are limited due to its main side effect, hemolysis, which is especially pronounced following intravenous administration. Here, we designed a hybrid cytolytic peptide, α-melittin, in which the N-terminus of melittin is linked to the C-terminus of an amphipathic α-helical peptide (α-peptide) via a GSG linker. The strong α-helical configuration allows α-melittin to interact with phospholipids and self-assemble into lipid nanoparticles, with a high efficiency for α-melittin encapsulation (> 80%) and a strong ability to control the structure of the nanoparticle (~20 nm). This α-melittin-based lipid nanoparticle (α-melittin-NP) efficiently shields the positive charge of melittin (18.70 ± 0.90 mV) within the phospholipid monolayer, resulting in the generation of a neutral nanoparticle (2.45 ± 0.56 mV) with reduced cytotoxicity and a widened safe dosage range. Confocal imaging data confirmed that α-melittin peptides were efficiently released from the nanoparticles and were cytotoxic to the melanoma cells. Finally, α-melittin-NPs were administered to melanoma-bearing mice via intravenous injection. The growth of the melanoma cells was blocked by the α-melittin-NPs, with an 82.8% inhibition rate relative to the PBS-treated control group. No side effects of treatment were found in this study. Thus, the excellent properties of α-melittin-NP give it potential clinical applications in solid tumor therapeutics through intravenous administration.