Heat shock protein 70 (HSP70), an evolutionarily conserved molecular chaperone, serves as a central regulator within tumor immune networks. This review summarizes the multiple immune regulatory mechanisms mediated by HSP70 through its specific domains: promoting antigen presentation and cross-presentation processes; prolonging immune response duration; regulating innate and adaptive immune responses; and interacting with immune checkpoint molecules like programmed death-1 ligand 1 (PD-L1). In translation of clinical research, HSP70 can serve as a vaccine adjuvant to enhance immunogenicity, while its inhibitors can overcome resistance to immunotherapy. Additionally, membrane-bound HSP70 represents a potential immunotherapeutic target, and its targeting strategies show significant synergistic effects when combined with immune checkpoint inhibitors. However, due to the functional redundancy of the molecular chaperone network, the clinical efficacy of single-agent HSP70 inhibition is limited. In-depth elucidation of HSP70's synergistic regulatory mechanisms within the chaperone interaction network has important implications for developing novel tumor immunotherapy strategies.
HSP70 Heat-Shock Proteins/metabolism* ; Humans ; Immunotherapy/methods* ; Neoplasms/immunology* ; Animals ; B7-H1 Antigen/metabolism*

Lymphoma is a malignant tumor originating from lymphatic tissue, which can be roughly divided into two types: Hodgkin's lymphoma and non-Hodgkin's lymphoma. It has the characteristics of high recurrence rate, high mortality rate, and short survival time. Tumor cells in lymphoma form a tumor microenvironment (TME) that inhibits host anti-tumor immunity with surrounding immune cells, while tumor-associated macrophages (TAMs) are a key cell in TME. TAMs promote immune evasion of tumor cells in some ways by producing various cytokines and/or abnormal expression of immune checkpoint molecules. Programmed death receptor-1 (PD-1) and its ligand 1 (PD-L1) are important negative regulatory factors for immune cell activation. Recent studies have shown that anti-PD-1/PD-L1 therapy represents a new strategy for lymphoma immunotherapy. This article will focus on the role and expression of TAMs and PD-1/PD-L1 in lymphoma, and explore the efficacy of anti-PD-1/PD-L1 immunotherapy in different types of lymphoma.
Humans ; Immunotherapy ; B7-H1 Antigen/immunology* ; Programmed Cell Death 1 Receptor/immunology* ; Tumor Microenvironment ; Lymphoma/immunology* ; Tumor-Associated Macrophages/immunology*

In recent years, research on immunotherapy has made great progress. Currently, immunotherapy has made significant breakthrough, especially programmed death 1/programmed death-ligand 1 (PD-1/PD-L1) checkpoint inhibitors (e.g, Nivolumab, Pembrolizumab, Atezolizumab, Durvalumab and Avelumab, etc.) have brought clinical benefits to patients with various pathological types of lung cancer, including squamous cell carcinoma, adenocarcinoma and small cell lung cancer. In this paper, the application value and current status of PD-1/PD-L1 checkpoint inhibitors in lung cancer were comprehensively analyzed by reviewing and interpreting representative clinical studies. Based on the results of various large-scale clinical trials results, the indications of immunotherapy in lung cancer have been continuously broadened, and the details of immunotherapy have also been constantly optimized. However, immunotherapy still faces many challenges, such as the selection of immune combination strategies, the exploration of biomarkers, the management of adverse events, the feasibility of application of driver gene mutation population and so on. In this article, we made a systematic review about the latest progress of PD-1/PD-L1 checkpoint inhibitors in lung cancer, in order to provide cutting-edge reference for the clinical workers.
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Animals ; Antineoplastic Agents, Immunological ; therapeutic use ; B7-H1 Antigen ; antagonists & inhibitors ; genetics ; immunology ; Humans ; Immunotherapy ; Lung Neoplasms ; drug therapy ; genetics ; immunology ; Programmed Cell Death 1 Receptor ; antagonists & inhibitors ; genetics ; metabolism

Objective To explore the expression patterns of immune negative regulator FoxP3+Treg and PD-L1 protein in cervical carcinoma and its precancerous lesions. Methods The expression patterns of FoxP3+Treg and PD-L1 protein in 45 cases of cervical lesions tissues of the cervix and 20 cases of normal cervix tissues by using immunohistochemistry (IHC). Results Compared with the normal cervix,the expressions of FoxP3+Treg (H=43.211,P=0.000) and PD-L1 protein (t=213.00,P=0.001) were significantly increased in cervical lesions. Compared with the low-grade squamous cell carcinoma,the invasiveness of FoxP3+Treg was increased in high-grade squamous cell carcinoma (H=28.307,P=0.000),along with increased expression of PD-L1 protein (t=239.000,P=0.028). The FoxP3+Treg expression was positively correlated with PD-L1 protein expression in abnormally differentiated cells (r=0.364,P=0.003). Conclusion Along with the progression of cervical cancer,the FoxP3+Treg amount increases in the local microenvironment,along with enhanced PD-L1 protein expression in abnormally differentiated cells.
B7-H1 Antigen ; metabolism ; Carcinoma, Squamous Cell ; Female ; Forkhead Transcription Factors ; metabolism ; Humans ; Immunohistochemistry ; T-Lymphocytes, Regulatory ; immunology ; Tumor Microenvironment ; immunology ; Uterine Cervical Neoplasms ; immunology

Antibody-based PD-1/PD-L1 blockade therapies have taken center stage in immunotherapies for cancer, with multiple clinical successes. PD-1 signaling plays pivotal roles in tumor-driven T-cell dysfunction. In contrast to prior approaches to generate or boost tumor-specific T-cell responses, antibody-based PD-1/PD-L1 blockade targets tumor-induced T-cell defects and restores pre-existing T-cell function to modulate antitumor immunity. In this review, the fundamental knowledge on the expression regulations and inhibitory functions of PD-1 and the present understanding of antibody-based PD-1/PD-L1 blockade therapies are briefly summarized. We then focus on the recent breakthrough work concerning the structural basis of the PD-1/PD-Ls interaction and how therapeutic antibodies, pembrolizumab targeting PD-1 and avelumab targeting PD-L1, compete with the binding of PD-1/PD-L1 to interrupt the PD-1/PD-L1 interaction. We believe that this structural information will benefit the design and improvement of therapeutic antibodies targeting PD-1 signaling.
Antibodies, Monoclonal ; immunology ; therapeutic use ; Antibodies, Monoclonal, Humanized ; immunology ; therapeutic use ; B7-H1 Antigen ; antagonists & inhibitors ; immunology ; Humans ; Neoplasms ; drug therapy ; immunology ; pathology ; Programmed Cell Death 1 Receptor ; antagonists & inhibitors ; immunology ; Signal Transduction ; drug effects ; immunology ; T-Lymphocytes ; immunology

Animals ; B7-H1 Antigen ; immunology ; Cell Line, Tumor ; Gene Expression Regulation, Neoplastic ; immunology ; Humans ; Interferons ; immunology ; Mice ; Neoplasm Proteins ; immunology ; Neoplasms ; immunology ; Up-Regulation ; immunology

Immunology-based therapy is rapidly developing into an effective treatment option for a surprising range of cancers. We have learned over the last decade that powerful immunologic effector cells may be blocked by inhibitory regulatory pathways controlled by specific molecules often called "immune checkpoints." These checkpoints serve to control or turn off the immune response when it is no longer needed to prevent tissue injury and autoimmunity. Cancer cells have learned or evolved to use these mechanisms to evade immune control and elimination. The development of a new therapeutic class of drugs that inhibit these inhibitory pathways has recently emerged as a potent strategy in oncology. Three sets of agents have emerged in clinical trials exploiting this strategy. These agents are antibody-based therapies targeting cytotoxic T-lymphocyte antigen 4 (CTLA4), programmed cell death 1 (PD-1), and programmed cell death ligand 1 (PD-L1). These inhibitors of immune inhibition have demonstrated extensive activity as single agents and in combinations. Clinical responses have been seen in melanoma, renal cell carcinoma, non-small cell lung cancer, and several other tumor types. Despite the autoimmune or inflammatory immune-mediated adverse effects which have been seen, the responses and overall survival benefits exhibited thus far warrant further clinical development.
B7-H1 Antigen ; CTLA-4 Antigen ; Carcinoma, Non-Small-Cell Lung ; Carcinoma, Renal Cell ; Cell Cycle Checkpoints ; immunology ; Immunotherapy ; adverse effects ; methods ; mortality ; Melanoma ; Neoplasms ; Programmed Cell Death 1 Receptor

BACKGROUNDOX40/OX40 ligand (OX40/OX40L) and programmed death-1/programmed death ligand-1 (PD-1/PD-L1) costimulatory signals play important roles in T cell-induced immune responses. The aim of this study was to investigate the roles of OX40/OX40L and PD-1/PD-L1 costimulatory pathways in mouse islet allograft rejection.

METHODSLentiviral vectors containing OX40L siRNA sequences and an adenovirus vector containing the PD-L1 gene were constructed. The streptozotocin-induced model of diabetes was established in C57BL/6 (H-2(b)) mice. Diabetic C57BL/6 mice were randomly allocated into five groups: group 1, untreated control; group 2, Ad-EGFP treatment; group 3, Ad-PD-L1 treatment; group 4, OX40L-RNAi-LV treatment; group 5, OX40L-RNAi-LV combined with Ad-PD-L1 treatment. Lentiviral vector and the adenovirus vector were injected, singly or combined, into the caudal vein one day before islet transplantation. The islets of DBA/2 (H-2(d)) mice were transplanted into the renal subcapsular space of the diabetic recipients. Recipient blood glucose and the survival time of the allografts were monitored. Antigen-specific mixed lymphocyte reaction was also evaluated.

RESULTSThe recombinant lentiviral RNA interference vector OX40L-RNAi-LV reduced OX40L protein expression by 70%. The recombinant adenovirus vector Ad-PD-L1 increased PD-L1 protein expression in vivo in C57BL/6 recipient mice. Combined OX40L-RNAi-LV/Ad-PD-L1 treatment induced a synergistic protective effect in pancreatic islet allografts. Allograft survival time in the combined treatment group was (92.27±9.65) days, not only longer than that of the control ((6.51±0.27) days) and Ad-EGFP groups ((7.09±0.13) days) (P < 0.01), but also significantly longer than that of Ad-PD-L1 and OX40L-RNAi-LV single treatment groups ((40.64±3.95) days and (55.14±5.48) days respectively, P < 0.01). The blood glucose concentration of recipient mice in the combined treatment group was also stable and kept within the normal range. Flow cytometry analysis showed that combined OX40L-RNAi-LV/Ad-PD-L1 treatment significantly decreased proliferation in an antigen-specific mixed lymphocyte reaction. After donor DBA/2 lymphocyte stimulation, 89.71% of lymphocytes from recipient combination treatment C57BL/6 mice were not split and proliferated. In contrast, after stimulation with third party Lewis rat lymphocytes, only 45.84% lymphocytes of C57BL/6 mice were not split and proliferated.

CONCLUSIONSThis study demonstrates the successful construction of the recombinant lentivirus vector OX40L-RNAi-LV and adenovirus vector Ad-PD-L1 for the blockade of OX40/OX40L and activation of PD-1/PD-L1 costimulatory pathways simultaneously in pancreatic islet allografts in diabetic mice. Combination therapy with these two vectors resulted in inhibition of T cell activation, synergistically prolonging the survival time of pancreatic islet allografts.

Animals ; B7-H1 Antigen ; genetics ; metabolism ; Graft Rejection ; genetics ; prevention & control ; Islets of Langerhans Transplantation ; immunology ; Male ; Mice ; Mice, Inbred C57BL ; OX40 Ligand ; genetics ; metabolism ; Receptors, OX40 ; genetics ; metabolism ; Transplantation, Homologous

OBJECTIVETo analyze the expression of co-stimulatory molecules PD-1/PD-L1 in peripheral blood mononuclear cells in lung cancer patients, and to explore its biological significance.

METHODSOne hundred and thirty-three lung cancer patients, 25 lung infection patients and 23 healthy donors were enrolled in this study. 100 µl of whole blood from these subjects were collected. Multi-color immunofluorescence staining and flow cytometry were used to detect PD-1/PD-L1 expression. The results were statistically analyzed.

RESULTSThe expression level of CD3⁺CD8⁺ T cells in the lung cancer patients was (38.83 ± 1.74)%, significantly lower than that in the control group [(43.25 ± 3.35)%, P < 0.05]. CD8⁺CD28⁺ T cell subset in the peripheral blood of lung cancer patients was (17.73 ± 1.21)% significantly lower than that of the healthy donors [(27.96 ± 2.72)%, P < 0.01]. The CD8⁺CD28⁻ T cell subset was (21.19 ± 1.92)% in the lung cancer patients, significantly higher than that of the healthy control group [(15.18 ± 2.93)%, P < 0.05]. The expression level of PD-1 on the surface of CD8⁺CD28⁺ T cells was (10.67 ± 1.12)% in the group of lung cancer patients, significantly higher than that of the control group [(5.32 ± 1.58)%, P < 0.01]. It was also found that the expression of PD-1 on CD8⁺CD28⁻ T cells was up-regulated in the group of lung cancer patients (7.46 ± 1.25)%, significantly higher than that of the healthy control group [(2.68+1.07)%, P < 0.01]. The expression level of PD-L1 on CD68⁺ cells in the lung cancer patients was (16.03 ± 2.06)%, significantly higher than that of the healthy control group [(9.32 ± 2.00)%, P < 0.05].

CONCLUSIONUp-regulation of PD-1/PD-L1 on peripheral blood cells in lung cancer patients negatively regulates the lymphocytes, inhibits the immune response for killing tumor cells, and promotes tumor development and immune escape.

Adenocarcinoma ; blood ; pathology ; B7-H1 Antigen ; metabolism ; CD28 Antigens ; metabolism ; CD3 Complex ; metabolism ; CD8 Antigens ; metabolism ; Carcinoma, Large Cell ; blood ; pathology ; Carcinoma, Squamous Cell ; blood ; pathology ; Case-Control Studies ; Female ; Humans ; Lung Neoplasms ; blood ; pathology ; Male ; Middle Aged ; Programmed Cell Death 1 Receptor ; metabolism ; Small Cell Lung Carcinoma ; blood ; pathology ; T-Lymphocytes ; immunology ; metabolism ; Up-Regulation

OBJECTIVETo explore the expression of soluble programmed death ligand-1 on lung cancer cells and to clarify its biological function through PD-1/PD-L1 pathway in regulating the function of T lymphocytes.

METHODSLabeled monoclonal antibody and flow cytometry were used to analyze the expression of PD-L1 and its receptor PD-l on lung cancer cells and human T lymphocytes, respectively. The level of sPD-L1 in the supernatant of lung cancer cells was determined with an ELISA kit. The inhibition of proliferation of T lymphocytes by mPD-L1 and sPD-L1 was studied using CCK-8 incorporation.

RESULTSLow or no expression [(16.08 ± 2.28)%] of PD-1 was found on resting T lymphocytes from human peripheral blood with flow cytometry, but up-regulated expression of PD-1 [(78.06 ± 7.21)%] was found on the surface of activated T lymphocytes. Soluble PD-L1 was found in supernatant of some lung cancer cell lines, such as H1299, HO8910, SPCA-1, H460, H446 cells, with PD-L1 expressing on their cell surface [(78.34 ± 10.25)%, (68.17 ± 11.56)%, (45.32 ± 7.98)%, (47.52 ± 9.62)% and (40.95 ± 8.56)%, respectively], but very low expression on A549 cells [(16.02 ± 6.28)%]. The level of mPD-L1 on H1299 cells was highest [(78.34 ± 10.25)%], compared with HO8910 cells (68.17 ± 11.56)%, SPCA-1 cells (45.32 ± 7.98)%, H446 cells (40.95 ± 8.56)%, and H460 cells (47.52 ± 9.62)%. At the same time, the sPD-L1 level on H1299 cells was low [(0.17 ± 0.01) ng/ml], compared with HO8910 cells (0.30 ± 0.03) ng/ml, SPCA-1cells (0.59 ± 0.03) ng/ml, H446 cells (0.34 ± 0.02) ng/ml, and H460 cells (0.57 ± 0.03) ng/ml, but not expressed on A549 cells. PD-L1 expressing H1299 cells inhibited the proliferation of T lymphocytes in the co-culture system. Supernatant of the cultured PD-L1(+) lung cancer cells also inhibited T cell proliferation. Anti-human PD-L1 blocking antibody could partly restore the proliferation capacity of T lymphocytes.

CONCLUSIONSMembrane-bound PD-L1 and soluble PD-L1 released from lung cancer cells can effectively inhibit the proliferation of T lymphocytes in mixed culture system and down-regulate cell-mediated immunity in vitro. This may lead to inactivation of tumor antigen-specific T cells and immune escape of lung cancer cells.

B7-H1 Antigen ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; Coculture Techniques ; Humans ; Immunity, Cellular ; Lung Neoplasms ; metabolism ; pathology ; Lymphocyte Activation ; Programmed Cell Death 1 Receptor ; metabolism ; T-Lymphocytes ; cytology ; immunology ; Tumor Escape ; Up-Regulation