Expression Levels Of Programmed Death-1 Research Articles

Effects of Ruxolitinib on Immune Checkpoint Molecule Expression in JAK2 V617F-Positive Cells.

This study aimed to explore the clinical significance of ruxolitinib and its effects on the proliferation and apoptosis of human erythroleukemia (HEL) cells and the expression of immune checkpoint molecules programmed death-1 (PD-1), programmed death-ligand 1 (PD-L1), and regulatory T cells (Tregs) in HEL cells and JAK2 V617F-positive patients with myeloproliferative neoplasms (MPNs). JAK2 V617F-positive patients with MPNs admitted to the Baoding No. 1 Hospital from January 2016 to September 2023 were recruited, including 30 patients for the newly diagnosed group and 10 for the treatment group. Additionally, 15 healthy volunteers were selected as the control group. JAK2 V617F mutation was detected by using fluorescence quantitative PCR, and the expression levels of phosphorylated JAK2 (p-JAK2), PD-1, and PD-L1 in fresh bone marrow were examined by immunohistochemistry. HEL cells were treated with ruxolitinib at different concentrations (0, 50, 100, 250, 500, and 1,000 nmol/L). Cell viability was detected by CCK-8 assay. The mRNA expression levels of JAK2, PD-1, and PD-L1 were determined by using fluorescence quantitative PCR. The protein expression of p-JAK2 was detected by Western blot and those of PD-1 and PD-L1 were evaluated by flow cytometry. The expression of PD-1, PD-L1, and Tregs after the 48-hour co-culture of primary bone marrow cells and HEL cells were also analyzed by flow cytometry. In the newly diagnosed group, the bone marrow myeloid cells highly expressed p-JAK2, PD-1, and PD-L1. The Tregs expression in their peripheral blood increased and was significantly higher than those in the treatment and control groups (all p < 0.05). Ruxolitinib at different concentrations could inhibit the proliferation of HEL cells and was positively correlated with treatment time and dose. Additionally, ruxolitinib could reduce p-JAK2, PD-1, and PD-L1 expression in HEL cells and Tregs expression. Ruxolitinib reduces the expression of p-JAK2, PD-1, and PD-L1 in JAK2 V617F-positive cells by specifically inhibiting the JAK2 signaling pathway, thereby suppressing the progression of MPNs.

Development and validation of an m6A RNA methylation regulator-based signature for the prediction of prognosis and immunotherapy in cutaneous melanoma.

Development and validation of an m6A RNA methylation regulator-based signature for the prediction of prognosis and immunotherapy in cutaneous melanoma.

Predictive Values of Programmed Death-1, CC Chemokine Ligand 20, and Treg/T Helper 17 Cytokines for Patients with Hepatitis B Virus-Related Acute-on-Chronic Liver Failure

Background: This study aimed to explore the correlations of programmed death-1 (PD-1) and CC chemokine ligand 20 (CCL20) with Treg/T helper 17 (Th17) balance in patients with HBV-ACLF. Methods: In this cross-sectional study, 50 patients with HBV-ACLF and 50 cases with chronic hepatitis B (CHB) diagnosed from February 2021 to February 2022 were selected, and another 50 healthy volunteers who received physical examinations in the same period were selected as a control group. The expression levels of PD-1, CCL20, and Treg/Th17 cytokines were detected by Western blotting, immunoturbidimetry, and enzyme-linked immunosorbent assay (ELISA), respectively. The correlations of PD-1 and CCL20 with Treg/Th17 cytokines were explored by Pearson analysis. The predictive values of PD-1, CCL20, and Treg/Th17 cytokines for the prognosis of HBV-ACLF patients were analyzed. Results: The expression levels of PD-1 and CCL20 were higher in the HBV-ACLF group than in the CHB and control groups (P &lt; 0.05). Severe HBV-ACLF patients had higher levels of PD-1 and CCL20 compared with mild and moderate HBV-ACLF patients (P &lt; 0.05). Hepatitis B virus-related acute-on-chronic liver failure patients with poor prognosis had higher levels of PD-1 and CCL20 than those with good prognosis (P &lt; 0.05). The levels of transforming growth factor β (TGF-β), interleukin 10 (IL-10), IL-23, and tumor necrosis factor α (TNF-α) were higher in the HBV-ACLF group than in the CHB and control groups (P &lt; 0.05). The levels of PD-1 and CCL20 in the HBV-ACLF group were positively correlated with those of Treg/Th17 cytokines (TGF-β, IL-10, IL-23, and TNF-α; P &lt; 0.05). The combined detection of PD-1, CCL20, and Treg/Th17 cytokines had higher sensitivity and lower specificity than single detection in predicting the prognosis of HBV-ACLF patients (P &lt; 0.05). Conclusions: The expression levels of PD-1 and CCL20 are higher in HBV-ACLF patients, being correlated with Treg/Th17 balance. The combined detection of PD-1, CCL20, and Treg/Th17 cytokines has a higher value for predicting the prognosis of HBV-ACLF patients.

The Effect of Secreted IL-10 from Mesenchymal Stem Cell on Immune Checkpoint Molecules.

Immunosuppression in sepsis is hypothesized to result from the increased expression of the immune checkpoint molecules programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1). PD-1 and PD-L1 blockade therapies have been reported to increase survival in septic animals. Currently, the interleukin (IL)-10 within mesenchymal stem cell (MSC) secretome is known for its immunomodulatory capacity. To study the effect of IL-10 within MSC secretome on the expression of immune checkpoints in the rat model of sepsis. Methods: We used 48 male Rattus norvegicus rats in this research and divided them into four groups: sham (rats without sepsis induction and treatment), control (sepsis-induced rats without treatment), T1 (sepsis-induced rats treated with 150 μL of secreted IL-10 from MSC), and T2 (sepsis-induced rats treated with 300 μL of secreted IL-10 from MSC). Forty-eight hours after sepsis induction, we terminated the rats and collected the blood to examine the PD-1 and PD-L1 expression levels. We found a decrease in the relative expression of PD-1 in the septic rat group given 150 μL and 300 μL of secreted IL-10 from MSC compared to the control group, but the decrease was not significant. We also found a decrease in the relative expression of PD-L1 mRNA in the septic rat group given 150 μL and 300 μL of secreted IL-10 from MSC compared to the control group. Administering secreted IL-10 from MSC reduces the expression of PD-1 and PD-L1 in sepsis. These findings suggest that MSC secretome can improve the immunosuppression in sepsis.

Activation of the Aryl Hydrocarbon Receptor Ameliorates Acute Rejection of Rat Liver Transplantation by Regulating Treg Proliferation and PD-1 Expression.

Aryl hydrocarbon receptor (AhR) plays important roles in modulating immune responses. However, the role of AhR in rat liver transplantation (LT) has not been explored. Safety and side effects of N -(3,4-dimethoxycinnamonyl) anthranilic acid (3,4-DAA) and 2-methyl-2H-pyrazole-3-carboxylic acid amide (CH223191) were evaluated. We used optimal doses of 2 drugs, 3,4-DAA, a drug used for mediating AhR activation, and CH223191, antagonist of AhR (3,4-DAA, CH223191, and 3,4-DAA + CH223191), intraperitoneally administered to recipients daily to investigate the role of AhR in the rat LT model. The recipient livers were used to observe the pathological changes, the cells infiltrating the graft, and changes of AhR and programmed death-1 (PD-1) by Western blot, real-time polymerase chain reaction, and immunofluorescence assays. The contents of Foxp3 + and PD-1 + T cells in the recipient spleen and peripheral blood mononuclear cells were evaluated by flow cytometry. In vitro, after isolating CD4 + T cells, they were treated with different AhR ligands to observe the differentiation direction and PD-1 expression level. The activation of AhR by 3,4-DAA prolonged survival time and ameliorated graft rejection, which were associated with increased expression of AhR and PD-1 in the livers and increased Foxp3 + T cells and PD-1 + T cells in recipient spleens, livers, and peripheral blood mononuclear cells. In vitro, primary T cells incubated with 3,4-DAA mediated increased proportion of Treg and PD-1 + T cells. However, the suppression of AhR with CH223191 reverses these effects, both in the LT model and in vitro. Our results indicated that AhR activation might reduce the occurrence of rat acute rejection by increasing the proportion of Treg and the expression of PD-1.

Blockade of TIM-3 and PD-1 enhances the antitumor effects of MAGE-A11 antigen-specific cytotoxic T lymphocytes

Cancer immunotherapy is an attractive approach for antigen-specific T cell-mediated antitumor therapy, especially for the induction of cytotoxic T lymphocytes (CTLs). An human leukocyte antigen (HLA)-A2-restricted melanoma-associated antigen-A11 (MAGE-A11) peptide was developed that exhibited a potent capacity to induce cytotoxicity towards MAGE-A11-positive breast cancer cells by activating CTLs. However, this antitumor immune response can be suppressed by inhibitory pathways. Programmed death-1 (PD-1) and T cell immunoglobulin domain and mucin domain 3 (TIM-3) pathways are two important pathways involved in the tumor-mediated immune suppression. The present study aimed to augment the efficacy of MAGE-A11 antigen-specific CTLs via blocking PD-1 and TIM-3. The results showed that the expression levels of PD-1 and TIM-3 were unregulated during T cell induction, expansion and target cell killing. Blockade of PD-1 and TIM-3 modulated T cell proliferation, transformation and survival. In addition, treatment of cells with antibodies against PD-1 and TIM-3 enhanced the cytotoxicity of MAGE-A11 antigen-specific CTLs against breast cancer cells. The aforementioned findings suggested that MAGE-A11 antigen-specific CTLs accompanied by PD-1 and TIM-3 blockade could be considered as a potential therapy approach for breast cancer.

Ex Vivo Expanded and Activated Natural Killer Cells Prolong the Overall Survival of Mice with Glioblastoma-like Cell-Derived Tumors.

Glioblastoma (GBM) is the leading malignant intracranial tumor and is associated with a poor prognosis. Highly purified, activated natural killer (NK) cells, designated as genuine induced NK cells (GiNKs), represent a promising immunotherapy for GBM. We evaluated the anti-tumor effect of GiNKs in association with the programmed death 1(PD-1)/PD-ligand 1 (PD-L1) immune checkpoint pathway. We determined the level of PD-1 expression, a receptor known to down-regulate the immune response against malignancy, on GiNKs. PD-L1 expression on glioma cell lines (GBM-like cell line U87MG, and GBM cell line T98G) was also determined. To evaluate the anti-tumor activity of GiNKs in vivo, we used a xenograft model of subcutaneously implanted U87MG cells in immunocompromised NOG mice. The GiNKs expressed very low levels of PD-1. Although PD-L1 was expressed on U87MG and T98G cells, the expression levels were highly variable. Our xenograft model revealed that the retro-orbital administration of GiNKs and interleukin-2 (IL-2) prolonged the survival of NOG mice bearing subcutaneous U87MG-derived tumors. PD-1 blocking antibodies did not have an additive effect with GiNKs for prolonging survival. GiNKs may represent a promising cell-based immunotherapy for patients with GBM and are minimally affected by the PD-1/PD-L1 immune evasion axis in GBM.

Higher Proportion of a Novel PD-1+ Foxp3+ γδ Regulatory T Cell Subset in De Novo and Recurrent AML

T cell immunodeficiency may be a common characteristic in acute myeloid leukemia (AML) and adoptive T cellular immunotherapy has a broad prospect for clinical treatment. γδ T cells is essential to anti-leukemia function through perforin (Perf) / granzyme B (Grmb) pathway and may become a new strategy for leukemia immunotherapy. However, γδ T cells have different functional subsets like regulatory cell subsets and relevant regulatory mechanism is still unknown. Programmed death-1 (PD-1) which is one of T cell inhibitory receptors may mediate T cell suppression and dysfunction in leukemia and relate to general regulatory T cells which express transcription factor forkhead box P3 (Foxp3). It would be interesting whether PD-1 pathway might involve in regulation of regulatory Foxp3+ γδ T cells. In this study, we first investigated the regulatory cell subsets of γδ T cells in patients with AML. The flow cytometry (FCM) was used to detect the expression proportions of γδ T cells and their subfamilies in peripheral blood of AML patients (including 15 cases of de novo AML, 5 cases of recurrent AML and 4 cases in complete remission (CR)). Real-time quantitative PCR(RQ-PCR)was used to detect the expression levels of PD-1, Foxp3, Grmb and Perf genes in the γδ T cells sorting by MACS technique from peripheral blood of de novo AML patients. Fifteen health individuals (HI) served as controls. The results showed decreasing trend of γδ T cell counts in AML patients. Compared with HI groups, higher expression levels of PD-1 gene in γδ T cells were found in de novo AML patients, while Grmb and Perf gene presented lower expression levels by RQ-PCR (P <0.05) (Figure A). The expression levels of PD-1 gene had a positive correlation to the Foxp3 gene in de novo AML group. It was noteworthy that we firstly found a novel PD-1+ Foxp3+ γδ T subset in peripheral blood of AML patients and HI controls with different frequencies. The proportions of Foxp3+ γδ T cells, PD1+ γδ T cells, and PD-1+ Foxp3+ γδ T cells were significantly higher either in de novo or the recurrent AML patients, respectively (P <0.05). The PD1+ Foxp3+ γδ T cells counts in AML patients showed the pattern as the recurrent AML > the de novo AML > the AML-CR groups (Figure B and C). In conclusion, a novel regulatory PD1+ Foxp3+ γδ T subset with lower expression levels of Grmb and Perf genes was found in peripheral blood of AML patients. Higher proportion of PD1+ Foxp3+ γδ T cells might influence the occurrence and development of AML. [Display omitted] DisclosuresLi:Guangdong Provincial Applied Science and Technology Research & Development Program (No. 2016B020237006): Research Funding; Guangzhou Science and Technology Project (No. 2015100010211): Research Funding; National Natural Science Foundation of China (91642111): Research Funding; Guangdong Provincial Basic Research Program (No. 2015B020227003: Research Funding. Wu:the Fundamental Research Funds for the Central Universities(No. 21617465): Research Funding; National Natural Science Foundation of China(No.8120038): Research Funding; the Natural Science Foundation of Guangdong Province (No. 2014A030313380): Research Funding.

Programmed cell death-1 single-nucleotide polymorphism rs10204525 is associated with human immunodeficiency virus type 1 RNA viral load in HIV-1-infected Moroccan subjects.

Human Immunodeficiency Virus (HIV-1) infections are characterized by dysfunctional cellular and humoral antiviral immune responses. The progressive loss of effector functions in chronic viral infection has been associated with the up-regulation of programmed death-1 (PD-1), a negative regulator of activated T cells and Natural Killer cells. In HIV-1 infection, increased levels of PD-1 expression correlate with CD8 + T-cell exhaustion. In vitro, PD-1 blockade using PD-1 antibodies led to an increase in HIV-1 specific CD8 + T and memory B cell proliferation. We aimed to investigate the impact of PDCD1 rs10204525 polymorphism on HIV-1 susceptibility, AIDS development, and treatment response outcomes in HIV-1 infection in a Moroccan population. A total of 214 HIV-1 seropositive and 250 seronegative subjects were enrolled to investigate the association between the between the single-nucleotide polymorphism (SNP) rs10204525 ofPDCD1gene and HIV-1 pathogenesis using a predesigned TaqMan SNP genotyping assay. No significant association was found between rs10204525 and susceptibility to HIV-1 infection and AIDS development (p > 0.05). Genotype frequencies were significantly associated with the viral load before ART (p = 0.0105). HIV-1 viral load was significantly higher among subjects with the CC compared to TT genotype (p = 0.0043). In treated subjects, the median of viral load levels was significantly higher in CC and CT groups than TT subjects (p < 0.005). However, analysis of the correlation between CD4 + T-cell levels andPDCD1polymorphism before and after ART showed no significant difference (p > 0.05). Our results demonstrated that rs10204525 polymorphism does not affect HIV-1 infection. However, this polymorphism may affect the response to treatment as measured by RNA viral load levels.

Transarterial chemoembolisation enhances programmed death-1 and programmed death-ligand 1 expression in hepatocellular carcinoma.

Immunotherapies represent a new alternative therapeutic approach for hepatocellular carcinomas (HCCs), and have shown promising results when used in combination therapy. The aim of this study was to evaluate the potential of transarterial chemoembolisation (TACE) to modulate programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) expression profiles in a cohort of surgically treated HCCs. A total of 82 surgically treated HCCs from patients who had undergone (n=32) or not undergone (n=50) preoperative TACE were included in the study. Immunohistochemical expression of PD-1 and of PD-L1 were analysed and compared according to TACE treatment. Pretreatment biopsies, which were available for 30 cases (20 with TACE and 10 without), were similarly analysed. Follow-up data were retrieved from patients' charts. PD-1 expression (≥1%) in intratumoral inflammatory cells (ICs) was observed in 46% of HCCs, and PD-L1 expression (≥1%) in ICs and PD-L1 expression in tumour cells (TCs) were observed in 46% and 16% of HCCs, respectively. A low level of PD-1 expression (<1%) was associated with strong and diffuse glutamine synthetase overexpression (8% versus 27%, P=0.024). HCCs from patients with TACE pretreatment showed significantly higher PD-L1 expression in TCs than those from patients without TACE pretreatment (2% versus 0.4%, P=0.027). PD-1 expression in ICs and PD-L1 expression in both ICs and TCs were higher in TACE-resected tumours than in corresponding pre-TACE biopsies (respectively: 1.8% versus 8.1%, P=0.034; 0.8% versus 7.1%, P=0.032; and 0% versus 2.4%, P=0.043). Our results, showing increases in PD-1 expression and PD-L1 expression in HCCs following TACE, support the use of TACE in combination with immunotherapy in selected cases to optimise tumour response.

PD-1 restrains IL-17A production from γδ T cells to modulate acute radiation-induced lung injury.

BackgroundCombining radiotherapy (RT) with programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) inhibitors has been shown to enhance anti-tumor effects in the treatment of non-small cell lung carcinoma (NSCLC). Pulmonary toxicity is a major adverse effect of thoracic RT in NSCLC patients, whether it is administered alone or in combination with PD-1/PD-L1 inhibitors. This study aimed to evaluate the potential pulmonary toxicity of RT combined with concurrent PD-1 inhibitor and to clarify the underlying mechanisms.MethodsRadiation-induced lung injury (RILI) was induced in C57BL/6 mice by given 24 Gy in three fractions on consecutive days, with or without concurrent injection of anti-PD-1 antibody. On days 3, 7, 14, and 28 after the first exposure to irradiation, lung tissue and peripheral blood samples were collected from the mice. Histological injury was analyzed, and inflammatory cell infiltration and interleukin (IL)-17A production in the lung tissues were quantified.ResultsMice that received irradiation with concurrent administration of anti-PD-1 antibody had the highest histological score for RILI. In the murine lung tissues, the levels of PD-1 and IL-17A expression were increased in γδ T cells but not in the other CD3+ T cells after irradiation. Concurrent blockade of PD-1 enhanced IL-17A production from γδ T cells in the lung tissues after irradiation. In the mice with acute RILI, concurrent administration of anti-PD-1 antibody exaggerated pulmonary inflammation, with significantly increased levels of neutrophilic infiltration and IL-17A detected in both the lung and blood.ConclusionsPD-1 could restrain IL-17A production from γδ T cells to modulate acute RILI. The concurrent administration of anti-PD-1 antibody aggravates the severity of acute RILI. More attention should be paid to pulmonary toxicity in patients undergoing thoracic RT with concurrent anti-PD-1 immunotherapy.

Prognostic Impact of PD-1 on Tumor-Infiltrating Lymphocytes in 433 Resected Esophageal Cancers

BackgroundImmune checkpoint inhibitors targeting the programmed death 1 (PD-1)/programmed death-ligand 1 (PD-L1) pathway have demonstrated antitumor effects in patients with various malignancies, including esophageal cancer. Thus, a better understanding of local immunity in esophageal cancer is crucial for improving treatment and clinical outcomes. MethodsWe evaluated PD-1 expression on tumor-infiltrating lymphocytes (TILs), as well as PD-L1 expression on cancer cells, by immunohistochemistry and immunofluorescence using a nonbiased database of 433 curatively resected esophageal cancers. With the idea of application as liquid biopsy, PD-1 expression status on peripheral lymphocytes was evaluated by flow cytometry. ResultsThe cutoff value of PD-1 expression was the median PD-1 count. Compared with cases of low PD-1 expression (n = 219), cases with high levels of PD-1 expression (n = 213) showed significantly worse overall survival (log-rank P = .0017). The prognostic effect of PD-1 differed according to the preoperative treatment status (P for interaction = .040); PD-1 expression was associated with high overall mortality among patients without preoperative therapy, while no such association was present among those with preoperative treatment. A stratification based on PD-1 and PD-L1 status was also significantly associated with overall survival (log-rank P = .0005). PD-1 expression on TILs was significantly associated with that on peripheral lymphocytes (P < .0001). ConclusionsPD-1 expression on TILs was associated with an unfavorable clinical outcome in esophageal cancer, supporting its role as a prognostic biomarker. The combination of PD-1 and PD-L1 expression enabled further classification of patients according to clinical outcome.

PD1 Blockade Enhances ICAM1-Directed CAR T Therapeutic Efficacy in Advanced Thyroid Cancer.

Advanced thyroid cancers, including poorly differentiated and anaplastic thyroid cancer (ATC), are lethal malignancies with limited treatment options. The majority of patients with ATC have responded poorly to programmed death 1 (PD1) blockade in early clinical trials. There is a need to explore new treatment options. We examined the expression of PD-L1 (a ligand of PD1) and intercellular adhesion molecule 1 (ICAM1) in thyroid tumors and ATC cell lines, and investigated the PD1 expression level in peripheral T cells of patients with thyroid cancer. Next, we studied the tumor-targeting efficacy and T-cell dynamics of monotherapy and combination treatments of ICAM1-targeting chimeric antigen receptor (CAR) T cells and anti-PD1 antibody in a xenograft model of ATC. Advanced thyroid cancers were associated with increased expression of both ICAM1 and PD-L1 in tumors, and elevated PD1 expression in CD8+ T cells of circulating blood. The expression of ICAM1 and PD-L1 in ATC lines was regulated by the IFNγ-JAK2 signaling pathway. ICAM1-targeted CAR T cells, produced from either healthy donor or patient T cells, in combination with PD1 blockade demonstrated an improved ability to eradicate ICAM1-expressing target tumor cells compared with CAR T treatment alone. PD1 blockade facilitated clearance of PD-L1 high tumor colonies and curtailed excessive CAR T expansion, resulting in rapid tumor clearance and prolonged survival in a mouse model. Targeting two IFNγ-inducible, tumor-associated antigens-ICAM1 and PD-L1-in a complementary manner might be an effective treatment strategy to control advanced thyroid cancers in vivo.

Profile of PD-1 and PD-L1 mRNA Expression in Peripheral Blood of Nasopharyngeal Carcinoma

Background: Programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) expression is associated with prognostic and respond to immunotherapy with immune checkpoint inhibitor in several solid malignancies. However, the prognostic roles of PD-1 and PD-L1 expression in nasopharyngeal carcinoma (NPC) are less clear. This study aims to investigate PD-1 and PD-L1 mRNA expression levels in peripheral blood of Indonesian NPC patients and its association with clinicopathological features.Materials and Methods: This study used blood samples of 21 NPC patients and 10 healthy volunteers as controls. Real-time polymerase chain reaction (PCR) was used to measure mRNA expression of PD-1 and PD-L1.Results: PD-1 mRNA expression levels were significantly lower in NPC patients (∆CT mean: 9.65±2.04) compared to healthy individuals (∆CT mean: 8.04±1.51) (p=0.031). In contrast, PD-L1 mRNA expression levels were higher in NPC patients (∆CT mean: 6.96±1.32) compared to healthy individuals (∆CT mean: 7.11±0.55), but the difference was not statistically significant (p=0.554). The expression of PD-1 was associated with tumour-node-metastasis (TNM) stage (p=0.030) but not associated with age (p=1.000), sex (p=1.000), body mass index (p=0.350), tumor stage (p=0.338), nodal stage (p=0.579), metastasis stage (p=0.371), and Eastern Cooperative Oncology Group (ECOG) status (p=0.228). Meanwhile PD-L1 expression was not associated with all clinicophatological features.Conclusion: The PD-1 mRNA expression levels were significantly lower, while PD-L1 expression levels were higher in NPC patients compared to healthy controls. PD-1 expression was correlated with TNM stage.Keywords: nasopharyngeal carcinoma, immune checkpoint inhibitors, PD-1, PD-L1

Immune Function and Mechanism of Costimulating Molecules PD-1 and OX40 in Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a T lymphocyte-mediated autoimmune disease, although its immune mechanism has not been fully studied. In this study, healthy controls (HC), osteoarthritis patients (OA), and RA patients were enrolled, and mice were evenly divided into control, collagen-induced arthritis (CIA), PD-1 Fc/CIA (PD-1 Fc membrane fusion protein administered to CIA mice), OX40 Fc/CIA (OX40 Fc membrane fusion protein administered to CIA mice), and PD-1 Fc + OX40 Fc/CIA groups. The expressions of programmed death-1 (PD-1) and OX40 in CD4+ T lymphocytes and the levels of sPD-1, immunoglobulin, and proinflammatory factors in patients and mice were measured. The results showed that the expression levels of PD-1 and OX40 in CD4+ T lymphocytes separated from the peripheral blood and synovial fluid of RA patients and the spleen of CIA mice were observably elevated. The levels of soluble PD-1, interleukin (IL)-2, IL-4, IL-5, IL-17, and interferon-γ (IFN-γ) in RA patients obviously increased. In animal experiments, PD-1 Fc not only increased the serum levels of immunoglobulin G (IgG), IgG1, and IgG2a in CIA mice, but also increased the levels of IL-4, IL-2, IL-5, IL-17, and IFN-γ in mouse spleen cells and joint tissues, which, however, were reversed by OX40 Fc. In conclusion, OX40 inhibition could reverse the progression of RA caused by PD-1 blocking, and PD-1 might be a potential target for RA. Clinical Trials.gov ID: HGH2018012203.

PD-1 Deficiency Promotes Macrophage Activation and T-Helper Cell Type 1/T-Helper Cell Type 17 Response in Pneumocystis Pneumonia.

Pneumocystis is an unusual, opportunistic fungal pathogen capable of causing Pneumocystis pneumonia (PCP) in immunocompromised hosts. Although PCP was discovered >100 years ago, its pathogenesis remains unclear. The inhibitory receptor PD-1 (programmed death 1), a negative regulator of activated T cells, has been reported to take part in tumor escape, immune tolerance, and infection immunity. In this study, we examined the role of the PD-1/PD-L1 (programmed death-ligand 1) pathway in patients with PCP and in mice. The expression levels of PD-1/PD-L1 in patients with PCP and in mice were measured by real-time PCR and flow cytometry. The effects of PD-1 deficiency are demonstrated using wild-type and PD-1-/- mice. Our data show that Pneumocystis infection promotes PD-1/PD-L1 expression; PD-1 deficiency enhances the phagocytic function of macrophages and the pulmonary T-helper cell type 1 (Th1)/Th17 response, which might contribute to Pneumocystis clearance; and PD-1 deficiency affects the polarization of macrophages. PCP mice treated with anti-PD-1 antibody showed improved pulmonary clearance of Pneumocystis. Collectively, our results demonstrate that the PD-1/PD-L1 pathway plays a role in regulating the innate and adaptive immune responses, suggesting that manipulation of this pathway may constitute an immunotherapeutic strategy for PCP.

Differences in PD-1 expression on CD8+ T-cells in chronic myeloid leukemia patients according to disease phase and TKI medication.

Malignant cells can increase in number using immune escape mechanisms such as immune checkpoints. In this study, we evaluated the expression of an immune checkpoint programmed death 1 (PD-1) on T-cell subsets in chronic myeloid leukemia (CML). We obtained bone marrow aspirate samples from CML patients and from individuals without evidence of hematologic malignancies (controls). PD-1 expression on T-cell subsets was measured using flow cytometric analysis. PD-1 expression levels on CD8+ T-cells were significantly lower in complete hematologic response (CHR) than in controls, chronic phase, and blast phase (BP). In CML patients receiving imatinib and dasatinib, PD-1 expression levels on CD8+ T-cells were lower than that at diagnosis. PD-1 expression levels on CD8+ T-cells were positively correlated with quantitative levels of the BCR/ABL fusion gene. PD-1 expression levels on CD4+ T-cells were higher in BP than in CHR. PD-1 expression levels on CD4+ T-cells did not differ significantly according to different medications or quantitative BCR/ABL1 fusion gene levels. Low PD-1 expression on CD8+ T-cells might play a role in maintaining CHR in CML patients. Immune monitoring of PD-1 expression on CD8+ T-cells may predict the disease course. In cases of refractory disease or resistance to imatinib or dasatinib, the use of PD-1 inhibitors would be helpful.

Prognostic significance of immune checkpoints in the tumour–stromal microenvironment of sebaceous gland carcinoma

BackgroundImmune checkpoint blockade strategies have gained attention in the treatment/prognosis of cancers by targeting the programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) pathway alone or in combination with cytotoxic T-lymphocyte-associated antigen...

Altered distribution and enhanced osteoclastogenesis of mucosal-associated invariant T cells in gouty arthritis.

This study was designed to investigate the role of mucosal-associated invariant T (MAIT) cells in gouty arthritis (GA) and their effects on osteoclastogenesis. Patients with GA (n = 61), subjects with hyperuricaemia (n = 11) and healthy controls (n = 30) were enrolled in this study. MAIT cells, cytokines, CD69, programmed death-1 (PD-1) and lymphocyte-activation gene 3 (LAG-3) levels were measured by flow cytometry. In vitro osteoclastogenesis experiments were performed using peripheral blood mononuclear cells in the presence of M-CSF and RANK ligand. Circulating MAIT cell levels were significantly reduced in GA patients. However, their capacities for IFN-γ, IL-17 and TNF-α production were preserved. Expression levels of CD69, PD-1 and LAG-3 in MAIT cells were found to be elevated in GA patients. In particular, CD69 expression in circulating MAIT cells was increased by stimulation with MSU crystals, suggesting that deposition of MSU crystals might contribute to MAIT cell activation. Interestingly, MAIT cells were found to be accumulated in synovial fluid and infiltrated into gouty tophus tissues within joints. Furthermore, activated MAIT cells secreted pro-resorptive cytokines (i.e. IL-6, IL-17 and TNF-α) and facilitated osteoclastogenesis. This study demonstrates that circulating MAIT cells are activated and numerically deficient in GA patients. In addition, MAIT cells have the potential to migrate to inflamed tissues and induce osteoclastogenesis. These findings provide an important role of MAIT cells in the pathogenesis of inflammation and bone destruction in GA patients.

Expression of PD-1/PD-L1 in head and neck squamous cell carcinoma and its clinical significance.

To investigate the role of programmed death-1 (PD-1), programmed death-ligand 1 (PD-L1), and P16 in patients with head and neck squamous cell carcinoma (HNSCC). A total of 95 paraffin-embedded samples of tumorous tissue of HNSCC were collected. Expression levels of PD-1, PD-L1, and P16 were determined by immunohistochemistry. A significantly higher proportion of PD-1 among patients infected with the human papillomavirus was found. PD-L1 expression is closely associated with the primary site of the tumor, postoperative recurrence, survival, PD-1 expression and P16 expression. Univariable analysis indicated that T stage, N stage, tumor node metastasis stage, tumor differentiation, and PD-L1 expression were all shown to be prognostic variables for overall survival in patients with HNSCC. In the multivariate analysis, only N stage (P = 0.010) and PD-L1 expression (P = 0.001) were found to be independent prognostic variables for overall survival. In addition, for disease recurrence, multivariate analysis showed that only PD-L1 expression was the associated independent risk factor. For the patients with negative PD-L1 expression, Kaplan-Meier analysis revealed that they had significantly worse outcomes in terms of overall survival (P = 0.001). Similarly, compared with the patients with positive PD-L1 expression, those with negative PD-L1 expression had a higher probability of recurrence (P = 0.026). The expression of PD-L1, PD-1, and P16 in HNSCC is significantly correlated. Human papillomavirus infection (P16 positive) is negatively related to postoperative recurrence. HNSCC patients with positive PD-L1/PD-1 expression tend to have better overall survival outcomes and lower probability of recurrence, providing more evidence for the PD-l-targeted immunotherapy of HNSCC.