Soluble Programmed Death-1 Research Articles

Soluble Programmed Cell Death-1 is a Novel Predictor of HBsAg Loss in Chronic Hepatitis B Patients When Long-Term Nucleos(t)ide Analog Treatment is Discontinued.

PurposeThe immunoinhibitory receptor, programmed death 1 (PD-1), plays a critical role in immune suppression during chronic viral infection. The significance of circulating soluble PD-1 (sPD-1) in patients with chronic hepatitis B who have discontinued long-term nucleos(t)ide analog (NA) treatment remains unknown.Patients and MethodsA prospective cohort study was conducted using serial blood samples from chronic hepatitis B patients who discontinued long-term NA treatment. The current analysis included 115 non-cirrhotic patients with HBV DNA negative and HBsAg positive at the moment of NA discontinuation. Levels of sPD-1 were measured in all available samples using sandwich enzyme-linked immunoassay.ResultsSixty-two patients experienced a clinical relapse and 14 occurred HBsAg loss, with 8-year cumulative rates of 56.6% and 23.4%, respectively. Time-dependent receiver operating characteristic curve analysis for sPD-1 derived 156 pg/mL, which is equivalent to the detectable threshold, as an optimal cut-off value for predicting 8-year clinical relapse. Patients with detectable sPD-1 at end of treatment (EOT) had a significant lower incidence of clinical relapse (48% vs 67%, hazard ratio [HR] 0.454, p = 0.006), but a remarkable higher probability of HBsAg loss (33.7% vs 2.4%, HR 9.17, p = 0.038), compared to those who with undetectable sPD-1, respectively.ConclusionEOT sPD-1 levels predicted clinical relapse and HBsAg loss after treatment discontinuation and may help to guide a finite NA treatment plan for patients with chronic hepatitis B virus infection.

The Programmed Death-1 Pathway Counter-Regulates Inflammation-Induced Osteoclast Activity in Clinical and Experimental Settings.

ObjectiveThe programmed death-1 (PD-1) pathway is essential for maintaining self-tolerance and plays an important role in autoimmunity, including rheumatoid arthritis (RA). Here, we investigated how membrane-bound and soluble (s)PD-1 influence bone homeostasis during chronic inflammation, exemplified in RA.MethodsBone mineral density and bone microstructure were examined in PD-1 and PD-L1 knockout (KO) mice and compared with wild-type (WT) mice. Receptor activator of nuclear factor kappa-B ligand (RANKL) was measured in serum, and the expression examined on activated bone marrow cells. Osteoclast formation was examined in cells from murine spleen and bone marrow and from human synovial fluid cells. sPD-1 was measured in chronic and early (e)RA patients and correlated to markers of disease activity and radiographic scores.ResultsPD-1 and PD-L1 KO mice showed signs of osteoporosis. This was supported by a significantly reduced trabecular bone volume fraction and deteriorated microstructure, as well as increased osteoclast formation and an increased RANKL/OPG ratio. The recombinant form of sPD-1 decreased osteoclast formation in vitro, but was closely associated with disease activity markers in eRA patients. Sustained elevated sPD-1 levels indicated ongoing inflammation and were associated with increased radiographic progression.ConclusionThe PD-1 pathway is closely associated with bone homeostasis, and lacking members of this pathway causes a deteriorated bone structure. The immunological balance in the microenvironment determines how the PD-1 pathway regulates osteoclast formation. In eRA patients, sPD-1 may serve as a biomarker, reflecting residual but clinically silent disease activity and radiographic progression.

Immuno‐Engineered Nanodecoys for the Multi‐Target Anti‐Inflammatory Treatment of Autoimmune Diseases

Overactivated T cells and overproduced pro-inflammatory cytokines form a self-amplified signaling loop to continuously exacerbate the dysregulated inflammatory response and propel the progression of autoimmune diseases (AIDs). Herein, immuno-engineered nanodecoys (NDs) based on poly(lactic-co-glycolic acid) nanoparticles coated with programmed death-ligand 1 (PD-L1)-expressing macrophage membrane (PRM) are developed to mediate multi-target interruption of the self-promoted inflammatory cascade in AIDs. The PRM collected from IFN-γ-treated RAW 264.7 cells possesses elevated surface levels of adhesion molecule receptors and pro-inflammatory cytokine receptors, and, thus, systemically administered PRM NDs afford higher accumulation level in inflamed tissues and stronger scavenging efficiency toward multiple pro-inflammatory cytokines. More importantly, IFN-γ treatment induces remarkable PD-L1 expression on PRM, thereby allowing PRM NDs to bind membrane-bound programmed death-1 (PD-1) on CD4+ T cell surfaces or neutralize free soluble PD-1, which reconstructs the PD-1/PD-L1 inhibitory axis to suppress CD4+ T cell activation and restore immune tolerance. As such, PRM NDs provoke potent and cooperative anti-inflammatory and immune-suppressive efficacies to alleviate autoimmune damages in Zymosan A-induced arthritis mice and dextran sulfate sodium-induced ulcerative colitis mice. This study provides an enlightened example for the immuno-engineering of cell-membrane-based NDs, rendering promising implications into the treatment of AIDs via multi-target immune-modulation.

Measurement of soluble PD-1 and soluble PD-L1 as well as PD-L1 and PD-1 from perioperative patients with gastric carcinoma.

Till now, no experiment has been performed to detect programmed death ligand 1 (PD-L1)/programmed death 1 (PD-1), soluble PD-L1/soluble PD-1 simultaneously in perioperative patients of gastric carcinoma. Our experiment aims at determining the clinical significance and possible mechanism of soluble PD-L1/soluble PD-1 in gastric carcinoma. Thirty patients undergone gastrectomy were selected as the experimental group. Tissue's programmed death ligand 1 and peripheral programmed death 1 were detected using immunofluorescence and flow cytometry. Soluble PD-L1 and soluble PD-1 were detected using enzyme-linked immunosorbent assay. First, preoperative programmed death 1 was higher than control group and decreased to normal post-operatively. Preoperatively ,elevated levels of programmed death 1 on cluster of differentiation (CD)4 T cells indicated less lymphatic metastasis (P<0.01) and small tumor volume (P<0.01); elevated programmed death 1 of CD8 T cells indicated big tumor volume (P<0.01) and well histological differentiation (P<0.01). Second, preoperative soluble PD-L1 and soluble PD-1 are lower than in control group. Post-operatively, the soluble PD-1 rose to normal, but the soluble PD-L1 showed no change. Third, programmed death ligand 1 can be observed in carcinoma tissue. Fourth, the area under the curve of soluble PD-1 (0.675) for diagnosis was worse than that of soluble PD-L1 (0.885). Kaplan-Meier analysis showed that soluble PD-1<245.26pg/ml in post-operative serum predicted a poor prognosis (overall survival percentage: 60%) at 2 years (P<0.05). Multivariate analysis revealed that carcinoembryonic antigen (>5ng/l) and soluble PD-1 after gastrectomy (>245.26pg/ml) were independent prognostic factors for overall survival (hazard ratio: 20.812, 95% confidence interval: 1.217-355.916, P=0.036; hazard ratio: 0.028, 95% confidence interval: 0.001-0.786, P=0.036, respectively). We propose that soluble PD-1 combined with programmed death ligand 1 are effective not only in protecting T cells from the adhesion by programmed death ligand 1 but also in preventing the occurrence and the development of tumor as well. Through multivariate analysis, we found that soluble PD-1 was an independent protective factor for post-operative prognosis of gastric carcinoma patients, which indirectly verified the vital function of soluble PD-1. Soluble PD-1 might be promising predictive biomarkers for the diagnosis and prognosis of gastric carcinoma patients.

Soluble PD-1 Ligands Regulate T-Cell Function in Waldenstrom's Macroglobulinemia

While immune checkpoint molecules contribute to the malignant development of several cancers, including certain types of lymphomas, their potential significance in malignant progression of Waldenstrom's Macroglobulinemia (WM), a low-grade B-cell lymphoma, has not fully been described. The main characteristic of WM is infiltration of lymphoplasmacytic cells in the bone marrow (BM) and increased monoclonal IgM production by malignant cells within BM microenvironment. While next generation sequencing analysis has identified mutations in the MYD88 gene as the driver of WM development, studies by our group have also highlighted a role for the BM microenvironment in pathophysiology of WM and shown that elevated levels of certain cytokines in the BM, such as IL-6 and IL-21, promote both cell proliferation and IgM secretion in WM.In this study, we investigated the impact of cytokines on the immune checkpoint receptor Programmed Death-1 (PD-1) and its ligands PD-L1 and PD-L2 and evaluated how these molecules contribute to malignant progression in WM.Using RT-PCR analysis we have shown that treatment of WM cell lines with IL-21 and IL-6 significantly induce PD-L1 and PD-L2 gene expression, implying that elevated levels of these cytokines within the BM microenvironment could be associated with increased PD-L1 and PD-L2 expression by malignant cells in WM patients. We therefore performed RT-PCR analysis on cells isolated from patients' BM and confirmed increased PD-L1 and PD-L2 expression by both WM and BM cells when compared normal BM cells. In contrast, flow cytometry analysis showed minimal expression of these ligands on the surface of the WM cells, with no significant difference between WM and normal BM cells, indicating that there might be a regulatory mechanism controlling surface expression of these ligands. Further analysis using ELISA and Western Blotting showed that PD-L1 and PD-L2 are found as secreted forms in both BM plasma and peripheral blood serum of the WM patients and their level is significantly higher in WM as compared to normal subjects. Interestingly, in vitro treatment of the WM cell lines by IL-21 and IL-6 increased secreted PD-L1 and PD-L2 in the culture media of the cells, providing an additional line of evidence for elevated PD-L1 and PD-L2 levels in WM patients. Subsequent analysis showed that the secreted form of the PD-L1 and PD-L2 binds to T-cells and induces signals that reduce T-cell proliferation and cell cycle progression, the effects that are associated with a reduction in p-ERK and cyclin A levels.In summary, our data identifies that secreted form of PD-1 ligands is elevated in WM and play an important role in regulating T-cell function. Given the capability of secreted form to be bioactive at distant sites, soluble PD-1 ligands may have potential to promote disease progression. DisclosuresAnsell:Seattle Genetics: Research Funding; Bristol-Myers Squibb: Research Funding; Affimed: Research Funding; Merck: Research Funding; Celldex: Research Funding.

Soluble PD-1 but Not PD-L1 Levels Predict Poor Outcome in Patients with High-Risk Diffuse Large B-Cell Lymphoma.

Simple SummarySoluble forms of checkpoint protein PD-1 and its ligand PD-L1 can be measured from circulation, but their source, function, and clinical impact in cancer remain incompletely understood. In this study, we used serum samples collected during a conduction of a prospective immunochemotherapy trial in patients with high-risk diffuse large B-cell lymphoma (DLBCL) and assessed their clinical significance. Our results demonstrate that sPD-1 levels in the peripheral blood at the time of diagnosis correlate with the quantities of tumor infiltrating PD1+ T cells and translate to inferior survival. To our knowledge, this is the first study to identify sPD-1 as a prognostic factor, providing interesting perspectives on future clinical trials in DLBCL, including patients’ stratification associated with checkpoint blockade.Interaction of checkpoint receptor programmed death 1 (PD-1) with its ligand 1 (PD-L1) downregulates T cell effector functions and thereby leads to tumor immune escape. Here, we aimed to determine the clinical significance of soluble PD-1 (sPD-1) and soluble PD-L1 (sPD-L1) in patients with diffuse large B-cell lymphoma (DLBCL). We included 121 high-risk DLBCL patients treated in the Nordic NLG-LBC-05 trial with dose-dense immunochemotherapy. sPD-1 and sPD-L1 levels were measured from serum samples collected prior to treatment, after three immunochemotherapy courses, and at the end of therapy. sPD-1 and sPD-L1 levels were the highest in pretreatment samples, declining after three courses, and remaining low post-treatment. Pretreatment sPD-1 levels correlated with the quantities of PD1+ T cells in tumor tissue and translated to inferior survival, while no correlation was observed between sPD-L1 levels and outcome. The relative risk of death was 2.9-fold (95% CI 1.12–7.75, p = 0.028) and the risk of progression was 2.8-fold (95% CI 1.16–6.56, p = 0.021) in patients with high pretreatment sPD-1 levels compared to those with low levels. In conclusion, pretreatment sPD-1 level is a predictor of poor outcome after dose-dense immunochemotherapy and may be helpful in further improving molecular risk profiles in DLBCL.

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.

EV PD-L1 is Correlated With Clinical Features and Contributes to T Cell Suppression in Pediatric Thyroid Cancer.

The contribution of blood extracellular vesicular (EV) programmed death-ligand 1 (PD-L1) and programmed death-1 (PD-1) in papillary thyroid cancer (PTC) is uncertain. We sought to determine the relationship of EV PD-L1/PD-1 with the clinical features of pediatric PTC and the role of EV PD-L1 in immunosuppression. Plasma levels of EV and soluble PD-L1 and PD-1 and levels of plasma cytokines in children with PTC and controls were determined by enzyme-linked immunosorbent assay. Levels of tumor PD-L1 and the tumor-infiltrating lymphocyte (TIL) score were determined by immunohistochemistry. Correlations of the plasma PD-L1/PD-1 level with clinicopathological characteristics, levels of plasma cytokines, tumor PD-L1 expression, and TIL score were analyzed. T-cell suppression by EVs from PTC patients was determined by incubation of PD-L1high or PD-L1low EVs with activated CD8+ T cells. Changes in CD69 and PD-1 expression and changes in tumor necrosis factor-α (TNFα) and interferon-γ (IFNγ) secretion were measured by flow cytometry. The levels of plasma PD-L1/PD-1 were significantly higher in children with PTC than in controls. The levels of plasma EV PD-L1 significantly correlated with tumor T stage, tumor PD-L1 expression, TIL score, and plasma cytokine content. Levels of plasma soluble PD-1 significantly correlated with patient age, plasma EV PD-L1, and IFNα concentration. PD-L1high EVs significantly inhibited the activation of CD8+ T cells. Plasma levels of EV PD-L1, but not soluble PD-L1, were associated with tumor T stage in children with PTC. Plasma EV PD-L1 emerges as a useful metric for assessing tumor T stage and T cell suppression in PTC.

Soluble PD1 levels are increased with disease activity in paediatric onset autoimmune hepatitis and inflammatory bowel disease

Introduction: Immune mediated liver diseases entail a broad category which are associated with increased morbidity and mortality amongst the paediatric population. Programmed Death 1 (PD1) is an inhibitory receptor mainly expressed by T cells, and when activated shed into plasma as soluble PD1(sPD1). The AIM of this study was to evaluate sPD1 levels in plasma of paediatric patients with Autoimmune Hepatitis (AIH), Primary Sclerosing Cholangitis (PSC), AIH and PSC overlap, Inflammatory Bowel Disease (IBD) alone, and concurrent PSC/IBD and AIH/IBD in order to identify a biomarker to response or predict relapse verses remission.Methods: Plasma samples were collected from 41 paediatric patients. AIH patients were further categorized into active, incomplete responders and responders, based on response to standard therapy. sPD1 levels were measured and compared between PSC, PSC/AIH, IBD alone, PSC/IBD and AIH/IBD patients and between active AIH, incomplete responders and responders. Flow cytometry was performed to further analyze CD45RA+, CD3CD4, CD8, CCR7, CXCR3, CD38 and PD1.Results: In the AIH group, those with active disease demonstrated a significantly higher sPD1 levels in comparison to responders (*p > .001). However, the incomplete responders didn’t show a reduction in sPD1 in comparison to active AIH and patients with IBD alone. Interestingly, patients with PSC showed significantly lower level of sPD1 compared to active AIH (*p < .002), whereas, patients with PSC in conjunction with AIH (*p < .006) or IBD (*p < .02) demonstrated a significant increase in sPD1. In addition, we have observed increased levels of circulating CD4 and CD8 bound PD1 in active AIH but not in PSC or responders suggesting T cells activation. CD4+ PD1 double positive cells demonstrated increased expression of CXCR3. Thus, suggesting the activation of PD1 + T cells is mediating through CXCR3 in Autoimmune hepatitis.Conclusions: Our study demonstrates that sPD1 levels correlate with active disease state of AIH and IBD. sPD1 levels did not correlate with PSC. However, PSC in conjunction with AIH or IBD showed higher levels of sPD1. This suggests that T cell activation plays a critical role in active AIH and IBD but not in PSC. Soluble PDI levels could be used as a clinical biomarker to assess response in patients with AIH and for prospectively monitoring PSC patients for development of IBD or AIH.

Predictive Value of Soluble Programmed Death-1 for Severe Sepsis and Septic Shock During the First Week in an Intensive Care Unit.

Programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) exists in both membrane-bound and soluble forms. In this study, we evaluated the predictive value of soluble PD-1 (sPD-1) for severity and 28-day mortality in patients with severe sepsis and septic shock during the first week in an intensive care unit (ICU). In this prospective cohort study, patients were classified into the severe sepsis group or the septic shock group according to the severity of their condition on ICU admission. All patients were also separated into the survivor or nonsurvivor groups according to their 28-day outcomes. Peripheral blood sPD-1 and soluble PD-L1 (sPD-L1) levels, PD-1 expression on CD4 and CD8 T cells, and PD-L1 expression on monocytes were measured and compared between the groups on days 1 and 7 after ICU admission. In all, 45 healthy volunteers and 112 patients were recruited. Serum sPD-1 levels were positively correlated with the severity of sepsis, sPD-L1 levels, PD-1 expression on CD4 or CD8 T cells, and PD-L1 expression on monocytes. The sPD-1 was an independent predictive factor for 28-day mortality both on day 1 and day 7. The area under the curve (AUC) of the sPD-1 on day 7 (0.871) was higher than that on day 1 (0.785) (P < 0.05), and better than the AUC of the percentages of PD-L1 on monocytes (0.770) on day 7 (P < 0.05). Serum sPD-1 shows valuable predictive ability for the severity and 28-day mortality of severe sepsis and septic shock during the first week of ICU treatment.

Reverse signaling via PD-L1 supports malignant cell growth and survival in classical Hodgkin lymphoma

Treatment with programmed death-1 (PD-1) blocking antibodies results in high overall response rates in refractory and relapsed classical Hodgkin lymphoma (cHL) patients, indicating that PD-1/PD-1 ligand interactions are integral to progression of this disease. Given the genetically driven increased PD-L1/2 expression in HL, we hypothesized that reverse signaling through PD-1 ligands may be a potential mechanism contributing to the growth and survival of Hodgkin Reed–Sternberg (HRS) cells in cHL. Our data show that engagement of PD-L1 using an agonistic monoclonal antibody increases cell survival and proliferation and reduces apoptosis in HL cell lines. We show that HL patients have significantly higher serum levels of soluble PD-1 than healthy controls, and find that both membrane-bound and soluble forms of PD-1 are able to induce PD-L1 reverse signaling in HL cell lines. PD-L1 signaling, which is associated with activation of the MAPK pathway and increased mitochondrial oxygen consumption, is reversed by PD-1 blockade. In summary, our data identify inhibition of reverse signaling through PD-L1 as an additional mechanism that accounts for clinical responses to PD-1 blockade in cHL.

Soluble PD-1 ligands regulate T-cell function in Waldenstrom macroglobulinemia

AbstractAlthough immune checkpoint molecules regulate the progression of certain cancers, their significance in malignant development of Waldenstrom macroglobulinemia (WM), an incurable low-grade B-cell lymphoma, remains unknown. Recently, cytokines in the bone marrow (BM) microenvironment are shown to contribute to the pathobiology of WM. Here, we investigated the impact of cytokines, including interleukin-6 (IL-6) and IL-21, on immune regulation and particularly on the programmed death-1 (PD-1) and its ligands PD-L1 and PD-L2. We showed that IL-21, interferon γ, and IL-6 significantly induced PD-L1 and PD-L2 gene expression in WM cell lines. Increased PD-L1 and PD-L2 messenger RNA was also detected in patients' BM cells. Patients' nonmalignant BM cells, including T cells and monocytes, showed increased PD-L1, but minimal or undetectable PD-L2 surface expression. There was also very modest PD-L1 and PD-L2 surface expression by malignant WM cells, suggesting that ligands are cleaved from the cell surface. Levels of soluble ligands were higher in patients' BM plasma and blood serum than controls. Furthermore, IL-21 and IL-6 increased secreted PD-L1 in the culture media of WM cell lines, implying that elevated levels of soluble PD-1 ligands are cytokine mediated. Soluble PD-1 ligands reduced T-cell proliferation, phosphorylated extracellular signal-regulated kinase and cyclin A levels, mitochondrial adenosine triphosphate production, and spare respiratory capacity. In conclusion, we identify that soluble PD-1 ligands are elevated in WM patients and, in addition to surface-bound ligands in WM BM, could regulate T-cell function. Given the capability of secreted forms to be bioactive at distant sites, soluble PD-1 ligands have the potential to promote disease progression in WM.

Analysis of circulating soluble programmed death 1 (PD-1), neuropilin 1 (NRP-1) and human leukocyte antigen-G (HLA-G) in psoriatic patients.

IntroductionCirculating soluble programmed death 1 (PD-1), neuropilin 1 (NRP-1) and human leukocyte antigen-G (HLA-G) take part in modulating immune tolerance causing disturbances in the molecular mechanisms responsible for maintenance of balance between effector and regulatory components of the immune system. Since their cell-surface expression levels were found to be changed in lesional and/or non-lesional skin of psoriatic patients, analysis of soluble PD-1, NRP-1 and HLA-G concentrations sheds more light on their role in detecting unbalanced immune tolerance in psoriasis.AimTo assess soluble PD-1, NRP-1 and HLA-G concentrations in psoriasis.Material and methodsThe study included 57 psoriatic patients and 29 controls. Duration of psoriasis was in the range 1 to 55 years; the median was 19 years. The plasma concentrations of soluble HLA-G (sHLA-G), soluble NRP-1 (sNRP-1) and soluble PD-1 (sPD-1) were examined using the ELISA method. Severity of the skin lesions was assessed by means of Psoriasis Area Severity Index (PASI), body surface area (BSA) and Physician Global Assessment (PGA).ResultsPsoriasis Area Severity Index in the studied group was in the range 3 to 43; the median was 12. Body surface area was in the range 2–75%; the median was 15%. The median value of PGA was 3. Soluble NRP concentration was significantly higher in the psoriatic patients (median: 1.59 pg/ml; range: 0.67–2.62 pg/ml) than in the control group (median: 1.35 pg/ml; range: 0.05–2.61 pg/ml) (p = 0.010). Soluble PD-1 and sHLA-G concentrations were not significantly different between the studied and control groups (p = 0.094 and p = 0.482, respectively).ConclusionsIncreased concentrations of sNRP-1 and unchanged values of sHLA-G and sPD-1 concentrations may be indicative of impaired immune tolerance mechanisms in psoriasis.

WITHDRAWN: Immune imbalance of PD-1 and 1 PD-Ls in liver tissues from patients with Hepatitis B-related hepatocellular carcinoma

// Yong Liu 1,2 , Guiyang Wang 3 , Rui Huang 3 , Yingying Hao 4 , Haiyan Chang 3 , Chen Tian 3 , Yang Li 3 , Xiang-An Zhao 3 , Juan Xia 3 , Yuxin Chen 3,5 and Chao Wu 3 1 Department of Experimental Medicine, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, China 2 Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, China 3 Department of Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, China 4 Department of Intensive Care Units, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, China 5 Department of Laboratory Medicine, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, China Correspondence to: Chao Wu, email: dr.wu@nju.edu.cn Yuxin Chen, email: yuxin_chen2015@163.com Keywords : PD-1; PD-L1; PD-L2; microenvironment; hepatitis B-related hepatocellular carcinoma Received: October 27, 2017&nbsp;&nbsp;&nbsp;&nbsp; Accepted: December 05, 2017&nbsp;&nbsp;&nbsp;&nbsp; Epub: January 12, 2018 Abstract 2 Dysregulated immune microenvironment, such as imbalance of programmed death-1 (PD-1) and its ligands (PD-Ls), plays a key role in hepatocarcinogenesis. Here we investigate the key immune checkpoint molecules, PD-1/PD-Ls, in liver tissues from patients with hepatitis B virus-related hepatocellular carcinoma (HBV-related HCC). We show that the characteristic of T cells in peripheral blood does not fully reflect the changes of immune microenvironment in tumor tissues. There is an imbalanced immune microenvironment in liver tissues, characterized by increased CD4/CD8 ratio and high expression of PD-1 on CD8 T cells in tumor tissues. Soluble PD-1 (sPD-1) levels in tumor tissues are increased, whereas sPD-L1 and sPD-L2 levels are decreased. Compared with control subjects, the patients with HBV-related HCC have higher serum sPD-1 and sPD-L1 levels, lower serum sPD-L2 levels. We also show that the altered immune microenvironment is not only found in tumor tissues, but also in non-tumor tissues from HBV-related HCC patients. The correlation between PD-1 and PD-L1 increases successively in hepatocellular carcinomas tissues, paracancerous tissues and adjacent non-tumor tissues. In tumor tissues, sPD-1 levels are negatively correlated with clinicopathological stages of HCC, while serum sPD-L1 levels have positive correlation with the clinicopathological stages. Combined, HBV infection alone may not affect the characteristics of T cell subpopulations, but might be related with the higher PD-1 levels in liver tissues. The immune imbalance of PD-1/PD-Ls in liver tissues may have important role in tumor microenvironment and immune escape, closely related with tumor initiation and progression.

Co-inhibitory receptors in female asthmatic patients: Correlation with IL-17 and IL-26

Background: Asthma is an immunological disorder in which T helper 2 (Th2)-type cells and inflammatory cytokines have a prominent role in its pathogenesis. B- and T-lymphocyte attenuator (BTLA), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed death 1 (PD-1) are co-inhibitory receptors that regulate T cell activation. Objective: In the present study of asthmatic patients we measured the soluble isoforms of BTLA (sBTLA), CTLA-4 (sCTLA-4) and PD-1 (sPD-1) in induced sputum fluid with the aim to evaluate their utility as responsible for exacerbation. Methods: Eighty patients with asthma and 30 healthy controls (HC) were included in the study. Sputum fluid concentrations of sBTLA, sCTLA-4 and sPD-1 were measured with ELISA. Comparisons were made with Mann-Whitney U test and correlations with IL-17, IL-26 levels and FEV1 (%) were assessed with Spearman’s Rank correlation test. Results: sBTLA levels were significantly higher in the severe and moderate asthmatic patients compared to healthy controls. Significant differences were observed between severe and moderate asthmatics (p < 0.0001). No significant differences were found between mild asthmatics and healthy controls (p = 0.799). Soluble PD-1 levels were higher in severe and moderate asthmatic patients compared to HC and no significant difference was observed between these two asthmatic groups (p = 0.124). Mild asthmatics and control subjects expressed similar sPD-1 levels (p = 0.856). Soluble CTLA-4 was exclusively expressed in certain severe asthmatic patients. IL-17 inflammatory cytokine was significantly correlated with BTLA and sPD-1. IL-17 and IL-26 cytokines were highly expressed in sputum asthmatic groups compared to sputum from HC. Severe asthmatic group was characterized by the highest levels of both IL-17 and IL-26 mediators. Soluble BTLA correlates positively with IL-17 (r = 0.817; p < 0.0001) and IL-26 (r = 0.805; p < 0.0001) inflammatory cytokines. IL-17 and IL-26 levels were associated with the asthma clinical severity from severe to mild asthma (p < 0.0001). The inflammatory cytokines IL-17 and IL-26 were positively correlated with the percentages of macrophages, PNN and FEV1 (%). Conclusion: Here, we provide the first report on the increased expression of sBTLA and sPD-1 in induced sputum of severe asthmatics. IL-26 and IL-17 appeared as a novel proinflammatory axis. Both sBTLA and sPD-1 might be involved in the pathogenesis of asthma and were associated with a poor prognosis.

Expression and clinical significance of programmed death-1 on lymphocytes and programmed death ligand-1 on monocytes in the peripheral blood of patients with cervical cancer.

The programmed death-1 (PD-1) signaling pathway serves a critical role in immune regulation and tolerance by suppressing the activation and proliferation of T cells. The aim of the present study was to investigate the effect of PD-1 and programmed death-ligand 1 (PD-L1) on the development of cervical carcinoma and cervical intraepithelial neoplasia (CIN). A total of 40 healthy controls (HC), 40 patients with CIN and 66 newly diagnosed cervical cancer patients were recruited. The expression level of PD-1 expression on peripheral cluster of differentiation (CD)4+ and CD8+ T cells and PD-L1 on monocytes was analyzed by flow cytometry. The expression level of soluble PD-L1 in serum was determined by an ELISA. The results of the present study demonstrated that the PD-1 expression level on CD4+ and CD8+ T cells was significantly increased in CIN and cervical cancer, compared with that in HC. In addition, the PD-1 expression level on CD4+ and CD8+ T cells was increased in cervical cancer, compared with that in CIN. However, the expression level of PDL-1 on CD14+ monocytes was increased in cancer and CIN, but limited in cancer and CIN. In addition, PD-1 expression on CD4+ T cells was positively associated with PD-1 expression on CD8+ T cells in cervical cancer (P<0.05). Further analyses revealed that the proportion of PD-1 on CD4+ and CD8+ T cells were positively associated with tumor stages. However, no difference in the degree of soluble PD-1 among cancer, CIN and HC cells was revealed. The results suggested that the PD-1 signaling pathway is involved in the development of CIN and cervical cancer.

Soluble PD-1 and PD-L1: predictive and prognostic significance in cancer.

The membrane-bound molecules programmed death 1 (PD-1) and its ligand PD-L1 (PD-1/PD-L1) belong to the immune checkpoint pathway. PD-1 pathway downregulates effector T cells in immune response, thereby causing immune suppression. Recent studies have revealed that membrane-bound PD-1 and PD-L1 also have soluble forms. These soluble forms increase the complexity and diversity of the composition and function of the PD-1/PD-L1 signaling pathway. However, the exact roles of these molecules remain unknown. The objective of this systematic review was to elucidate the biological significance of soluble PD-1/PD-L1 in human cancers and evaluate whether they are potential diagnostic, therapeutic, or prognostic biomarkers. We expect to provide new clues for future research on soluble PD-1/PD-L1 pathway in human malignant tumors.

Circulating soluble programmed death-1 levels may differentiate immune-tolerant phase from other phases and hepatocellular carcinoma from other clinical diseases in chronic hepatitis B virus infection.

Programmed death-1 (PD-1) is involved in the immune dysfunction of hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC). This study analyzed the association of circulating soluble PD-1 (sPD-1) levels with the phases and clinical diseases in chronic HBV infection. Serum sPD-1 levels were determined by enzyme linked immunosorbent assay in patients with different phases and liver diseases of chronic HBV infection. The sPD-1 levels in patients with chronic HBV infection were significantly elevated compared with HBV infection resolvers or healthy controls. According to phases, sPD-1 level in immune-tolerant phase (IT) was significantly lower than in other phases. Multivariate analysis showed that sPD-1 was an independent factor associated with IT. Area under the receiver operating characteristic (ROC) curves (AUC) showed that sPD-1 was significantly discriminative of IT from other phases with a cut-off of 1.535 ng/mL (AUC, 0.984; P<0.001). According to clinical diseases, sPD-1 level in HBV-related HCC was significantly higher than in other clinical diseases. Multivariate analysis showed that sPD-1 was an independent factor associated with HCC. The sPD-1 was significantly discriminative of HCC from other clinical diseases with a cut-off of 6.058 ng/mL (AUC, 0.962; P<0.001). The sPD-1 levels were significantly associated with HCC patients’ overall survival. HCC resection resulted in remarkable reduction in sPD-1 levels. These results demonstrate the involvement of sPD-1 in the disease course of chronic HBV infection and indicate the potential to apply sPD-1 as a biomarker for differentiating IT from other phases and HCC from other disease conditions in chronic HBV infection.

Soluble B and T Lymphocyte Attenuator Correlates to Disease Severity in Sepsis and High Levels Are Associated with an Increased Risk of Mortality.

Introduction and aimsB- and T-lymphocyte Attenuator (BTLA), Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and Programmed Death 1 (PD-1) are co-inhibitory receptors that regulate T cell activation. In the present study of ICU-treated patients we measured plasma concentrations of their soluble isoforms, with the aim to evaluate their potential as sepsis biomarkers and utility as prognostic indicators.Methods101 patients with sepsis, 28 patients with non-infectious critical illness (ICU controls) and 31 blood donors (healthy controls, HC) were included in the study. Plasma concentrations of soluble BTLA (sBTLA), CTLA-4 (sCTLA-4) and PD-1 (sPD-1) were measured with ELISA in serial blood samples. Comparisons were made with Mann-Whitney U test and correlations were assessed with Spearman’s Rank correlation test. Cox proportional hazard models, with sBTLA and sPD-1 as fixed and sBTLA as time-varying covariates, were used to determine association with 28-day mortality.ResultssBTLA levels were significantly higher in the sepsis cohort (median 14 ng/mL, IQR 8–29) compared to ICU controls (9 ng/mL, IQR 5–26, p = 0.048) and HC (2.9 ng/mL, IQR 0.9–9.1, p<0.01), and correlated to SOFA score. sBTLA levels were higher in 28 day sepsis non-survivors than in survivors (baseline median 28 ng/mL, IQR 13–41 vs 13 ng/mL, IQR 8–23, p = 0.04). After adjustment for age and comorbidities, the relative risk of 28 day mortality was nearly 5-fold higher in sepsis patients with a baseline sBTLA > 21 ng/mL, compared to those with a level below this threshold. sBTLA was even more associated with mortality in the time-varying analysis. sPD-1 levels were lower in the sepsis cohort compared to HC but not compared to ICU controls and were not associated with mortality. sCTLA-4 was detectable in only one subject.ConclusionPlasma concentrations of soluble BTLA were increased early in sepsis/septic shock and correlated to severity of disease. A baseline concentration >21ng/mL was associated with a poor prognosis.

Soluble programmed death-1 levels are associated with disease activity and treatment response in patients with autoimmune hepatitis

Purpose: Autoimmune hepatitis (AIH) is a chronic liver disease caused by impaired immune regulation. Programmed death-1 (PD-1) is an inhibitory receptor mainly expressed by T cells and with its ligands, PD-L1 and PD-L2 present on antigen-presenting cells. We hypothesised the PD-1 axis to be impaired in AIH and investigated systemic levels of soluble(s) PD-1 and T cells ability to up-regulate PD-1 following in vitro activation in AIH patients.Materials and methods: We included 67 AIH patients; 9 with active disease, 31 responders and 27 incomplete-responders to standard therapy. Forty-seven healthy controls (HC) were included for comparison. Soluble PD-1 was measured by enzyme-linked immunosorbent assay. The PD-1 expression on T cells was measured using flow cytometry before and after 48-h stimulation in vitro with CD3/CD28 in 13 AIH patients and 10 HC.Results: Soluble PD-1 was significantly elevated in AIH patients with active disease [0.24 ng/mL (range 0.16–0.28)] and in incomplete responders to standard therapy [0.17 (0.11–0.22)] compared with responders [0.11 (0.08–0.16), p = .008 and p = .01, respectively] and HC [0.12 (0.05–0.16), p = .02, both]. Following in vitro activation, PD-1 was significantly up-regulated (3.3-fold) on CD4+ T cells from AIH patients compared with HC (1.5-fold) (p = .0006).Conclusions: AIH patients with active disease and incomplete response to standard treatment have similarly increased sPD-1 levels. Further, AIH patients have increased ability to up-regulate PD-1 following in vitro activation. Together these data suggests an impaired PD-1 axis in AIH.