Project description:Malignant tumor cells are equipped with mechanisms that can help them escape the surveillance by host immune system. Immune checkpoint molecules can transduce coinhibitory signals to immunocompetent cells and exert immunosuppressive roles in antitumor immunity. Programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) are the two important checkpoint molecules with great potential in targeted cancer therapy. Several antibodies targeting PD-1 and PD-L1 have been approved for clinical use. In this review, we focus on the recent development of targeting PD-1 and PD-L1 in gastric cancer (GC) therapy.
Project description:Programmed cell death-1 (PD-1) and programmed cell death-ligand 1 (PD-L1) have been identified as novel targets of immunotherapy of lung cancer. In present study, we evaluated the metabolic characteristics of lung cancer by using 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (18 F-FDG PET/CT) with regard to PD-L1 protein expression. PD-L1 protein expression was evaluated by immunohistochemistry with the antibody clone SP142 in 579 surgically resected primary lung cancer patients. Cases with less than 5% tumor membrane staining were considered negative. We examined the association between the frequency of PD-L1 protein expression and the maximum standardized uptake value (SUVmax) in preoperative 18 F-FDG PET/CT. The cut-off values for SUVmax were determined by receiver operating characteristic curve analyses. The SUVmax was significantly higher in nonsmall cell lung cancer (NSCLC) patients with PD-L1 protein expression compared with those without PD-L1 protein expression (P < 0.0001). However, there was no correlation between SUVmax and PD-L1 protein expression in patients with neuroendocrine tumors (P = 0.6545). Multivariate analysis revealed that smoking, the presence of pleural invasion, and high SUVmax were independent predictors of PD-L1 positivity. PD-L1-expressing NSCLC had a high glucose metabolism. The SUVmax in preoperative 18 F-FDG PET/CT was a predictor of PD-L1 protein expression in patients with NSCLC.
Project description:The aim of the present study was to evaluate programmed death-1 (PD-1) and programmed death-1 ligand-1 (PD-L1) expression in gastric carcinoma and to assess their effect on survival rate. A total of 170 surgically resected specimens were obtained from patients diagnosed with gastric carcinoma at St. Vincents Hospital, The Catholic University of Korea. Paraffin tissue sections from tissue microarray blocks were subjected to immunohistochemical analysis of PD-1 and PD-L1. In addition, PD-1 expression on CD4+ and CD8+ T cells isolated from peripheral blood mononuclear cells and gastric cancer tissues was evaluated by multicolor flow cytometry. PD-1 and PD-L1 were expressed in 30.0 and 60.5% of the gastric cancer tissues, respectively. The expression of PD-L1 was higher in patients with advanced T (P=0.035) and Tumor, Node and Metastasis stage (P=0.05). The patients with positive PD-L1 expression had shorter disease-free survival time than those without PD-L1 expression (P=0.005). Additionally, PD-L1 expression was significantly associated with poor prognosis (P=0.015). PD-1 and PD-L1 expression levels were significantly higher on CD8+ T cells than on CD4+ T cells (P<0.001). The data of the present study suggested that PD-L1 expression may be an independent indicator of poor prognosis in patients with gastric cancer. Furthermore, PD-L1 expression may play a role in immune evasion of gastric cancer.
Project description:Introduction: Inhibitors of programmed cell death 1 (PD1) and its ligand (PDL1) have exhibited favorable long-term survival in many types of advanced-stage cancer and current approvals have to date been granted in certain tumour types irrespective of PD-L1 status. Methods: We extracted the following information: study sample size, trial period, cancer types, intervention of treatment, type of PD-L1 antibody, immunohistochemistry (IHC) scoring method, number and percentage of PD-L1 < 1% population, and median follow- up time. PD-L1 expression was defined as percentage of number of PD-L1-stained tumor cells (TPS), area of tumor infiltrated by PD-L1-stained immune cells (IPS), number of PD-L1-stained cells (tumor cells, lymphocytes and macrophages; CPS). Different trials used distinct method to define low PD-L1 expression. The risk of bias of the included trials was assessed by using the Cochrane risk of bias tool for RCTs. Results: Here, a total of 34 trials were included to extract individual patient data (IPD) to evaluate the survival benefit of first line PD1/PDL1 inhibitors vs. standard-of-care (SOC) in patients with PDL1 < 1%. In term of anti-PD-1/PD-L1 monotherapy, OS (HR = 0.90, 0.81-1.01) and PFS (HR = 1.11, 0.97-1.27) between PD-1/PD-L1 inhibitor group and SOC group were comparable. In term of anti-PD-1/PD-L1 combination therapy, PD-1/PD-L1 inhibitor group exhibited longer OS (median 19.5 months vs. 16.3 months; HR = 0.83, 0.79-0.88, p < 0.001) and PFS than those of SOC group (median 8.11 months vs. 6.96 months; HR = 0.82, 0.77-0.87, p < 0.001).Subgroup analysis showed that survival benefit was mainly observed in non-small cell lung cancer (NSCLC) (HROS = 0.74; HRPFS = 0.69; p < 0.001), small-cell lung cancer (SCLC) (HROS = 0.58, p < 0.001; HRPFS = 0.55, p = 0.030), esophageal squamous cell carcinoma (ESCC) (HROS = 0.62, p = 0.005; HRPFS = 0.79, p < 0.001), melanoma (HROS = 0.53, p < 0.001) and nasopharyngeal carcinoma (NPC) (HRPFS = 0.35, p = 0.013). Conclusion: Anti-PD-1/PD-L1 combinational therapy rather than monotherapy exhibit survival benefit in the low PD-L1 population in the first-line setting, and the survival benefit was mainly observed in specific tumor types.
Project description:After two decades of unchanged paradigms, the treatment strategies for advanced urothelial bladder cancer have been revolutionized by emerging programmed death ligand-1 (PD-L1)/programmed death-1 (PD1) inhibition therapy. Increased evidence is demonstrating the efficacy of PD-L1/PD1 inhibition therapy in both second-line and first-line settings. However, the percentage of patients who benefit from anti-PD-L1/anti-PD1 therapy is still low. Many questions have been raised in the development of biomarker-driven approaches for disease classification and patient selection. In this perspective, we discuss PD-L1/PD1 expression in urothelial bladder carcinoma, review approved anti-PD-L1/anti-PD1 agents for bladder cancer treatment and current ongoing studies investigating combination treatment strategies, and explore PD-L1 expression status for the evaluation of bladder cancer immunotherapy.
Project description:In order to explore the potential of immune checkpoint blockade in sarcoma, we investigated expression and clinical relevance of programmed cell death-1 (PD-1), programmed death ligand-1 (PD-L1) and CD8 in tumors of 208 sarcoma patients. Primary untreated osteosarcoma (n = 46), Ewing sarcoma (n = 32), alveolar rhabdomyosarcoma (n = 20), embryonal rhabdomyosarcoma (n = 77), synovial sarcoma (n = 22) and desmoplastic small round cell tumors (DSRCT) (n = 11) were examined immunohistochemically. PD-L1 expression was predominantly detected in alveolar and embryonal rhabdomyosarcomas (15% and 16%, respectively). In the alveolar subtype PD-L1 expression was associated with better overall, event-free and metastases-free survival. PD-1 expression on lymphocytes was predominantly seen in synovial sarcomas (18%). High levels of CD8+ lymphocytes were predominantly detected in osteosarcomas (35%) and associated with worse event-free survival in synovial sarcomas. Ewing sarcoma and DSRCTs showed PD-1 on tumor cells instead of on tumor infiltrating lymphocytes. Overall, expression and clinical associations were found to be subtype dependent. For the first time PD-1 expression on Ewing sarcoma (19%) and DSRCT (82%) tumor cells was described.
Project description:IntroductionChronic infections lead to the functional exhaustion of T cells. Exhausted T cells are phenotypically differentiated by the surface expression of the immunoinhibitory receptor, such as programmed death-1 (PD-1). The inhibitory signal is produced by the interaction between PD-1 and its PD-ligand 1 (PD-L1) and impairs the effector functions of T cells. However, the expression dynamics of PD-L1 and the immunological functions of the PD-1/PD-L1 pathway in chronic diseases of pigs are still poorly understood. In this study, we first analyzed the expression of PD-L1 in various chronic infections in pigs, and then evaluated the immune activation by the blocking assay targeting the swine PD-1/PD-L1 pathway.MethodsIn the initial experiments, anti-bovine PD-L1 monoclonal antibodies (mAbs) were tested for cross-reactivity with swine PD-L1. Subsequently, immunohistochemical analysis was conducted using the anti-PD-L1 mAb. Finally, we assessed the immune activation of swine peripheral blood mononuclear cells (PBMCs) by the blockade with anti-PD-L1 mAb.ResultsSeveral anti-PD-L1 mAbs tested recognized swine PD-L1-expressing cells. The binding of swine PD-L1 protein to swine PD-1 was inhibited by some of these cross-reactive mAbs. In addition, immunohistochemical analysis revealed that PD-L1 was expressed at the site of infection in chronic infections of pigs. The PD-L1 blockade increased the production of interleukin-2 from swine PBMCs.ConclusionsThese findings suggest that the PD-1/PD-L1 pathway could be also involved in immunosuppression in chronic infections in pigs. This study provides a new perspective on therapeutic strategies for chronic diseases in pigs by targeting immunosuppressive pathways.
Project description:BackgroundThe predictive significance of programmed death ligand 1 (PD-L1) for programmed death 1 (PD-1) inhibitors remains unclear in gastric cancer (GC) due to the dynamic alteration by treatments. We aimed to elucidate the effects of trastuzumab (Tmab) on PD-L1 expression in GC.MethodsPD-L1 expression was evaluated by multicolour flow cytometry analysis after co-culturing GG cell lines and immune cells with Tmab. IFN-γ in the co-culture experiments was quantified. Immunohistochemistry (IHC) for PD-L1 expression using clinical samples was also performed to confirm PD-L1 alteration by Tmab.ResultsPD-L1 expression was significantly upregulated by Tmab in HER2-amplified GC cell lines co-cultured with peripheral blood mononuclear cells (PBMCs). PD-L1 upregulation by Tmab was also observed in the GC cells co-cultured with NK cells in time-dependent manner, but not with monocytes. IFN-γ concentration in conditioned media from co-cultured PBMCs and NK cells with Tmab was significantly higher and anti-IFN-γ significantly suppress the Tmab-induced PD-L1 upregulation. IHC also suggested PD-L1 upregulation after Tmab treatment.ConclusionsTmab can upregulate PD-L1 expression on GC cells through interaction with NK cells. These results suggest clinical implications in the assessment of the predictive significance of PD-L1 expression for PD-1 inhibitors.
Project description:Evidence suggests that programmed death receptor-1/programmed death ligand-1 (PD-1/PD-L1) targeted inhibitors act as an immune checkpoint blockade, indicating that these compounds may be useful in cancer immunotherapy by inhibiting the immune response between T-cells and tumors. Previous studies have shown that ginsenosides can regulate the expression of PD-1 and PD-L1 in target diseases; however, it remains unknown whether ginsenosides act as a blockade of PD-1/PD-L1 interactions. In this study, we used competitive ELISA to investigate 12 ginsenosides for their ability to block PD-1/PD-L1 interactions. In addition, we performed a protein-ligand docking simulation and examined the hydrophobic interactions and hydrogen bonds formed at the interfaces between the ginsenosides and PD-L1/PD-1. Eight out of the 12 ginsenosides studied showed inhibition of PD-1/PD-L1 interactions at 35% at the maximum concentration (1 μM). Among them, Rg3 and Compound K (C-K) demonstrated the highest inhibitory effects. Rg3 and C-K were further identified for their interaction efficacy with PD-1/PD-L1, which supported our results demonstrating the blocking activity of these compounds against PD-1/PD-L1 binding interactions. Collectively, our findings suggest that some ginsenosides, including Rg3 and C-K, inhibit PD-1/PD-L1 binding interactions. Therefore, these compounds may prove useful as part of an overall immuno-oncological strategy.
Project description:BackgroundThe role of checkpoint axes in transplantation has been partially addressed in animal models but not in humans. Occurrence of fulminant myocarditis with allorejection-like immunologic features in patients under anti-PD1 (programmed death cell protein 1) treatment suggests a key role of the PD1/PD-L1 (programmed death ligand 1) axis in cardiac immune homeostasis.MethodsWe cross-sectionally studied 23 heart transplant patients undergoing surveillance endomyocardial biopsy. Endomyocardial tissue and peripheral blood mononuclear cells were analyzed by flow cytometry. Multivariate logistic regression analyses including demographic, clinical, and hemodynamic parameters were performed. Murine models were used to evaluate the impact of PD-L1 endothelial graft expression in allorejection.ResultsWe found that myeloid cells dominate the composition of the graft leukocyte compartment in most patients, with variable T-cell frequencies. The CD (cluster of differentiation) 4:CD8 T-cell ratios were between 0 and 1.5. The proportion of PD-L1 expressing cells in graft endothelial cells, fibroblasts, and myeloid leukocytes ranged from negligible up to 60%. We found a significant inverse logarithmic correlation between the proportion of PD-L1+HLA (human leukocyte antigen)-DR+ endothelial cells and CD8+ T cells (slope, -18.3 [95% CI, -35.3 to -1.3]; P=0.030). PD-L1 expression and leukocyte patterns were independent of demographic, clinical, and hemodynamic parameters. We confirmed the importance of endothelial PD-L1 expression in a murine allogeneic heart transplantation model, in which Tie2Crepdl1fl/fl grafts lacking PD-L1 in endothelial cells were rejected significantly faster than controls.ConclusionsLoss of graft endothelial PD-L1 expression may play a role in regulating CD8+ T-cell infiltration in human heart transplantation. Murine model results suggest that loss of graft endothelial PD-L1 may facilitate alloresponses and rejection.