PD-L1表达调控与肿瘤免疫治疗的研究进展

程序性细胞死亡蛋白1(programmed cell death protein 1,PD-1)/程序性死亡配体1(programmed death-ligand 1,PD-L1)是导致肿瘤免疫逃逸的重要免疫检查点分子,阻断PD-1/PD-L1可以重新激活细胞毒性T细胞对肿瘤的杀伤作用,是一种重要的肿瘤免疫治疗方式。肿...     

膀胱尿路上皮癌中PD-L1和PD-L2的表达及临床意义

目的 探讨膀胱尿路上皮癌(urothelial bladder cancer,UBC)中程序性死亡配体-1(programmed death-ligand 1,PD-L1)以及程序性死亡配体-2(programmed death-ligand 2,PD-L2)的表达及临床意义.方法 采用免疫组化法检测58例UBC组织中...     

舒尼替尼抑制小鼠骨髓来源树突状细胞表面PD-L1和PD-L2的表达

目的观察小鼠髓源性树突状细胞(DC)在舒尼替尼刺激下,其表面程序性死亡分子1配体1(PD-L1)和PD-L2的表达变化。方法取小鼠骨髓细胞,对照组加入二甲基亚砜,实验组分别加入(100、200、300)ng/m L舒尼替尼,刺激48 h,用流式细胞术检测DC表面PD-L1和PD-L2的表达水平。结果与对照组相比,实验组中成熟DC(m DC)和总DC(包括m DC和im DC)表面PD-L1的表达水平显著降低;表达PD-L1的未成熟DC(im DC)、m DC和DC百分比均显著降低,表达PD-L2的m DC百分比显著降低;表达PD-L2的DC百分比在100 ng/m L、300 ng/m L舒尼替尼组中显著降低。结论舒尼替尼可显著降低小鼠DC表面PD-L1、PD-L2的表达。     

PD-1/PD-L1在骨肉瘤中的研究进展

PD-1是一种主要表达于活化的CD4+T细胞、CD8+T细胞、B细胞、NK细胞、单核细胞和DC等免疫细胞上的跨膜蛋白.PD-1及其配体PD-L1是一对共刺激分子,在正常情况下,这对分子活化后的信号通路可调节外周组织中T细胞的分化,进而调控机体对外来或自身抗原的免疫应答反应,以防免疫过激情况的发生.但在肿瘤发生时,肿瘤细...     

PD-1和PD-L1在脓毒症免疫反应中的研究进展

脓毒症是当前重症监护病房患者的主要死亡原因,同时其幸存者也会出现长期的免疫抑制和高复发感染。目前对脓毒症的临床治疗还是以抗生素、静脉补液和血管加压为主,尚无针对性的药物治疗。但随着抗生素耐药率不断升高,免疫治疗作为一种新的治疗方式备受期待。脓毒症患者多伴有急性白细胞免疫功能异常障碍和免疫抑制,这可能是患者发病率和死亡率不断增加的重要危险因素。靶向抑制特定细胞表面抑制性免疫检查点受体和配体,如程序性死亡受体-1(PD-1)、程序性死亡-配体1(PD-L1)等靶点能够提高宿主对感染的抵抗力。主要对PD-1和PD-L1在脓毒症免疫反应中的作用及相关机制的研究进展进行总结,为其在脓毒症治疗中的进一步应用提供理论依据。     

PD-1/PD-L1在复发性流产患者外周血T淋巴细胞中的表达及意义

目的:探究程序性死亡因子1(PD-1)/程序性死亡因子配体1(PD-L1)在复发性流产患者外周血T淋巴细胞中的表达及意义。方法:选取2015年7月至2017年2月本院收治的复发性流产患者57例为观察组,另选取42例正常妊娠妇女为对照组,采用流式细胞仪检测两组PD-1/PD-L1在外周血T淋巴细胞表达水平。并对患者实施淋巴细胞免疫治疗,检测治疗过程中PD-1/PD-L1水平变化情况及妊娠结局。结果:观察组CD3⁺、CD8⁺显著低于对照组,CD4⁺、CD4⁺/CD8⁺显著高于对照组(P<0.05);观察组PD-1/CD4⁺、PD-1/CD8⁺、PD-L1/CD4⁺、PD-L1/CD8⁺显著低于对照组(P<0.05);患者治疗后4周、治疗后8周PD-1/CD4⁺、PD-1/CD8⁺、PD-L1/CD4⁺、PD-L1/CD...     

PD-1/PD-L1信号通路与肿瘤免疫逃逸

PD-1及其配体PD-L1、PD-L2广泛表达于多种细胞表面,是一组与免疫负调控有关的共刺激分子。PD-1/PD-L1信号通路的激活有利于肿瘤逃脱机体免疫监视,但具体的肿瘤免疫逃逸机制尚未清楚。就抗PD-1和抗PD-L1抗体疗效而言,仍然需要对肿瘤免疫逃逸机制做更深入的研究。文章就现有研究成果作一综述如下。     

PD-1/PD-L1对脓毒症患者免疫细胞影响的研究进展

脓毒症在世界各地的发病率及死亡率都逐年上升。研究认为,在脓毒症免疫抑制阶段,PD-1能够与PD-L1结合引起免疫细胞增殖、活化及分泌等功能抑制,发挥负性免疫调节作用,导致患者死亡风险增加。文章就脓毒症发生发展过程中,围绕PD-1与PD-L1结合后引起中性粒细胞、NK细胞、T细胞及B细胞等免疫细胞功能抑制的机制进行整理,并对目前抗PD-1/PD-L1抗体治疗脓毒症的研究进展进行简要综述。     

弥漫大B细胞淋巴瘤中PD-1、PD-L1的表达

目的探讨弥漫大B细胞淋巴瘤(diffuse large B-cell lymphoma,DLBCL)中程序性死亡受体-1(programmed death-1,PD-1)及程序性死亡配体-1(programmed death-ligand 1,PD-L1)的表达及临床意义。方法采用免疫组化法检测184例DLBCL组织中PD-1、PD-L1的表达,分析两者表达与DLBCL临床病理特征的关系。结果 184例DLBCL中肿瘤细胞PD-1、PD-L1阳性率分别为1. 63%、43. 48%;微环境细胞PD-1、PD-L1阳性率分别为11. 41%、26. 09%。肿瘤细胞及微环境细胞PD-1的表达与患者性别、年龄、Hans分型、CD5、EBER、ALK以及CD30的表达差异均无显著性(P均 0. 05)。非生发中心B细胞样(nongerminal center B-cell-like,non-GCB)型DLBCL肿瘤细胞(47. 55%)及微环境细胞(31. 47%)中PD-L1的阳性率高于生发中心B细胞样(germinal center B-cell-like,GCB)型DLBCL肿瘤细胞(29. 27%)及微环境细胞(7. 32%)(P均0. 05); EBV+DLBCL肿瘤细胞(75. 00%)及微环境细胞(58. 33%)中PD-L1的阳性率高于EBV-DLBCL肿瘤细胞(40. 74%)及微环境细胞(24. 07%)(P均0. 05); CD30+DLBCL(66. 67%)微环境细胞中PD-L1的阳性率高于CD30-DLBCL微环境细胞(27. 00%)(P=0. 005)。结论 PD-L1在non-GCB型以及EBV+DLBCL肿瘤细胞及微环境细胞中有更高的阳性率;且PD-L1在CD30+DLBCL微环境细胞中有更高的阳性率。     

程序性死亡蛋白配体-1/程序性死亡蛋白-1在老年胃癌患者外周血CD8+T淋巴细胞中的表达及临床意义

目的 通过分析程序性死亡蛋白配体-1/程序性死亡蛋白-1(programmed death ligand-1/programmed death-1,PD-L1/PD-1)在老年胃癌患者外周血CD8+T淋巴细胞中表达情况,探讨其临床意义.方法 选择同一时期90例老年胃癌患者(具有不同临床分期)及90例老年健康体检者,分别采取新鲜外周血后经流式细胞仪检测血中CD8+T淋巴细胞表面PD-L1/PD-1表达情况,结合老年胃癌患者的临床分期,分析PD-L1/PD-1在不同胃癌分期中的表达意义.结果 PD-L1/PD-1在老年胃癌患者外周血CD8+T淋巴细胞呈高表达,相较于老年健康者差异具有统计学意义(t=7.043,P<0.05);外周血CD8+T淋巴细胞的PD-L1/PD-1阳性表达均随着临床分期的增加而增加,呈明显的正相关性(r=0.883,P<0.05);外周血CD8+T淋巴细胞的PD-1阳性表达随着临床分期的增加而增加,两者之间呈正相关性(r=0.811,P<0.05);临床分期较晚的老年胃癌患者外周血CD8+T淋巴细胞PD-L1/PD-1表达比其他相对较早的临床分期老年胃癌患者显著上升(t=4.377,P<0.05).结论 PD-L1/PD-1信号通路异常在老年胃癌患者病变的发生发展过程中发挥了重要作用,外周血CD8+T淋巴细胞PD-L1/PD-1的表达对评判患者的预后具有指导作用.     

Expression of programmed cell death 1/programmed cell death ligand 1 in the tumor microenvironments of primary gastrointestinal diffuse large B cell lymphomas

Background

Gastrointestinal diffuse large B cell lymphoma (GI DLBCL) is the most common gastrointestinal lymphoma. However, there has not been a comprehensive investigation into the expression patterns of programmed cell death 1 (PD-1) and programmed cell death ligand 1(PD-L1) in GI DLBCL tissues.

High PD-L1 expression in gastric cancer (GC) patients and correlation with molecular features

BackgroundThe programmed death receptor ligand 1 (PD-L1) immunohistochemistry (IHC) 22C3 pharmDx assay is a widely used selection method for pembrolizumab treatment in gastric cancer (GC) patients, especially in the U.S. The present study investigated the relationship between PD-L1 expression and the clinical features, molecular markers, and molecular subtypes of GC.MethodsPD-L1 expression was assessed based on combined positive score (CPS) using PD-L1 IHC 22C3 pharmDx in the Asian Cancer Research Group (ACRG) GC cohort (N = 300), which has been previously genomically profiled. PD-L1 positivity was defined as PD-L1 CPS ≥ 1. The association between PD-L1 expression and clinical features, tumor burden, and molecular subtypes (ACRG and The Cancer Genome Atlas [TCGA]) was analyzed.ResultsOf the 300 tumors, 178 (59.3 %) had PD-L1 CPS ≥ 1 and 122 (40.7 %) had PD-L1 CPS < 1. PD-L1 CPS ≥ 1 was significantly associated with stage I tumor (P = 0.022), high microsatellite instability (MSI-H) (P < 0.001), Epstein-Barr virus (EBV) positivity (P = 0.008), and positive Helicobacter pylori status (P = 0.001). PD-L1 CPS ≥ 1 was observed in 96/193 (49.7 %) EBV-negative/microsatellite stable (MSS) tumors. In gene expression profiling, PD-L1 CPS was highly correlated with mutational load (P < 0.001) as well as EBV (P < 0.001) and MSI subtypes (P < 0.001); 27/300 (9%) GC patients had a very high PD-L1 (≥ 20) score (MSI-H, n = 10; EBV, n = 6; and non-EBV/MSS, n = 11). OS was longer in patients with PD-L1 CPS ≥ 1 tumors than in those with PD-L1 CPS < 1 tumors (median OS not reached vs. 40 months; P = 0.008; log-rank test).ConclusionsPD-L1 is expressed in 59.3 % of GC patients and is associated with MSI and EBV positivity. These results provide a basis for identifying GC patients who may benefit from anti-PD-1/PD-L1 therapy.     

TIGIT and PD-1 may serve as potential prognostic biomarkers for gastric cancer

Gastric Cancer (GC) is the fifth leading cause of cancer-related death in the world, and in urgent need of specific therapeutic targets to acquire prominent effectiveness. T-cell immunoglobulin and immunoreceptor tyrosine–based inhibitory motif (ITIM) domain (TIGIT) and programmed cell death protein 1 (PD-1) are identified to be abnormally overexpressed in various types of cancers including GC. This study aimed to investigate whether TIGIT and PD-1 could serve as potential prognostic biomarkers for GC. Firstly, TCGA GC dataset analysis and correlation analysis were utilized to inspect the relationship between expression of TIGIT, PD-1 and CD8 + T cells in GC and adjacent normal tissues. Then, flow cytometry was used to verify the data after collecting the peripheral blood, GC and adjacent normal tissues from 150 GC patients. Lastly, quantitative RT-PCR was performed to detect the expression of CD155, CD113, CD112 and TIGIT in six human GC cell lines and 631 GC patients in KM Plotter Database to conduct prognostic analysis. As results, we found that TIGIT and PD-1 were upregulated in GC tissues with high CD8 + T cells infiltration, while correlation analysis indicated they were in high-positive correlation. In addition, the flow cytometry analysis further showed that the high-expression of TIGIT in tumor microenvironment of GC could suppress the function of infiltrative CD8 + T cells, which leads to the escape of GC cells from immune killing. Furthermore, CD155 and CD112 were found abnormally upregulated in GC tissues and cell lines and the high expression of CD155, CD112 and TIGIT demonstrated poor prognosis results. In conclusion, these results provided potential therapeutic targets and prognostic biomarkers for treatment of GC in clinic.     

DX5+ NKT cells induce the death of colitis-associated cells: involvement of programmed death ligand-1

NKT cells are activated by CD1d and show an immune regulating function. Here, we investigated whether DX5+ NKT cells could be used to reduce colitis in a chronic colitis mouse model and studied the potential immunological mechanisms involved. Chronic colitis was induced either by transfer of enriched CD62L+ CD4+ T cells to severe-combined-immunodeficient mice or by feeding dextran sodium sulfate to immune competent mice. DX5+ NKT cells were transferred to mice with chronic colitis. Co-transfer of DX5+ NKT cells, but not CD8+ control cells, prevented the onset of colitis, and the immune regulatory effect of DX5+ NKT cells was completely abrogated by injecting CD1d blocking antibody. Moreover, DX5+ NKT cells reduced established colitis in both chronic colitis models. In vitro, DX5+ NKT cells induced cell death of colon-infiltrating lymphocytes isolated from diseased mice. This effect was inhibited in the presence of either anti-CD1d or anti-programmed death ligand-1 (PD-L1) blocking antibodies. The specific potency of DX5+ NKT cells in regulating chronic colitis in two mouse models is demonstrated. In vitro testing suggests that DX5+ NKT cells activated by CD1d induce cell death of colitis-inducing lymphocytes, which is mediated through PD-L1. Therefore, DX5+ NKT cells could be important in the regulation of immune responses associated with chronic colitis.     

Association of serine/threonine kinase 11 mutations and response to programmed cell death 1 inhibitors in metastatic gastric cancer

Programmed cell death 1 (PD-1) inhibitors have shown therapeutic efficacy in metastatic gastric cancer (mGC). However, no predictive biomarkers have been established in mGC. Inactivating mutations in serine/threonine kinase 11 (STK11) are associated with poor response to PD-1 inhibitors in KRAS-mutant lung adenocarcinoma. Therefore, we hypothesized that STK11 inactivating mutations would be associated with inferior clinical response to PD-1 inhibitors in mGC. We analyzed 59 mGC patients who had been treated with PD-1 inhibitors and whose tumors had been analyzed by targeted high-throughput sequencing. STK11 mutations were identified in 30 (50.8%) patients, and were all missense mutations. Three patients (5.1%) had STK11 gene amplification and mutation, simultaneously. Patients with STK11 mutations had prolonged overall survival (median: 19.0 vs 11.6 months, p = 0.15), and progression-free survival (4.2 vs 1.9 months, p = 0.06) when treated with PD-1 inhibitors, but these differences were not statistically significant. Patients with STK11 inactivating mutations without STK11 gene amplification had significantly prolonged progression-free survival compared to patients with wild type STK11 or STK11 gene amplification (4.8 vs 1.0 months, p = 0.04). However, in multivariate Cox regression analysis with high microsatellite instability (MSI-H), the number of tumor mutations, PD Ligand-1 (PD-L1)+, Epstein-Barr virus positivity (EBV)+, and type of PD-1 inhibitor used (pembrolizumab vs nivolumab), only MSI-H and PD-L1+ were significantly associated with longer progression-free survival. In mGC, the presence of STK11 mutation was not predictive of the response to PD-1 inhibitors. Instead, patients with MSI-H or PD-L1+ tumors displayed superior clinical responses to PD-1 inhibitors.     

Programmed death ligand 1 is over-expressed by neutrophils in the blood of patients with active tuberculosis

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains one of the world's largest infectious disease problems. Despite decades of intensive study, the immune response to Mtb is incompletely characterised, reflecting the extremely complex interaction between pathogen and host. Pathways that may alter the balance between host protection and pathogenesis are therefore of great interest. One pathway shown to play a role in the pathogenesis of chronic infections, including TB, is the programmed death-1 (PD-1) pathway. We show here that the expression of the programmed death ligand 1 (PD-L1), which interacts with PD-1, is increased in whole blood from active TB patients compared with whole blood from healthy controls or Mtb-exposed individuals, and that expression by neutrophils is largely responsible for this increase.     

Multitalented EspB of enteropathogenic Escherichia coli (EPEC) enters cells autonomously and induces programmed cell death in human monocytic THP-1 cells

Enteropathogenic Escherichia coli (EPEC) subvert host cell signaling pathways by injecting effector proteins via a Type 3 Secretion System (T3SS). The T3SS-dependent EspB protein is a multi-functional effector protein, which contributes to adherence and translocator pore formation and after injection exhibits several intracellular activities. In addition, EspB is also secreted into the environment. Effects of secreted EspB have not been reported thus far. As a surrogate for secreted EspB we employed recombinant EspB (rEspB) derived from the prototype EPEC strain E2348/69 and investigated the interactions of the purified protein with different human epithelial and immune cells including monocytic THP-1 cells, macrophages, dendritic cells, U-937, epithelial T84, Caco-2, and HeLa cells. To assess whether these proteins might exert a cytotoxic effect we monitored the release of lactate dehydrogenase (LDH) as well as propidium iodide (PI) uptake. For comparison, we also investigated several homologs of EspB such as IpaD of Shigella, and SipC, SipD, SseB, and SseD of Salmonella as purified recombinant proteins. Interestingly, cytotoxicity was only observed in THP-1 cells and macrophages, whereas epithelial cells remained unaffected. Cell fractionation and immune fluorescence experiments showed that rEspB enters cells autonomously, which suggests that EspB might qualify as a novel cell-penetrating effector protein (CPE). Using specific organelle tracers and inhibitors of signaling pathways we found that rEspB destroys the mitochondrial membrane potential – an indication of programmed cell death induction in THP-1 cells. Here we show that EspB not only constitutes an essential part of the T3SS-nanomachine and contributes to the arsenal of injected effector proteins but, furthermore, that secreted (recombinant) EspB autonomously enters host cells and selectively induces cell death in immune cells.