PD-1/PD-L1信号通路与慢性乙型肝炎

目的：程序性死亡分子-1（programmed death-1,PD-1）是近年来发现的属于B7/CD28家族的重要协同刺激分子,与其配体（programmed death -1 ligand,PD-L）结合后在调节T淋巴细胞的活化、分化及增殖功能方面起着重要作用。在慢性HBV感染不同阶段,PD-1表达水平存在差异,且与肝脏炎症程度、ALT及病毒载量等密切相关。通过不同途径阻断PD-1/PD-L1通路可以使耗竭的T淋巴细胞功能得到改善,提示可能是未来抗病毒治疗的方向之一。     

PD-1/PD-L 1抗体在非小细胞肺癌治疗中的研究现状

程序性死亡因子1(programmed death-1,PD-1)存在于活化的T细胞和 B细胞表面,是一种重要的免疫共抑制分子。当 PD-1与程序性死亡配体1/2(programmed death-ligand 1/2, PD-L1/2)结合后,可以引起一系列的免疫抑制作用,并使肿瘤逃避免疫破坏。阻断 PD-1/PD-L1通路,则可能减弱其对免疫活性细胞的抑制作用,从而达到增强细胞免疫、杀灭肿瘤细胞的目的。目前大量研究证明PD-1/PD-L1抗体在非小细胞肺癌治疗中有显著的抗肿瘤活性。本文将对其研究现状加以综述。     

PD-1/PD-L1在肿瘤治疗中的进展

免疫治疗因其显著的疗效,已成为肿瘤治疗领域的研究热点.程序性死亡受体1(programmed cell death-1,PD-1)存在两个配体,PD-L1(B7-H1)和PD-L2(B7-DC)可与T细胞表面受体PD-1结合,在免疫应答反应中起重要的负调节作用.由于PD-1与其配体结合可导致T细胞的活化、增殖被抑制,甚至诱导T细胞的凋亡,使肿瘤细胞躲避免疫监视,发生免疫逃逸现象.肿瘤细胞能够持续高表达PD-L1,降低机体免疫应答能力.通过阻断PD-1/PD-L1信号通路,可重新激活衰竭T细胞,增强免疫应答反应,加强对肿瘤的控制.抑制多种免疫位点的疗效明显优于单一的PD-1或PD-L1抗体免疫治疗.本文将从PD-1/PD-L1信号通路出发,陈述其机制,研究进展以及在肿瘤免疫联合治疗现状等方面进行综述.     

程序性细胞死亡分子-1/程序性死亡配体信号通路在风湿性疾病中的研究进展

程序性细胞死亡分子-1(programmed cel]death-1,PD-1)/程序性死亡配体(programmed death ligand,PD-L)信号通路是近年来公认的存在于T、B细胞活化过程中的一条重要的协同刺激信号通路,包括:表达在活化的T、B细胞表面的PD-1和表达在抗原递呈细胞(APC)表面的PD-L.PD-L分为2种:PD-L1和PD-L2.PD-1、PD-L相互识别,介导的生物学作用主要是抑制T、B细胞的增殖,抑制细胞因子的分泌,促进细胞凋亡.在维持机体自身免疫耐受中具有重要意义,阻断PD-1/PD-L信号通路会诱导或加重风湿性疾病.     

PD-1/PD-L1抑制剂相关活动性结核病的临床特点及文献复习

目的:研究程序性细胞死亡蛋白1(programmed death-1,PD-1)及其配体(programmed death-ligand 1,PD-L1)的抑制剂(PD-1/PD-L1抑制剂)与结核病的关系,提高对肿瘤患者使用PD-1/PD-L1抑制剂治疗期间出现活动性结核病的认识。方法:回顾性分析2017年2月至2022年10月深圳市第三人民医院肺病二科诊治的5例使用PD-1/PD-L1抑制剂治疗的恶性肿瘤合并活动性肺结核患者的临床资料、诊断过程及预后。同时,查阅2016年1月1日至2022年6月25日PubMed、Cochrane Library、中国知网发布的与使用PD-1/PD-L1抑制剂治疗的结核病相关文献报告,总结应用PD-1/PD-L1抑制剂中出现活动性结核病的临床特点。结果:5例患者中,男性4例,女性1例,在PD-1/PD-L1抑制剂使用前均未进行结核病筛查,在使用PD-1/PD-L1抑制剂治疗3～12个月时出现活动性肺结核,并经病原学检查确诊。患者抗结核治疗后,2例好转,2例治愈,1例病亡;2例重启PD-1/PD-L1抑制剂治疗。同时,通过数据库检索到12篇文献,包含...     

PD-1/PD-L1抑制途径与自身免疫性糖尿病

PD-1(CD279)是一种负性协同刺激分子,属于CD28超家族成员,呈诱导性表达于活化的T、B和自然杀伤细胞表面.PD-L1(B7-H1,CD274)和PD-L2(B7-DC,CD273)是PD-1的两个配体.PD-1和PD-L1相互作用可以使活化的自身反应性T细胞获得负性信号,抑制其对自身抗原持续的免疫应答.若PD...     

PD-1/PD-L通路对乙型肝炎病毒感染结局的影响

程序性死亡因子-1(programmed death 1,PD-1)是可以表达在T淋巴细胞膜表面的负向协同刺激分子受体,他与PD-1配体(programmeddeath 1 ligand,PD-L)形成通路后,可以减弱T淋巴细胞免疫反应,甚至导致T淋巴细胞功能衰竭.近来研究表明PD-I/PD-L通路的形成可以影响HBV...     

慢性乙型肝炎患者抗病毒治疗与免疫细胞上PD-1/PD-L1表达的关系

在我国,乙型肝炎病毒(hepatitis B virus,HBV)在体内不断复制并由此导致的肝细胞免疫病理损伤是H B V感染后慢性化及病情加重的原因,因此,抗病毒是阻止病情进展的有效手段.在多种与宿主免疫调控异常有关的发病机制中,程序性死亡分子1(programmed death 1,PD-1)/程序性死亡分子1配体1(PD-1 ligand 1,PD-L1)通路被认为与HBV感染后结局相关,本文就慢性乙型肝炎(chronic hepatitis B,CHB)患者抗病毒治疗与免疫细胞上PD-1/PD-L1表达间关系进行综述.     

PD-1/PD-L1信号通路在乙型病毒性肝炎免疫调节作用的研究进展

程序性死亡分子1(programmed death-1,PD-1)是由pdcdl基因编码的一个抑制性共刺激分子,在维持外周耐受中起着关键性的作用,并在慢性病毒感染、肿瘤免疫及自身免疫性疫病的发生过程中发挥重要的生物学作用,受到广泛的关注.本文主要综述PD-1/PD-L1信号通路在乙型病毒性肝炎免疫调节作用的研究进展.     

PD-L1和PD-L2在支气管哮喘中的研究进展

支气管哮喘(哮喘)是一种伴随气道高反应性、可逆性气流阻塞、气道重塑的慢性气道炎症性疾病。许多研究表明,程序性死亡蛋白1(PD-1)与其配体程序性死亡配体1(PD-L1)和PD-L2之间的相互作用在T细胞激活、耐受和免疫介导的组织损伤中发挥关键作用。但PD-1与其配体PD-L1和PD-L2在哮喘气道高反应性和气道炎症发展...     

Expression of PD-1, PD-L1, and PD-L2 in the liver in autoimmune liver diseases

OBJECTIVES: PD-L1 (also B7-H1) and PD-L2 (also B7-DC) are ligands for programmed death-1 (PD-1), which is a member of the CD28/B7 superfamily of costimulatory molecules and plays an inhibitory role on the periphery. Impaired regulation of this system may cause disruption to self-tolerance leading to autoimmunity; however, the role of these molecules in the liver is unknown. Therefore, we examined the expression of PD-1, PD-L1, and PD-L2 in the liver in autoimmune liver diseases. METHODS: We examined the liver expression of these molecules in autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) with no previous medical treatment using immunohistochemical staining and real-time PCR, and compared with chronic hepatitis type C (CHC) as a control. RESULTS: Although PD-1, PD-L1, and PD-L2 were expressed in the liver in AIH, PBC, as well as CHC, the expressions were relatively lower in PBC. In AIH, despite more severe inflammation than in CHC, the expression of these molecules was not greater than in CHC, and when compared with the relative expression of PD-L1, PD-L2 was lower in AIH. PD-L1 and PD-L2 expressions were well correlated with the level of IFN-gamma; however, relatively decreased induction for PD-L1 and PD-L2 by IFN-gamma was observed in AIH or PBC than in CHC. CONCLUSION: Modulation of PD-1/PD-L1 and PD-L2 systems may play a role in the development of autoimmune liver diseases.     

Crystal structure of the complex between programmed death-1 (PD-1) and its ligand PD-L2

Programmed death-1 (PD-1) is a member of the CD28/B7 superfamily that delivers negative signals upon interaction with its two ligands, PD-L1 or PD-L2. The high-resolution crystal structure of the complex formed by the complete ectodomains of murine PD-1 and PD-L2 revealed a 1:1 receptor:ligand stoichiometry and displayed a binding interface and overall molecular organization distinct from that observed in the CTLA-4/B7 inhibitory complexes. Furthermore, our structure also provides insights into the association between PD-1 and PD-L1 and highlights differences in the interfaces formed by the two PD-1 ligands (PD-Ls) Mutagenesis studies confirmed the details of the proposed PD-1/PD-L binding interfaces and allowed for the design of a mutant PD-1 receptor with enhanced affinity. These studies define spatial and organizational constraints that control the localization and signaling of PD-1/PD-L complexes within the immunological synapse and provide a basis for manipulating the PD-1 pathways for immunotherapy.     

PD-1/PD-L1 Blockade Accelerates the Progression of Atherosclerosis in Cancer Patients

PD-1(programed death-1)/PD-L1(programed death-1 ligand) blockade represents a major breakthrough of anti-cancer therapies, however, it may come with increased risk of cardiovascular morbidity, such as myocarditis, acute coronary syndrome, arrhythmias, etc. Although the PD-1/PD-L1-blockade-related acute coronary syndrome (ACS) is rare, it can be fatal. Previous studies have implicated a role of the PD-1/PD-L1 axis in the development of atherosclerosis. This review explores a hypothesis that PD-1/PD-L1 blockade accelerates the progression of atherosclerosis and promotes plaque rupture, by synthesizing the evidence of vascular inflammation, as well as plaque progression, destabilization and rupture via T-cell activation and effector function. In order to improve the prognosis of cancer patients and decrease the cardiotoxicity of PD-1/PD-L1 blockade therapy, early recognition of PD-1/PD-L1-blockade-related ACS is important.     

结直肠癌PD-1/PD-L1阻断治疗的耐药研究现状

PD-1/PD-L1阻断治疗是一种新的肿瘤治疗策略,在过去的十年中,PD-1/PD-L1阻断治疗在很多的恶性肿瘤中应用,取得了一定成功.而对于结直肠癌,只有DNA错配修复蛋白缺失(dMMR)微卫星高度不稳定(MSI-H)患者对PD-1/PD-L1的阻断治疗有积极的反应.原发性和获得性耐药,最终可能导致患者的疾病进展.因...     

Targeting the PD1/PD-L1 axis in melanoma: Biological rationale,clinical challenges and opportunities

A dynamic interplay exists between host and tumor, and the ability of the tumor to evade immune recognition often determines the clinical course of the disease. Significant enthusiasm currently exists for a new immunotherapeutic strategy: the use of immunomodulatory monoclonal antibodies that directly enhance the function of components of the anti-tumor immune response such as T cells, or block immunologic checkpoints that would otherwise restrain effective anti-tumor immunity. This strategy is based on the evidence that development of cancer is facilitated by the dis-regulation and exploitation of otherwise physiological pathways that, under normal circumstances, down-regulate immune activation and maintain tolerance to self. Among these pathways an important role is covered by the Programmed death-1 (PD-1)/PD-Ligand (L) 1 axis. An emerging concept in cancer immunology is that inhibitory ligands such as PD-L1 are induced in response to immune attack, a mechanism termed “adaptive resistance”. This potential mechanism of immune resistance by tumors suggests that therapy directed at blocking the interaction between PD-1 and PD-L1 might synergize with other treatments that enhance endogenous antitumor immunity. The anti-PD-1 strategy can be effective in several solid tumors such as renal cell carcinoma (RCC) or non-small cell lung cancer (NSCLC), however in this review we summarize the biological role of PD-1/PD-L1 on cancer by focusing our attention in the biological rationale, clinical challenges and opportunities to target the PD-1/PD-L1 axis in melanoma.     

Expression pattern of PD-1/PD-L1 in primary liver cancer with clinical correlation

Immunotherapy, including ICIs, has emerged as an invaluable treatment option for advanced PLC. Nevertheless, the expression patterns of PD-L1 and PD-1 in PLC remain incompletely understood. In this study, the expression pattern and clinical correlation of PD-L1 and PD-1 were analysed in 5245 PLC patients. The positivity rates of PD-L1 and PD-1 were very low in the patient PLCs, but the positivity rates of PD-L1 and PD-1 were higher in the ICC and cHCC-ICC than in HCC. The expression of PD-L1 and PD-1 correlated with the malignant phenotypes and clinicopathological characteristics of PLC. Interestingly, PD-1 positivity might serve as an independent prognostic factor. Based on a systematic analysis of a large amount of PLC tissues, we proposed a novel classification of PD-1/PD-L1 expression in HCC and ICC. In light of this stratification, we observed a close correlation between PD-L1 levels and PD-1 expression in HCC and ICC.     

The PD-1/PD-L costimulatory pathway critically affects host resistance to the pathogenic fungus Histoplasma capsulatum

The PD-1 costimulatory receptor inhibits T cell receptor signaling upon interacting with its ligands PD-L1 and PD-L2. The PD-1/PD-L pathway is critical in maintaining self-tolerance. In this study, we examined the role of PD-1 in a mouse model of acute infection with Histoplasma capsulatum, a major human pathogenic fungus. In a lethal model of histoplasmosis, all PD-1-deficient mice survived infection, whereas the wild-type mice died with disseminated disease. PD-L expression on macrophages and splenocytes was up-regulated during infection, and macrophages from infected mice inhibited in vitro T cell activation. Of interest, antibody blocking of PD-1 significantly increased survival of lethally infected wild-type mice. Thus, our studies extend the role of the PD-1/PD-L pathway in regulating antimicrobial immunity to fungal pathogens. The results show that the PD-1/PD-L pathway has a key role in the regulation of antifungal immunity, and suggest that manipulation of this pathway represents a strategy of immunotherapy for histoplasmosis.     

The PD-1/PD-L1 complex resembles the antigen-binding Fv domains of antibodies and T cell receptors

Signaling through the programmed death 1 (PD-1) inhibitory receptor upon binding its ligand, PD-L1, suppresses immune responses against autoantigens and tumors and plays an important role in the maintenance of peripheral immune tolerance. Release from PD-1 inhibitory signaling revives "exhausted" virus-specific T cells in chronic viral infections. Here we present the crystal structure of murine PD-1 in complex with human PD-L1. PD-1 and PD-L1 interact through the conserved front and side of their Ig variable (IgV) domains, as do the IgV domains of antibodies and T cell receptors. This places the loops at the ends of the IgV domains on the same side of the PD-1/PD-L1 complex, forming a surface that is similar to the antigen-binding surface of antibodies and T cell receptors. Mapping conserved residues allowed the identification of residues that are important in forming the PD-1/PD-L1 interface. Based on the structure, we show that some reported loss-of-binding mutations involve the PD-1/PD-L1 interaction but that others compromise protein folding. The PD-1/PD-L1 interaction described here may be blocked by antibodies or by designed small-molecule drugs to lower inhibitory signaling that results in a stronger immune response. The immune receptor-like loops offer a new surface for further study and potentially the design of molecules that would affect PD-1/PD-L1 complex formation and thereby modulate the immune response.     

Involvement of PD-L1 on tumor cells in the escape from host immune system and tumor immunotherapy by PD-L1 blockade

PD-1 is a receptor of the Ig superfamily that negatively regulates T cell antigen receptor signaling by interacting with the specific ligands (PD-L) and is suggested to play a role in the maintenance of self-tolerance. In the present study, we examined possible roles of the PD-1/PD-L system in tumor immunity. Transgenic expression of PD-L1, one of the PD-L, in P815 tumor cells rendered them less susceptible to the specific T cell antigen receptor-mediated lysis by cytotoxic T cells in vitro, and markedly enhanced their tumorigenesis and invasiveness in vivo in the syngeneic hosts as compared with the parental tumor cells that lacked endogenous PD-L. Both effects could be reversed by anti-PD-L1 Ab. Survey of murine tumor lines revealed that all of the myeloma cell lines examined naturally expressed PD-L1. Growth of the myeloma cells in normal syngeneic mice was inhibited significantly albeit transiently by the administration of anti-PD-L1 Ab in vivo and was suppressed completely in the syngeneic PD-1-deficient mice. These results suggest that the expression of PD-L1 can serve as a potent mechanism for potentially immunogenic tumors to escape from host immune responses and that blockade of interaction between PD-1 and PD-L may provide a promising strategy for specific tumor immunotherapy.