慢性乙型肝炎患者PD-1/PD-L1信号通路的免疫调节作用研究进展

程序性死亡分子-1（PD-1）是T淋巴细胞膜表面表达的负向协同刺激分子, 与其主要配体（PD-L1）形成通路后,可以减弱T淋巴细胞的免疫反应,甚至导致T淋巴细胞功能衰竭。PD-1/PD-L1信号通路在乙型肝炎病毒感染后的效应T细胞免疫耐受中具有重要作用,阻断该途径可能是抗病毒治疗的方向之一,具有良好的应用前景。     

程序性死亡受体1/程序性死亡配体1免疫检测点阻滞剂在实体瘤治疗中的临床研究

近年来程序性死亡受体1/程序性死亡配体1(PD-1/PD-L1)免疫检测点阻滞剂在实体瘤治疗上取得振奋人心的效果。PD-1主要表达于活化的T、B细胞,在限制自身免疫及过度炎症反应方面起重要作用;肿瘤微环境中PD-1/PD-L1的高表达使T细胞活性受到过度抑制,从而发生肿瘤免疫逃逸;PD-L1表达水平可能是预测检测点阻滞剂疗效的标志物。免疫治疗因其持久的反应性及较小毒副作用使部分肿瘤患者获益明显。本文旨在阐述主要的PD-1/PD-L1检测点阻滞剂(单抗)近年来在恶性黑色素瘤、肺癌、尿路上皮癌、肾细胞癌等治疗上研究的现状并在获益人群中筛选出可能具有价值的生物学标志物。     

程序性死亡蛋白-1及配体在心肌炎发病中的作用

心肌炎是目前临床仍面临挑战的一类心血管疾病,发病机制复杂,临床预后差。程序性死亡蛋白-1(PD-1)是重要的免疫检查点,与程序性死亡配体-1(PD-L1)结合可负向调节机体免疫反应,在心肌炎的发生发展中起重要作用。本文从PD-1/PD-L1调控T淋巴细胞活化、抑制肌钙蛋白抗体和心肌炎症反应等方面综述了PD-1/PD-L1在心肌炎发生中的作用,以期为有效诊治心肌炎寻求新靶点。     

Immune-related adverse events in various organs caused by immune checkpoint inhibitors

Current cancer immunotherapies target immune checkpoint molecules such as the inhibitory receptor programmed cell death-1 (PD-1), one of its ligands, programmed cell death ligand-1 (PD-L1), and cytotoxic T-lymphocyte antigen 4 (CTLA-4), a competitive ligand for CD28 binding to stimulatory receptors CD80 and CD86. Multiple biological drugs use monoclonal antibodies targeting PD-1, PD-L1 and CTLA-4 as cancer immunotherapies. These are termed immune checkpoint inhibitors (ICIs). However, activation of the immune system by ICIs can induce the development of immune-related adverse events (irAEs), which can affect multiple organ systems. The most frequent irAEs are cutaneous and mimic various types of spontaneous skin disorders. Most irAEs are classified as autoimmune conditions mediated by ICI-activated CD8⁺ cytotoxic T cells, some of which are also related to activated B cells and production of pathogenic antibodies. Interestingly, blockade of CTLA-4 mainly induces activation of T cells and inhibition of T_reg cells. On the other hand, the mechanisms underlying anti-PD-1/PD-L1 ICI-induced irAEs are more complicated. PD-1 is a receptor expressed on T and B cells, which binds not only PD-L1, but also PD-L2. The role of PD-L1 is dominant in Th1 and Th17 immunity, while PD-L2 works mainly in Th2 immunity. Better understanding of the mechanisms underlying irAEs will allow for better management of irAEs and improve outcomes and quality of life in cancer patients.     

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。     

Expression and significance of PD-1 and PD-L1 in patients with recurrent spontaneous abortion: A protocol for systematic review and meta-analysis

Background:Recurrent spontaneous abortion (RSA) accounts for the most common complication of early pregnancy in humans. As an immune checkpoint pathway, programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) can be exploited by tumor cells to evade immuno-surveillance. Many studies have shown that the expression of PD-1/PD-L1 is involved in RSA. However, the correlation between the expression of PD-1/PD-L1 and RSA is still controversial. We conducted meta-analysis to further explore the correlation between the expression of PD-1/PD-L1 and RSA, to provide a basis for clinical prevention and treatment.Methods:We will search PubMed, Embase, Web of Science, Google Scholar, Chinese National Knowledge Infrastructure, Chinese VIP Information, Wanfang Database, and Chinese Biomedical Literature Database for related published studies before February 2021. Two review authors will search and assess relevant studies independently. Case control studies and cohort studies will be included. The Revman 5.3 software was applied to carry out the meta-analysis for the included literature.Results:The findings of this systematic review will be disseminated in a peer-reviewed publication and/or presented at relevant conferences.Conclusion:This study will provide a new theoretical basis for the prevention and treatment of RSA.Trial registration number:DOI 10.17605/OSF.IO/CZD23.Ethics and dissemination: Formal ethical approval is not required, as the data are not individualized.     

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。     

Costimulatory molecule programmed death-1 in the cytotoxic response during chronic hepatitis C

Hepatitis C virus (HCV)-specific CD8~+ T cells play an important role in the resolution of HCV infection. Nevertheless, during chronic hepatitis C these cells lack their effector functions and fail to control the virus.HCV has developed several mechanisms to escape immune control. One of these strategies is the upregulation of negative co-stimulatory molecules such us programmed death-1 (PD-1). This molecule is upregulated on intrahepatic and peripheral HCV-specific cytotoxic T cells during acute and chronic phases of the disease, whereas PD-1 expression is low in resolved infection. PD-1 expressing HCV-specific CD8~+ T cells are exhausted with impairment of several effector mechanisms, such as: type-1 cytokine production, expansion ability after antigen encounter and cytotoxic ability. However, PD-1 associated exhaustion can be restored by blocking the interaction between PD-1 and its ligand (PD-L1). After this blockade, HCV-specific CD8~+ T cells reacquire their functionality. Nevertheless,functional restoration depends on PD-1 expression level.High PD-1-expressing intrahepatic HCV-specific CD8~+ T cells do not restore their effector abilities after PD-1/ PD-L1 blockade. The mechanisms by which HCV is able to induce PD-1 up-regulation to escape immune control are unknown. Persistent TCR stimulation by a high level of HCV antigens could favour early PD-1 induction, but the interaction between HCV core protein and gC1q receptor could also participate in this process. The PD-1/PD-L1 pathway modulation could be a therapeutic strategy, in conjunction with the regulation of others co-stimulatory pathways, in order to restore immune response against HCV to succeed in clearing the infection.     

Herpesviruses and autophagy: catch me if you can!

Autophagy is an evolutionarily conserved cellular degradation pathway involving the digestion of intracellular components via the lysosomal pathway. The autophagic pathway constitutively maintains cellular homeostasis by recycling cytoplasmic organelles and proteins, but it is also stimulated by environmental stress conditions, such as starvation, oxidative stress, and the accumulation of misfolded proteins. It also acts as a cellular defense mechanism against microorganisms by contributing to both the innate and adaptive immunity, and by eliminating intracellular pathogens (xenophagy). There is growing evidence that host cells try to control Herpesvirus infections by activating the autophagic machinery. However, it is well-known that Herpesviruses are smart pathogens and several, such as HSV-1, HCMV and HHV-8, are known to have developed numerous defense strategies for evading the host's immune response. Inhibition of the antiviral autophagic mechanism has also been reported. Autophagy has also been shown to enhance the major histocompatibility complex presentation of at least two viral proteins, the EBV-encoded EBNA-1 and the HSV-1 encoded gB. In this review, we present an overview of recent advances in our understanding of the complex interplay between autophagy and Herpesviruses.     

Crohn's disease: NOD2, autophagy and ER stress converge

Polymorphisms in NOD2, encoding an intracellular pattern recognition receptor, contribute the largest fraction of genetic risk for Crohn's disease among the >40 risk loci identified so far. Autophagy plays a prominent role in the innate immune response towards intracellular bacteria. The discovery of the autophagy genes ATG16L1 and IRGM as risk factors for Crohn's disease turned autophagy into the spotlight in inflammatory bowel disease (IBD). Remarkably, NOD2 has recently been identified as a potent autophagy inducer. A physical interaction of NOD2 and ATG16L1 appears to be required for autophagic clearance of intracellular pathogens. Moreover, Crohn's disease-associated NOD2 and ATG16L1 variants exhibit a defect in the induction of an autophagic response and hence predict autophagy as a key converging mechanism that leads to Crohn's disease. Another pathway that is closely intertwined with autophagy and mutually cross-regulated is the unfolded protein response (UPR), which is induced by endoplasmic reticulum (ER) stress. Genes involved in the UPR (XBP1, ORMDL3) have also been genetically associated with Crohn's disease and ulcerative colitis. Moreover, the intestinal epithelium at the interface between host and microbe appears particularly affected by IBD-associated hypomorphic function of autophagy and the UPR. The functional convergence of main genetic risk factors for IBD on these innate immune pathways has hence important implications for the host's interaction with the microbiota. Moreover, the genetic convergence on these molecular mechanisms may open novel therapeutic options for IBD that deserve further exploration.     

B7-H1 is a ubiquitous antiapoptotic receptor on cancer cells

B7-H1 is an immunoglobulin-like immune suppressive molecule broadly detectable on the majority of human and rodent cancers, and its functions have been attributed to delivering an inhibitory signal to its counter-receptor programmed death-1 (PD-1) on T cells. Here we report that B7-H1 on cancer cells receives a signal from PD-1 to rapidly induce resistance against T cell-mediated killing because crippling signaling capacity of B7-H1 but not PD-1 ablates this resistance. Importantly, loss of B7-H1 signaling is accompanied by increased susceptibility to immune-mediated tumoricidal activity. In addition to resistance against T-cell destruction, B7-H1+ cancer cells also become refractory to apoptosis induced by Fas ligation or the protein kinase inhibitor Staurosporine. Our study reveals a new mechanism by which cancer cells use a receptor on immune cells as a ligand to induce resistance to therapy.     

免疫检查点抑制剂在肺癌治疗中的应用研究进展

免疫检查点抑制剂是一类针对细胞程序性死亡受体1(PD-1)、程序性死亡配体1(PD-L1)以及毒性T淋巴细胞抗原4(CTLA-4)的人源化单克隆抗体药物。在非小细胞肺癌患者的治疗方面,免疫检查点抑制剂表现出了显著且更加持久的疗效。本文就当前这类药物在肺癌治疗中的作用机制、临床研究最新进展以及相关生物标志物的预后和预测作用进行综述。     

PD-1-PD-L1 immune-checkpoint blockade in malignant lymphomas

Tumor cells can evade immune surveillance through overexpressing the ligands of checkpoint receptors on tumor cells or adjacent cells, leading T cells to anergy or exhaustion. Growing evidence of the interaction between tumor cells and microenvironment promoted the emergence of immune-checkpoint blockade. By targeting programmed cell death-1 (PD-1) pathway, cytotoxic activity of T cell is enhanced significantly and tumor cell lysis is induced subsequently. Currently, various antibodies against PD-1 and programmed death-ligand 1 (PD-L1) are under clinical studies in lymphomas. In this review, we outline the rationale for investigation of PD-1-PD-L1 immune-checkpoint blockade in lymphomas and discuss their prospect of applications in clinical treatment.     

PD-L1 expression on peripheral T-cells and association with coronary heart disease patients: A protocol for systematic reviews and meta-analysis

Background:As immune checkpoint pathways, programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) can be exploited by tumor cells to evade immuno-surveillance. Inflammation and immune processes play decisive roles in the occurrence and development of coronary heart disease (CHD). The low expression level of PD-1/ PD-L1 or anti-PD-1/PD-L1 therapy can accelerate the immune processes in CHD and aggravates disease based on numerous studies. However, the expression of PD-L1 and CHD still remains controversial to date. We conducted this meta-analysis to detect the value of PD-L1 expression on peripheral T-cells in CHD.Methods:We will search PubMed, Embase, Web of Science, Google Scholar, Chinese National Knowledge Infrastructure, Chinese VIP Information, Wanfang Database, and Chinese Biomedical Literature Database for related published studies before February 2021. Two review authors will search and assess relevant studies independently. Case control studies and cohort studies will be included. The Revman 5.3 software was applied to carry out the meta-analysis for the included literature.Results:The findings of this systematic review will be disseminated in a peer-reviewed publication and/or presented at relevant conferences.Conclusion:This study will provide a new theoretical basis for the immunological prevention and treatment of CHD.Trial registration number:DOI 10.17605/OSF.IO/X3R52.Ethics and dissemination:Formal ethical approval is not required, as the data are not individualized.     

神经元自噬在缺血缺氧性脑损伤中的作用

自噬是广泛存在于真核细胞中通过溶酶体机制降解自身成分的一种代谢途径.自噬不仅可通过激活经典的自噬小体-溶酶体途径,而且还可通过影响凋亡和坏死的发生、发展对细胞死亡进行调控.目前,自噬在急性脑缺血缺氧后神经元损伤方面的作用及其具体机制尚不明确.研究表明,缺血缺氧后的自噬具有神经保护作用,如维持神经元稳态、减少神经元死亡等;但也有研究认为,自噬能通过激活多种通路加重缺血缺氧后神经元损伤,甚至诱导神经元死亡.     

Role of autophagy in HIV infection and pathogenesis

The aim of autophagy is to re‐establish homeostasis in response to a variety of stress conditions. By forming double‐membrane vesicles, autophagy engulfs damaged or superfluous cytoplasmic material and recycles degradation products for new synthesis or energy production. Of note, the same mechanism is used to capture pathogens and has important implications in both innate and adaptive immunity. To establish a chronic infection, pathogens have therefore evolved multiple mechanisms to evade autophagy‐mediated degradation. HIV infection represents one of the best characterized systems in which autophagy is disarmed by a virus using multiple strategies to prevent the sequestration and degradation of its proteins and to establish a chronic infection. HIV alters autophagy at various stages of the process in both infected and bystander cells. In particular, the HIV proteins TAT, NEF and ENV are involved in this regulation by either blocking or stimulating autophagy through direct interaction with autophagy proteins and/or modulation of the mTOR pathway. Although the roles of autophagy during HIV infection are multiple and vary amongst the different cell types, several lines of evidence point to a potential beneficial effect of stimulating autophagy‐mediated lysosomal degradation to potentiate the immune response to HIV. Characterization of the molecular mechanisms regulating selective autophagy is expected to be valuable for developing new drugs able to specifically enhance the anti‐HIV response.     

PD-L1与记忆性T细胞在肝囊型包虫病患者CD4~+T淋巴细胞中的表达及意义

目的检测程序性死亡受体配体-1(PD-L1)及记忆性T细胞在肝囊型包虫病患者CD4+T淋巴细胞中的表达,探讨其在细粒棘球蚴感染免疫逃避中的作用。方法具有包虫活性的肝包虫病患者42例,健康对照20例,取血,分离PBMC,流式细胞术检测PD-L1(CD274+)、CD45RO+及CD4+CD45RO+CD274+细胞比例,并分析PD-L1与CD45RO的相关性。结果肝囊型包虫病患者PBMC中PD-L1、CD45RO+及CD4+CD45RO+CD274+细胞比例均显著高于健康对照组(P<0.05);肝囊型包虫病患者的PD-L1与CD45RO呈显著正相关(P<0.05),健康对照组二者无显著相关关系(P>0.05)。结论在肝囊型包虫病患者的免疫反应中,PD-L1可能通过记忆性T淋巴细胞发挥促进包虫免疫逃避的作用。     

Cell apoptosis and granulomatous lung diseases

Apoptosis, also known as activation-induced cell death or programmed cell death, is an active suicide mechanism that is involved in normal tissue turnover during embryogenesis and adult life. There are many examples of apoptosis in the immune system, including programmed cell death of T cells during negative intrathymic selection of the TCR repertoire and, in the postthymic phase, death of responsive T cells upon specific activation of the TCR/CD3 complex. Induction of apoptosis assures rapid disappearance of the immune response upon antigenic clearance, avoiding the metabolic costs involved in sustaining a large number of effector cells. The knowledge that failure of immune cells to die is the cause of a number of immune-mediated disorders has opened intriguing new avenues of exploration into the pathogenetic events leading to the accumulation of immunoinflammatory cells at sites of ongoing inflammation in granulomatous disorders, including granulomas initiated by infectious agents, such as Mycobacterium tuberculosis, or in sarcoidosis. In this paper we review recent results obtained in experimental animal models and patients with immune granuloma suggesting that the positive induction by ligands binding to membrane receptors or the induction or loss of intracellular suppressor signals regulates immunoregulatory mechanisms that drive the progressive development of the granulomatous structure. The great advances in understanding how mechanisms for the activation or downregulation of apoptosis have a pathogenetic role in the outcome of granulomatous disorders are also briefly considered.     

Apoptosis, a protective mechanism for pathogens and their hosts

In this review we summarize the great amount of recent information on the apoptosis in aspects of the host-parasite interaction. Although apoptosis is a form of programmed cell death which plays a pivotal role in normal tissue development a plethora of pathogens including parasitic protista and helminths are able to modulate host apoptosis pathways to their own advantage. Here in we present and discuss new research data and results describing the phenomenon as a process have been controlled by gene expression, biochemical reactions and receptor-ligand interactions at the cell membrane surface. Section 1 describes apoptosis as ongoing process in normal tissue development. Section 2 analyzes the role of apoptosis in outcome of infection and pathogenesis of several disorders evoked by viruses and bacteria. The cellular mechanisms of cell death during infection with unicellular parasites such as Leishmania sp. and Plasmodium sp. are described in Section 3. In the next paragraph the potency of parasitic protista and helmiths for modulation host apoptosis pathways to their own advantage is discussed. The involvement of apoptosis in immunoregulation of the host immune function was proposed as a one of possible mechanism in creation of the host-parasite relationship. The molecular and cellular mechanisms of parasite-induced immune response via apoptosis pathways are discussed. We conclude that novel strategies for the management of the host-parasite relationships need to be explained into the mechanisms by which parasites induced apoptosis in contribution to the activity of immune system of the host.     

细胞自噬与心血管疾病中炎症反应的相关性

细胞自噬既是保守的细胞防御机制,也是程序性细胞死亡(即调亡)机制,其可维持细胞自身内环境的稳态。心血管疾病多伴有炎症反应并与细胞自噬密切相关。新近研究表明:一方面,自噬可以通过清除堆积蛋白和保持线粒体稳态对抗心血管疾病的炎症反应,此效应可能与抑制炎症小体以及钙蛋白酶依赖的白介素-1α的活性有关;另一方面,自噬在某些情况下也可促进炎症反应,自噬相关蛋白和高尔基体重组-堆叠蛋白参与了自噬的促炎效应。以本文简要综述细胞自噬在心血管疾病炎症反应中的作用,探讨自噬与炎症反应的相关分子机制,为心血管疾病中炎症反应的治疗提供新的思路。