TLR介导的信号通路在肝纤维化中的作用

Toll样受体(Toll - like receptor,TLR)是在天然免疫与获得性免疫应答中发挥重要作用的模式识别受体(Pattern recognition receptors,PRRs).TLR识别来源于病原体或机体损伤产生的“危险信号”,介导多种炎症因子释放,激发机体对病原体的免疫反应,启动固有免疫并进一步活...     

NOD样受体在炎症反应中的调控作用

天然免疫(innate immunity)是机体免疫系统直接抵御病原体入侵的最初阶段,通过机体自身的特异性模式识别受体(pattern-recognition receptors,PRRs)来识别病原体特有的保守结构病原相关分子模式(pathogen-associated molecular patterns,PAMPs)。细胞内NOD样受体(NLRs)是胞浆型PRRs中的一个重要家族,病原体侵袭细胞可上调其表达,启动机体的免疫应答和炎症反应,在机体天然免疫应答中发挥独特的功能。最近有研究证明,NLRs的突变与一些人类免疫性疾病相关,并且在细菌感染和炎症反应的控制中起重要作用。该文将讨论NLRs在炎症疾病中的调控作用。     

流感病毒感染的模式识别及下游相关信号通路

流感病毒(influenza virus)轻症感染可由机体免疫系统清除,但重症感染则诱发肺脏免疫损伤。流感病毒的病原体相关分子模式(pathogen-associated molecular patterns,PAMPs)可被位于细胞膜、细胞器膜及胞质内的重要模式识别受体(pattern recognition receptors,PRRs)介导识别,活化一系列激酶及转录因子,诱导促炎细胞因子和趋化因子的表达、成熟和分泌,进一步激活天然免疫及获得性免疫应答细胞,介导炎症反应和诱导免疫病理损伤。PRRs是研究天然免疫应答启动机制及抑制重症感染诱导免疫病理损伤的重要靶点。现就Toll样受体(toll-like receptors,TLRs)中的TLR3、TLR7/8、TLR4、RIG-I样受体(RIG-I like receptors,RLRs)和NOD样受体(NOD-like receptor,NLR)在流感病毒感染中的识别及下游信号通路在免疫病理损伤中的作用机制作一综述。     

泛素化调控抗病毒天然免疫的研究进展

天然免疫是宿主防御病原微生物入侵的第一道防线,其活化主要通过天然免疫细胞上的模式识别受体(pattern recognition receptors, PRRs)识别病原微生物上相对保守的相关分子模式(pathogen-associated molecular patterns, PAMPs).病毒相关的核酸成分可以被机体Toll样受体(Toll-like receptors, TLRs)、维甲酸诱导基因Ⅰ受体(RIG-I-like receptors, RLRs)以及胞浆DNA受体(cytoplasmic DNA sensors)等识别,通过一系列复杂的细胞信号通路诱导Ⅰ型干扰素(typeⅠinterferon)及炎症因子的表达,从而激发机体抗病毒反应.泛素化修饰是细胞内广泛存在的蛋白质翻译后修饰方式,在宿主防御病原微生物感染的动态调控过程中发挥着重要的作用.已有大量文献报道,天然免疫抗病毒信号通路中的多个关键接头分子可发生泛素化修饰,进而调控机体抗病毒免疫应答反应.本文综述了泛素化修饰在抗病毒天然免疫中的作用及其调控机制.     

鱼类模式识别受体的研究进展

天然免疫（innate immunity）是基于对病原微生物成分的非克隆性识别而启动的快速防御反应。天然免疫系统可通过胚系编码的模式识别受体（pattern-recognition receptors,PRR）识别恒定不变的病原基元,即病原相关分子模式（pathogen-associated molecular patterns,PAMPs）,启动信号级联转导,最终PRRs信号激活宿主免疫和前炎性基因的表达,引发针对所识别病原的免疫反应。目前PRRs主要分为5类,即C-型Lectins、Toll样受体（Toll-like receptors,TLRs）、视黄酸诱导基因I样受体（retinoic acid inducible gene I-like receptors,RLRs）、包含核苷酸结合区和亮氨酸富集区蛋白（the nucleotide-binding domain,leucine-rich repeatcontaining proteins,NLRs,也称NOD样受体）和最近发现的AIM样受体（absent in melanoma（AIM）-like receptors,ALRs）。近年来,随着5种鱼类基因组序列草图的完成,大量鱼类PRRs基因被发现,一些PRRs的配体特异性及其相关信号途径正在逐渐明晰。为此,将对鱼类Toll样受体（TLRs）、视黄酸诱导基因I样受体（RLRs）和NOD样受体（NLRs）的研究进展进行综述。     

Toll样受体信号转导途径研究进展

Toll样受体(Toll-like receptors,TLRs)属于模式识别受体(pattern recognition receptors,PRRs)家族,识别高度保守的微生物组分-病原相关分子模式(pathogen-associated molecular pat-terns,PAMPS)。迄今为止,在人类基因组中已发现10个Toll样受体。这些受体通过感知不同的微生物刺激,招募特异接头蛋白,激活一系列信号级联反应,引发针对病原体的特异性免疫应答,是连接天然免疫和适应性免疫应答的桥梁。哺乳动物Toll样受体的发现引领天然免疫的研究进入飞速发展的时代。本文将对Toll样受体信号转导途径的最新进展作一综述,以便更好地理解Toll样受体介导的分子免疫机制,这将有助于研发免疫治疗的分子靶标,最终有效预防、控制Toll样受体介导的疾病。     

Toll样受体对病原真菌的天然免疫识别

天然免疫系统是宿主抵御病原入侵的第一道防线,在机体抗感染免疫中发挥重要作用。Toll样受体(Toll-like receptors,TLRs)是天然免疫系统最重要的模式识别受体(pattern recognitionreceptors,PRRs)之一,通过识别病原真菌的病原相关分子模式(pathogen-associated molecularpatterns,PAMPs),招募特异接头蛋白,激活一系列信号级联反应,引发炎症因子、趋化因子等的释放和树突状细胞(dendritic cells,DCs)的成熟,发挥抗真菌感染作用。通过简要介绍宿主的TLRs及信号通路的研究进展,总结了目前TLRs对不同病原真菌PAMPs的天然免疫识别及信号通路研究现状,以期对进一步研究宿主天然免疫系统与病原真菌相互作用的分子机制提供参考。     

RIG-Ⅰ介导的TLR非依赖性模式识别

天然免疫在机体抗病毒感染的过程中发挥重要作用.近年来,识别和感受病原体的一系列模式识别受体受到广泛关注,TLR（Toll-like receptor）便是这一领域中的热点,随着研究的深入,一类TLR非依赖性模式识别受体,逐渐活跃在天然免疫识别的舞台,这其中,解旋酶（helicase）家族中的重要成员--维甲酸诱导基因Ⅰ（retinoic acid-induced geneⅠ,RIG-Ⅰ）,主要识别并直接结合到某些5＇端磷酸化RNA病毒,通过蛋白质-蛋白质接触方式,与其受体MAVS（mitochondrial antiviral signaling protein）也称作VISA（virus induced signaling adaptor）、IPS-1（IFN-promoter stimulating factor）或Cardif结合,活化TBK1和IKKe,激活转录因子NF-kB、IRF-3,引起Ⅰ型干扰素分泌上调,发挥抗病毒效应.RIG-Ⅰ途径除了在天然免疫中发挥抗病毒作用以外,也是一些病毒逃逸机体免疫的靶点,如HCV、HAV、GB病毒等.     

Toll样受体（TLR）介导的天然免疫间的相互调节

模式识别受体（PRR）在宿主细胞识别与抵御微生物病原体中起到了重要作用。Toll样受体（TLR）是研究比较清楚的一类PRR,可以识别多种病原体成份,启动天然免疫反应。此外,近来发现了几类其他模式识别受体,如C型凝集素受体（CLR）,核苷酸寡聚结合域（NOD）样受体（NLR）和视黄酸诱导基因I（RIG—I）样受体（RLR）,表明机体的天然免疫反应受到多种机制的精密调控。本文着重综述TLR与其他PRR在识别病原体和介导天然免疫信号通路间的相互关系。     

野猪Toll 样受体基因的结构和功能鉴定

Toll样受体(Toll-like receptors,TLRs)是介导天然免疫和获得性免疫的病原模式识别受体(Pattern recognition receptor,PRRs),能识别表达在病原微生物上高度保守的病原相关分子模式(Pathogen associated molecular patterns,PAMPs),并通过一定的信号转导途径引起核内相关基因的表达,启动和调节机体的免疫反应。     

补体系统基因单核苷酸多态性及其与疾病的关系

天然免疫系统在病原微生物入侵的初始阶段发挥着重要的防御作用,其中补体系统可快速识别、杀伤和清除病原微生物,对疾病的发生、发展和转归起着重要的作用。文章综述了补体系统各成份单核苷酸多态性与疾病的关联研究进展,在DNA水平上揭示了补体系统遗传多态性对疾病发生、发展和转归的影响,对疾病的预防和个体化治疗具有重要的意义。     

Regulation of innate immunity by the molecular machinery of macroautophagy

Innate immune responses are the first line of defence for an organism to restrict invading pathogens. They fulfil two main functions, namely detection of the pathogen to successively alarm the appropriate components of the immune system and early inhibition of the infection to prevent demise of the infected organism before a more tailored immune response, usually mediated by the adaptive immune system, can be mounted. Autophagy and phagocytosis, modified by the autophagic core machinery, contribute to these functions by regulating pathogen detection, influencing the production of innate immune mediators and directly restricting intracellular and extracellular pathogens as an effector mechanism of innate immunity. These aspects of the involvement of mainly macroautophagy in innate immune responses will be discussed in this review.     

Type I interferons in regulation of mucosal immunity

The mucosal system is the first line of defense against many pathogens. It is continuously exposed to dietary and microbial antigens, and thus the host must maintain a homeostatic environment between commensal microbiota and pathogenic infections. Following infections and inflammatory events, a rapid innate immune response is evoked to dampen the inflammatory processes. Type I interferons, a family of pleiotropic cytokines and major products of the innate immune response, have a key role in these early immune events at the mucosa, as reviewed here. With the emergence of new discoveries of immune cell types in mucosal tissues and their reactions to commensal and pathogenic organisms, we also review the opportunities for exciting research in this field.     

无脊椎动物清道夫受体的免疫调控

在长期进化的过程中,无脊椎动物逐渐形成了受体识别-信号传导-免疫应答为特征的天然免疫体系,以清除凋亡细胞或外界的病原微生物。清道夫受体（SRs）是一类位于细胞表面的跨膜受体,也是一类参与无脊椎动物天然免疫反应的重要模式识别受体。清道夫受体参与免疫反应的异己靶标识别,通过下游信号级联调控抗菌肽合成和吞噬作用。本文综述了无脊椎动物清道夫受体的种类、结构及其参与天然免疫的调控机制,探讨了无脊椎动物清道夫受体研究中尚待解决的问题。     

禽坦布苏病毒诱导的宿主免疫应答

禽坦布苏病毒(Avian Tembusu virus,ATMUV)是近年来在我国新发现的一种病毒,可感染多种蛋禽,感染动物临床特征为采食量下降,产蛋量骤减,甚至停产,感染后期呈神经症状,如腿和翅膀麻痹、共济失调等。ATMUV在我国多个省市地区流行,给我国甚至世界养禽业带来严重影响。固有免疫是机体抵抗病原感染的第一道重要防线,是机体与生俱来的抵御病原微生物的能力。适应性免疫是机体免疫系统在抗原刺激下产生特异性抗体及免疫效应细胞的过程,以建立针对某种病原微生物的抵抗力,是机体免疫系统的重要部分。本文将从禽坦布苏病毒诱导宿主固有免疫应答和适应性免疫应答两方面进行综述。     

Role of glycosphingolipid-enriched microdomains in innate immunity: microdomain-dependent phagocytic cell functions

The innate immune system is the first line of defense against pathogenic microorganisms, such as bacteria, fungi, and viruses. Phagocytes, such as neutrophils and macrophages, play an important role in the innate immune system by recognizing, engulfing, and eliminating pathogens. It has been suggested that lipid membrane microdomains/rafts of phagocytes are involved in these innate immune responses, including superoxide generation, cell migration, and phagocytosis. Lactosylceramide (LacCer), a neutral glycosphingolipid, forms glycosphingolipid-enriched microdomains together with the Src family kinase, Lyn, on the neutrophil plasma membrane. LacCer-enriched microdomains have been suggested to play important roles in innate immune function of neutrophils. However, the molecular mechanisms underlying these phenomena remain largely unknown. Recent proteomic analyses of microdomains from phagocytes have provided insight into membrane microdomain-mediated functions in the processes of phagocytosis. In this review, we discuss the membrane microdomain-associated immune functions of phagocytes, focusing on those functions of LacCer-enriched microdomains and recent proteomic approaches to determine the molecular mechanisms underlying these functions.     

Insect Antiviral Innate Immunity: Pathways,Effectors, and Connections

Insects are infected by a wide array of viruses some of which are insect restricted and pathogenic, and some of which are transmitted by biting insects to vertebrates. The medical and economic importance of these viruses heightens the need to understand the interaction between the infecting pathogen and the insect immune system in order to develop transmission interventions. The interaction of the virus with the insect host innate immune system plays a critical role in the outcome of infection. The major mechanism of antiviral defense is the small, interfering RNA pathway that responds through the detection of virus-derived double-stranded RNA to suppress virus replication. However, other innate antimicrobial pathways such as Imd, Toll, and Jak-STAT and the autophagy pathway have also been shown to play important roles in antiviral immunity. In this review, we provide an overview of the current understanding of the main insect antiviral pathways and examine recent findings that further our understanding of the roles of these pathways in facilitating a systemic and specific response to infecting viruses.     

MicroRNA调控固有免疫应答的分子机制

MicroRNA（miRNA）是近几年继siRNA之后非编码RNA研究的又一热点．它通过与靶mRNA的特异性结合,在转录后水平上对基因表达进行调控．研究表明,miRNA可能参与脊椎动物固有免疫应答的多个环节．在病原微生物感染时,它们不仅成为重要的固有免疫受体活化后的信号调节分子,而且能够直接干扰病毒复制而发挥抗病毒效应．miRNA可能与经典的固有免疫应答体系共同组成机体抵御病原微生物入侵的“第一道防线”．同时,病原微生物,特别是病毒还可以通过自己编码miRNA或者改变宿主细胞miRNA表达谱直接或间接地干扰很多宿主免疫相关基因的表达,实现逃逸机体免疫清除的目的．因此,miRNA水平的相瓦作用可能是病原微生物与其宿丰展开免疫“博弈”的重要战场．     

Monocyte/Macrophage-Mediated Innate Immunity in HIV-1 Infection:From Early Response to Late Dysregulation and Links to Cardiovascular Diseases Onset

Although monocytes and macrophages are key mediators of the innate immune system, the focus has largely been on the role of the adaptive immune system in the context of human immunodeficiency virus(HIV) infection. Thus more attention and research work regarding the innate immune system—especially the role of monocytes and macrophages during early HIV-1 infection—is required. Blood monocytes and tissue macrophages are both susceptible targets of HIV-1 infection,and the early host response can determine whether the nature of the infection becomes pathogenic or not. For example,monocytes and macrophages can contribute to the HIV reservoir and viral persistence, and influence the initiation/extension of immune activation and chronic inflammation. Here the expansion of monocyte subsets(classical, intermediate and non-classical) provide an increased understanding of the crucial role they play in terms of chronic inflammation and also by increasing the risk of coagulation during HIV-1 infection. This review discusses the role of monocytes and macrophages during HIV-1 pathogenesis, starting from the early response to late dysregulation that occurs as a result of persistent immune activation and chronic inflammation. Such changes are also linked to downstream targets such as increased coagulation and the onset of cardiovascular diseases.     

病原DNA识别及其诱导天然免疫调节机制研究进展

机体天然免疫系统拥有一系列可以探测和抵制微生物侵袭的机制.目前,关于病原RNA的细胞内识别机制有了较为深入的研究和相关报道,但细胞内病原DNA的识别和相应的天然免疫应答机制仍未完全被揭示.阐明上述机制有助于了解和治疗一系列微生物感染相关的疾病,包括病毒和细菌感染类疾病、病毒相关的肿瘤、自身免疫性疾病等.近年来,细胞内多个充当"DNA传感器"的分子和干扰素调节分子被认为在细胞质DNA诱导宿主天然免疫反应过程中起着关键性调节作用.综述了对细胞内病原DNA的主要识别分子、信号通路以及相关的天然免疫调控机制.