组织特异抗原异位表达与免疫耐受

诱导和维持T细胞耐受是免疫系统区分自我和非我的关键。自身免疫调节因子(autoimmune regulator,AIRE)作为转录因子,在胸腺髓质上皮细胞中可驱动一系列组织特异抗原基因的表达,从而在诱导中枢免疫耐受的过程中发挥重要作用。外周免疫耐受的机制复杂一些,清除耐受是其重要机制之一。外周淋巴结的基质细胞可表达部分组织特异抗原,递呈给T淋巴细胞,激活并最终清除它。中枢免疫耐受和外周免疫耐受机制可清除潜在的自身反应性T淋巴细胞,维持对自身组织耐受。一旦免疫耐受被打破,将发生自身免疫反应和自身免疫疾病。     

Fas/FasL与系统性红斑狼疮的关系

Ｆａｓ系统参与淋巴细胞凋亡及自身免疫耐受维持 ,所以 ,Ｆａｓ和ＦａｓＬ基因改变引起的相应蛋白质分子变化所导致的功能丧失 ,可能与自身免疫病的发生密切相关。Ｆａｓ基因和ＦａｓＬ基因的功能缺失会引起小鼠产生淋巴增生 (ｌｙｍｐｈｏｐｒｏｌｉｆｅｒａｔｉｏｎ ,ｌｐｒ)和广泛性淋巴增生病 (ｇｅｎｅｒａｌｉｚｅｄｌｙｍｐｈｏｐｒｏｌｉｆ ｅｒａｔｉｏｎｄｉｓｅａｓｅ ,ｇｌｄ)两种类似人类系统性红斑狼疮 (ＳＬＥ)的自身免疫病[1] 。这两种小鼠出现淋巴结病和脾肿大 ,产生大量的ＩｇＧ和ＩｇＭ型自身抗体 ,包括抗ＤＮＡ抗体和类…     

粘膜耐受在预防和治疗自身免疫病中的作用

粘膜应用自身抗原诱导外周免疫耐受状态 ,依赖应用抗原剂量 ,诱导产生两种粘膜耐受机制 :高剂量偏向产生T细胞克隆无能 /排除 ,低剂量偏向产生分泌抑制性细胞因子(TGF β ,IL 4,IL 10 )的T细胞克隆扩增。大量研究表明鼻内或口服应用抗原诱导粘膜耐受可有效预防几种实验性自身免疫病 (EAE ,EAMG ,EAN ,EAU ,IDDM和CIA) ,在同等剂量鼻内应用比口服诱导粘膜耐受更有效。基于动物实验结果 ,对人类自身免疫病MS、RA和葡萄膜炎的临床试验正在进行。耐受原与CTB偶联可拓宽粘膜耐受的有效性 ,加强对临床疾病的抑制。然而 ,粘膜免疫与抗原应用途径、种类和疾病发病时间有关 ,可能表现为双重作用 ,尤其在发展中的自身免疫病 ,粘膜应用抗原可能加重病情。     

通过目标区域测序寻找新的自身免疫性甲状腺疾病候选基因及相关位点

自身免疫性甲状腺疾病(autoimmune thyroid disease, AITD)是一种主要由T细胞介导的器官特异性自身免疫性疾病,包括格雷夫斯病(Graves disease, GD)和桥本甲状腺炎(Hashimoto thyroiditis, HT),其发病率与遗传因素紧密相关。本研究旨在确定与AITD相关的易感基因及位点。本研究通过对100例AITD(51例HT和49例GD)患者和50例健康体检者的基因组进行目标区域测序,并对基因多态性与AITD之间的相关性进行了统计学分析,进一步进行连锁分析找到易感基因及相关位点。本研究发现了BACH2基因的5个单核苷酸多态性(single nucleotide polymorphism, SNP)位点(rs12205059、 rs62408219、 rs7742121、 rs7756574、 rs12204886)完全连锁,ARID5B基因10个SNP位点(rs12778514、 rs3740354、 rs3740353、 rs9633555、 rs9633557、 rs9633534、 rs3740352、 rs2393730、 rs...     

MiRNA在自身免疫性心肌炎中的研究进展

自身免疫性心肌炎(autoimmune myocarditis,AMC)常因机体的细胞和体液免疫功能障碍，引发心肌组织周围炎症细胞浸润，诱发自身免疫反应，进而逐渐发展为慢性损伤和扩张性心肌病，严重影响患者的预后。微小核糖核酸(microRNA,miRNA)常在自身免疫性心肌炎中表达失调，调控基因表达或免疫细胞激活与分化，参与调节心肌细胞的生长和凋亡。本文分别从miRNA在自身免疫性心肌炎中的潜在作用机制、诊断及预后的生物标志物及治疗方面，对miRNA在自身免疫性心肌炎中的研究进展及存在的问题进行简要阐述。     

TLR/MyD88信号通路与自身免疫性疾病

Toll样受体(Toll-like receptor,TLR)是近年来发现的一类模式识别受体,通过识别病原相关分子模式(pathogen-associated molecular pattern,PAMP),激活天然免疫.TLR信号还通过上调抗原提呈细胞(antigen presenting cells,APC)表面共刺激分子及APC分泌的炎症细胞因子调节获得性免疫.TLR/MyD88信号在自身免疫性疾病的发病过程中起重要作用.本文介绍了TLR/MYD88信号通路及其在自身免疫病如实验性自身免疫脑脊髓膜炎、类风湿性关节炎、实验性自身免疫性葡萄膜炎、实验性自身免疫性心肌炎和自身免疫性肾小球肾炎等发生发展中的作用.     

调节性T细胞抑制作用机制的研究进展

调节性T细胞(Treg)对维持机体免疫动态平衡具有重要作用。不仅诱导产生自身免疫耐受,防止自身免疫疾病的发生,而且能够限制免疫防御中T、B细胞过度活化,避免造成组织损伤。最近研究发现,Treg可能导致效应性免疫细胞失活,降低机体对肿瘤和病原的免疫应答。尽管Treg可能通过调节免疫细胞活化、增值和分化及效应等多环节产生抑制作用,但其抑制机制仍未清楚。本文对近几年国外研究Treg可能的抑制作用机制的进展作一综述。     

实验性自身免疫性心肌炎动物模型的建立与评价

实验性自身免疫性心肌炎动物模型（ experimental autoimmune myocarditis, EAM）作为自身免疫性心肌炎机制、诊断、药物治疗等实验研究的重要载体,在心肌炎科学研究中发挥着重要的作用。本文针对EAM模型的建立及评价予以综述,分别对心肌自身抗原、心肌自身抗原表位、活化自身免疫细胞、干酪乳杆菌细胞壁成分等介质诱导的EAM模型进行整理总结,分析比较各造模方法的特点并阐述EAM模型的评价方法,为建立客观的EAM模型提供有效依据。     

自身免疫病的分子遗传学

自身免疫病影响着大约5％的人口,这类疾病的特点是患者体内存在大量的针对自身抗原的自身抗体,这些自身抗体通过不同的模式引起机体的损伤。一些严重的自身免疫病如类风湿性关节炎、系统性红斑狼疮可引起致残和死亡。总之,自身免疫病的发病率和致残率呈现出一个全球性的健康问题。由于这种健康问题巨大的严重性和广泛性,引起了全球性的自身免疫病病因学的研究热潮。多代家系和大量双胞胎的流行病学调查清晰的显示自身免疫病遗传因素的存在。至少有20多个疾病易感基因被认为与环境因素相互作用引起自身免疫病的发生和发展。基于这种遗传研究热潮,多个遗传研究小组采用基因组范围的易感基因的扫描工作,在人类和鼠模型中鉴定出多个遗传易感位点,这些位点可能含有自身免疫病的致病基因。本文就人类和鼠模型中定位的易感基因位点作一综述。     

细胞因子与自身免疫性甲状腺疾病的相关性研究进展

自身免疫性甲状腺疾病(autoimmune thyroid disease,AITD)是内分泌系统的一种常见疾病,其具体发病机制尚不明确。AITD是遗传、免疫等因素综合作用的结果。细胞因子是一类具有调节免疫反应能力的小分子蛋白质。本文主要介绍了白细胞介素、干扰素、肿瘤坏死因子与AITD发生发展的关系,综述了其参与AITD的发病机制及作为AITD预测因子的可能性,为细胞因子作为AITD的诊断途径及治疗靶点提供新思路。     

Autoimmune regulator (AIRE) gene is expressed in human activated CD4+ T-cells and regulated by mitogen-activated protein kinase pathway

The autoimmune regulator (AIRE) gene is a gene responsible for autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy. Here we show that AIRE is expressed in human peripheral CD4-positive T-cells, and most highly in antigen-and interleukin 2-stimulated T (IL-2T) cells. Mitogen-activated protein kinases (MAPKs), including MAPK kinase (MEK) 1/2 and p38 MAPK, were phosphorylated in IL-2T cells and the expression of the AIRE gene was inhibited by a specific p38 MAPK inhibitor (SB203580), thereby indicating that AIRE gene expression is controlled by the MAPK pathway in IL-2T cells. These data suggested the possible significance of the AIRE gene in the peripheral immune system.     

Regulation of human autoimmune regulator (AIRE) gene translation by miR-220b

Although mutations of autoimmune regulator (AIRE) gene are responsible for autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), presenting a wide spectrum of many characteristic and non-characteristic clinical features, some patients lack AIRE gene mutations. Therefore, something other than a mutation, such as dysregulation of AIRE gene, may be a causal factor for APECED or its related diseases. However, regulatory mechanisms for AIRE gene expression and/or translation have still remained elusive. We found that IL-2-stimulated CD4⁺ T (IL-2T) cells showed a high expression of AIRE gene, but very low AIRE protein production, while Epstein–Barr virus-transformed B (EBV-B) cells express both AIRE gene and AIRE protein. By using microarray analysis, we could identify miR-220b as a possible regulatory mechanism for AIRE gene translation in IL-2T cells. Here we report that miR-220b significantly reduced the expression of AIRE protein in AIRE gene with 3′UTR region transfected 293T cells, whereas no alteration of AIRE protein production was observed in the open reading frame of AIRE gene alone transfected cells. In addition, anti-miR-220b reversed the inhibitory function of miR-220b for the expression of AIRE protein in AIRE gene with 3′UTR region transfected cells. Moreover, when AIRE gene transfected cells with mutated 3′UTR were transfected with miR-220b, no reduction of AIRE protein production was observed. Taken together, it was concluded that miR-220b inhibited the AIRE gene translation through the 3′UTR region of AIRE gene, indicating that miR-220b could serve as a regulator for human AIRE gene translation.     

The immune response to melanoma is limited by thymic selection of self-antigens

The expression of melanoma-associated antigens (MAA) being limited to normal melanocytes and melanomas, MAAs are ideal targets for immunotherapy and melanoma vaccines. As MAAs are derived from self, immune responses to these may be limited by thymic tolerance. The extent to which self-tolerance prevents efficient immune responses to MAAs remains unknown. The autoimmune regulator (AIRE) controls the expression of tissue-specific self-antigens in thymic epithelial cells (TECs). The level of antigens expressed in the TECs determines the fate of auto-reactive thymocytes. Deficiency in AIRE leads in both humans (APECED patients) and mice to enlarged autoreactive immune repertoires. Here we show increased IgG levels to melanoma cells in APECED patients correlating with autoimmune skin features. Similarly, the enlarged T cell repertoire in AIRE(-/-) mice enables them to mount anti-MAA and anti-melanoma responses as shown by increased anti-melanoma antibodies, and enhanced CD4(+) and MAA-specific CD8(+) T cell responses after melanoma challenge. We show that thymic expression of gp100 is under the control of AIRE, leading to increased gp100-specific CD8(+) T cell frequencies in AIRE(-/-) mice. TRP-2 (tyrosinase-related protein), on the other hand, is absent from TECs and consequently TRP-2 specific CD8(+) T cells were found in both AIRE(-/-) and AIRE(+/+) mice. This study emphasizes the importance of investigating thymic expression of self-antigens prior to their inclusion in vaccination and immunotherapy strategies.