TLR9、IFN-α和BAFF水平与系统性红斑狼疮的相关性研究

目的检测系统性红斑狼疮(SLE)患者外周血单个核细胞(PBMCs)Toll样受体(TLR)-9 mRNA及血清干扰素(IFN)-α、B细胞活化因子(BAFF)水平,探讨TLR9与SLE疾病活动的关系及与IFN-α、BAFF在SLE发病中可能的相互作用。方法应用实时荧光定量聚合酶链反应(real-time PCR)检测40例SLE患者及20例健康对照者PBMCs中TLR9 mRNA水平;采用酶联免疫吸附法(ELISA)检测60例SLE患者及20例健康对照者血清IFN-α、BAFF水平。结果 1SLE患者外周血单个核细胞TLR9 mRNA表达水平较健康对照组上调(P0.05);TLR9 mRNA表达水平与SLE疾病活动指数(SLEDAI)、血沉(ESR)呈正相关(P0.01,P0.05);与补体3(C3)呈负相关(P0.05)。2SLE患者血清中BAFF、IFN-α水平高于健康对照(P均0.05);BAFF、IFN-α水平均与SLEDAI呈正相关(P0.05)。3SLE患者中抗ds-DNA抗体阳性者TLR9 mRNA、BAFF与IFN-α水平高于阴性者(P均0.05)。4SLE患者外周血单个核细胞TLR9mRNA表达水平与血清中BAFF、IFN-α水平正相关(P0.01);血清中BAFF与IFN-α呈正相关(P0.05)。结论 SLE患者外周血单个核细胞TLR9 mRNA表达上调,血清中BAFF、IFN-α分泌增加,均与疾病活动相关。SLE患者外周血单个核细胞TLR9 mRNA表达与血清IFN-α、BAFF水平之间及BAFF和IFN-α之间均呈显著正相关,提示TLR9、BAFF及IFN-α参与了人类SLE的发病过程并相互调控,在SLE疾病活动维持中起重要作用。     

Toll样受体7及I型干扰素通路在系统性红斑狼疮中的作用研究

探讨Toll样受体7(TLR7)及I型干扰素(IFN-α)通路在系统性红斑狼疮(SLE)发病中的作用。采用实时荧光定量PCR方法检测42例SLE患者和34例正常人外周血TLR7mRNA以及4个干扰素调节基因mRNA的表达水平,同时观察TLR7mRNA的表达量与SLE疾病活动相关指标和干扰素积分(IFN score)的关系。结果,SLE患者外周血TLR7mRNA的表达水平显著增高;TLR7mRNA的表达水平与SLEDAI积分、肾脏损伤指数、抗双链DNA(dsDNA)抗体、抗RNA相关抗体水平及干扰素积分呈正相关;与补体C3、C4、白细胞数呈负相关。TLR7—IFN-α通路可能参与了SLE的病理过程。     

JMJD3参与IFN-α和TLR7诱导的B细胞活化及凋亡

目的:探索组蛋白去甲基化酶JMJD3对B细胞活化和凋亡的影响。方法:磁珠分选纯化正常人及SLE患者外周血B细胞,用IFN-α、R848或IFN-α+R848处理纯化的B细胞,流式细胞仪检测CD86+或CD69+的细胞百分率以及CD86+Annexin V+或CD69+Annexin V+的细胞百分率;实时定量PCR和Western blot方法检测JMJD3的表达。结果:获得的B细胞纯度高达95%;IFN-α能够增强TLR7对B细胞的活化和凋亡;IFN-α也增加TLR7信号诱导的B细胞表达JMJD3,且JMJD3高表达依赖于MAPK通路,而不是NF-κB信号通路;SLE患者外周血B细胞高表达JMJD3,且JMJD3抑制剂能够抑制IFN-α+R848诱导的CD19+B细胞活化及凋亡。结论:JMJD3参与IFN-α和TLR7诱导的B细胞活化及凋亡,提示JMJD3抑制剂可能具有缓解SLE症状的作用。     

干扰素和肿瘤坏死因子对人脐静脉内皮细胞表达HLA-Ⅱ类抗原的影响

采用cell-ELISA法对IFN-α、γ及rTNFα单独或协同影响人脐静脉内皮细胞（HUVEC）表达HLA-Ⅱ类抗原作了定量观察。结果表明,IFNγ直接刺激 HUVEC可依浓度和时间依赖的方式提高其 HLA-Ⅱ类抗原表达量,而rTNFα、IFNα单独处理HUVEC无效。当rTNFα和IFNγ同时诱导时,对HUVEC表达HLA-DR、DP、DQ均表现抑制作用。但是,当先用IFNγ诱导HUVEC 24h后,再加入rTNFα则发现DR、DP、DQ的表达升高,起促进作用。     

Toll 样受体7及Ⅰ型干扰素通路在系统性红斑狼疮中的作用研究

探讨Toll样受体7(TLR7)及Ⅰ型干扰素(IFN-α)通路在系统性红斑狼疮(SLE)发病中的作用.采用实时荧光定量PCR方法检测42例SLE患者和34例正常人外周血TLR7mRNA以及4个干扰素调节基因mRNA的表达水平,同时观察TLR7mRNA的表达量与SLE疾病活动相关指标和干扰素积分(IFN score)的关系.结果,SLE患者外周血TLR7mRNA的表达水平显著增高;TLR7mRNA的表达水平与SLEDAI积分,肾脏损伤指数、抗双链DNA(dsDNA)抗体、抗RNA相关抗体水平及干扰素积分呈正相关;与补体C3、C4、白细胞数呈负相关.TLR7-IFN-α通路可能参与了SLE的病理过程.     

IFN-γ诱导人单核细胞MICs分子表达

目的：研究IFN-γ对MHC—I类链相关分子（MICs）表达的调节作用。方法：采用密度梯离离心法分离人外周血单个核细胞（PBMC），以免疫磁珠法从PBMC中特异性分选单核细胞，以细胞因子IFN-γ、TNF-α或IFN—α刺激PBMC、纯化单核细胞或单核细胞系U937、THP-1后，以流式细胞术检测单核细胞表面MICs分子表达。结果：IFN-γ选择性上调人PBMC中单核细胞表面MICs表达；IFN-γ对人原代单核细胞及单核细胞系U937、THP-1细胞表面MICs分子表达均有诱导或上调作用，细胞因子TNF—α、IFN—α对单核细胞MICs分子表达无影响。IFN-γ诱导或上调表达的MICs分子不能被MICA或MICB特异性单克隆抗体（mAb）所识别，可能是一种新的MIC分子或MIC等位基因。结论：IFN-γ能诱导或上调人单核细胞表面MICs分子表达。     

Ⅰ型干扰素参与调节SLE外周T细胞活化和TLR表达谱的研究

血清高水平Ⅰ型干扰素(typeⅠinterferon)是系统性红斑狼疮(SLE)患者重要的病理特征之一,外周高水平IFN-α对T细胞的免疫调节作用值得深入探讨。本研究首先比较分析了SLE患者外周血T细胞活化和TLR分子表达格局,结果显示SLE患者外周血CD4~+或CD8~+T细胞和正常人相比呈现出更加活化的表型变化,其表面活化标志CD69和HLA-DR表达阳性率均高于正常人;分析T细胞表达TLR分子格局发现,SLE患者较正常人T细胞中TLR分子的表达有明显升高,其中CD4~+T细胞中TLR8和TLR9的升高明显,而在CD8~+T细胞中明显升高的TLR分子有TLR3和TLR8;结合SLE病理状态下外周高水平IFN-α的持续存在,我们进一步分析了IFN-α对正常T细胞活化和TLR分子表达谱的影响,结果显示IFN-α协同TCR信号可以促进T细胞的活化,并上调T细胞中部分TLR分子的表达,其中CD4~+和CD8~+T细胞中TLR8的表达均明显上升。综合分析SLE患者和经IFN-α活化的正常T细胞的活化和TLR分子表达谱的变化格局,提示SLE病理状态下高水平的Ⅰ型干扰素可以与T细胞的持续活化有关,其对T细胞表达TLR分子格局的影响,特别是与核酸类分子配体相关的TLR分子的表达增高为内源性核酸类配体参与T细胞的活化提供了分子基础。     

浆细胞样树突状细胞在感染性、免疫性疾病中的研究进展

浆细胞样树突状细胞（PDC）来源于淋巴系造血干／祖细胞,能选择性的诱导免疫应答,并在一定条件下诱导免疫耐受,在抗病毒感染中起重要作用,并可能参与了某些自身免疫性疾病的发生。PDC产生的Ⅰ型IFN（IFN-α／β）在抗病毒过程中很关键,而一定条件下PDC诱导的免疫耐受与调节性T细胞的产生相关。自身免疫性疾病中持续高水平的Ⅰ型IFN提示PDC可能参与此类疾病的发病机制。     

细胞因子对HLA-B27启动子的调节作用及其在强直性脊柱炎发病机制中的意义

目的： 构建含HLA-B27启动子的HeLa稳定转染细胞株，观察7种细胞因子对HLA-B27启动子及其上游NF-κB及ISRE顺式作用元件活性的调节作用，探讨强直性脊柱炎（AS）等B27相关疾病的发生机制。方法:转染HeLa细胞，抗生素筛选单克隆构建含HLA-B27启动子的稳定转染细胞株。构建HeLa-B27稳定细胞株和HeLa-NF-κB稳定细胞株，在瞬时转染pISRE-luc的HeLa细胞中加入白细胞介素1α（IL-1α）、 白细胞介素1β（IL-1β）、 肿瘤坏死因子α（TNF-α）、干扰素α（IFN-α）、干扰素β（IFN-β）、 干扰素γ（IFN-γ）和转化生长因子β（TGF-β），观察7种细胞因子对B27启动子及其上游NF-κB和ISRE作用元件的调节作用。另外在HeLa-B27 稳定细胞株培养液中同时加入3种细胞因子单克隆抗体和相应细胞因子，观察其对启动子活性的调节作用。结果:TNF-α、IFN-α、IFN-β 和 IFN-γ 均能明显增强HeLa细胞B27启动子活性。细胞培养96 h 后，IFN-β为最强的启动子诱导剂（5.4倍，P<0.05）；细胞培养8 h 内，TNF-α、IL1-α 和 IL1-β,可诱导NF-κB的活性增加30倍左右（P<0.05），IFN-α 和IFN-β 可诱导ISRE的活性增加12倍左右（P<0.05），抗TNF-α 抗体对于I类IFN 增加的B27 启动子活性没有明显的抑制作用。结论：TNF-α和IFN 可通过结合于B27 启动子中各种转录因子结合元件调控HLA-B27启动子的转录活性，IFN-β 可能在强直性脊柱炎等B27 相关的脊柱关节病的发病机制中起着重要作用。     

Toll样受体2和Toll样受体4在HBV感染后的免疫作用

Toll样受体（TLR）是启动固有免疫和调节适应性免疫的重要分子,参与肝脏对病毒及细菌的免疫TLR2、TLR4过程。在HBV的慢性化进程中,TLR2、TLR4与Thl和Th2的免疫平衡及调节性T细胞（Treg）的免疫抑制相关,HBV感染后,HBcAg刺激巨噬细胞产生TNF—α的作用需要TLR2参与,HBeAg的表达与否与TLR2的表达状态有关,而TLR4通过诱导iNOS的表达和激发HBV特异性免疫在体内抗HBV过程中起重要作用：     

Role of Natural Interferon-α Producing Cells (Plasmacytoid Dendritic Cells) in Autoimmunity

The type I interferons (IFNs) have antiviral, cytostatic and prominent immunomodulatory effects, which all are of great importance during viral infections. However, prolonged exposure of the immune system to type I IFN can break tolerance and initiate an autoimmune reaction, eventually leading to autoimmune disease. Recent observations in patients with systemic lupus erythematosus (SLE) have revealed that such individuals have endogenous IFN-α inducers, causing an ongoing IFN-α production and consequently a continuous stimulation of the immune system. These IFN-α inducers consist of small immune complexes (IC) containing DNA or RNA and act on the principal IFN-α producing cell, the natural IFN-α producing cell (NIPC), also termed the plasmacytoid dendritic cell (PDC). The NIPC/PDC is a key cell in both the innate and adaptive immune response but can also, either directly or via produced IFN-α, have a pivotal role in autoimmunity. In this review we summarize recent data concerning NIPC/PDC, including their activation, regulation, function and possible role in autoimmune diseases, especially SLE.     

The genetics and biology of Irf5-mediated signaling in lupus

Recently much attention was attracted to the importance of the type I interferon pathway in the initiation and development of the autoimmune disease systemic lupus erythematosus (SLE). Many SLE patients have increased serum levels of IFN-α and display an IFN gene expression “signature” characterized by strong overexpression of IFN-responsive genes in leukocytes and target tissues. Moreover, about 20% of cancer patients treated with IFN-α therapy manifest symptoms resembling SLE and some later develop the disease. One of the key genes of the IFN-α pathway, IRF5, was found to be strongly associated with SLE. Two functional SNPs lead to alternative splicing and altered steady-state level of IRF5 gene expression. Besides, the gene has a polymorphic inserion/deletion in exon 6, which contributes to the diversity in the isoform pattern of IRF5. Interestingly, recent studies have not found association of IRF5 with the other autoimmune diseases, such as rheumatoid arthritis or psoriasis, suggesting the unique role for IRF5 in the development of lupus. Here, we present the current knowledge on IRF5 genetics and its biological function and discuss the possible ways in which IRF5 contributes to susceptibility to SLE.     

Interferon alpha as a primary pathogenic factor in human lupus

Interferon alpha (IFN-α) is a critical mediator of human systemic lupus erythematosus (SLE). This review will summarize evidence supporting the role for IFN-α in the initiation of human SLE. IFN-α functions in viral immunity at the interface of innate and adaptive immunity, a position well suited to setting thresholds for autoimmunity. Some individuals treated with IFN-α for chronic viral infections develop de novo SLE, which frequently resolves when IFN-α is withdrawn, supporting the idea that IFN-α was causal. Abnormally high IFN-α levels are clustered within SLE families, suggesting that high serum IFN-α is a heritable risk factor for SLE. Additionally, SLE-risk genetic variants in the IFN-α pathway are gain of function in nature, resulting in either higher circulating IFN-α levels or greater sensitivity to IFN-α signaling in SLE patients. A recent genome-wide association study has identified additional novel genetic loci associated with high serum IFN-α in SLE patients. These data support the idea that genetically determined endogenous elevations in IFN-α predispose to human SLE. It is possible that some of these gain-of-function polymorphisms in the IFN-α pathway are useful in viral defense, and that risk of SLE is a burden we have taken on in the fight to defend ourselves against viral infection.     

干扰素治疗相关的自身免疫性副作用研究进展

干扰素(IFNs)是一种广泛存在的具有强烈抗病毒作用的细胞因子,IFN-α被认为是目前慢性乙型肝炎和丙型肝炎的标准治疗方法.病毒感染时,尤其是丙型肝炎病毒(HCV)感染,包含核酸的免疫复合物诱导的IFN-α产生增加,持续性的免疫系统激活诱导自身免疫性损伤.IFN为基础的治疗可以加重这种自身免疫损伤.IFNs可以影响多种类型的细胞,使多个系统受到影响.因此,用IFN-α治疗的患者可以出现广谱的自身免疫性疾病,如自身免疫性甲状腺、风湿性关节炎、冷球蛋白血症、结节病、系统性红斑狼疮、1型糖尿病和重症肌无力等.     

Interferon-α induces unabated production of short-lived plasma cells in pre-autoimmune lupus-prone (NZB×NZW)F1 mice but not in BALB/c mice

IFN-α is known to play a critical role in the pathogenesis of systemic lupus erythematosus (SLE), but the mechanisms remain unclear. We previously showed that within weeks, exposure to IFN-α in vivo induces lupus in pre-autoimmune lupus-prone NZB×NZW F1 (NZB/W) but not in BALB/c mice. In the current study, we show that in vivo expression of IFN-α induces sustained B-cell proliferation in both BALB/c and NZB/W mice. In NZB/W but not BALB/c mice, B-cell proliferation was accompanied by a rapid and unabated production of autoantibody-secreting cells (ASCs) in secondary lymphoid organs, suggesting that a B-cell checkpoint is altered in the autoimmune background. The majority (>95%) of ASCs elicited in IFN-α-treated NZB/W mice were short-lived and occurred without the induction of long-lived plasma cells. A short course of cyclophosphamide caused a sharp drop in IFN-α-elicited short-lived plasma cells, but the levels recovered within days following termination of treatment. Thus, our work provides new insights into effectiveness and limitations of the current SLE therapies.     

Patients with systemic lupus erythematosus (SLE) have a circulating inducer of interferon-alpha (IFN-α) production acting on leucocytes resembling immature dendritic cells

Patients with active SLE often have an ongoing production of IFN-α. We therefore searched for an endogenous IFN-α-inducing factor (IIF) in SLE patients and found that their sera frequently induced production of IFN-α in cultures of peripheral blood mononuclear cells (PBMC) from healthy blood donors, especially when the PBMC were costimulated with the cytokines IFN-α2b and granulocyte-macrophage colony-stimulating factor (GM-CSF). The phenotype of the IFN-α-producing cells (IPC) as determined by flow cytometry corresponded to that of the natural IPC, resembling immature dendritic cells. The IIF activity in SLE sera was sometimes as high as that of a virus and was present especially in patients with active disease and with measurable IFN-α levels in serum. The IIF had an apparent molecular weight of 300–1000 kD and appeared to consist of both immunoglobulin and DNA, possibly being immune complexes. This endogenous IFN-α inducer may be of pathogenic significance, since a reported occasional adverse effect of IFN-α therapy in patients with non-autoimmune disorders is development of anti-dsDNA antibodies and SLE.     

The role of dead cell clearance in the etiology and pathogenesis of systemic lupus erythematosus: dendritic cells as potential targets

Overwhelming apoptosis combined with a deficiency in clearing apoptotic cells is thought to be an important etiopathogenic event in the autoimmune disease systemic lupus erythematosus (SLE). Lazy macrophages, complement or DNase I deficiency as well as insufficient natural IgM might be important factors leading to such a clearance deficiency. A defective clearance of apoptotic cells leads to the activation and maturation of plasmacytoid and myeloid dendritic cells (DCs) by material derived from secondary necrotic cells carrying modified autoantigens. This results in the presentation of autoantigens to autoreactive T and B cells in an immunogenic manner, thereby leading to autoantibody production, chronic inflammation and severe tissue damage. Since DC activation and IFN-α production by plasmacytoid dendritic cells play a critical role in the course of SLE pathogenesis, therapeutic intervention to end this vicious cycle might be a promising approach for treating the disease.