共刺激信号分子表达异常与自身免疫性疾病的关系

目的 分析类风湿性关节炎（RA）和系统性红斑狼疮（SLE）细胞免疫异常中共刺激活化信号途径的异同点,探讨细胞活化的共刺激信号途径对于RA和SLE发病的意义。方法 采用流式细胞术分析SLE和RA患者T细胞表面共刺激分子CD28、CD152／CTLA-4、CD154／CD40L和ICOS表达情况。结果 ①RA患者CD4^＋T细胞比例明显增加,SLE患者以CD8^＋T细胞增加显著。②SLE患者CD4^＋和CD8^＋T细胞上CD28和CD152的表达增加;RA患者T细胞亚群上CD28分子的表达减少,CD152分子的表达增加。③RA患者CD4^＋T细胞上CD154分子表达增加,CD8^＋T细胞上CD154分子表达减少,T细胞亚群上可诱导共刺激分子（ICOS）的表达无明显变化;SLE患者CD4^＋和CD8^＋T细胞上CD1254或ICOS分子的表达均减少。结论 RA和SLE患者机体的免疫异常中存在着明显的分子信号途径差异。     

共刺激分子CD40L在RA患者T细胞亚群中的异常表达

目的　探讨共刺激分子CD4 0L在类风湿关节炎 (RA)患者的T细胞亚群上的表达异常与免疫功能紊乱的关系。方法　用流式细胞仪采用直接免疫荧光法测定 4 6例RA患者和 2 0例健康对照人外周血T细胞表面标志CD3、CD4、CD8的表达情况及CD4 0L在CD4 + T和CD8+ T细胞上的表达。用IMMAGE免疫分析仪 ,速率散射比浊法测定血清中免疫球蛋白的水平。结果　RA患者CD3+ CD4 + 细胞较正常对照组显著增高 (P <0 .0 5 ) ,CD3+ CD8+ 细胞较正常对照组显著降低 (P <0 .0 5 ) ,CD4 + T细胞和CD8+ T细胞上的CD4 0L的表达都较对照组显著增高 (P <0 .0 5 ) ;血清中 3种免疫球蛋白IgG、IgA、IgM的水平均较对照组显著增高 (P <0 .0 5 )。结论　RA患者以CD4 + T细胞活化为主 ,CD4 + T细胞和CD8+ T细胞上高表达的CD4 0L为T细胞活化提供第二信号 ,促使RA患者的细胞免疫功能亢进 ,同时诱导B细胞增生 ,产生大量免疫球蛋白。CD4 0 CD4 0L途径在RA免疫功能紊乱中起了重要作用     

CD40-CD40L共刺激分子与自身免疫性疾病

大量研究证实CD4 0分子与其配体CD4 0L结合所产生的共刺激信号在B细胞的增殖、分化、抗体的分泌和类型转换以及T细胞活化、效应性细胞因子分泌中起重要作用。近年来发现 ,CD4 0、CD4 0L异常表达与一些疾病的免疫病理密切相关。本文仅就CD4 0 CD4 0L的生物学特性、功能和在自身免疫性疾病中的致病作用及其可能的治疗策略作一综述     

129 CD40-CD40L共刺激分子与自身免疫性疾病

大量研究证实CD40分子与其配体CD40L结合所产生的共刺激信号在B细胞的增殖、分化、抗体的分泌和类型转换以及T细胞活化、效应性细胞因子分泌中起重要作用.近年来发现,CD40、CD40L异常表达与一些疾病的免疫病理密切相关.本文仅就CD40-CD40L的生物学特性、功能和在自身免疫性疾病中的致病作用及其可能的治疗策略作一综述.     

CD40—CD40L共刺激分子与自身免疫性疾病

大量研究证实CD40分子与其配体CD40L结合所产生的共刺激信号在B细胞的增殖、分化、抗体的分泌和类型转换以及T细胞活化、效应性细胞因子分泌中起重要作用。近年来发现,CD40、CD40L异常表达与一些疾病的免疫病理密切相关。本文仅就CD40－CD40L的生物学特性、功能和在自身免疫性疾病中的致病作用及其可能的治疗策略作一综述。     

Fas／Apo—1（CD95）系统与细胞凋亡研究新进展

Ｆａｓ／Ａｐｏ－１（ＣＤ９５）系统与机体免疫功能和细胞凋亡的关系十分密切，近几年来一直是免疫学家和临床医师关注的热点。本文综述了Ｆａｓ／Ａｐｏ－１在Ｉｐｒ突变小鼠和胸腺Ｔ细胞发育中研究的新进展，重点阐述了Ｆａｓ／Ａｐｏ－１系统诱导凋亡的分子机理。     

共刺激分子CD28：CTLA4／B7及CD40／CD40L和SLE

共刺激分子CD28：TCLA-4／B7和CD40／CD40L对B细胞的增殖、分化、抗体的分泌和T细胞的活化、细胞因子的分泌具有重要作用，其对系统性红斑狼疮的发生、发展具有重要的促进作用。本文综述了CD28：TCLA-4／B7和CD40／CD40L生物学特性、功能及在系统性红斑狼疮发生、发展中的作用，以及免疫学治疗的临床应用前景。     

共刺激分子与类风湿性关节炎患者T细胞的平衡失控

共刺激分子和凋亡受体CD95(Fas)分子的异常表达与T细胞的异常活化及其亚群平衡偏移密切相关，本研究拟通过对类风湿性关节炎(RA)患者T细胞亚群上表面CD30和CD95分子表达的检测，探讨细胞信号分子在参与RA免疫紊乱中的作用。     

关节炎中B7:CD28/CTLA-4共刺激途径的实验研究

目的：探讨Ｂ＆：ＣＤ２８／ＣＴＬＡ－４共刺激信号大关节炎发病机制中的作用。方法：经牛Ⅱ型胶原诱导ＳＤ大鼠建立关节炎动物模型;采用ＣＴＬＡ－４Ｉｇ作为负性调节因子,分析其对关节炎大鼠中特异性体液反应和组织病理学表现的影响。结果：ＣＴＬＡ＿４Ｉｇ可阻止ＳＤ大鼠发生胶原诱发 关节炎,降低大导ＢＩＩＣ的体液免疫反应。结论：Ｂ７：ＣＤ２８／ＣＴＬＡ－４共刺激信号在诱发Ｔ细胞介导的自身免疫病中起作用,ＣＴＬＡ     

小鼠树突状细胞表面PD-L1分子对T淋巴细胞协同刺激效应的研究

目的：琛讨小鼠髓系DCs表面PD-L1分子在树突状细胞介导T细胞免疫应答中的作用。方法：采用流式细胞术分别检测未成熟DCs和凋亡肿瘤细胞负载并经CD40配基化的成熟DCs表面免疫分子的表达；混合淋巴细胞反应(MLR)和抗PD-L1单抗阻断试验分析未成熟DCs和成熟DCs表达的PD-L1分子对T淋巴细胞的协同刺激／抑制效应；^3H-TdR掺入试验检测未成熟DCs和成熟DCs对T淋巴细胞的促增殖效应；ELISA测定各组MLR反应上清中IL-10、IFN-γ的分泌水平；MTT比色法检测成熟DCs激发的肿瘤抗原特异性CTL对肿瘤细胞的杀伤效应。结果：未成熟DCs表面高表达PD-L1，负性调节未成熟DCs对自体T淋巴细胞的促增殖作用，抑制T细胞分泌IL-10、IFN-γ；凋亡肿瘤细胞负载并经CD40配基化的成熟DCs中等水平表达PD-L1，具有显著增强对自体T细胞的体外激发、扩增和细胞毒效应的作用，并可增加T细胞的IFN-γ分泌。结论：未成熟DCs高表达PD-L1抑制了对T细胞共刺激效应；CD40配基化成熟的DCs中度表达。PD-L1有助于激发T细胞介导免疫应答。     

Aberrant integrin activation induces p38 MAPK phosphorylation resulting in suppressed Fas-mediated apoptosis in T cells: Implications for rheumatoid arthritis

Delayed Fas-mediated apoptosis in T cells is associated with inflammatory diseases including rheumatoid arthritis (RA). CD3⁺ T cells in RA synovia expressed high amounts of phospho-p38 MAPK. Exposure to RA synovial fluid or soluble collagen, a degradation product of extracellular matrix abundant in RA synovium, induced the phosphorylation of p38 MAPK in Jurkat T cells accompanied by resistance against Fas-mediated apoptosis. Blocking β1 integrin by antibody diminished this effect. In addition, ectopic expression of auto-activated β1 integrin variant in T cells profoundly induced the phosphorylation of p38 MAPK. Suppression of p38 MAPK sensitized T cells to Fas-mediated apoptosis and increased caspase-8 and caspase-3 cleavage. A physical interaction of p38 MAPK and caspase-8 was demonstrated by using confocal microscopic imaging and co-immunoprecipitation assay. RA synovial fluid markedly increased the formation of phospho-p38 MAPK/caspase-8 complex in Jurkat T cells. In conclusion, abnormal activation of p38 MAPK to prevent Fas-mediated apoptosis may represent a common survival mechanism of RA synovial T cells contributing to the persistent inflammation of affected synovium.     

T细胞凋亡受体和共刺激分子的表达变化与终末期肾功能衰竭患者细胞免疫功能的关系研究

目的：探究终末期肾功能衰竭患者T细胞亚群的凋亡受体CD95分子与共刺激分子CD28、CDl52（CTLA-4）的表达与细胞免疫功能的关系。方法：采用流式细胞术检测外周血T细胞的凋亡受体CD95（Fas）与共刺激分子CD28／CDl52表达。结果：终末期肾功能衰竭患者CD3^＋T细胞和CD4^＋T细胞比例明显高于健康对照组，CD4／CD8比值增加（P=0．008），CD4^＋T细胞和CD8^＋T细胞上CD95分子表达均上调（P=0．001），以CD8^＋T细胞上CD95分子增加更为明显；CD28和CD152分子在不同T细胞亚群上的表达均上调（P〈0．05），然而，CD4^＋T细胞以CD28分子表达增加为主，而CD8^＋T细胞则CD152分子表达增加为主。结论：终末期肾功能衰竭患者的细胞亚群失衡，共刺激分子CD28和CD152表达异常增加，提示T细胞活化与抑制性调节发生紊乱。T细胞亚群上凋亡受体CD95分子表达增加，以CD8^＋T细胞为主，说明终末期肾功能衰竭者淋巴细胞的减少可能通过两种途径——受体配体途径和负性共刺激分子CD152抑制信号途径，其中以CD8^＋T细胞减少为主，造成患者细胞免疫缺陷。     

Death-inducing receptors and apoptotic changes in lymphocytes of patients with heart transplant vasculopathy

The specific role of lymphocyte apoptosis and transplant-associated atherosclerosis is not well understood. The aim of our study was to investigate the impact of T cell apoptotic pathways in patients with heart transplant vasculopathy. Amongst 40 patients with cardiac heart failure class IV who have undergone heart transplantation, 20 recipients with transplant-associated coronary artery disease (TACAD) and 20 with non-TACAD were investigated one year postoperative. Expression of CD95 and CD45RO, and annexin V binding were measured by FACS. Soluble CD95, sCD95 ligand (sCD95L), tumour necrosis factor receptor type 1 (sTNFR1), and histones were measured in the sera by ELISA. The percentage of cells expressing CD3 and CD4 was significantly reduced in TACAD as well as in non-TACAD patients as compared with control volunteers. Interestingly, the proportion of CD19+ (B cells) and CD56+ (NK) cells was increased in TACAD groups (versus non-TACAD; P < 0.01, and P < 0.001, respectively). In contrast to sCD95, the expression of CD95 (APO-1/Fas) and CD45RO (memory T cells), and sCD95L were significantly increased in non-TACAD and TACAD patients. T cell activation via CD95 with consecutive apoptosis was increased in both groups. The concentration of sTNFR1, IL-10 and histones was significantly elevated in sera from TACAD than non-TACAD patients, and in both groups than in healthy controls. These observations indicate that the allograft may induce a pronounced susceptibility of CD4+ T cells to undergo apoptosis and antibody-driven activation-induced cell death. This data may suggest a paradox immune response similar to that seen in patients with autoimmune diseases.     

CD40L demethylation in CD4(+) T cells from women with rheumatoid arthritis

We have previously demonstrated that DNA demethylation of CD40L on the X chromosome is responsible for female susceptibility to systemic lupus erythematosus (SLE). It is unknown whether aberrant methylation of the CD40L gene also contributes to the higher incidence of rheumatoid arthritis (RA) in females. In this study, we used real-time RT-PCR and flow cytometry to compare CD40L expression levels, and bisulfite sequencing to assess the methylation status of the CD40L promoter region. The results show that CD40L is upregrulated in CD4(+) T cells of female patients with RA. In addition, the CD40L promoter region in CD4(+) T cells from female RA patients was found to be demethylated, which corresponded with increased CD40L mRNA expression. These findings suggest that DNA demethylation contributes to CD40L expression in RA CD4(+) T cells and may in part explain the female preponderance of this disease.     

Survival of lymphocytes is not restricted by IDO-expressing fibroblast from rheumatoid arthritis patients

Objective: Rheumatoid arthritis (RA) is characterized by expansion of fibroblast-like synoviocytes (FLS) in inflamed joints and activation of lymphocytes. Tryptophan (trp) is an essential amino acid indispensable for the biosynthesis of proteins and critical for survival of lymphocytes. Indoleamine 2,3-dioxygenase (IDO) that initiates the degradation of trp and tryptophanyl-tRNA synthetase (TTS) essential for tryptophan synthesis, regulate trp bioavailability. Here, we tested the hypothesis that triggered by cytokines, enhanced IDO activity modulate regulatory function of otherwise non-tolerogenic FLS isolated from RA patients.

Materials and methods: IDO and TTS mRNA expression were evaluated by RT-PCR. IDO enzymatic activity was confirmed using HPLC. Resting or PHA-activated PBMC from healthy volunteers and RA patients were co-cultured with IDO expressing untreated (FLS_C) or IFNγ-treated (FLS_IFNγ) RA FLS. Lymphocyte survival and proliferation were evaluated by flow cytometry analysis and tritiated thymidine incorporation, respectively.

Results: RA FLS_IFNγ produce functionally active IDO and constitutively express TTS. RA FLS_C and FLS_IFNγ increased survival of resting lymphocytes in both studied groups, and decreased proliferation of healthy, but not RA, PBMC. Only FLS_IFNγ diminished survival of activated CD3⁺CD4^?, but not CD3⁺CD4⁺, healthy T cells and similar tendency was observed in rheumatoid cells. Importantly, IDO inhibitor, 1-methyl-DL-tryptophan (1-MT), failed to reverse this effect. PBMC, irrespective of their state (resting versus activated) or origin (healthy or RA), expressed high level of TTS mRNA.

Conclusions: We suggest that RA FLS express functionally active IDO but control survival and expansion of healthy cells in IDO-independent mechanism and exert weaker, if any, suppressive effect on rheumatoid cells.     

Microvascular abnormalities in patients with rheumatoid arthritis

Microvascular involvement represents one of the first apparent steps in many autoimmune diseases such as rheumatoid arthritis (RA). Early in the disease, peripheral microangiopathy may be easily recognized and studied by videocapillaroscopy. The aim of this study has been to observe the differences in labial microcirculation between healthy patients and patients suffering from RA. A total of 30 healthy patients and 30 patients suffering from RA were examined. The patients with conditions known to compromise microcirculation, such as diabetes, hypertension, or some pharmacological treatments were not included in the study. All the patients were non-smokers. Labial capillaroscopy was used to investigate the characteristics of microcirculation. Visibility, course, tortuosity, as well as the possible presence of microhemorrhages, the average caliber of the capillary loops and the number of visible capillary loops per square millimeter were evaluated for each patient. The investigation was simple, non-invasive, and repeatable for each patient. In patients suffering from RA, it was possible to observe a reduced caliber of capillaries, as well as greater elongated capillaries, in comparison to controls. This study shows that capillary alterations in patients suffering from RA occur in labial mucosa microcirculation; such evidence could be extremely important in the diagnosis of suspected RA.     

Long-term safety of abatacept in patients with rheumatoid arthritis

Abatacept is a selective T cell co-stimulation modulator that was first approved by the Italian Medicines Agency and reimbursed by the Italian National Health Service when used to treat active rheumatoid arthritis “not sufficiently responsive to other disease-modifying anti-rheumatic drugs (DMARDs) including at least one TNF inhibitor”, and is now also approved as a first line biological agent.     

乐尔脉对脑缺血再灌注损伤后期大鼠海马神经细胞凋亡的作用

 目的： 探讨乐尔脉胶囊（LEM）对脑缺血再灌注损伤后期大鼠海马神经细胞凋亡的作用与机制。方法: 采用大鼠左侧大脑中动脉内栓线阻断法(MCAO)造成局灶性脑缺血再灌注模型。缺血2 h再灌注30 d后,应用原位末端标记法（TUNEL）检测海马神经细胞凋亡,免疫组化、RT-PCR 法检测海马神经细胞Fas、Bax、caspase-3、caspase-9蛋白及 mRNA的表达,并进行阳性细胞计数及Mias图像程序分析结果。结果: 大鼠缺血再灌注30 d后,模型组缺血侧海马CA1、CA2区凋亡细胞显著高于假手术组(P<0.05), Fas、Bax、 caspase-3、caspase-9蛋白表达明显增加,fas、bax、caspase-3、caspase-9 mRNA的表达上调(P<0.05)。LEM2.00 g/kg、0.87 g/kg和氟桂利嗪可显著减少海马神经细胞凋亡数,降低Fas、Bax、caspase-3、caspase-9蛋白表达,fas、bax、caspase-3、caspase-9 mRNA的表达下调,LEM 0.87 g/kg作用次于2.00 g/kg。LEM对bax mRNA有显著抑制作用。结论: LEM抑制海马神经细胞的凋亡,明显地减轻缺血再灌注后期大鼠海马神经细胞的损伤,其作用机制与调节细胞凋亡信号转导通路及相关蛋白有关。     

系统性红斑狼疮患者的Th2偏移不受CD40/CD154影响

目的 探讨系统性红斑狼疮(SEE)患者外周血Th极化状况的改变以及其受CD40/CD154和地塞米松(Dex)的影响.方法 使用ELISA法检测SEE患者和对照组血浆IFN-γ和IL-10水平,分离、培养外周血单个核细胞(PBMC),应用CD40 mAb和Dex进行干预,使用ELISA法检测培养液上清IFN-γ和IL-10水平.结果 SLE患者血浆IFN-γ水平明显低于对照组(P<0.01,P<0.05),活动期组血浆IL-10水平明显高于缓解期组和对照组(均P<0.01);CD40 mAb对PBMC培养液上清IFN-γ和IL-10水平无影响(均P>0.05);Dex可使SLE患者PBMC培养液上清IFN-γ水平升高(P<0.05,P<0.01),Dex可以明显降低SEE患者和对照组PBMC培养液上清IL-10水平(均P<0.05).结论 SEE患者血浆IFN-γ水平降低、IL-10水平增高,存在Th2偏移;此种改变不受CD40/CD154影响但能被Dex抑制.