γδT细胞在结核杆菌免疫应答中的作用

γδＴ细胞是新近发现的一类独特的细胞群体,它在免疫应答中的作用及其作用机制引起的人们的关注。在γδＴ细胞的多种刺激物中,结核杆菌能够非常有效地活化γδＴ细胞。本文介绍近年来γδＴ细胞识别的结核杆菌抗原成分、作为效应细胞的作用、结核杆菌活化的γδＴ亚群（即Ｖγ２／Ｖδ２亚群）,以及结核病患者体内的γδＴ细胞变化等方面研究进展。     

流感病毒感染中的T细胞应答

本文中总结了应用T细胞受体转基因模型和主要组织相容性复合物Ⅰ类四聚体研究流感感染时的效应细胞和记忆细胞应答,包括抗原特异性CDC4CD+T细胞的生成,多样性及其向肺部的移动,以及其在清除病毒中的作用.对于效应细胞和记忆细胞在病毒感染中的作用以及效应细胞如何转变为记忆细胞,都有比较详尽的阐述.     

CD1限制性T细胞应答与微生物感染

人CD1c同种型分子也与天然免疫有关。CD1c可被细胞毒性γδT细胞识别,这群细胞多分布于肠道,表达Vδ1γδTCRs,具有限的多样性。其功能可能与CD1d—自身反应性自然杀伤T细胞相似,在应激或感染状态下引发天然免疫应答。     

中华鳖对T3菌苗抗原的免疫应答

通过T3菌苗免疫中华鳖后的血清间接凝集抗体效价 (IAT)与免疫保护率 (PRP)的变化探讨了中华鳖的免疫应答规律。中华鳖对T3菌苗能产生较强的应答反应 ,免疫的二龄鳖PRP可达 82 6± 15 2 (19) % ,IAT达 1978 1± 716 4(19)。它对T3菌苗的免疫效应期为 3天 ,第 2 0天时免疫应答处于高峰 ,IAT与PRP分别为 176 8 0± 44 7 6 (4)与 91 7± 14 4(4) % ,持续 10天左右开始下降 ,到第 3个月左右基本上回复到免疫开始时水平。结论为 :中华鳖的免疫应答反应基本介于鱼类与鸟类之间 ,但较偏向于鸟类。     

对特异性免疫应答中几个问题的探讨

以T细胞的分化、功能和活化过程为切入点,描述了特异性免疫应答的过程,并对特异性免疫应答的几个疑难问题进行了探讨。     

树突细胞、病原体与免疫应答

当微生物侵入机体后,可诱导不同类型的免疫应答,对于胞内微生物,如病毒和某些细菌,CD4^ T细胞分化为分泌IFN-γ和具有一系列特定功能的Th1细胞,而对于胞外病原体,如蠕虫,则诱导产生Th2细胞,其所产生的细胞因子（IL-4,IL-5t IL-10)介导IgE和嗜酸性粒细胞破坏病原体,产生正确的免疫应答类型对机全生死攸关,在麻风病中,结核样型产生保护性Ⅰ型麻风反应,瘤型则为致死的Ⅱ型麻风反应。     

T细胞免疫在抗结核杆菌感染中的研究进展

结核分枝杆菌是引起结核病的病原体,该细菌可侵犯全身各组织器官。结核病是一种慢性传染性疾病,具有持久性特点。该细菌为胞内寄生菌,特异性免疫以细胞免疫为主,主要包括CD4＋T细胞免疫和CD8＋T细胞免疫。结核分枝杆菌特异性免疫应答的特点之一是感染早期T细胞免疫应答延迟。其机制与结核杆菌抑制免疫细胞（CD4＋和CD8＋T细胞及DC）凋亡延迟应答,通过特异性Treg细胞抑制作用延迟应答以及结核杆菌慢性感染期间存在IFN-γ信号调节网络和ESAT-6抗原的慢性刺激作用有关,以此可调节和维持免疫应答。深入了解抗原特异性T细胞特异性免疫应答的机制,有益于抗结核疫苗的研制,为临床工作提供理论依据和科学方法。     

Gamma delta T cell responses associated with the development of tuberculosis in health care workers

This study evaluated T cell immune responses to purified protein derivative (PPD) and Mycobacterium tuberculosis (Mtb) in health care workers who remained free of active tuberculosis (HCWs w/o TB), health care workers who went on to develop active TB (HCWs w/TB), non-health care workers who were TB free (Non-HCWs) and tuberculosis patients presenting with minimal (Min TB) or advanced (Adv TB) disease. Peripheral blood mononuclear cells (PBMC) were stimulated with Mtb and PPD and the expression of T cell activation markers CD25+ and HLA-DR+, intracellular IL-4 and IFN-gamma production and cytotoxic responses were evaluated. PBMC from HCWs who developed TB showed decreased percentages of cells expressing CD8+CD25+ in comparison to HCWs who remained healthy. HCWs who developed TB showed increased gammadelta TCR+ cell cytotoxicity and decreased CD3+gammadelta TCR- cell cytotoxicity in comparison to HCWs who remained healthy. PBMC from TB patients with advanced disease showed decreased percentages of CD25+CD4+ and CD25+CD8+ T cells that were associated with increased IL-4 production in CD8+ and gammadelta TCR+ phenotypes, in comparison with TB patients presenting minimal disease. TB patients with advanced disease showed increased gammadelta TCR+ cytotoxicity and reduced CD3+gammadelta TCR- cell cytotoxicity. Our results suggest that HCWs who developed TB show an early compensatory mechanism involving an increase in lytic responses of gammadelta TCR+ cells which did not prevent TB.     

DNA疫苗初免-BCG加强免疫法提高小鼠抗结核分枝杆菌感染效率的研究

对结核分枝杆菌DNA四价疫苗(编码Ag85B,MPT64,MPT70和TB10.4抗原)初发免疫、卡介苗(BCG)加强免疫后小鼠产生免疫应答的能力和抗结核杆菌感染效率进行了分析.攻毒后细菌计数结果显示,DNA初免、BCG加强组肺脏和脾脏载菌数的对数值比阴性对照组下降1.0～1.3(P<0.01),且显著低于DNA四价苗和BCG组(P<0.05).3次免疫后,BCG加强组外周血中CD4 和CD8 T淋巴细胞显著增多(P<0.05);经4种抗原分别刺激,BCG加强组脾细胞产生的抗原特异性IFN-γ和IL-2水平显著高于其他免疫组,其中Ag85B抗原诱导产生的IFN-γ浓度为1250ng/L,IL-2浓度为230ng/L,分别是DNA四价苗组的1.6,1.7倍(P<0.05),是BCG组PPD诱导产生相应细胞因子浓度的2.6倍和2.2倍(P<0.05);此外,BCG加强组肺脏中分泌穿孔素的淋巴细胞数量也显著增加(P<0.05).结果表明,DNA初发免疫、BCG加强免疫法能显著提高小鼠CD4 ,CD8 T细胞介导的免疫应答,增强小鼠抗结核杆菌感染能力,是提高结核病疫苗免疫效果的新途径.     

Conventional, regulatory, and unconventional T cells in the immunologic response to Helicobacter pylori

Infection by the gastroduodenal pathogen Helicobacter pylori elicits a complex immunologic response in the mucosa involving neutrophils, plasma cells, eosinophils, and lymphocytes, of which T cells are the principal orchestrators of immunity. While so-called classical T cells (e.g. T-helper cells) that are activated by peptide fragments presented on antigen-presenting cells have received much attention in H. pylori infection, there exists a diverse array of other T cell populations that are potentially important for the outcome of the ensuing immune response, some of which have not been extensively studied in H. pylori infection. Pathogen-specific regulatory T cells that control and prevent the development of immunopathology associated with H. pylori infection have been investigated, but these cells can also benefit the bacterium in helping to prolong the chronicity of the infection by suppressing protective immune responses. An overlooked T cell population, the more recently described Th17 cells, may play a role in H. pylori-induced inflammation, due to triggering responses that ultimately lead to the recruitment of polymorphs, including neutrophils. The so-called innate or unconventional T cells, that include two conserved T cell subsets expressing invariant antigen-specific receptors, the CD1d-restricted natural killer T cells which are activated by glycolipids, and the mucosal-associated invariant T cells which play a role in defense against orally acquired pathogens in the intestinal mucosa, have only begun to receive attention. A greater knowledge of the range of T cell responses induced by H. pylori is required for a deeper understanding of the pathogenesis of this bacterium and its ability to perpetuate chronic infection, and could reveal new strategies for therapeutic exploitation.     

结核分枝杆菌海藻糖磷酸磷酸酶诱导小鼠体液和细胞免疫应答

目的 研究结核分枝杆菌(M．tuberculosis)海藻糖磷酸磷酸酶(TPP)诱导小鼠体液和细胞免疫。方法 差速离心分离结核分枝杆菌H37Rv和卡介苗(BCG)的各细胞组分,通过Western杂交检测抗原TPP在结核分枝杆菌H37Rv和BCG中的亚细胞定位情况。分别用5×10~6CFU的BCG和50μg的TPP蛋白免疫C57BL/6小鼠,检测小鼠血清中抗TPP的IgG1和IgG2a抗体效价。取免疫小鼠的脾细胞,体外抗原刺激,用酶联免疫斑点试验(ELISPOT)检测γ干扰素(IFN-γ)分泌细胞。结果 TPP亚细胞定位于结核分枝杆菌H37Rv和BCG的胞壁和细胞膜组分。TPP蛋白免疫后小鼠产生的TPP特异性IgG1和IgG2a抗体效价明显高于BCG免疫小鼠,并且IgG2a的抗体效价高于IgG1。体外抗原刺激TPP蛋白和BCG免疫小鼠的脾细胞,都能诱导较高的IFN-γ分泌。结论 结核分枝杆菌细胞壁蛋白TPP能诱导小鼠Ⅰ型辅助性T细胞介导的免疫反应,可作为抗结核疫苗的候选抗原。