原发性肝癌组织中B7-H3表达与浸润的CD8^+ T细胞数负相关北大核心CSCD

目的探讨原发性肝癌组织中B7-H3的表达与CD8+T细胞浸润之间的关系。方法采用免疫组织化学技术分析原发性肝癌组织和正常肝组织中B7-H3的表达、CD8+T细胞的浸润数量,对B7-H3的表达与CD8+T细胞浸润数量的相关性进行统计学分析。结果 63例肝癌患者中B7-H3高表达26例(41.3%),低表达37例(58.7%),总阳性率为90.5%,其中正常肝组织基本不表达B7-H3。B7-H3高表达组CD8+T细胞浸润数量明显低于B7-H3低表达组,CD8+T细胞浸润数量与肝癌组织中B7-H3的表达呈负相关。肝癌组织中B7-H3的表达和CD8+T细胞数量在肝癌患者的临床病理分期、是否有局部淋巴结转移以及远隔器官转移等方面具有显著性差异。结论原发性肝癌组织中高表达B7-H3,与肿瘤组织中CD8+T细胞浸润呈负相关。     

B7家族的新成员-B7-H1、B7-H2、B7-H3、B7-DC

T细胞的活化需要TCR与抗原肽-MHC的第一信号,以及共刺激因子的第二信号系统.B7家族是重要的共刺激分子,属于免疫球蛋白家族.除B7-1和B7-2外,近几年又发现了B7家族的新成员--B7-H1、B7-H2、B7-H3、B7-DC等,与T、B细胞的活化及免疫应答等有关.深入研究B7家族成员的结构和作用机制,有助于T、B细胞活化机制以及免疫耐受、肿瘤免疫研究的深入和发展.     

CD8+T调节细胞的研究进展

调节性T细胞(Regulation T cell, Treg)是参与外周耐受性调节的一个重要细胞群。目前发现具有耐受调节作用的T细胞包括了CD4+ Treg细胞、 Th3细胞、 Treg1细胞、 NKT(nature killer cells)细胞、 Th17细胞和CD8+Treg细胞等[1]。     

CD40配基化调节小鼠树突状细胞上B7-H3分子表达的研究

目的 探讨CD40配基化对小鼠骨髓来源树突状细胞上B7-H3分子表达的调节作用及其生物学意义。方法 采用GM-CSF和IL-4联合方案体外诱导小鼠髓系DC，并利用mCD40-CHO和TNF-α分别刺激凋亡肿瘤细胞负载的Dc制备成熟DC；采用间接免疫荧光标记法检测成熟Dc上B7-H3分子的表达；RT-PCR检测B7-H3 mRNA转录水平；混合淋巴细胞反应（MLR）和B7-H3单抗阻断实验分析CD40配基化的DC表面B7-H3分子在T细胞活化中的作用；^3H-TdR掺入试验检测DC对T淋巴细胞的促增殖效应；ELISA测定各组MLR反应和DC培养上清中IFN-γ分泌水平。结果 B7-H3分子在DC不同分化发育阶段均有表达，CD40配基化能显著上调凋亡肿瘤细胞负载的DC中B7-H3表达，TNF-α激发的DC弱表达（P〈0．05）；阻断CD40配基化的DC上B7-H3分子能抑制T细胞增殖和IFN-γ分泌；CD40配基化促进凋亡肿瘤细胞负载的DC分泌IFN-γ量也明显高于TNF-α组（P〈0．05）。结论 体外CD0配基化DC的B7-H3分子上调性表达有助于其刺激T细胞增殖和IFN-γ的产生。     

IL-7通过调节CD127表达调控脓毒症患者CD8 +T细胞的体外活性

目的:观察脓毒症患者中膜型CD127(membrane-bound CD127,mCD127)和可溶型CD127(soluble CD127,sCD127)的表达,探讨IL-7调控脓毒症患者CD8 +T细胞活性的机制。 方法:采用前瞻性研究队列,入组47例脓毒症患者和18例健康对照者,分离血清和外...     

人胎盘源间充质干细胞对脐血CD8~+T细胞活化及周期和IL-17分泌的影响

目的:探讨人胎盘源间充质干细胞(hPMSCs)对脐血CD8+T细胞活化、周期及IL-17分泌的调节作用,为其在临床细胞治疗中的应用提供理论依据。方法:应用消化法分离、培养hPMSCs,体外扩增培养3代后用于实验;应用免疫磁珠法分选脐血CD8+T细胞;应用流式细胞术(FCM)分析hPMSCs对植物血凝素(PHA)刺激下脐血CD8+T细胞早期表型CD25、CD69表达和细胞周期的影响;佛波酯(PMA)刺激下脐血CD8+T细胞对IL-17分泌的影响。结果:hPMSCs体外可使脐血CD8+T细胞滞留于细胞周期的G0/G1期,下调活化脐血CD8+T细胞早期表型CD25、CD69的表达,上调其IL-17的分泌。结论:hPMSCs体外可通过对脐血CD8+T细胞周期的影响抑制其活化,并且上调脐血CD8+T细胞IL-17的分泌。     

特异性CD8+T细胞与人巨细胞病毒感染

人巨细胞病毒(Human Cytomegalovirus,HCMV)是疱疹病毒科β属的一种双链DNA病毒,在正常人群中普遍易感,在发达国家人群血清HCMV抗体检出率约40％ ～ 60％,而在发展中国家几乎达到100％ [1].与其他人类疱疹病毒不同,HCMV原发性感染通常为隐性感染,临床上表现为无症状状态,潜伏感染是依赖病毒复制的慢性免疫抑制而不是依赖病毒转录模式的改变.对于免疫抑制人群来说,HCMV容易发生激活感染,病毒复制难以控制,可以出现明显的组织损坏.HCMV激活感染是异基因造血于细胞移植和实体器官移植后患者发病率和死亡率不断攀升的主要原因,骨髓抑制、肾毒性、耐药病毒株的出现等治疗的不良反应限制了抗病毒药的抢先治疗[2-3].     

协同刺激分子B7-H3在非小细胞型肺癌中的表达及其临床意义

目的:探讨非小细胞型肺癌组织中协同刺激分子B7-H3的表达及其与患者的病理参数、预后及CD3+T淋巴细胞的浸润程度的相关性。方法:收集2005年1月至2005年9月在苏州大学附属第四人民医院行手术切除术的非小细胞型肺癌患者组织标本87例,免疫组织化学的方法检测非小细胞型肺癌中协同刺激分子B7-H3的表达和CD3+T淋巴细胞的浸润程度。结果:协同刺激分子B7-H3在非小细胞型肺癌组织中高表达,该分子的表达与患者的年龄、性别、淋巴结的转移情况、肿瘤的大小、病理分型无相关性(P>0.05),但与患者的生存期呈负相关。且该分子在肺癌中的表达水平与浸润的T细胞呈负相关。结论:协同刺激分子B7-H3的表达在非小细胞型肺癌组织中诊断和预后判断中具有潜在的临床应用价值。     

膈下迷走神经切断对外周血CD4+/CD8+T细胞比值的影响

近年来越来越多的证据显示 ,神经系统和免疫系统存在着密切的相互影响。免疫系统在接受抗原刺激迅速作出反应的同时 ,还将免疫信息传递到中枢神经系统 ,影响该系统的活动并接受其调节。目前 ,对免疫信息向中枢传递的途径有几种假说 ,其中受到重视的是神经机制 ,特别是迷走神经可能起重要的作用。免疫信息可能通过刺激迷走神经感觉神经纤维或旁神经节细胞引起电活动将免疫信息上传至脑。本研究中我们切断大鼠膈下迷走神经后 ,通过观察外周血ＣＤ4 /ＣＤ8 Ｔ细胞比值的改变 ,探讨了迷走神经在神经系统调节免疫系统功能的环路中所起的作用。1…     

活动性肺结核病人外周血CD4~+/CD8~+Tim-3~+ T细胞群内记忆细胞分布特点

目的研究活动性肺结核病人外周血CD4+/CD8+Tim-3+T细胞群内记忆细胞分布特点。方法分离22例初治活动性肺结核病人PBMCs,用流式细胞仪分析比较CD4+/CD8+Tim-3+/Tim-3-T细胞群内的中央型记忆细胞(Tcm)和效应型记忆细胞(Tem)的分布。结果活动期初治肺结核病人外周血CD4+Tim-3+T细胞群包含更少的中央型记忆细胞(P<0.0001)和较多的效应型记忆细胞(P=0.0139),CD8+Tim-3+T细胞群包含较少的效应型记忆细胞(P=0.0065)。结论活动期初治肺结核CD4+Tim-3+T细胞群内含有更多的效应型记忆细胞可能会促使Tem对抗原的快速保护性免疫应答效应下降,从而促进结核分枝杆菌潜伏感染向活动性病变转变。Tim-3对记忆性T细胞分化、形成及功能的影响尚需进一步研究。     

IL-21R expression on CD8+ T cells promotes CD8+ T cell activation in coxsackievirus B3 induced myocarditis

IL-21 is a multi-functional cytokine which can promote survival, proliferation and activation of T and B lymphocytes including CD8 T cells. Previous studies have shown that autoimmune CD8+ T cells are the primary pathogenic effector cell in coxsackievirus B3 (CVB3) induced myocarditis in C57Bl/6 mice. To evaluate the role of IL-21 in promoting CD8+ T cell mediated cardiac injury in myocarditis, C57Bl/6 and IL-21RKO mice were infected with CVB3. IL-21RKO mice developed significantly less myocarditis than C57Bl/6 animals although cardiac virus titers were equivalent between the mouse strains. Numbers of CD8+IFNγ+ cells were decreased in IL-21RKO mice but numbers of either CD4+IFNγ+ or CD4+IL-4+ cells were not significantly different from C57Bl/6 animals indicating a selective effect of IL-21 signaling on the CD8+ T cell response. To confirm that IL-21 signaling exclusively functions at the level of the CD8+ T cell in CVB3 induced myocarditis, purified CD8+ cells were isolated from either C57Bl/6 or IL-21RKO donors and adoptively transferred into CD8KO recipients prior to CVB3 infection. CD8KO recipients given either C57Bl/6 or IL-21RKO CD8+ cells showed equivalent reconstitution of the CD8+ cells in the spleen but the recipients given C57Bl/6 CD8+ cells showed significantly greater myocarditis than recipients of IL-21RKO CD8+ cells. These data demonstrate that IL-21 signaling directly in the CD8+ cell population is required for CVB3-induced myocarditis.     

Lower percentage of CD8+ T cells in peripheral blood of patients with sporotrichosis

PurposeTo characterize the peripheral immunity and immunity response of patients with sporotrichosis, in this study we determined the lymphocyte subsets in the peripheral blood of Chinese patients with sporotrichosis.MethodsIn this retrospective study, peripheral blood was collected from 69 sporotrichosis patients (37, fixed cutaneous form; 32 lymphocutaneous) and 66 healthy controls. Lymphocyte subsets were analyzed using flow cytometry.ResultsCompared to controls, the percentage of CD8+ T cells was lower in sporotrichosis patients. The percentage of CD8+ T cells in peripheral blood tended to become lower with disease duration and disease severity, although the difference was not statistically significant for either acute, subacute and chronic patients or fixed cutaneous and lymphocutaneous patients.ConclusionOur data indicate that the decrease of CD8+ T cells in peripheral blood of patients with sporotrichosis is associated with disease severity, although the difference was not statistically significant for either duration or clinical forms of the disease. Combining antifungal agents and immunomodulators in patients with long disease duration and lymphocutaneous may be more beneficial than antifungal monotherapy.     

Specific CD8+ T cells recognize human herpesvirus 6B

The importance of human herpesvirus 6 (HHV‐6) species as human pathogens is increasingly appreciated. However, we do not understand how infection is controlled in healthy virus carriers, and why control fails in patients with disease. Other persistent viruses are under continuous surveillance by antigen‐specific T cells, and specific T‐cell repertoires have been well characterized for some of them. In contrast, knowledge on HHV‐6‐specific T‐cell responses is limited, and missing for CD8⁺ T cells. Here we identify CD8⁺ T‐cell responses to HHV‐6B, the most widespread HHV‐6 species, in healthy virus carriers. HHV‐6B‐specific CD8⁺ T‐cell lines and clones recognized HLA‐A2‐restricted peptides from the viral structural proteins U54 and U11, and displayed various antigen‐specific antiviral effector functions. These CD8⁺ T cells specifically recognized HHV‐6B‐infected primary CD4⁺ T cells in an HLA‐restricted manner, produced antiviral cytokines, and killed infected cells, whereas HHV‐6A‐infected cells were not recognized. Thus, HHV‐6B‐specific CD8⁺ T cells are likely to contribute to control of infection, overcoming the immunomodulatory effects exerted by the virus. Potentially, HHV‐6‐associated disease could be addressed by active or passive immunotherapy that reconstitutes virus‐specific CD8⁺ T‐cell responses.     

小鼠B7-H3对T细胞的体外正性协同刺激作用

小鼠B7-H3作为协同刺激分子的生物学功能至今尚未明确.本文拟通过构建小鼠B7-H3基因的真核表达载体,获取稳定表达小鼠B7-H3基因的细胞株,并进一步通过体外实验研究其对T淋巴细胞体外活化及功能的调节作用.作者运用RT-PCR技术从小鼠肝脏组织中获得全长小鼠B7-H3基因,并构建真核表达载体pIRES2-B7-H3,...     

B7-1-dependent co-stimulation results in qualitatively and quantitatively different responses by CD4+ and CD8+ T cells

To characterize better the co-stimulatory activity of native B7-1 in the absence of other receptor/ligand interactions that might contribute to the response, B7-1 was purified by monoclonal antibody (mAb) affinity chromatography. Immobilization of purified B7-1 with anti-T cell receptor (TCR) mAb on cell-sized latex microspheres provided an effective stimulus for activation of both CD4⁺ and CD8⁺ T cells as measured by proliferation, development of effector function, and changes in motility and adhesion. The CD4⁺ T cell response was prolonged and resulted in efficient interleukin-2 production and clonal expansion. In contrast, CD8⁺ responses were transient. Proliferation and clonal expansion peaked on days 3 and 4, coincident with maximal expression of lytic effector function, and the cells then died. These results demonstrate that B7-1 mediated co-stimulation is sufficient for the induction of effector function in both helper and cytotoxic T cell precursors, but suggest that B7-1 co-stimulation is not sufficient to sustain helper-independent CD8⁺ CTL responses. When the dose responses of CD4⁺ and CD8⁺ T cells to B7-1 were compared, CD8⁺ T cells were found to require higher densities of B7-1 to attain an equivalent level of activation, suggesting that the level of expression of B7-1 by APC may influence the development of helper or CTL responses. Finally, in contrast to results obtained by others with B7-1 transfectants, purified B7-1 did not provide co-stimulation when presented on a surface separate from the TCR stimulus.     

替比夫定对慢性乙型肝炎患者外周血CD4~+ CD25~+ CD127~(low) T和CD8~+ CD25~+ T细胞频率的影响及临床意义

目的探讨核苷类药物替比夫定对慢性乙肝患者(CHB)外周血中CD4+CD25+CD127lowT细胞和CD8+CD25+T细胞比例的影响,并结合临床指标分析其临床意义。方法替比夫定抗病毒治疗22例CHB患者,在治疗前及治疗后3,6个月时,分别以流式细胞仪检测外周血中CD4+CD25+CD127lowT细胞和CD8+CD25+T细胞比例,实时荧光定量RT-PCR检测Foxp3 mRNA的表达水平,荧光定量PCR检测血清HBV DNA水平,酶联免疫吸附法检测HBV标志物,全自动生化分析仪检测ALT水平。结果 CHB患者外周血中CD4+CD25+CD127lowT细胞和CD8+CD25+T细胞比例显著高于对照组。替比夫定治疗3个月时,这两群细胞比例显著下降,Foxp3 mRNA的表达也显著下降;HBV DNA水平降至检测水平以下的CHB患者,其CD4+CD25+CD127lowT细胞也降至正常水平。治疗3、6个月时,HBeAg阴转率分别为9.1%和18.2%,发生HBeAg血清学转换者的CD4+CD25+CD127lowT细胞和CD8+CD25+T细胞比例均降至正常水平。结论替比夫定能快速有效抑制CHB患者的病毒复制...     

CD40 ligand-positive CD8+ T cell clones allow B cell growth and differentiation

A fraction of activated CD8⁺ T cells expresses CD40 ligand (CD40L), a molecule that plays a key role in T cell-dependent B cell stimulation. CD8⁺ T cell clones were examined for CD40L expression and for their capacity to allow the growth and differentiation of B cells, upon activation with immobilized anti-CD3. According to CD40L expression, CD8⁺ clones could be grouped into three subsets. CD8⁺ T cell clones expressing high levels of CD40L (≥80% CD40L⁺ cells) were equivalent to CD4⁺ T cell clones with regard to induction of tonsil B cell proliferation and immunoglobulin (Ig) production, provided the combination of interleukin (IL)-2 and IL-10 was added to cultures. CD8⁺ T cell clones, with intermediate levels of CD40L expression (10 to 30% CD40L⁺ cells), also stimulated B cell proliferation and Ig secretion with IL-2 and IL-10. B cell responses induced by these CD8⁺ T cell clones were neutralized by blocking monoclonal antibodies specific for either CD40L or CD40. By contrast, CD40L^?? T cell clones (?5 % CD40L⁺ cells), only induced marginal B cell responses even with IL-2 and IL-10. All three clone types were able to activate B cells as shown by up-regulation of CD25, CD80 and CD86 expression. A neutralizing anti-CD40L antibody indicated that T cell-dependent B cell activation was only partly dependent on CD40-CD40L interaction. These CD40L^?? clones had no inhibitory effects on B cell proliferation induced by CD40L-expressing CD8⁺ T cell clones. Taken together, these results indicate that CD8⁺ T cells can induce B cell growth and differentiation in a CD40L-CD40-dependent fashion.     

卵巢癌细胞培养上清诱导CD4+CD25-T细胞分化为CD4+CD25+调节性T细胞

目的研究卵巢癌细胞培养上清液是否能诱导外周血CD4^＋CD25^- T细胞转变为CD4^＋CD25^＋调节性T细胞。方法将外周血CD4^＋CD25^- T细胞分离后，对照组用CD3和CD28单抗活化，实验组在对照基础上加用卵巢癌细胞株SKOV3培养上清，72h后分离各组的CD25^＋和CD25^-T细胞，溴化脱氧尿嘧啶掺入标记法测定增殖能力及对静息的自体同源CD4^＋CD25^- T细胞的增殖抑制能力，流式细胞仪测定细胞糖皮质激素诱发型TNF受体（glucocorticoid-induced TNFR,GITR）与CTLA-4分子的表达，RT-PCR检测细胞卿mRNA的表达。结果与对照组相反，实验组的CD4^＋CD25^＋T细胞具有免疫抑制功能，自身增殖能力下降，GITR和CTLA-4分子的表达和CD4^＋CD25^＋调节性T细胞相似，并被诱导表达转录因子Foxp3 mRNA。结论卵巢癌细胞分泌的可溶性物质能诱导外周血CD4^＋CD25^-T细胞转化为CD4^＋CD25^＋调节性T细胞。