同种特异T细胞疫苗诱导移植物存活期延长的研究：Ⅱ.抗独特型T…

同种特异Ｔ细胞疫苗免疫诱导出同种免疫反应低下，同种移植物存活时间显著延长，推测其作用机制可能是同种特异ＴＣＶ免疫诱导机体抗同种特异ＴＣＶＴ细胞的上调。实验证实了“抗ＴＣＶ－Ｔ细胞”的存在。     

T细胞疫苗的实验设想、证实及应用

把引起自身免疫性疾病的自身反应性T细胞或导致同种移植排斥反应的同种反应性T细胞看作是致病性T细胞,将它们活化并灭活后,以疫苗的形式免疫动物,诱导机体产生针对致病性T细胞或同种反应性T细胞的免疫应答,从而消除或减轻这些细胞的致病作用;表现为对自身免疫性疾病和对同种移植物排斥的防治作用。这一方法称为T细胞疫苗接种（TCV）。TCV的作用机制是上调免疫网络中的抑制性作用,产生了抗独特型T细胞,抑制了相应克隆T细胞的作用。用TCR多肽免疫替代TCV亦是有效的方法。TCV或TCR多肽免疫对防治自身免疫性疾病有潜在的应用价值,对控制同种排斥反应也是一条有效措施。     

抗激活小鼠T细胞抗原单抗抑制同种移植物排斥反应的作用及其机理

为阐明活化 T 细胞主动免疫同系小鼠诱导同种移植物存活期延长的机理,利用本室制备的抗活化小鼠 T 细胞抗原单克隆抗体(2H_3)观察它对同种免疫反应的影响;结果表明给接受同种移植物的受者转输2H_3能显著地延长同种心肌移植物的存活时间;在 ConA 诱导的淋巴细胞增生反应、混合淋巴细胞反应和诱导同种 T 杀伤性细胞的体外实验中加入2H_3,观察到2H_3对上述反应的明显抑制作用。提示活化 T细胞主动免疫同系小鼠诱导同种移植物存活期延长的机理,可能与免疫动物体内产生了相应的抗体,抑制了同种免疫反应的进行有关。     

同种特异T细胞疫苗诱导移植物存活期延长的研究——Ⅰ.同种特异T细胞疫苗诱导的细胞免疫水平低下

在体外实验中观察了同种特异T细胞疫苗（TCV）免疫鼠T淋巴细胞对同种抗原和有丝分裂原（ConA）的反应能力。B6同种抗原特异TCV免疫的BALB/c小鼠对B6同种抗原的反应（MLR）能力明显变抑制,对无关第三者同种抗原AKR的反应能力也显著下降,表明存在抗原非特异性的抑制作用。在BALB/c同种抗原特异TCV免疫的B6小鼠中,获得一致的结果。在观察两组TCV免疫动物T细胞对Cond诱导的淋巴细胞增殖实验中,与正常小鼠 T细胞反应性比较,TCV免疫动物 T细胞的增殖能力显著下降,表现为抗原非特异作用。此与MLR中ConA-T细胞免疫动物的结果相一致。在CML实验里,同种抗原特异TCV免疫小鼠的脾细胞体外诱导同种CTL活性明显受到抑制,CTL 活性十分低下。体外实验结果表明:同种特异TCV免疫小鼠可诱发同种抗原反应和对ConA诱发的增殖反应能力显著低下,表现为抗原非特异性作用。     

同种特异T细胞疫苗诱导移植物存活期延长的研究——Ⅲ.抗T细胞抗体的活性分析

本文观察了TCV免疫小鼠血清对同种抗原和非特异抗原刺激的淋巴细胞反应性的影响,结果显示,TCV免疫小鼠血清能显著抑制ConA诱导的淋巴细胞增殖和同种MLR,表明该血清中存在有抑制T细胞功能的“抑制因子”。实验还发现TCV免疫小鼠血清中存在针对多种不同抗原决定簇的抗体,包括有TCV特异的、活化T细胞的和正常淋巴细胞的。TCV吸收实验证明TCV免疫小鼠血清中能特异地与TCV结合的抗体不能与其它活化T细胞结合。经细胞膜分子SDS-PAGE和免疫印迹分析,TCV免疫小鼠血清中的抗体所识别的细胞膜抗原分子量大约为15kD,35/38kD左右。     

T细胞疫苗诱导同种移植物存活期延长

以同种细胞体内免疫小鼠，取免疫脾细胞经体外低剂量ＣｏｎＡ培养扩增后，用戊二醛来活法制备了Ｔ细胞疫苗，然后以此免疫同系正常小鼠，观察小鼠同种心肌移植物存活时间的改变，Ｔ细胞疫苗免疫组移植存活时间显著延长，与正常对照组比较Ｐ〈０．００１；但发现在Ｔ细胞疫苗免疫中，与用于免疫制备Ｔ细胞凋苗同一来源的移植物存活期又比无关来源的同种移植物存活期显著延长，而后者与抗原非特异活化Ｔ细胞免疫组比较无显著差异，结果     

未成熟树突细胞免疫诱导同种移植物存活延长

目的利用未成熟DC免疫受鼠诱导同种移植物存活延长,分析未成熟DC在诱导同种免疫低应答反应中的可能机理。方法以小鼠耳后心肌移植为模型,观察未成熟DC和成熟DC免疫受鼠同种移植心肌的存活情况。同时检测未成熟DC免疫的小鼠脾细胞对同种细胞的CTL活性。结果未成熟DC免疫受鼠的同种移植物存活时间明显延长,平均存活期从9.1±0.73d延长到25.4±4.27d,联合使用阿霉素效果更好,平均存活期为30.5±3.98d;C57BL/6未成熟DC免疫的Balb/c小鼠脾细胞对C57BL/6靶细胞的杀伤(3H-TdR释放率为16.32％)明显低于经成熟DC免疫的受鼠的脾细胞(3H-TdR释放率为39.58％)。结论未成熟DC免疫可诱导同种移植心肌的存活明显延长,可能与受鼠体内的效应T细胞对移植物细胞杀伤低下有关。     

雷帕霉素对同种移植耐受模型CD4+CD25+ T细胞活性的影响

目的：研究雷帕霉素（Rapa）对同种移植耐受个体CD4^＋CD25^＋ T细胞体内负免疫调节作用的影响.方法：建立同种皮肤移植模型, 受体鼠术前预输注供体鼠脾细胞, 术后给予环孢素A（CsA）进行耐受诱导.移植后第14天提取耐受诱导模型鼠的T细胞, 经不同浓度Rapa和/或IL-2体外处理后, 混合淋巴细胞反应（MLR）确定T细胞特异增殖水平;流式细胞术（FCM）检测CD4^＋CD25^＋ T细胞比例变化;RT-PCR检测Foxp3 mRNA表达情况;ELISA检测细胞培养不同时间后上清中IL-10的变化.然后将Rapa和/或IL-2处理的T细胞过继转移给同种移植后的BALB/c-SCID鼠, 观察移植物存活状态.结果：CsA加供体脾细胞预先注射可明显延长小鼠移植皮片的存活期（P＜0.05）;移植耐受状态的T细胞经Rapa和/或IL-2体外处理后CD4^＋CD25^＋ T细胞比例升高、增殖水平明显降低、 Foxp3表达量明显增加;过继转输给同种移植SCID鼠后, 其移植皮片存活时间显著延长（P＜0.05）.结论：Rapa可体外扩增耐受诱导模型中CD4^＋CD25^＋ T细胞, 使CD4^＋CD25^＋ T细胞相关的Foxp3和IL-10明显升高, 过继免疫后, 小鼠同种移植物存活时间明显延长, 而低浓度IL-2可以协同Rapa的这一作用.     

卵清白蛋白特异性T细胞免疫诱导BALB/c小鼠的调节性免疫应答

目的：研究T细胞免疫后正常小鼠的调节性免疫应答，方法：应用体外扩增的卵清白蛋白（OVA）特异的T细胞克隆免疫BALB／c小鼠，3H－TdR掺入法分析细胞增殖，3H－TdR标记靶细胞检测杀伤T细胞的杀伤效应，间接免疫荧光法分析血清中抗T细胞抗体水平。结果：T细胞免疫后能诱导BALB/c小鼠产生调节性T细胞的增殖反应，对靶细胞的杀伤效应以及针对于活化的T细胞的体液免疫应答，并进一步降低机体对OVA抗原的应答，结论：T细胞免疫能诱导正常机体的调节性免疫应答。     

T细胞接种对SLE样小鼠防治作用的探讨

本文在空肠弯曲菌（CJ-S131）免疫诱导的小鬼SLE样综合征模型上,观察了T细胞接种（T CellVaccination,TCV）的预防和治疗作用。用于 TCV的细胞为 CJ-S131预致敏的同系小鼠 T细胞。结果显示TCV可明显地抑制CJ-S131诱导的特异性迟发型超敏反应,相反却显著地增强抗dsDNA抗体和抗外膜蛋白抗体生成。因此TCV对SLE样小鼠没有预防及治疗作用。本文对此现象进行了讨论。     

移植免疫中T细胞疫苗作用机制的初步分析

为分析Ｔ细胞疫苗同种兔疫抑制作用的机制，在体外观察了Ｔ细胞疫苗免疫小鼠细胞免疫应答能力的改变，分别在ＭＩＣ实验中，观察了免疫小鼠血清和免疫小鼠脾细胞对同种应答细胞反应能力的影响。结果表明：免疫小鼠淋巴细胞ＣｏｎＡ转化反应能力及同种抗原反应能力均显著降低，免疫小鼠血清及其脾细胞不同程度地抑制了同种应答细胞的反应能力，但以上作用并未表现出抗原特异性。     

T细胞疫苗抗同种移植排斥反应的研究

应用Ｔ细胞疫苗于同种心脏移植的研究，用Ｃｏｎ Ａ和ＣＤ３单抗诱导受同种特异性抗原（Ｃ５７ＢＬ／６（Ｈ－２＾ｂ）小鼠脾细胞）免疫的ＢＡＬＢ／Ｃ（Ｈ－２＾ｄ）小鼠，取后者脾细胞所制备的Ｔ细胞疫苗具有延长同种心脏移植物的存活期。受Ｔ细胞疫苗接种的ＢＡＬＢ／Ｃ（Ｈ－２＾ｄ）鼠脾细胞对经Ｃｏｎ Ａ激活或未激活的Ｃ５７ＢＬ／６小鼠脾细胞皆表现出特异的强烈的增殖反应，而对同系脾细胞呈低的反应。Ｔ细胞疫苗表型分析     

T Cell Receptor (TCR) Repertoire in Alloimmune Responses

A large number of alloantigenic determinants could be generated by both the direct and indirect alloantigen presentation pathways. Hence, a heterogeneous population of T cells expressing a wide variety of receptors would be expected to respond to this diverse array of alloantigenic determinants. However, T cells expressing highly restricted T cell receptor (TCR) variable genes have been reported in a variety of alloimmune responses. A similar phenomenon has been observed in a wide variety of other immune responses, from those induced by superantigens, to very specific responses induced by a single peptide presented by a single MHC molecule. Given this scenario, the limited number of T cell clones which dominate an allograft rejection response, or for that matter an autoimmune response or a tumor specific response, could be therapeutically targeted by virtue of the selected TCR expression.     

The Mechanisms and Applications of T Cell Vaccination for Autoimmune Diseases: a Comprehensive Review

Autoimmune diseases (ADs) are a spectrum of diseases originating from loss of immunologic self-tolerance and T cell abnormal autoreactivity, causing organ damage and death. However, the pathogenic mechanism of ADs remains unclear. The current treatments of ADs include nonsteroidal anti-inflammatory drugs (NSAIDS), antimalarials, corticosteroids, immunosuppressive drugs, and biological therapies. With the need to prevent side effects resulting from current treatments and acquire better clinical remission, developing a novel pharmaceutical treatment is extremely urgent. The concept of T cell vaccination (TCV) has been raised as the finding that immunization with attenuated autoreactive T cells is capable of inducing T cell-dependent inhibition of autoimmune responses. TCV may act as an approach to control unwanted adaptive immune response through eliminating the autoreactive T cells. Over the past decades, the effect of TCV has been justified in several animal models of autoimmune diseases including experimental autoimmune encephalomyelitis (EAE), murine autoimmune diabetes in nonobese diabetic (NOD) mice, collagen-induced arthritis (CIA), and so on. Meanwhile, clinical trials of TCV have confirmed the safety and efficacy in corresponding autoimmune diseases ranging from multiple sclerosis (MS) to systemic lupus erythematosus (SLE). This review aims to summarize the ongoing experimental and clinical trials and elucidate possible molecule mechanisms of TCV.     

树突状细胞在榄香烯复合瘤苗主动免疫效应中的作用

本实验以HCa F或L6 1 5榄香烯复合瘤苗 (H TCV或L TCV )、H TCV溶解物 (TH )、短小棒状菌 (CP )免疫小鼠 ,分离制备其脾脏DC ,在体外分别用相应瘤细胞溶解物 (H或L )和瘤苗溶解物 (TH或TL )冲激后 ,以MTT法检测其诱导同系小鼠脾不粘附细胞增殖的能力。结果表明用榄香烯复合瘤苗或其溶解物免疫DC供鼠和体外冲激DC ,可增强其诱导同系小鼠脾不粘附细胞增殖的作用 ,给DC供鼠注射CP可进一步增强DC的这一作用     

Ethanol impairs major histocompatibility complex (MHC) class II molecule-mediated but not MHC class I molecule-mediated T cell response in alcohol-consuming mice

The goal of this study was to determine whether alcohol affects alloantigen-induced proliferative and cytolytic activity of T cells in mice, and whether the altered immune response was in part due to a defect of IL-2 activity. The ability of spleen cells from individual alcohol-consuming C57BL/6 mice to generate allo-specific mixed lymphocyte response (MLR) and cytotoxic T lymphocyte (CTL) was compared to that of mice fed on an isocaloric maltose diet and regular diet. Allospecific MLR and CTL were generated by sensitizing spleen cells of C57BL/6 mice against spleen cells from BALB/c mice, and the allo-specific CTL activity was determined by the ability of the CTL to kill 51Cr-labeled P815 mastocytoma target cells. Our results showed that the allo-specific MLR of the responder cells from alcohol-consuming mice was significantly reduced (40% reduction, p<0.0 1), and the addition of exogenous interleukin 2 (IL-2) could not reverse the suppression of MLR induced by ethanol. However, our results clearly showed that ethanol has little suppressive effect on allo-reactive CTL of alcohol-consuming mice as compared to the alloreactivity of the control mice (P>0.05). Finally, we also demonstrated that ethanol did not impair the alloantigen-induced IL-2 production in the mixed lymphocyte cultures (P>0.1).     

CD28:B7 interaction is necessary for the protective effect of T cell vaccination in EAE

The mechanisms of T cell vaccination (TCV) are still unclear, especially the molecular interactions for recognition of autoreactive T cells by the immune system. Here we investigated the role of CD28:B7 interaction in TCV-induced protection in the murine EAE model. We demonstrate that there is increased expression of both B7-1 and B7-2 on autoreactive Th1 cells compared to Th2 cells. Blockade of B7 on the vaccinating autoreactive T cell surface or blockade of CD28 in recipient mice reduced the protective effect of TCV. Furthermore, we showed that TCV significantly inhibited Ag-specific CD4 and CD8 T cell proliferation and decreased Ag-specific IFN-gamma production by CD4 T cells in mice undergoing TCV, and blocking of B7 on the surface of vaccinating T cells reduced this inhibition on Ag-specific CD4 and CD8 T cell proliferation, more significantly on Ag-specific CD4 T cell proliferation. These data indicated that B7 expression on autoreactive T cells is necessary for the recognition of autoreactive T cells by the immune system and subsequent protection from EAE in mice undergoing TCV.