Regulation of CD8 T Cell Immunity by TNF Receptors

描述(申请人提供)：CD8+T细胞在 防御病毒、细胞内细菌和原生动物感染。至 提供保护性免疫，针对这些病原体的疫苗需要诱导出有效的 CD8+T细胞记忆。尽管它们在疫苗接种中的重要性得到了承认， 记忆性T细胞产生的潜在机制仍然很差 明白了。T细胞存储器的大小取决于 克隆性扩增和随后激活的抗原特异性T细胞的死亡 细胞。理解记忆T细胞的产生取决于 阐明细胞增殖和凋亡的调控机制 体内激活CD8+T细胞。我们的长期目标是了解 CD8+T细胞记忆的分子和细胞基础我们已经开始了研究 肿瘤坏死因子受体(TNFR)在调节血管生成中的作用 利用淋巴细胞性脉络膜脑膜炎病毒(LCMV)模型研究CD8+记忆T细胞 在老鼠身上。初步研究表明，这一功能显著增强。 在TNFR I-和TNFR I&中LCMV特异性记忆CD8+T细胞的数量 II缺陷小鼠，与野生型(+1+)小鼠相比。这样做的目的是 应用是理解TNFR调节产生的机制 记忆性CD8+T细胞。我们假设在细胞中缺乏凋亡信号 TNFR缺陷小鼠导致记忆CD8+T细胞数量增加， 否则将被删除。这项提议的目标是 三个方面：第一，阐明下调CD8+T细胞的机制基础 TNFR对细胞的反应，通过(1)检测TNFR缺乏对 体外和体内LCMV特异性CD8+T细胞的增殖和凋亡； (2)确定对TNFR介导的效应负责的配体：TNFa与LTA。 第二，剖析TNFR信号在CD8+T细胞上的重要性(直接 效应)与非CD8+T细胞(间接效应)在调节世代中的作用 通过使用骨髓嵌合体和 CD4基因缺陷的小鼠。第三，研究TNFR在功能上的作用 巨噬细胞病毒特异性CD8+T细胞的体内外特性免疫学 内存可以通过数量(增加的数量)来说明 抗原特异性T细胞)和定性(敏感度提高)的差异 在记忆T细胞中。我们的初步研究表明，失去TNFR I会导致 记忆性CD8+T细胞数量(“数量”)增加。我们会检查一下 TNFR缺陷和+/+LCMV特异性记忆的质的差异 通过比较CD8+T细胞产生细胞因子和 执行细胞介导的细胞毒作用，作为抗原浓度CD8的函数 要求和时间。TNFR缺乏的记忆CD8+T细胞的功能将 在(1)LCMV免疫小鼠和(2)DNA疫苗免疫小鼠中进行体内试验 致死性CD8+T细胞介导的中枢神经系统的保护性免疫研究 免疫病理学。尽管有几条证据表明， 在T细胞介导的自身免疫中，潜在的调节机制是 不是很清楚。本应用程序中建议的实验将提供 (一)开发有效疫苗的关键信息；(二) 了解自身免疫性疾病的发病机制，以及(Iii)制定 针对免疫介导性疾病的免疫疗法。

DESCRIPTION (provided by applicant): CD8+ T cells play a critical role in defense against viral, intracellular bacterial, and protozoan infections. To confer protective immunity, vaccines against these agents need to elicit potent CD8+ T-cell memory. Despite recognition of their importance in vaccinations, the underlying mechanisms in the generation of memory T cells remains poorly understood. The magnitude of T cell memory is dependent upon, the extent of clonal expansion and, the subsequent death of activated antigen-specific T cells. Understanding the generation of memory T cells is contingent upon elucidating the mechanisms that regulate proliferation and apoptosis of activated CD8+ T cells in vivo. Our long-term goal is to understand the molecular and cellular basis of CD8+ T cell memory. We have initiated studies investigating the role of TNF receptors (TNFRs) in regulating the generation of CD8+ memory T cells using the lymphocytic choriomeningitis virus (LCMV) model in mice. Preliminary studies have revealed that there is a dramatic enhancement in the number of LCMV-specific memory CD8+ T cells in TNFR I-and TNFR I & II-deficient mice, as compared to wild type (+1+) mice. The goal of this application is to understand the mechanisms by which TNFRs regulate generation of memory CD8+ T cells. We hypothesize that lack of apoptotic signals in TNFR-deficient mice leads to increased number of memory CD8+ T cells, that otherwise would be slated for deletion. The objectives of this proposal are three fold: First, to elucidate the mechanistic basis of downregulating CD8+ T cell responses by TNFRs, by (1) examining the effect of TNFR deficiency on the proliferation and apoptosis of LCMV-specific CD8+ T cells in vitro and in vivo; (2) determining the ligand responsible for TNFR-mediated effects:TNFa vs. LTa. Second, to dissect the importance of TNFR signaling on CD8+ T cells (direct effects) vs. non-CD8+ T cells (indirect effects) in regulating the generation of LCMV-specific memory CD8+ T cells, by using bone marrow chimeras and CD4-deficient mice. Third, to examine the role of TNFRs on the functional attributes of LCMV specific CD8+ T cells in vitro and in vivo. Immunological memory can be accounted for by both quantitative (increased number of antigen-specific T cells) and qualitative (heightened sensitivity) differences in memory T cells. Our preliminary studies show that loss of TNFR I lead to increased number ("quantity") of memory CD8+ T cells. We will examine for qualitative differences between TNFR-deficient and +/+ LCMV-specific memory CD8+ T cells by comparing the activation thresholds to produce cytokines and perform cell-mediated cytotoxicity as a function of antigen concentration, CD8 requirement, and time. The function of TNFR deficient memory CD8+ T cells will be tested in vivo in (1) LCMV-immune mice and (2) DNA vaccine-immunized mice by studying protective immunity against lethal CD8+ T cell-mediated CNS immunopathology. Despite several lines of evidence of a suppressive role for TNF in T-cell-mediated autoimmunity, the underlying regulatory mechanisms are not well understood. The proposed experiments in this application will provide critical information towards (i) development of effective vaccines; (ii) understanding the pathogenesis of autoimmune disorders, and (iii) formulating immunotherapies against immune-mediated diseases.