ALLOGENEIC RESPONSE:ROLE OF T CELL RECEPTOR DIVERSITY

T细胞受体的相互作用，II类组织相容性 分子和抗原是免疫识别所必需的。 T细胞受体和II类分子的多样性是 参与产生特异性反应。 而 产生潜在多样性的机制被明确定义， 塑造T细胞受体的力量， 与抗原的相互作用尚未完全理解， 人类 尽管多样性的许多方面都对这一点产生了影响， 交互作用，本研究将重点放在生殖系的重要性， T细胞受体基因的多样性（剧目）在一个特定的 细胞免疫反应，并将检查以下内容：（1） 库对功能特异性的影响 同种异体反应性T淋巴细胞克隆，通过以下模式测量： HLA分型面板的识别;（2）库的影响 对上述表达的T细胞受体的一级结构的影响 通过cDNA序列分析测量的同种异体反应性克隆;和（3） 非MHC、非T细胞受体成分的作用 （遗传/环境）对功能特异性和结构的影响 上述同种异体反应性克隆所利用的T细胞受体。 的 T细胞对同种异体人II类分子的应答将是 用于对可用的T细胞进行采样，作为一个模型， 抗原识别 控制胸腺选择的影响 通过MHC对表达的T细胞受体，HLA相同的兄弟姐妹 将被用作研究中的应答者。 通过T 细胞受体V片段探针，应答者携带不同的 亲本T细胞受体β链基因的组合。 的 刺激物（应答者的HLA重组同胞）共享 一种HLA单倍型与应答者，仅在类 第二HLA单倍型的II区。 虽然刺激器和 反应者在DR、DQ和DP位点上不同， 使用的方案将优先产生识别 DR分子。 为了进一步将DR特异性T细胞 对少数刺激决定因素的反应，启动 已经选择了组合，使得应答器和刺激器 表达仅相差三个氨基酸的DR变体。 与 这种方案，T细胞反应可以集中在有限的， 精确定义的分子差异，从而限制了 反应异质性。 在功能层面上， 同种异体反应性T细胞克隆特异性和异质性 使用该预充组合产生的，将使用 HLA分型板和单克隆抗体阻断研究。 对 分子水平，T细胞应答的异质性， 特异性T细胞受体基因使用将通过cDNA研究 T细胞受体α和β可变区的测序 基因. 如果有的话，差异化利用的部分将 使用克隆基因的杂交研究进行检查， 序列特异性探针和DNA序列分析来检测 基因片段的缺失或改变， 响应者。

The interaction of a T cell receptor, a class II histocompatibility molecule and antigen is essential for immune recognition. Diversity of both the T cell receptor and the class II molecule is involved in generating the specificity of the response. While the mechanisms which generate potential diversity are clearly defined, the forces which shape the T cell receptors available for interaction with antigen are not yet completely understood in the human. Although many aspects of diversity impinge on this interaction, this study will focus on the importance of germline diversity (repertoire) of T cell receptor genes in a specific cellular immune response and will examine the following: (1) The effect of the repertoire on the functional specificity of alloreactive T lymphocyte clones as measured by the patterns of recognition of an HLA-typed panel; (2) The effect of the repertoire on the primary structure of T cell receptors expressed by the above alloreactive clones as measured by cDNA sequence analysis; and (3) The effect of nonMHC, nonT cell receptor components (genetic/environmental) on the functional specificity and structure of T cell receptors utilized by the above alloreactive clones. The T cell response to an allogeneic human class II molecule will be used to sample the available T cell, repertoire as a model of an antigen recognition. To control the influence of thymic selection by MHC on the expressed T cell receptors, HLA identical siblings will be used as responders in the study. By RFLP analysis with T cell receptor V segment probes, the responders carry different combinations of parental T cell receptor beta chain genes. The stimulator (an HLA recombinant sibling of the responders) shares one HLA haplotype with the responders and differs only at the class II region of the second HLA haplotype. Although the stimulator and responders differ at DR, DQ and DP loci, the priming and selection protocols used will preferentially generate clones which recognize the DR molecule. In order to further focus the DR-specific T cell response on a small number of stimulatory determinants, the priming combination has been selected so that responders and stimulator express DR variants which only differ by three amino acids. With this protocol, the T cell response can be focused on a limited and precisely defined molecular difference and, thereby, restrict the heterogeneity of that response. On a functional level, the specificity and heterogeneity of alloreactive T cell clones generated with this priming combination will be characterized using an HLA-typed panel and monoclonal antibody blocking studies. On a molecular level, heterogeneity of the T cell response and specific T cell receptor gene usage will be studied by cDNA sequencing of variable regions of T cell receptor alpha and beta genes. Segments, if any, which are differentially utilized will be examined using hybridization studies with cloned genes and sequence specific probes and DNA sequence analysis to detect deletion or alteration of genetic segments in one of the responders.