ANALYSIS OF SELF PEPTIDES ASSOCIATED WITH MHC CLASS II

CD4T细胞在诱导免疫反应中起着关键作用， 识别与MHC类复合的外源抗原的多肽 II在APC的表面。大多数MHC分子在细胞上表达 表面被来自内源蛋白质的多肽占据。在……里面 为了被T细胞识别，外来肽需要与之竞争 与MHC分子结合的自体肽。自体多肽：MHC复合体 参与T细胞受体表型的阴性和阳性选择。 在T细胞介导的自身免疫中，自体多肽：MHC复合体成为靶点 自身反应性T细胞。这个项目的总体目标是研究 自体多肽：MHC复合体的产生及其对T细胞的影响 曲目。四个具体问题将被问到。首先，什么是 天然多肽与MHC-II类分子的结合特性 在多肽和MHC II类结构、动力学和pH方面的分子- 依赖？第二，自体多肽：MHC II类复合体是如何产生的 在活细胞里？第三，对自身的耐受性是怎样的：MHC II类 建筑群建立了吗？最后，自体多肽的曲目是什么？ 与不同组织在体外和体内表达的MHC II类分子结合， MHC-II类基因的等位基因差异如何影响自体多肽 曲目是什么？为了进行这些研究，我们最近开发了一种技术 与MHC II类和a类相关的自体肽的鉴定 针对这样一种多肽的单抗：MHC复合体。一个 生化和分子方法与定量相结合 多肽的免疫化学和流式细胞仪分析：MHC II类相互作用将 用来回答上述问题。现有的转基因小鼠具有 多肽供体蛋白的组织特异性表达将用于 研究T细胞对该多肽的耐受性。的水平的影响 MHC-II类复合体对多肽的耐受性将被研究 通过在体内慢性注射针对该基因的单抗 很复杂。为了推广这些研究，其他丰富的多肽 在各种组织和单倍型上与MHC II类结合将被鉴定， 和抗其他多肽的单抗：MHC II类复合体将 已生成。

CD4 T cells play a key role in the induction of immune responses, recognizing peptides derived from foreign antigens complexed to MHC class II on the surface of APCs. Most of the MHC molecules expressed on the cell surface are occupied by peptides derived from endogenous proteins. In order to be recognized by T cells, foreign peptides need to compete with self peptides for binding to MHC molecules. Self peptide:MHC complexes are involved in negative and positive selection of T cell receptor repertoire. In T cell-mediated autoimmunity, self peptide:MHC complexes become targets of autoreactive T cells. The overall goal of this project is to study generation of self peptide:MHC complexes and their influence on the T cell repertoire. Four specific questions will be asked. First, what are the characteristics of binding of naturally processed peptides to MHC class II molecule in terms of peptide and MHC class II structure, kinetics, and pH- dependence? Second, how is a self peptide:MHC class II complex generated in living cells? Third, how is tolerance to self peptide:MHC class II complexes established? Finally, what is the repertoire of self peptides bound to MHC class II expressed by different tissues in vitro and in vivo, and how do allelic differences in MHC class II influence the self peptide repertoire? To carry out these studies, we recently developed a technique of identification of self peptides associated with MHC class II and a monoclonal antibody specific for one such peptide:MHC complex. A combination of biochemical and molecular methods with quantitative immunochemical and FACS analysis of peptide:MHC class II interaction will be used to answer the above questions. Existing transgenic mice with tissue-specific expression of the peptide donor protein will be used to study T cell tolerance to the peptide. The influence of the level of expression on tolerance to the peptide:MHC class II complex will be studied by chronic in vivo injection of monoclonal antibody specific to this complex. In order to generalize these studies, other abundant peptides bound to MHC class II on various tissues and haplotypes will be identified, and monoclonal antibodies to other peptide:MHC class II complexes will be generated.