PROCESSING OF ANTIGENS FOR HLA-RESTRICTED PRESENTATION

本申请的长期目标是阐明以下途径： 在抗原呈递内产生MHC分子/肽复合物 cell. 本提案的具体目标是， 在遗传学上表征了一组突变抗原呈递细胞， 不能将多种可溶性抗原呈递给II类限制性抗原， T细胞，但可呈递肽抗原。 这些方法是：使用 抗原和DR限制性肽特异性T细胞蛋白水解酶 更广泛地评估突变体的能力， 抗原;确定突变体是否存在抗原缺陷 通过内吞途径进行加工;使用体细胞杂种， 确定8个专性染色体中存在多少互补群 独立呈递缺陷突变体;以确定人类是否 非淋巴样细胞和鼠淋巴样细胞可以补充缺陷 在突变体中;确定受影响的基因是否映射到X 染色体或染色体6的HLA-D区域;以及 表型相似的突变体，使用逆转录病毒插入诱变作为 最终克隆突变基因的工具。 此外，隔离 其他抗原加工突变体的免疫选择 将寻找特异性溶细胞T细胞。 这些研究可能会导致 更好地理解MHC限制性抗原加工/呈递， 因此，可以提供对HLA相关的病理生理学的见解， MHC限制性T细胞可能发挥作用的疾病。

The long term objective of this application is to elucidate pathways for generating an MHC molecule/peptide complex within an antigen presenting cell. The specific aims of this proposal are to functionally and genetically characterize a group of mutant antigen presenting cells, which are unable to present a variety of soluble antigens to class II restricted T cells but can present a peptide antigen. The approaches are: to use proteolytic digests of antigen and DR restricted peptide specific T cell clones to more extensively evaluate the mutants' ability to present antigen; to determine whether the mutants are defective in antigen processing via the endocytic pathway; to use somatic cell hybrids to determine how many complementation groups exist among 8 obligate independent presentation defective mutants; to determine whether human non-lymphoid cells and murine lymphoid cells can complement the defect(s) in the mutants; to determine whether the affected gene(s) map to X chromosome or the HLA-D region of chromosome 6; and to isolate phenotypically similar mutants using retroviral insertional mutagenesis as a tool for eventual cloning of the mutant gene(s). In addition, isolation of other antigen processing mutants by immunoselection with antigen specific cytolytic T cells will be pursued. These studies may lead to a better understanding of MHC restricted antigen processing/presentation and may thus provide insights into the pathophysiology of HLA associated diseases in which MHC restricted T cells are likely to play a role.