Investigation on the molecular mechanisms of antigen presentation and recognition.

抗原呈递和识别的分子机制研究。

基本信息

批准号：
14370115
负责人：
NISHIMURA Yasuharu
金额：
$ 8.9万
依托单位：
Kumamoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

项目摘要

Presentation of antigenic peptides by antigen presenting cells and consequent stimulation of CD4^+ T cells is crucial in the regulation of immune response. In this research project, we studied on the recognition of antigenic peptide by T cell receptor (TCR) and signal transduction pathway in CD4^+ T cells stimulated with altered peptide ligands (APL). In addition, we established a method for ES cell-based genetic engineering of dendritic cells (DC). The following results were obtained.1)We developed an experimental system to dentify diverse T-cell epitopes from T-cell epitope-expression library, using an epitope presenting vector based on CLIP-substituted invariant chain. Using the libraries in which randomized amino acid residues were narrowed down into three successive ones, we characterized the degeneracy in the epitopes of the GAD65-reactive Th-cell clones derived from IDDM patients, and identified several microbe-derived antigens to which the Th-cell clones cross-reacted.2)We foun … More d that a human CD4^+ T cell clone showed full proliferation in response to over-expressed partially agonistic peptide/HLA-DR4 complex. However, a protein tyrosine kinase ZAP-70, which is believed to be essential for TCR-mediated T cell activation, was not tyrosine-phosphorylated and activated. Instead, we found that other kinases B-Raf and PKCm were activated in the T cells, suggesting the presence of new signaling pathways leading to full T cell proliferation that is independent of ZAP-70 activation.3)We established a method to generate mouse ES cell-derived DC (ES-DC). Genetic modification of ES-DC can be done by transfection of ES cells and subsequent differentiation to DC. OVA antigen-specific cytotoxic T lymphocytes were efficiently primed in vivo by injecting mice with ES-DCs introduced with an OVA-expression vector. Double-transfectant ES-DC expressing a chemokine along with OVA provided potent protection from OVA-expressing tumor cells. In addition, we demonstrated prevention of experimental autoimmune encephalomyelitis by treatment with genetically modified ES-DC. Less

通过抗原呈递细胞和随之而来的CD4^+ T细胞的刺激对抗原性宠物表示至关重要。在该研究项目中，我们研究了T细胞受体（TCR）对抗原肽的识别，以及用改变的肽配体（APL）刺激的CD4^+ T细胞中的信号转移途径。此外，我们还建立了一种基于ES细胞的树突状细胞基因工程（DC）的方法。 1）我们使用基于基于夹子取代的不变链的表位呈现向量的表位来从T细胞表位表达式文库中牙齿牙齿的T细胞表位牙齿牙齿牙齿牙齿牙齿牙齿牙齿牙齿牙齿牙齿牙齿牙齿牙齿牙齿牙齿牙齿牙齿牙齿牙齿牙齿牙齿牙齿的，从而获得以下结果。1）1）。使用将随机氨基酸存活的文库缩小为三个成功的图书馆，我们表征了来自IDDM患者的GAD65反应性TH细胞克隆的脱位，并确定了几个微生物衍生的抗原，并在th-ded Clone crossected forsect.2）中表明了th-clone form.2），这表明了人类的反应。部分激动剂肽/HLA-DR4复合物。然而，据信对于TCR介导的T细胞激活至关重要的蛋白酪氨酸激酶ZAP-70并非被酪氨酸磷酸化和激活。取而代之的是，我们发现其他激酶B-RAF和PKCM我们建立了一种生成小鼠ES细胞衍生的DC（ES-DC）的方法。 ES细胞的遗传修饰可以通过转染ES细胞并随后分化为DC来完成。 OVA抗原特异性细胞毒性T淋巴细胞通过在体内有效启动，通过将小鼠注入带有OVA表达载体的ES-DC。表达趋化因子以及OVA的双转移ES-DC为表达OVA表达的肿瘤细胞提供了有效的保护。此外，我们通过一般修饰的ES-DC治疗可以预防实验性自身免疫性脑脊髓炎。较少的