中文摘要：

TAP2、tapasin和calreticulin（CRT）是MHC-Ⅰ类内源性抗原加工和递呈途径肽组装复合体（PLC）中的3个重要蛋白质.虽然对于肽组装复合体及其单个蛋白组分在抗原加工递呈中的作用,国内外已有大量的研究,但是由于研究手段的缺乏,其在复合体中的相对重要性还未得到清楚和定量的分析.本文中我们建立了一种新型的抗原递送方法,利用猪链球菌溶血酶（SLY）对鼠纤维母细胞系K41及其CRT缺陷细胞系K42、tapasin缺陷细胞系90a及tapasin、TAP2双缺陷细胞系91a进行穿孔并定量递送入鸡卵清白蛋白（ovalbumin,OVA）,使其被内源性加工处理后的多肽SIINFEKL与小鼠H2-Kb装配成复合物并被递呈至细胞表面.通过利用小鼠T杂交瘤细胞B3Z和单克隆抗体25D1.16识别并检测不同细胞表面SIINFEKL与小鼠H2-Kb复合物,我们发现CRT缺陷细胞系K42的抗原提呈能力相比91a及90a,较K41有着更大幅度的下降,说明CRT在提呈过程中可能有着较预期更重要的作用.本文是首个对抗原递呈途径蛋白相对重要性的研究,其研究结果对于进一步研究MHC-Ⅰ类抗原加工和递呈途径相关蛋白的作用提供了理论依据与研究手段.

英文摘要：

TAP2, tapasin and calreticulin （CRT） are three crucial components of the peptide loading complex （PLC） in MHC class Ⅰ antigen processing and presentation. While the functions of the proteins within the complex have been progressively defined, the hierarchical importance of the components has not been clearly and quantitatively analyzed. To compare the efficiency of MHC class I antigen processing in different cell lines, we established a novel suilysin-mediated antigen delivery method to quantitatively analyze antigen processing in a number of cell lines, including K41, the CRT-deficient line K42, the tapasin-deficient line 90a and the tapasirdTAP2-defieient eeU line 91a. We ranked the importance of the components of MHC class I antigen processing such as CRT, TAP and tapasin using OVA challenge as the antigen model. Surprisingly, CRT was shown to be the most important component of the PLC, even though TAP was speculated to be the most crucial protein involved in the pathway. This is the first report that ranks the components of the antigen-processing pathway. Further investigation is required for elucidation of the roles played by the individual proteins within the complex.