双语第十一章抗原提呈细胞与抗原的处理及提呈双语.ppt

第十一章抗原提呈细胞与抗原的处理及提呈(Section 11 Antigen Presentation) 第一节 抗原提呈细胞的种类与特点(Chapter 1 Antigen Presenting Cells) Antigen Presenting Cells Definition: the cells that can capture, process and present foreign antigen to T cells are named as antigen presenting cells(APCs). Classification of APCs According to their ability to express class ⅡMHC molecules and costimulatory molecules: Professional APCs: dendritic cells, macrophages and B lymphocytes. Non-professional APCs: endothelial cells, epithelial cells, fibroblasts, etc. DCs (Dentritic Cells) DCs are the most potent APCs known. DCs initiate most acquired immune responses, particularly for primary response. Classifications of DCs Myeloid DC and Lymphoid DC; Immature DC and Mature DC; Immature DC express numerous receptors(Fc receptors, mannose receptors) but very little classⅡMHC molecules and T cell costimulatory molecules, its principal function is antigen capture and processing; Mature DC strongly express classⅡMHC molecules and T cell costimulatory molecules, its principal function is antigen presentation to T cells. DC of lymphatic tissue: interdigitating DC, follicular DC; DC of non-lymphatic tissue: interstitial DC, Langerhans cell; DC of body fluid: veiled cell, blood DC. 第二节 抗原的处理和提呈(Chapter 2 Antigen Processing and Presentation) APC将胞质内自身产生的或者摄取入胞内的抗原分子降解并加工处理成一定大小的多肽片段，使多肽适合与MHC分子结合，然后以抗原肽-MHC复合物的形式表达于APC表面，此过程称为抗原加工或抗原处理(antigen processing)； 在APC与T细胞接触的过程中，表达于APC表面的抗原肽-MHC复合物被T细胞所识别，从而将抗原信息提呈给T细胞，此过程称为抗原提呈(antigen presentation)。抗原提呈是APC表面的抗原肽与MHC分子结合的复合物与T细胞表面的TCR结合为TCR-抗原肽-MHC三元体，从而活化T细胞的全过程。 Endogenous antigen (generated within the APC), presented with classⅠMHC molecule to the CD8+T cell. Exogenous antigen (taken up by endocytosis), presented with classⅡMHC molecule to the CD4+T cell. Pathways of Antigen Processing and Presentation The cytosolic (classⅠ) pathway; The endocytic (classⅡ) pathway; Non-classical antigen presenting pathway; CD1 related antigen p