中科院细胞与分子免疫学课程课件6.ppt

* * * * * * * * * * * * * * * * * * * The major functions of T cell integrins are to mediate adhesion to APCs, endothelial cells and extracellular matrix proteins The avidity of integrins and the expression of integrins will be increased by: Inflammatory Cytokines TCR recognize antigen Integrin function: 1 retention of antigen-stimulated T cells in lymphoid organs 2 retention of activated T cells at peripheral sites of infection and antigen persistence Selectins and Selectin Ligands: Regulate the migration of leukocytes to various tissues. HEV Selectins and Selectin Ligands: L-selectin: is expressed at high levels on na?ve T lymphocytes L-selectin ligand: expressed on the specialized endothelial high endothelial venules Effector Molecules of T lymphocyte CD40 ligands Activated CD4+ T cells express a surface protein CD40 ligand. CD 40 were expressed on B cells, macrophage cells, dendritic cells, and endothelial cells, CD40L: CD40 can stimulate B cells to produce antibodies as well as macrophage to destroy microbes. Homing to lymph node L-selectin VLA-4 Homing to inflamed vascular endothelium CD45RA CD45RO Differential splicing of CD45 mRNA in na?ve armed T cells CD2 LFA-1 CD44 Adhesion molecules Na?ve Activated + - + + - + + - ++ ++ ++ ++ + - Difference of accessory molecules between the avtivated T cells and Na?ve cells MHC II 类分子呈递抗原的过程： 对上堂课回顾： MHC I 类分子呈递抗原的过程： T淋巴细胞在识别MHC分子呈递的多肽过程中特性有： T细胞只识别自身MHC分子所呈递的抗原 CD4＋识别MHC II类分子呈递的抗原，是细胞外抗原，蛋白所经过的降解途径是通过内吞小体的作用。 CD8＋识别MHC I 类分子呈递的抗原，是细胞内抗原。 * * * * * * * * * * * * * * * * * * * * * * Chapter 6 Antigen Receptors and Accessory Molecules of T Lymphocytes T cell receptor and accessory molecules: According to function, the molecules of the T cell surface are divided into : TCR: recognition antigen Stable adhesion molecules Signaling T Cell Receptor Structure of the αβ TCR Structure of the αβ TCR 1) Vαβ contain CDR, three CDR in α chain are juxtaposed to three similar regions in the β chain. 2) The β chain