CORECEPTOR ANTIGEN- CD4 NONSPECIFIC SIGNAL CD4 T CELL TCR RECEPTOR #1 ACTIVATION PEPTIDE- SPECIFIC CO-STIMULATOR SIGNAL "ARMED" B7 ANTIGEN- NONSPECIFIC #2= EFFECTOR CD28 Th CELL Naive "unactivated"CD4 T cell becomes“ACTIVATED
路℃ CORECEPTOR CDa ANTIGEN- CD8 T CELL NONSPECIFIC SIGNAL ACTIVATION RECEPTOR PEPTIDE- SPECIFIC "ARMED" CO-STIMULATOR SIGNAL EFFECTOR B7 ANTIGEN- #2 Tk CELL CD28 NONSPECIFIC Naive“unactivated" CD8 T cell becomes“ACTIVATED
B7--CD28 VERSUS B7---CTLA-4 3 SIGNAL CD4 T CELL #1 ACTIVATION 7 SIGNAL "ARMED" B7 #2 EFFECTOR CD28 Th CELL D SIGNAL DOWN- #1 REGULATION ACTIVATION OF T CELL BLOCKED STOP B7 RESPONSE SIGNAL CTLA-4
Fig 8.11 Crosslinking of CD28 dellvers the co-stimulatory signal CTLA-4 binds B7(CD80 or CD86)more avidly than does during activation of naive T cells and induces the expression of CTLA-4(CD152) CD28 and delivers inhibitory signals to activated T cells naive T cell activated T oell 6 台68686 CD28 T-Cell recepto CD4 LN CTLA-4 (CD152 B7 Antigen MHC class antigen-presenting cell antigen-presenting cell
第二节T细胞亚群 CD4+、CD8+亚群CD4T细胞识别由 13~17个氨基酸残基组成的抗原肽，并受 自身的MHCⅡ类限制。CD8+T细胞识别 8~10个氨基酸组成的抗原肽，并受MHC I类限制。 ·TCRT细胞和TCRYδT细胞
第二节 T细胞亚群 • CD4 + 、CD8 +亚群 CD4+T细胞识别由 13~17个氨基酸残基组成的抗原肽，并受 自身的MHC II类限制。CD8 + T细胞识别 8~10个氨基酸组成的抗原肽，并受MHC I类限制。 • TCRαβT细胞和TCRγδT细胞