抗原识别和免疫反应的淋巴细胞.ppt

Antigen recognition and immune response of T lymphocytes
Ⅰ. Recognition of antigen by T lymphocytes
Ⅱ. The course of T lymphocytes activation
Ⅲ. Responses of effector T lymphocytes
The course of immune response
Antigen recognition
specific binding of antigen to antigen receptor
Immune response
activation of lymphocytes and production of effector agents
Immune reaction
antigen elimination or neutralization by effector agents
Ⅰ. Antigen recognition
Characteristics of  TCR antigen recognition
recognize MHC-plex on APC cells
recognize linear amino acid antigen determinants
MHC restriction——
CD4+T --MHC-II-peptide
CD8+T --MHC-I-peptide
(Ⅰ) Nonspecific binding between T cell and APC
Nonspecific binding between T and APC
(Ⅱ) Specific binding between T cell and APC
Stable binding between T and APC
low affinity binding between LFA-1and ICAM-1
TCR and CD4 coreceptor recognize MHC-plex
TCR signaling enhance the affinity between LFA-1 and ICAM-1
T cell
T cell
T cell
APC
APC
APC
(Ⅲ)Binding of costimulatory molecules between T cell and APC
CD28/B7、LFA-1/ICAM-1、CD2/CD58…
(Ⅳ) immunological synapse
Raft-like structure:
Centre----TCR:MHC-plex
Surrounding ----pairs of adhension molecules