[The molecular mechanism of costimulatory signal for T cell activation].
The initiation of T cell responses against antigens requires two distinct signals. The first, the essential signal is the engagement of T cell receptor to antigen peptide in the context of MHC molecules on antigen presenting cells (APC). The presence of the second signal (costimulatory signal) determines whether responding T cells to be fully responsive or to be anergic (antigen specific nonresponsiveness). There are numbers of such costimulatory receptor/ligand pairs including B7/CD28: CTLA4, VCAM-1/VLA4, ICAM-1/LFA-1, HSA/unknown, and LFA-3/CD2. Among those ligand receptor pairs, B7/CD28 pathway is chosen and the molecular mechanism how T cell responses are regulated by B7/CD28 is discussed.
Uede
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Section of Immunopathogenesis, Hokkaido University.
D000818:Animals; D018122:B7-1 Antigen; D018106:CD28 Antigens; D006801:Humans; D008213:Lymphocyte Activation; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*
D018122:B7-1 Antigen; D018106:CD28 Antigens