Modulation of T cell proliferative response by accessory cell interactions.
Antigen-specific activation of the T cell is accomplished by engagement of the T cell receptor (TCR) by an antigen (Ag)/MHC complex presented on the surface of an antigen- presenting cell (APC). However, it has been demonstrated that engagement of the TCR by Ag/HC complexes alone is normally insufficient to lead to a proliferative response and the development of effector function. Thus it has been proposed that the APC also provides additional signals which serve to modulate the T cell's response. These second or costimulatory signals are thought to be critical in the generation of a T cell-driven immune response. Several receptors have been proposed to be capable of serving as costimulatory receptors. Candidate molecules include CD28 and LFA-1 as well as other receptors. In this review the studies that we have performed to clarify the role of both LFA-1 and CD28 in providing costimulatory activity for T cell activation are discussed. In addition, we present evidence that under certain conditions, TCR signalling alone can be sufficient to lead to T cell proliferation.
Green
J M
JM
Department of Medicine, University of Chicago, Ill., USA.
Thompson
C B
CB
D000818:Animals; D017951:Antigen Presentation; D001692:Biological Transport / Q000276:immunology; D018106:CD28 Antigens / Q000276:immunology; D016466:CHO Cells; D002478:Cells, Cultured; D006224:Cricetinae; D006801:Humans; D008213:Lymphocyte Activation; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology; D017260:Receptor-CD3 Complex, Antigen, T-Cell / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D018106:CD28 Antigens; D016169:Lymphocyte Function-Associated Antigen-1; D017260:Receptor-CD3 Complex, Antigen, T-Cell