title: Molecular events in the T cell-mediated suppression of the immune response.
abstract: To understand the mechanism of T cell-mediated suppression, we have established a number of suppressor T cell (Ts) clones of both CD4+ and CD8+ phenotypes that exert a definite suppressive effect on antigen-induced proliferative response of normal and cloned CD4+ helper T cells (Th). When an antigen-activated Ts clone was added to Th clones that were subsequently stimulated with antigen and APC, the increase of intracellular Ca2+ in the latter was greatly inhibited. The suppression was unidirectional where Ts suppressed Th but not vice versa. A Ts clone could not suppress other Ts clones. Exactly the same suppression of Ca2+ response could be induced by the treatment of T cells with an anti-I-J antibody. The anti-I-J suppressed the Ca2+ response of Th clones induced by antigen-pulsed APC and anti-TcR alpha beta antibody, whereas the responses to anti-CD3 and Con A were not inhibited. The difference in the effect of anti-TcR alpha beta and anti-CD3 suggests that the suppression is caused by a functional uncoupling of TcR alpha beta and CD3. The stimulation of Ts clones with anti-CD3, on the other hand, induced a unique suppressor factor that potently inhibits the antigen- and anti-TcR induced proliferation of CD4+ Th clones.
authors.affiliation: Department of Immunology, Faculty of Medicine, University of Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tada
authors.forename: F Y
authors.initials: FY
authors.lastname: Hu
authors.forename: H
authors.initials: H
authors.lastname: Kishimoto
authors.forename: M
authors.initials: M
authors.lastname: Furutani-Seiki
authors.forename: Y
authors.initials: Y
authors.lastname: Asano
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D002999:Clone Cells; D006801:Humans; D007108:Immune Tolerance; D050378:T-Lymphocytes, Regulatory / Q000502:physiology*
chemical_list: D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D016827:CD8 Antigens