Accessory molecules and T cell activation. II. Antibody binding to L3T4a inhibits Ia-independent mouse T cell proliferation.
Monoclonal antibody (mAb) blocking assays using L3T4- and lymphocyte function-associated antigen-1 (LFA-1)-specific reagents were used as an approach to investigate the involvement of these accessory molecules in various T cell activation pathways. As previously reported, rat mAb to L3T4a and LFA-1A functional epitopes efficiently blocked antigen-driven T helper cell proliferation. In contrast, antigen- and Ia-independent T cell triggering induced by appropriate mAb to the Thy-1 or the T cell receptor molecules were found to be inhibitable by L3T4a- but not LFA-1A-specific mAb, although the extent of inhibition varied, depending on the cell type and the activating signal examined. These results provide further evidence that the inhibiting effects of L3T4-specific mAb on T cell responses may be due, in addition to an impairment of L3T4-class II major histocompatibility complex molecular interaction, to a down regulatory signal possibly transmitted by the L3T4 molecule itself.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000937:Antigen-Antibody Reactions; D000938:Antigen-Presenting Cells / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000276:immunology*; D003207:Conalbumin / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D008815:Mice, Inbred Strains; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D000949:Histocompatibility Antigens Class II; D011948:Receptors, Antigen, T-Cell; D003207:Conalbumin