Effect of anti-HLA antisera on macrophage-T-cell interactions.

Human T lymphocytes were shown to proliferate in response to tetanus toxoid antigen only in the presence of macrophages. This response was inhibited by anti-DRw but not by anti-HLA (A and B loci) antisera added to the cultures and by pretreatment of macrophages but not of T cells with anti-DRw antisera and complement. Macrophages pulsed for 18 hr with antigen and then washed were capable of triggering T-cell proliferation. Addition of anti-DRw but not anti-HLA (A and B loci) antisera during the pulse period inhibited the macrophages' ability to trigger T-cell proliferation. The data obtained indicate that human T cells recognize and proliferate in response to antigen presented by the macrophages in association with Ia-like antigens.