Antigen-reactive T cells can be activated buy autologous macrophages in the absence of added antigen.

T cells responsive to macrophages (M phi) in the autologous mixed lymphocyte reaction (AMLR) contain those cells that can be induced to proliferate by soluble antigens. Negative solution (5-bromo-2-deoxyuridine and light) of T cells activated by autologous M phi also removed those cells required for reactivity to Candida albicans and purified protein derivative. Positive selection of T cells responsive to autologous M phi yields a population that is simultaneously enriched in antigen reactivity. Some patients demonstrating cutaneous anergy and diminished in vitro blast transformation in response to soluble antigen also lack T cells responsive to the AMLR to M phi. When considered in conjunction with previously reported data, these findings indicate the AMLR occurring between T cells and M phi in the absence of soluble antigen represents self recognition occurring between antigen-reactive T cells and antigen-presenting M phi.