Ir gene regulation of T cell proliferation: requirement for Ia and antigen expression on the same accessory cell

These results demonstrate that only splenic macrophages expressing both Ir products (function) and the antigen (GAT) were able to reconstitute the T cell response of cultures in which the splenic macrophage monolayer had been treated with appropriate anti I-A antibodies. This inhibition was not a result of induced suppression caused by anti-Ia treatment but rather a masking of Ia antigen which prevents the T cell receptor(s) from recognizing either the Ir gene product and specific antigen in complex or separately.