Dendritic cells induce T cell proliferation to synthetic antigens under Ir gene control.

Dendritic cells prepared by a modification of the method of Steinman and Cohn are I-A+ and FcR-. They are extremely potent at activating not only allogeneic T cell proliferation but also antigen-specific syngeneic T cell proliferation. Dendritic cells from nonresponder strains are unable to present antigens to responder X nonresponder T cells, suggesting that they may be a site of Ir gene product expression.