Restricted recognition of H-2 subregion coded alloantigens in delayed-type hypersensitivity.

Subcutaneous (sc) immunization of mice with H-2K, I, or D incompatible spleen cells induces a state of host-versus-graft (HvG) delayed-type hypersensitivity (DTH). The DTH reaction is elicited by challenging the immunized mice in a hind foot with similar allogeneic spleen cells and is measured as the subsequent foot swelling. DTH effector T cells specific for H-2I-coded alloantigens, but not for H-2K/D-coded alloantigens, can be induced in a graft-versus-host (GvH) model as well. In this paper we report that under HvG as well as under GvH conditions the recognition of class II antigens by DTH effector T cells is restricted by class I molecules. Furthermore, DTH effector T cells induced by sc immunization with class I antigens appear to be restricted by class II molecules.