The role of target antigens coded by subregions of the mouse H-2 complex in the nature of growth of sarcoma I tumor allograft.

The nature of the development of tumor grafts of Sarcoma I in allogeneic mice is determined by the immunogenicity of membrane markers of tumor cells coded by the major H-2 system. Minor (non-H-2) systems fail to assert themselves in tumor transplantation. The role of various subregions of the H-2 system may already be followed in normal Sa I recipients: a more striking differentiation is achieved in hosts treated with xenogeneic antilymphocyte serum. Those presenting the strongest barrier were specificities coded by the entire region of the H-2 complex. Of the subregions of the H-2 system studied here, H-2K meant a stronger barrier to tumor growth than the H-2D region. When the tumor antigenic specificities of both H-2K and H-2D regions were extended to include also those of the H-21 regions, tumor growths were for the most part restricted; on the other hand, the inclusion in tumor antigen specificities coded by H-2KAB of the JE region specificities brought about a moderate stimulation in tumor growth. This differences in the fate of tumor allograft may be due to a quantitatively or qualitatively different development of the host's immune response against various tumor antigen specificities coded by subregions of the H-2 system or to a varying ability of the tumor grow across different barriers of the H-2 system.