Immune recognition of tumor cells in vivo. I. Role of H-2 gene products in T lymphocyte activation against minor histocompatibility antigens displayed by adenocarcinoma cells.

Challenges from ADK-1t adenocarcinoma cells of BALB/c (H-2d, Mlsb) mouse origin are rejected by DBA/2 (H-2d, Mlsa) mice on the basis of differences in a limited number of minor histocompatibility antigens. This T lymphocyte-dependent reaction is highly specific, and efficiently triggered only by Ia+ leukocytes infiltrating the tumor mass. ADK-1t challenges depleted of Ia+ infiltrating BALB/c leukocytes grow and kill DBA/2 mice, whereas the simultaneous injection of Ia+-inactivated BALB/c leukocytes induces tumor rejection. The expression of Mlsb-incompatible determinants on the Ia+ BALB/c leukocyte membrane is irrelevant in the induction of this efficient T lymphocyte reaction against BALB/c minor histocompatibility antigens. By contrast, a critical requirement is H-2 matching between the Ia+ leukocytes and the recipient mice at the inductive phase of the reaction.