Quantitative differences in the expression of parentally-derived H-2 antigens in F1 hybrid mice affect T-cell responses.

Quantitative absorption with specific anti-H-2 sera has shown that the H-2Kb and H-2Dd antigens coded by the B10.A(5R) haplotype are expressed in about fourfold lower amount on the spleen cells of [B10.A(5R) X B10.A(2R)]F1 hybrids than on parental B10.A(5R) cells. In contrast, the H-2Kk and H-2Db antigens of B10.A(2R) are expressed equally on parental and F1 cells. These quantitative differences are reflected in cytotoxic T-cell (Tc-cell) function. Macrophage target cells from F1 mice are killed less efficiently than B10.A(5R) targets by alloreactive or H-2 restricted Tc cells specific for H-2Kb or H-2Dd, and spleen cells of F1 mice are less efficient stimulators of alloreactive Tc cells specific for B10.A(5R) H-2 antigens, whereas F1 and B10.A(2R) cells are equal as targets and stimulators for Tc cells recognizing B10.A(2R) H-2 antigens.