Previous in vivo studies suggests that the expression of H-Y antigen on male tissues and the response by female hosts are at least in part determined by the H-2 complex This chapter discusses in vitro studies of H-2 restricted T-cell cytotoxic responses to H-Y antigen. From the studies, it can be concluded that the secondary in vitro cytotoxic responses to H-Y antigen are mediated by cytotoxic T-lymphocytes and the H-Y target cell antigen is specified by the H-2 complex. The results suggest that the H-Y target antigen maps at the D-end of H-2 in an H-2b system and at the K-end in an H-2d system. F1 female cells sensitized to one parental male cell lyse only targets homologous with that parental cell. The expression of H-Y antigen on male tissues and the response by female hosts are determined by the H-2 complex.

A new method in which induction of mixed lymphocyte responses and cytotoxicity can be performed under identical conditions is described. This enables the investigation of the relationship between MLR and cytotoxicity. A micro method for the 51Cr release assay for cytotoxicity is described using both mitogen-induced blasts and tumors as target cells. Under the conditions used data obtained is suitable for linear regression analysis, enabling quantitative comparisons to be made.