Frequency of responsiveness to the H-Y antigen among the B10.W lines.

B10.W females were immunized against syngeneic male cells (via the footpad and also i.p. in some strains) and their spleen cells were then restimulated in vitro and tested in the cell-mediated lympholysis assay for H-Y-specific killing of target cells. Only seven of the 33 tested lines were anti-H-Y responders. The effector cells obtained from each of the responder lines were then tested against male and female cells of other B10.W lines, as well as a number of classic B10 congenic lines, and the MHC molecules providing the context for H-Y recognition were identified. They were: Kk, Kw3, Kw7, Kw17, Kw27, Dk, and Dp. None of the strains generated effector cells capable of recognizing the H-Y antigen simultaneously in the context of the K and D molecules. The WOA1 females generated effector cells by using the Kw7 molecule for context of recognition, whereas the WR7 females produced cells recognizing the H-Y antigen exclusively in the context of the Dk molecule despite the fact that both lines share the Kw7 gene. Some of the effector cells cross-reacted with both male and female cells of other strains and this cross-reactivity could be attributed to the recognition of allogeneic MHC molecules controlled by K or D region genes. Interestingly, STA39 females generated Dp- but not Kw3-restricted anti-H-Y responses, whereas SAA48 females generated Kw3- but not Dw3-restricted responses; the Kw3-restricted cells cross-reacted with the Dp molecule. This cross-reaction might explain why the STA39 females do not mount a Kw3-restricted anti-H-Y response. Because the Kw3 + H-Y combination resembles Dp, the anti-Kw3 + H-Y T cells are functionally eliminated when tolerance of Dp molecules is attained in the STA39 mice.