Antigen and MHC restriction specificity of two types of cloned male-specific T cell lines.

Two types of H-Y antigen-specific cloned T cell lines were established. Clone 2-1 is an IAb restricted proliferating T cell line and clone 10-2 is an H-2Db restricted proliferating and cytotoxic T cell line. Clone 2-1 proliferated in response to H-Y antigen with an IAb restriction in the absence of IL 2. IAb mutant B6.C-H-2bm12 (bm12) mice did not stimulate this clone. This defect may be the cause of the unresponsiveness to H-Y antigen with cytotoxic T lymphocytes (CTL) in bm 12 mice (i.e., the failure of activation of H-Y-specific helper T cells). Although (B10.A X bm12)F1 mice are known to show functional complementation, as demonstrated by the presentation of insulin to helper T cells and the H-Y-specific CTL response, the F1 male cells could not stimulate this clone. The IA determinant restricting H-Y antigen presentation to helper T cells and/or the H-Y antigenic determinant seems to differ between C57BL/6 (B6) and the F1 mice. Monoclonal anti-IAb antibodies but not anti-H-Y antibodies blocked the proliferation of this clone. The clone had no cytotoxic activity unless Con A was added to the cytotoxicity assay culture. Clone 10-2 proliferated in response to H-Y antigen with an H-2Db restriction. Proliferation was not observed unless specific stimulator cells and IL 2 were supplied to the culture; IL 2 alone could not support this clone. The clone did not respond to male cells from the H-2Db mutant B6.C-H-2bm14 (bm14). The clone had cytotoxic activity against male H-2Db+ cells but not against male bm14 cells. This evidence indicates that the mutation of bm14 occurred in the structural gene coding for a molecule on which a determinant restricting the recognition of H-Y antigen by B6 CTL exists. The phenotypes of clone 2-1 were Thy-1.2+, Ly-1.2-, Ly-2.2-, IAb-, and H-2Kb+, and the phenotypes of clone 10-2 were Thy-1.2+, Ly-1.2-, Ly-2.2+, IAb-, and H-2Kb+.