SIMULTANEOUS IMMUNOSELECTION IN-VITRO FOR H-Y OR H-2D ANTIGEN-LOSS VARIANTS OF A MOUSE-DERIVED B-CELL LINE

Cytotoxic T lymphocytes (CTL) specifically reactive with the male tran splantation antigen (H-Y) were used to immunoselect in vitro for antig en loss among cells from an Abelson murine leukemia virus (AbMuLV) tra nsformed lymphoblastoid cell line. Numerous variant cell clones were r ecovered that had lost expression of either H-Y or the restricting maj or histocompatibility class I molecule, H-2D. In all experiments, low- level gamma-irradiation applied prior to immunoselection increased the frequency of antigen loss, but when different time intervals between mutagenesis and immunoselection were used, the proportion of H-Y to H- 2D antigen loss was affected, suggesting that the antigens selected ag ainst remain on the surface of the cell for differing amounts of time following allele loss.