Tumour-induced immunity to H-Y-disparate skin grafts without concomitant priming of CTL

A tumour, ET-5, arising as a subcutaneous mass in a C57BL/6 male mouse after treatment with a mutagen, has been found to elicit immunity to H-Y antigen in B6 female mice that have rejected the tumour. Anti-H-Y immunity is demonstrable in vivo by accelerated rejection of male skin grafts, and by the ability of spleen cells from ET-5-primed female mice to transfer immunity against H-Y antigen to immunodeficient hosts given indicator male skin grafts. However, spleen cells from ET-5-immune female mice fail to generate CTL specific for H-Y antigen when co-cultured with male stimulator cells in vitro. This finding implies that the generation of H-Y-specific immunity in vivo can occur in the absence of priming of CTL, and thus calls into question the necessity for CTL participation in H-Y-disparate tumour graft rejection.