Cell-mediated cytotoxicity to non-MHC alloantigens on mouse epidermal cells. I. H-2 restricted reactions among strains sharing the H-2(k) haplotype

Epidermal cells (EC) obtained by trypsinization of tail skin of H-2(k) haplotype mouse strains AKR, B10.BR, B10.K, CBA, C3H, and RF were used as stimulators and targets of cell-mediated cytotoxicity (CMC) in 3-hour chromium-release assays. Host splenic effector cells were generated by priming mice with an injection of EC and boosting in mixed culture with irradiated donor-strain EC stimulators; then assayed for CMC towards donor-strain EC and lymphoid cell (LC) targets. When C3H is the donor strain and any of the other strains the host, little CMC is registered with EC targets. However, when C3H is the host and any of the other strains the donor, the CMC registered with donor-strain EC targets invariably is greater than that registered with LC targets, even with mitogen-induced lymphoblasts, indicating that C3H mice respond to non-H-2 alloantigens preferentially expressed by EC. The CMC evoked in C3H hosts by EC from any of the other other H-2(k) strains cross-reacts with EC targets from all of them, indicating extensive sharing of target-cell determinants. However, the CMC is H-2 restricted, and mapping tests with recombinant lines on the C57BL/10 background proved that the restriction depends on antigens mapping in the K region of the H-2 complex. T cell elimination tests indicate that the effector cells in these reactions are cytotoxic T lymphocytes. Moreover, tests conducted with medium supplemented with adult mouse serum instead of fetal calf serum indicate that the reactions are not dependent on xenogeneic serum but represent true examples of H-2-restricted CMC directed towards non-H-2 alloantigens expressed preferentially on EC.