Development of graft-vs.-host disease-like syndrome in cyclosporine- treated rats after syngeneic bone marrow transplantation. I. Development of cytotoxic T lymphocytes with apparent polyclonal anti-Ia specificity, including autoreactivity

either of Lewis or ACI labelled target cells (labelled Lewis target cells/cold ACI targets at 1 : 1 and 1:5 ratios, 35.2 "4-7.8 and 52.3 -+ 6.4% inhibition, respectively [~ _+SE]; labelled Lewis targets/cold Lewis targets at 1:1 and 1:5 ratios, 30.2 + 6.9 and 57.1 _+ 8.4% inhibition, respectively; labelled ACI targets/cold Lewis targets at 1:1 and 1:5 ratios, 22.9 "4-7.7 and 43.1 _+ 9.2% inhibition, respectively; labelled ACI targets/cold ACI targets at 1:1 and 1:5 ratios, 25.8 + 4.9 and 47.6 + 8.0% inhibition, respectively). In a few experiments, BN target cells were also used as cold target-inhibitors and were found to be equally as inhibitory as cold ACI or Lewis targets. Comparatively, YAC tumor cells added as cold targetinhibitors were ineffective. These results support the hypothesis that there is one cell capable of recognizing both ACI and Lewis cold targets. If there was polyclonal activation ofanti-la-reactive ceils, with each clone recognizing distinct specificities, the cold target-inhibition studies would have revealed a significant difference between the ability of cold ACI and Lewis targets to mediate inhibition of lysis of the labelled targets.