Hzl lymphocytes stimulated in the CML assay by B6 cells kill not only B6 but also M505 targets. (Hzl and M505 are strains that differ from B6 by recent mutations that occurred in the H-2Kb gene.) When the Hzl anti-B6 lymphocytes are adsorbed on M505 monolayer, the nonadherent cells still react with B6 but not with M505 targets. This result suggests that different antigenic determinants carried by the same H-2 molecule stimulate different T cell clones. The implication of this finding is that probably large numbers of T cell clones are stimulated by a foreign H-2 haplotype coding for a great number of antigenic determinants.
This work was supported by Grants AI 11650 and AI 12589 from the National Institutes of Health, Bethesda, Maryland.