Evidence for Multiple Clones of Cytotoxic T Cells Responding to Antigenic Determinants on the Same Molecule¹

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-2K^b 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.