The functional transformation of cytotoxic lymphocytes into T-suppressors under the influence of two mediators.

A set of CTL-lines in the system differing in the whole H-2 complex, as well as in distinct subregions of H-2, was established. These lines were routinely tested in Cr51-release assay to insure that they retained lytic activity and antigen-specificity. The result of the interaction of CTL with H-2Kb-molecule and alpha1-thymosine was transition of CTL into a reversible state of anergy.

Peptides of a major histocompatibility complex class I (Kb) molecule cause prolongation of skin graft survival and induce specific down-regulatory T cells demonstrable in the mixed lymphocyte reaction.

Six individual peptides of the major histocompatibility complex (MHC) class I molecule H-2Kb were synthesized. Intravenous injection of peptide 6 into mice prolonged the survival of Kb (BL/6 or B10.MBR) skin grafts on allogeneic R101 and B10.