Utilization of the MHC Class I (H-2Kb) Purified Molecule and its Synthetic Peptides for Inhibition of Kb-Specific Suppressor T Cells and their Induction In Vivo by the MHC Peptides

Six synthetic peptides of the MHC class I molecule corresponding to individual H-2K^b participants in amino acid sequences of domains α₁ (peptide 1 and 2) and α₂ (peptides 3,4, 5,6) were selected. K^b-specific suppressor T cells (Ts) were induced in vivo in mice, then pretreated with a set of peptides and assayed by proliferation decrease in a three-cell lymphocyte culture (MLC). The effector function of Ts was abolished by the complex of the α₂-domain peptides (but nol by the α₁-domain peptides) and decreased by particular peptides separately (4, 5, 6) of the α₂-domain. Both α₁- and α₂-domain peptides. added in high concentration, decreased otherwise efficient enrichment of Ts during the absorption-elution procedure on the syngeneie macrophage (Mφ) monolayers. A similar significant effect was observed using the purified K^b molecule (100μg/ml) in the allogeneic Mφ monolayer. Interaction between Ts receptors and some MHC peptides indicates in effector Ts activation in vivo by induction with peptides 5 and 6 of the α₂-domain. The fine mechanisms of interaction between MHC class I molecule epitopes and T-cell receptors of each of the T-cell subsets separately are presently being studied.