THE NATURE OF EPITOPES RECOGNIZED BY T-LYMPHOCYTES IN THE ALLOGENEIC IMMUNE-RESPONSE

The theoretical and experimental analyses of epitopes of a classical M HC molecule of class I H-2K(b) responsible for incompatibility reactio ns after transplantation were carried out. The search of the MHC-bindi ng motifs in the molecule primary structure along with the direct expe rimental data on antigenic peptides of this molecule containing such m otifs have shown that reactions of indirect allogeneic recognition wit hin the context of classical MHC molecules of a recipient contribute l ittle to the development of allogeneic reaction. Assessment of cross-r eactivity of the:cell population exhibiting Kb-specific memory for mut ant forms of this MHC molecule has shown that the most essential role belongs to the direct recognition of narrow structural patterns formed by the allogeneic MHC molecule associated with endogenous peptides. P ractically in all mutant forms of classical MHC class I molecules reve aled in the graft rejection tests, mutations give rise to amino acid s equences identical to the same fragments of some known allelic forms o f the same molecules, which may be the basis of the limited structural variety of MHC molecules responsible for allogeneic reactions.