Localization of tolerogenic epitopes in the α1 helical region of the rat class I major histocompatibility complex molecule

Abstract Induction of tolerance to organ allografts remains an elusive goal in transplant biology. Tolerance toward heart allografts was induced by preoperative intrathymic (IT) inoculation of extracted soluble histocompatibility antigens (HAg) in combination with a single dose of anti-T-cell antibodies. 1 In contrast, peritransplant intravenous (iv) or intraportal administration of HAg combined with a short course of cyclosporine (CyA) prolonged allograft survival but did not induce transplantation tolerance. 2 IV injection of peptides corresponding to amino acid (AA) residues 75–84 of the human HLA-B7 protein combined with a short course of CyA before and after grafting induced donor-specific tolerance to heart allograft in rats. 3 The present experiments examined the localization of tolerogenic epitopes in rat class I major histocompatibility complex RTI.A u and RT1.A 1 molecules.