title: Neonatal tolerance induction in the thymus to MHC-class II-associated antigens. I. Preferential induction of tolerance to Mls antigens and resistance to allo-MHC antigens.
abstract: Neonatal tolerance inducibility of self-major histocompatibility complex (MHC)-class II-associated antigens was compared with that of allo-class II antigens. BALB/c (H-2d, Mlsb) mice, less than 24 hr after birth, were intravenously injected with bone marrow cells of either (BALB/c X DBA/2)F1 (H-2d, Mlsb/a, semiallogeneic at the Mls locus) or (BALB/c X B10.BR)F1 (H-2d/k, Mlsb; semiallogeneic at the MHC), as antigens. The mice were tested for in vivo immune activity of class II-reactive T cells by means of the popliteal lymph node-swelling assay. They developed tolerance, irrespective of type of antigens, showing profoundly suppressed host-versus-graft reaction, and those tolerized to the allo-MHC antigens accepted skin grafts of the corresponding allogeneic mice. In the thymus and spleen of the Mls-tolerant mice, antigen-specific class II-reactive T-cell activity was completely abolished, without the apparent involvement of suppressor cells. In contrast, the activity in allo-MHC-tolerant mice was not reduced in either thymus or peripheral lymphoid organs, suggesting that systemic hyporesponsiveness is attributable to reversible suppression of immune competent cells. The resistance for cell-level tolerance induction to allo-class II antigens may not be ascribed to the active participation of allo-MHC antigens in prevention of or in escape from tolerance induction or both, since an injection of bone marrow cells of both Mls and H-2-semiallogeneic (DBA/2 X B10.BR)F1 (H-2d/k, Mlsa/b) mice could induce tolerance to Mlsa-H-2d antigens in newborn thymus cells.
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000276:immunology*; D016026:Bone Marrow Transplantation; D002678:Chimera; D006087:Graft vs Host Reaction; D006183:H-2 Antigens / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006789:Host vs Graft Reaction; D007108:Immune Tolerance; D051379:Mice; D008807:Mice, Inbred BALB C / Q000276:immunology; D008811:Mice, Inbred DBA / Q000276:immunology; D016038:Skin Transplantation; D013154:Spleen / Q000637:transplantation; D013601:T-Lymphocytes / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology*
chemical_list: D006183:H-2 Antigens; D000949:Histocompatibility Antigens Class II