title: Allo-I-J determinants participate in maintenance of neonatal H-2 tolerance.
abstract: To evaluate the role of IJ antigens in maintenance of the tolerant state in adult H-2 tolerant mice, we have attempted to abolish tolerance by injecting monoclonal antibodies (mab) specific for host, donor, or third party IJ antigens into adult H-2 tolerant mice. Abolition of tolerance was evidenced by the rejection of fresh test skin grafts bearing the tolerated antigens. Whole H-2 tolerant mice treated with anti-IJ mab specific for donor (allo) IJ antigens rejected their test skin grafts, indicating that tolerance had been abolished. When two other types of tolerant mice were tested, we found that mice tolerant of class II antigens alone, but not mice tolerant of an IJ thru D disparity, were susceptible to the anti-donor IJ mab treatment. In addition, adult tolerant mice were unaffected by treatment with either anti-host or anti-third party IJ mab. When tested in vitro, lymphoid cells from tolerant mice, the tolerance of which was abolished by anti-IJ mab, remained unresponsive to the tolerogen, just as untreated (control) tolerant mice, in several in vitro assays (e.g., mixed lymphocyte reaction, cytotoxic T cell precursor frequency and bulk cell-mediated lysis without growth factor). Mice treated with antidonor IJ mab, however, unlike mice treated with anti-host or third party IJ mab, were capable of generating tolerogen-specific T cells in the absence of exogenous growth factor. Thus in the strain combinations we used, adult mice tolerant of either the entire H-2 region or of the class II major histocompatibility complex region alone are susceptible to abolition of the tolerant state by treatment with anti-donor IJ mab. Coincidentally, lymphoid cells from these mice generate sufficient endogenous T helper activity to activate the tolerogen-specific cytotoxic T cells. We suspect that these latter cells may be responsible for rejection of grafts bearing the tolerated antigens.
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000276:immunology; D000911:Antibodies, Monoclonal; D000937:Antigen-Antibody Reactions; D006084:Graft Rejection; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D007108:Immune Tolerance; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000949:Histocompatibility Antigens Class II