title: Ir-associated murine alloantigens: demonstration of multiple Ia specificities in H-2 alloantisera after selective absorptions.
abstract: Quantitative absorptions of anti-H-2 alloantisera with increasing concentrations of T cell-derived tumor cells of donor H-2 type has been found to remove antibodies to H-2K region antigens selectivelymsimilar results were obtained after absorptions with thymocytes of the donor strainl In each case residual antibodies reacting with Ir-associated B cell alloantigens (Ia antigens) were unmasked by this procedure. Antisera which initially contained comparable titers of Ia and H-2 activity were depleted of H-2 activity at absorbing cell concentrations which did not appreciably alter the Ia reactivities, indicating that Ia antigens, if expressed on these T cell populations, must have been present at very low concentrations relative to H-2D and H-2K region antigens. Further absorptions with spleen cells from cross-reactive strains demonstrated a multiplicity of shared and unique Ia specificites in these sera. The multiple Ia antigens detected appeared all to be codominantly expressed on the same subpopulation of lymphoid cells.
mesh_terms: D000042:Absorption; D000818:Animals; D000918:Antibody Specificity; D003165:Complement System Proteins; D003601:Cytotoxicity Tests, Immunologic; D006649:Histocompatibility Antigens; D007106:Immune Sera; D007518:Isoantibodies / Q000032:analysis*; D007942:Leukemia, Experimental / Q000276:immunology; D007959:Lymphocyte Culture Test, Mixed; D008223:Lymphoma / Q000276:immunology; D008297:Male; D051379:Mice; D013045:Species Specificity; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology; D013950:Thymus Gland / Q000166:cytology
chemical_list: D006649:Histocompatibility Antigens; D007106:Immune Sera; D007518:Isoantibodies; D003165:Complement System Proteins