title: The expression of Ia antigens on immunocompetent cells in the guinea pig. II. Ia antigens on macrophages.
abstract: Only 15 to 25% of purified oil-induced guinea pig macrophages could be lysed by treatment with anti-Ia serum and C. Those cells remaining alive after treatment were not damaged and were metabolically active since they readily phagocytized latex beads. However, the "Ia-negative" macrophages were markedly deficient in their ability to present protein antigens to immune T lymphocytes and to function as stimulator cells when mixed with allogeneic T cells in the mixed leukocyte reaction. It thus appears that Ia antigens are expressed on a subpopulation of macrophages and that this subpopulation plays a critical role in the activation of T cell proliferation to soluble protein antigens and to alloantigens.
mesh_terms: D000818:Animals; D003165:Complement System Proteins; D003601:Cytotoxicity Tests, Immunologic; D066298:In Vitro Techniques; D007518:Isoantibodies; D007519:Isoantigens; D007959:Lymphocyte Culture Test, Mixed; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D007518:Isoantibodies; D007519:Isoantigens; D003165:Complement System Proteins