title: Modulation of the immune response by plasma protease inhibitors. II. Alpha 2-macroglobulin subunits inhibit natural killer cell cytotoxicity and antibody-dependent cell-mediated cytotoxicity.
abstract: In two different cytolytic assays, dose-dependent inhibition of antibody-dependent cell-mediated cytotoxicity and natural killing by alpha 2-macroglobulin (alpha 2m) and its subunits was observed. Alpha 2m subunits were approximately four times more inhibitory in both assays than the native alpha 2m molecule on a molar basis. Analysis of trypsin protein esterase activity demonstrated that alpha 2 subunits were four times more active than the parent molecule.
mesh_terms: D000920:Antibody-Dependent Cell Cytotoxicity / Q000187:drug effects*; D003602:Cytotoxicity, Immunologic / Q000187:drug effects*; D004229:Dithiothreitol / Q000494:pharmacology; D004306:Dose-Response Relationship, Immunologic; D006801:Humans; D007111:Immunity, Cellular / Q000187:drug effects; D007460:Iodoacetamide / Q000494:pharmacology; D009961:Orosomucoid / Q000378:metabolism / Q000494:pharmacology; D011480:Protease Inhibitors / Q000097:blood / Q000494:pharmacology*; D011487:Protein Conformation; D014361:Trypsin Inhibitors / Q000494:pharmacology; D000511:alpha-Macroglobulins / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D009961:Orosomucoid; D011480:Protease Inhibitors; D014361:Trypsin Inhibitors; D000511:alpha-Macroglobulins; D004229:Dithiothreitol; D007460:Iodoacetamide