title: A rosette assay for the determination of C 1 q receptor-bearing cells.
abstract: A rosette assay for the identification of cells with receptors for C 1 q is described. Glutaraldehyde-treated bovine erythrocytes bound C 1 q specifically, and the reagent thus prepared provided a valid indicator for rosette formation mediated by C 1 q receptors. The presence of these receptors on the membrane of a subset of human peripheral lymphocytes (mainly non-G cells) and on B-derived lymphoblastoid cells was confirmed. Rosette formation was dependent on the number of C 1 q molecules bound per indicator cell and was specifically inhibited by soluble native C 1 q and pepsin-resistant C 1 q fragments. These data, together with the reduced binding activity of C 1 r-C 1 s-associated C 1 q, indicated that the C 1 q binding sites for lymphoid membranes are expressed on the collagen-like moiety, C 1 q rosette formation provided a simple new procedure for fractionation of human lymphocyte populations and separation from phagocytes that do not express receptors for C 1 q.
mesh_terms: D000818:Animals; D002417:Cattle; D002469:Cell Separation; D003172:Complement C1 / Q000378:metabolism*; D004306:Dose-Response Relationship, Immunologic; D004912:Erythrocytes / Q000276:immunology; D005976:Glutaral / Q000494:pharmacology; D006801:Humans; D008214:Lymphocytes / Q000276:immunology; D011951:Receptors, Complement / Q000032:analysis*; D012397:Rosette Formation
chemical_list: D003172:Complement C1; D011951:Receptors, Complement; D005976:Glutaral