In vivo administration of anti-I-A antibody induces the internalization of B cell surface I-A and I-E without affecting the expression of surface immunoglobulin.
Injection of a hybridoma anti-Ia antibody into adult mice results in a dramatic reduction in the expression of B cell sIa without affecting the expression of sIgD or sIgM. This anti-Ia-mediated modulation of B cell sIa occurs within 3 hr and attains it maximum effect within 18 hr after injection of antibody. There is a rapid reexpression of B cell Ia when such sIa- B cells are cultured in vitro. Culture of B cells in vitro with anti-Ia antibody has no discernible effect on the expression of B cell sIa, nor does it prevent the reexpression of sIa on sIa- B cells obtained from anti-Ia-injected mice. Injection of anti-I-A antibody suppresses the expression of both I-A and of I-E, and similarly, injection of anti-I-E suppresses the expression of B cell I-E and I-A antigens. When fluorescein-labeled monoclonal anti-I-A antibody is injected into mice, a significant fraction of B cell sIa can be demonstrated to be internalized by the B cell. The potential immunologic significance of this phenomena of anti-Ia-mediated modulation of B cell sIa is discussed.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000502:physiology; D000937:Antigen-Antibody Reactions; D000954:Antigens, Surface / Q000032:analysis*; D001402:B-Lymphocytes / Q000276:immunology*; D016650:Fluorescein-5-isothiocyanate; D005452:Fluoresceins; D000949:Histocompatibility Antigens Class II / Q000032:analysis / Q000276:immunology*; D007700:Kinetics; D051379:Mice; D008809:Mice, Inbred C3H; D008808:Mice, Inbred CBA; D008811:Mice, Inbred DBA; D011947:Receptors, Antigen, B-Cell / Q000032:analysis*; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013861:Thiocyanates
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D005452:Fluoresceins; D000949:Histocompatibility Antigens Class II; D011947:Receptors, Antigen, B-Cell; D013861:Thiocyanates; D016650:Fluorescein-5-isothiocyanate