title: Induction of an immune response to a self antigen.
abstract: The question has been addressed whether the endogenous B cell population of a mouse can be induced to secrete antibodies specific for a self antigen present in serum. The antigen studied was the fifth component of mouse complement (C5). Nude BALB/c mice which are C5 sufficient were used as a source of potentially C5-reactive B cells and endogenous serum C5 provided the antigenic stimulus. We purposely avoided immunization with C5 in adjuvant. T cells from C5-deficient mice which lack this component in serum and are therefore not tolerant of C5 were injected into nude mice as a source of T cell help for anti-C5 reactive B cells. Control groups received T cells from C5-sufficient euthymic donors, which are tolerant of C5. Initiation of a response to C5 was monitored by testing the hemolytic function of serum. Reduction of C5-dependent hemolysis was observed in sera of mice which had received T cells from C5-deficient donors. Recipients of T cells from C5-sufficient donors maintained normal hemolytic complement levels throughout the test period of 45 days. Reduction of functional complement levels correlated with the presence of immune complexes of anti-C5/C5. C5-specific antibodies were mainly IgG1 and carried the IgG1 allotype of BALB/c providing unequivocal evidence that they were derived from the endogenous B cell population of the C5-sufficient host.
authors.affiliation: Basel Institute for Immunology, Switzerland.
authors.forename: B
authors.initials: B
authors.lastname: Stockinger
authors.forename: B
authors.initials: B
authors.lastname: Hausmann
mesh_terms: D000818:Animals; D000936:Antigen-Antibody Complex / Q000032:analysis; D001323:Autoantibodies / Q000032:analysis / Q000096:biosynthesis*; D003182:Complement C5 / Q000032:analysis / Q000276:immunology*; D007108:Immune Tolerance; D007116:Immunization, Passive; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D006377:T-Lymphocytes, Helper-Inducer / Q000378:metabolism / Q000637:transplantation
chemical_list: D000936:Antigen-Antibody Complex; D001323:Autoantibodies; D003182:Complement C5