title: Cardiac myosin-induced myocarditis. Heart autoantibodies are not involved in the induction of the disease.
abstract: We recently demonstrated that cardiac myosin is capable of inducing autoimmune myocarditis in genetically predisposed mice. This disease parallels coxsackievirus B3-induced autoimmune myocarditis in many respects and is associated with high-titer autoantibodies specific for cardiac myosin. The following lines of evidence suggest that these autoantibodies are not involved in the induction of autoimmune myocarditis: 1) immunoperoxidase staining of heart sections from cardiac myosin-immunized A/J and A.SW mice revealed IgG depositions only along damaged muscle fibres in infiltrated areas, but not in intact tissue; 2) myosin autoantibodies did not bind to the surface of viable cardiac myocytes isolated from mice, but only reacted with myocytes permeabilized with detergent; 3) mice treated with a single high dose of cyclophosphamide, which reduces the humoral immune response, still developed severe myocarditis, despite the fact that their autoantibody titers were reduced to the level of adjuvant-injected controls; and 4) passive transfer of high-titer myosin autoantibodies failed to induce myocarditis, although the titers in the recipients were comparable to those found in mice with cardiac myosin-induced disease. Together, the results suggest that high-titer myosin autoantibodies are secondary rather than primary to the disease.
authors: Institute for General and Experimental Pathology, Medical School, University of Innsbruck, Austria.
authors: N
authors: N
authors: Neu
authors: B
authors: B
authors: Ploier
authors: C
authors: C
authors: Ofner
mesh_terms: D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D000954:Antigens, Surface / Q000276:immunology; D001323:Autoantibodies / Q000276:immunology*; D003520:Cyclophosphamide / Q000494:pharmacology; D007116:Immunization, Passive; D007136:Immunoglobulins / Q000378:metabolism; D051379:Mice; D008805:Mice, Inbred A; D009205:Myocarditis / Q000276:immunology*; D009206:Myocardium / Q000276:immunology*; D009218:Myosins / Q000276:immunology*
chemical_list: D000954:Antigens, Surface; D001323:Autoantibodies; D007136:Immunoglobulins; D003520:Cyclophosphamide; D009218:Myosins