CD4+ T and B cells cooperate in the immunoregulation of Experimental Autoimmune Myasthenia Gravis

C57Bl6 mice (B6 mice) immunized with Torpedo acetylcholine receptor (TAChR) in Freund's adjuvants (FA) develop Experimental Autoimmune Myasthenia Gravis (EAMG). In mouse EAMG Th2 cytokines may be protective. Aluminum hydroxide (Alum) was used to immunize B6 mice to the TAChR and prime CD4+ T and B cells secreting Th2 cytokines. Mice immunized with TAChR/Alum developed anti-AChR CD4+ T cells response, but minimal antibody levels and symptoms. TAChR/Alum treatments prior immunization with TAChR/FA protected mice from EAMG. Cell transfer experiments demonstrated that B and CD4+ T cells mediated the protective effect by causing intense reduction of complement-fixing anti-TAChR IgG subclasses.