INDUCTION OF EXPERIMENTAL AUTOIMMUNE MYASTHENIA-GRAVIS WITH ACETYLCHOLINE-RECEPTORS USING A NONIONIC BLOCK-COPOLYMER AS ADJUVANT

To induce autoimmune diseases in animals, the auto-antigen has to be e mulsified in adjuvants (e.g., complete Freund's adjuvant) containing m icrobial products such as Mycobacterium tuberculosis. But these powerf ul immunoadjuvants are not without undesirable immune response to the microbial proteins and induction of adjuvant arthritis, which could in terfere with the antigen specific autoimmune response to be tested. Th is study was performed to evaluate the requirement of microbial produc ts in the induction of experimental autoimmune diseases, and to identi fy an adjuvant without unwanted immune responses. C57BL/6 mice were in oculated with Torpedo acetylcholine receptors (T-AChR) emulsified in T itermax (TM), an adjuvant containing nonionic block copolymer and no m icrobial products, and evaluated for experimental autoimmune myastheni a gravis (EAMG) susceptibility. Mice immunized with T-AChR in TM demon strated characteristic myasthenic muscle weakness with electrophysiolo gical defect, elevated serum anti-AChR antibodies, and muscle AChR los s. None of the mice that received TM alone had muscle weakness, serum anti-AChR antibodies or muscle AChR loss. The data imply that microbia l products are not critical in the induction of autoimmune disease lik e myasthenia gravis in mice. Further, nonionic block copolymer could b e an ideal adjuvant in the induction of autoimmune diseases in animals .