The present invention is directed to the treatment of autoimmune diseases, in particular of myasthenia gravis. This invention provides novel autoimmune dominant peptides derived from the acetylcholine receptor, as well as methods for preparing the peptides. The present invention further provides complexes comprising these peptides associated with an appropriate major histocompatibility complex (MHC) molecule and methods for making these complexes. The complexes of the present invention can be used therapeutically or prophylactically for treating myasthenia gravis.