This invention relates to the design and construction of a gene encoding an encephalogenic epitope of proteolipid protein (PLP), design and construction of a gene encoding an encephalogenic epitope of myelin based protein (MBP), to methods of expression of a PLP epitope, to methods of expression of a MBP epitope, to methods of in vivo secretion of a PLP epitope, and to methods of transferring the partial PLP gene to a host to ameliorate the progression of an immune response to self antigens derived from myelin proteins, to methods of in vivo secretion of a MBP epitope, and to methods of transferring the partial MBP gene to a host to ameliorate the progression of an immune response to self antigens derived from myelin proteins.