This invention provides a method of treating or preventing a disease in an animal associated with one or more self-protein(s), -polypeptide(s), or -peptide(s) that is present or involved in a non-physiologic process in the animal comprising administering to the animal a self-vector comprising a polynucleotide encoding the self-protein(s), -polypeptide(s) or -peptide(s) associated with the disease. Administration of the self-vector comprising a polynucleotide encoding the self-protein(s), -polypeptide(s) or -peptide(s) modulates an immune response to the self-protein(s), -polypeptide(s) or -peptide(s) expressed from administration of the self-vector. The invention also provides a composition comprising a polynucleotide encoding one or more self-protein(s), -polypeptide(s), or -peptide(s) that is present non-physiologically in a treated animal useful in treating or preventing a disease associated with the self-protein(s), -polypeptide(s), or -peptide(s) present in and/or the target of a non-physiologic process in the animal.