Mycobacterium avium subsp. paratuberculosis (Map) is the causative organism of Johne's disease or paratuberculosis, a debilitating chronic gastroenteritis of domestic and wild ruminants. At present no effective therapeutics or vaccine candidates are available and early detection along with good management practices are the only ways to control paratuberculosis. Antigens of Map have also been used for the development of DNA vaccine. Therefore, this book, provides information about potent T cell antigen family protein of Map, PE (proline-glutamic acid rich), which has been identified, expressed in prokaryotic system. The bicistronic constructs was also generated to express two potent antigens in eukaryotic system. Further the immunogenicity was also studied alone as well as with two antigens and also immunomodulatory effect of gamma interferon in murine model. Studies revealed the importance of the bicistronic construct to develop DNA vaccine against paratuberculosis infection in animals.