Paratuberculosis (Johne's disease) is a chronic infectious, granulomatous enteric disease of domestic and wild ruminants caused by Mycobacterium avium subsp. paratuberculosis (Map). To date, no effective prophylactic candidates are available for early protection against the paratuberculosis infection in animals. Numerous secretory proteins Map have shown to be potent immunogens and can be used as subunit vaccines/DNA vaccine and also can be used as a specific detection .This book, therefore provides a novel antigen family protein of Map, PPE (proline-proline-glutamic acid rich) an unique antigen, which has been characterized, expressed in prokaryotic as well as eukaryotic system to preliminary study it's existence and further immunoreactivity was studied alone as well as with an adjuvant model gamma interferon in murine model to elucidate its importance to develop DNA vasccine against paratuberculosis infection in animals.