DNA encoding a single mycobacterial antigen protects against leprosy infection

The continuing incidence of leprosy infection around the world and the inab ility of Mycobacterium bovis bacille Calmette-Guerin (BCG) to protect certa in populations clearly indicates that an improved vaccine against leprosy i s needed. The immune dominant 35 kDa protein, shared Mycobacterium leprae a nd Mycobacterium avium, but not Mycobacterium tuberculosis or BCG, is recog nised by > 90% of leprosy patients, making it an ideal candidate antigen fo r a subunit vaccine. Immunization of outbred Swiss Albino mice with a DNA-3 5 vaccine stimulated specific T cell activation and IFN-gamma production. D NA-35 immunization induced significant levels of protection against M. lepr ae footpad infection, comparable to that produced by BCG. Therefore, DNA im munization with the 35 kDa antigen is effective against M. leprae infection and genetic immunization with a combination of antigens holds the potentia l for an improved vaccine against leprosy. (C) 2001 Elsevier Science Ltd. A ll rights reserved.