Abstract
We have developed a novel tuberculosis (TB) vaccine; a combination of the DNA vaccines expressing mycobacterial heat shock protein 65 (HSP65) and interleukin 12 (IL-12) delivered by the hemagglutinating virus of Japan (HVJ)-liposome (HSP65+IL-12/HVJ). This vaccine provided remarkable protective efficacy in BALB/C mouse and guinea pig models compared to the BCG vaccine, on the basis of an induction of the CTL activity and improvement of the histopathological tuberculosis lesions, respetively. This vaccine strongly induced CTL against HSP antigen and M.tuberculosis antigens
Furthermore, we extended our studies to a cynomolgus monkey model, which is currently the best animal model of human tuberculosis. This novel vaccine provided a higher level of the protective efficacy than BCG based upon the assessment of mortality, the ESR and immune responses. The combination of HSP65 + IL-12/HVJ and BCG by the priming-booster method showed a synergistic effect in the TB-infected cynomolgus monkey (100% survival). In contrast, the survival of the BCG Tokyo group was 33%. These data indicate that our novel DNA vaccine might be useful against M.tuberculosis for human clinical trials. [H-17-Shinko-5] of Research on Emerging and Re-emerging Infectious Diseases in Health Sciences Research grants from Japan.
