DNA vaccines against tuberculosis.

This edited transcript of a presentation at the 'Vaccines Beyond 2000' conference describes a series of investigations by the authors throwing light on the mechanisms of protective immunity against tuberculosis in mice and raising hope for a new kind of vaccine to replace bacille Calmette-Guérin (BCG). DNA encoding only one or a few protein antigens was found capable of conferring persistent protection equal to the effect of BCG. The essential features seem to be an endogenous origin of the antigen within transfected mouse cells which favours the development of CD8+/CD44hi/IFN-gamma-producing T cells with antigen-specific cytotoxicity. Such cells were the most efficient in adoptive transfer of protection from infected or DNA-vaccinated mice to naive mice.