| abstract |
Genes encoding Mycobacterium tuberculosis (M.tb) proteins were cloned into eukaryotic expression vectors to express the encoded proteins in mammalian muscle cells in vivo. Animals were immunized by injection of these DNA constructs, termed polynucleotide vaccines or PNV, into their muscles. Immune antisera was produced against M.tb antigens. Specific T-cell responses were detected in spleen cells of vaccinated mice and the profile of cytokine secretion in response to antigen 85 was indicative of a Th1 type of helper T-cell response (i.e., high IL-2 and IFN- gamma ). Protective efficacy of an M.tb DNA vaccine was demonstrated in mice after challenge with M. bovis BCG, as measured by a reduction in mycobacterial multiplication in the spleens and lungs of M.tb DNA-vaccinated mice compared to control DNA-vaccinated mice or primary infection in naive mice. |