RESUMO
HIV-1 p24 was cloned into multiple cloning site of pMV261, extrachromosomal expression vectors carrying BCG replication origin and BCG-specific heat-shock promoter, and then introduced into BCG and E. coli. Western blot experiments showed that the p24 efficiently expressed in recombinant BCG (rBCG), but not in E. coli. Recombinant p24 expression induced by a single heat-shock of rBCG was maintained longer than 3 weeks. Immunoblot experiments with intact rBCG did not show any distinctive positive signal, suggesting that the recombinant protein was not secreted or exposed at the surface of BCG. The guinea pigs immunized with live rBCG showed delayed type hypersensitivity (DTH) by the systemic area as well as an effective humoral immunity, suggesting that tbis rBCG is believed to elicit eKcient immune responses against p24, even though the expression is restricted only in the cytoplasm as reported previously with other antigen. These results demonstrate that BCG can be developed as a live recombinant vaccine vector against a broad spectrum of infectious disease.