Perspectives and limitations of the mycobacterial expression system

To develop multivalent vaccines expressing foreign antigens in BCG strains, a genetic system for BCG and Mycobacterium smegmatis is being developed that uses vectors derived from the M. fortuitum pAL5000 plasmid. In this paper we present recent advances of our laboratory in this line of research: i) optimal conditions for M. fortuitum electroporation, ii) demonstration that host range properties of pAL5000-based vectors depend on certain open reading frames, iii) cloning of expression signals derived from the BCG Moreaux 65 kD antigen, and iv) construction of expression vectors for M. smegmatis.