Secretion of Mammalian Proteins from Mycobacteria

Mycobacterium bovis Bacille Calmette Gu�rin (BCG) has several features that make it desirable as a vaccine vehicle for foreign antigens. BCG is a live vaccine and stimulates a strong cell-mediated immune response, is extremely safe, and can be given at birth (1 ). Using recently developed tools to produce recombinant mycobacteria, BCG has been engineered to express antigens from HIV, Pneumococcus, Leuhmania , and Borrelia (2 –6 ). Each of these strains elicits cell-mediated and/or humoral immune responses against their surrogate antigens.