COMMENSAL BACTERIA AS VECTORS FOR MUCOSAL VACCINES AGAINST SEXUALLY-TRANSMITTED DISEASES - VAGINAL COLONIZATION WITH RECOMBINANT STREPTOCOCCI INDUCES LOCAL AND SYSTEMIC ANTIBODIES IN MICE

There is a need to develop vaccines to control the spread of sexually transmitted diseases (STDs). Novel immunization strategies that elicit a mucosal immune response in the genital tract, may show improved pro tection by preventing or at least limiting entry of the pathogenic mic ro-organism. However, it has proven difficult to obtain a local immune response in the vaginal mucosa. Our approach is based on the use of r ecombinant bacteria capable of colonizing mucosal surfaces as live vac cine vectors. The human commensal Streptococcus gordonii, engineered t o express the E7 protein of human papillomavirus type 16, was used for intravaginal immunization of mice. A single inoculum of recombinant b acteria was sufficient to establish colonization of the murine vagina and therefore induce papillomavirus-specific vaginal IgA and serum IgG . Evidence that mucosal colonization with recombinant commensal bacter ia can induce a local immune response in the female genital tract repr esents a significant step toward the development of new vaccines again st STDs. (C) 1997 Elsevier Science Ltd.