Sex steroids and risk of female genital tract infection

Sex steroids are central to regulation of the dual roles of the female reproductive tract: support of reproduction and protection against deleterious pathogen invasion. The mechanisms by which sex steroids orchestrate the balance between reproduction and protection against pathogenic microorganisms, however, are complex and poorly understood. Epidemiologic studies have revealed associations between sex steroids and diagnosis, shedding, transmission of sexually transmitted diseases and their clinical sequelae, as well as disruptions to the normal vaginal flora. Experimental approaches, including animal models, have provided some insight into the mechanism of these associations, though often with contradictory results. Inherent limitations in traditional approaches to understanding the physiology of sex steroid regulation of immunity in the female genital tract will require significant interdisciplinary collaboration.