Innate immunity, the female reproductive tract and the toll-like receptors

Sexually transmitted diseases (STDs) are a major worldwide health problem that compromise reproductive fecundity as well as cut short the lives of millions of men, women and children.

Despite advances in the management of these infections, only limited success has been achieved in curtailing the morbidity and mortality associated with them. The commoner sexually transmitted diseases with the largest health and socio-economic impact include infections by the herpes simplex virus type 2 (HSV-2), Chlamydia trachomatis, the gonococcus, and human immunodeficiency viruses [(HIV), the causative agent of acquired immune-deficiency syndrome (AIDS)]. In addition maternal genital tract carriage of the group B streptococcus and bacterial vaginosis is associated with premature birth and neonatal mortality and morbidity through ascending maternal and fetal infection.

Because of this growing global health problem, prevention and effective treatment need to be developed. Even more, understanding the regulation of the female reproductive tract immune system holds therapeutic promise. Advances in the development of effective vaccines against these infections are likely to become possible when the immunological host defence mechanisms against these infections are clarified.

During the last decade, Toll-like Receptors (TLR) have been identified as a major part of innate immune system. Several reports have determined and characterized TLRs in different tissues and organs. Reports from our laboratory and others have demonstrated the existence of TLRs in the female reproductive tract and the cycle-dependent expression of TLRs in endometrium. Currently we are investigating the role that TLRs play in mediating innate immunity in the female reproductive tract as well as the effect of sex hormones in modulating the function of these receptors in maintaining innate immunity in this tract.