Innate Immunity in the Human Endometrium and Ovary

PROBLEM: Microbial infections of the upper female genital tract perturb the function of the endometrium and ovary. Defense of these tissues is predominantly dependent on innate immunity. This review gives a perspective on innate immunity in the non-pregnant upper female genital tract of women. METHOD OF STUDY: Literature review of innate immunity in the human endometrium and ovary. RESULTS: The endometrium is defended against microbes by physical barriers, antimicrobial peptides, complement, Toll-like receptors (TLRs), and other pattern recognition receptors. Endometrial epithelial and stromal cells express TLRs, which sense pathogen-associated molecular patterns (PAMPs), leading to an inflammatory response with the influx of neutrophils and macrophages. Innate immunity in the endometrium is regulated by steroids, eicosanoids, and cytokines. Granulosa cells also express TLRs and respond to PAMPs. CONCLUSION: Pattern recognition receptors have roles in endometrial and ovarian inflammation, and innate immunity is central to the defense of the endometrium against pathogens.