Innate immune defences in the human endometrium

Area of Science:

• Reproductive immunology
• Innate immunity
• Gynecological microbiology

Background:

• The human endometrium provides innate immune defense against uterine infections, vital for successful pregnancy.
• Uterine infections are linked to preterm birth, infertility, and ectopic pregnancy.
• Natural antimicrobial peptides (AMPs) are key mediators of innate immunity at mucosal surfaces.

Purpose of the Study:

• To investigate the role and expression of AMPs in the human endometrium.
• To understand how endometrial AMPs contribute to protection against uterine pathogens throughout the menstrual cycle.
• To identify specific AMP families and their functions within the female genital tract.

Main Methods:

• Analysis of AMP expression in endometrial tissue.
• Characterization of defensins and whey acidic protein (WAP) motif proteins in the endometrium.
• Investigation of leukocyte-derived AMPs, including neutrophils, during menstruation.

Main Results:

• The endometrium expresses beta-defensins (1-4) and secretory leukocyte protease inhibitor (SLPI), with varied expression across the menstrual cycle.
• SLPI exhibits anti-protease, antimicrobial, and epithelial cell growth-modulating activities.
• Neutrophils contribute alpha-defensins, lactoferrin, lysozyme, and elafin, enhancing antimicrobial defense during menstruation.
• Other AMPs like granulysin are also implicated in endometrial immunity.

Conclusions:

• The endometrium employs a dynamic arsenal of AMPs, including defensins and WAP proteins, for continuous innate immune protection.
• Sequential AMP production throughout the female genital tract offers broad defense against diverse pathogens, including sexually transmitted infections.
• Endometrial AMPs are critical for maintaining reproductive health and preventing infection-related complications.