Vaginal epithelial surface and mucosal barrier

The vaginal epithelial surface and mucosal barrier constitute a multi-layered defense system essential for reproductive health and protection against pathogens. The barrier is composed of a non-keratinized stratified squamous epithelium that undergoes cyclic changes in thickness and glycogen content under the influence of estrogen (Anderson et al., 2014, PMID: 24680591). Overlying this epithelium is the cervicovaginal mucus (CVM), a complex hydrogel primarily made of mucins like MUC5B and MUC5AC, which traps pathogens and facilitates their clearance (Ensign et al., 2012, PMID: 22446038). A critical component of this barrier is the acidic environment (pH 3.5–4.5) maintained by lactic acid-producing Lactobacillus species, which inhibits the growth of many pathogens (Ravel et al., 2011, PMID: 21173251). Disruption of this barrier, whether through hormonal changes, chemical irritation, or dysbiosis, significantly increases susceptibility to sexually transmitted infections such as HIV and HSV (Hickey et al., 2011, PMID: 21477470). Therapeutic strategies often focus on reinforcing this barrier through the use of topical microbicides, pH-restoring gels, or hormone replacement therapies to treat atrophy (Valenta, 2005, PMID: 15913920).

Other names

Vaginal mucosaVaginal epitheliumCervicovaginal mucosal barrierVaginal lining

Drugs targeting this system typically act by enhancing the physical barrier, delivering antimicrobial agents, restoring the acidic pH, or stimulating epithelial proliferation and cornification through estrogen receptor activation.