Vaginal epithelial barrier

The vaginal epithelial barrier refers to the physical and functional barrier formed by the stratified squamous epithelium lining the vagina, which plays a crucial role in protecting the female genital tract from pathogens and maintaining reproductive health[1][2][3][4][5][6][7]. The vaginal epithelial barrier is formed by non-keratinized, stratified squamous epithelial cells that constitute multiple layers: basal, parabasal, intermediate, and superficial cells[2][4]. These cells accumulate glycogen under estrogenic stimulation, which supports a healthy Lactobacillus-dominated microbiome, contributing to acidic pH and optimal vaginal health[1][3][4]. The barrier employs cellular junctions—such as tight junctions (E-cadherin, claudins, occludins, JAMs)—to restrict pathogen entry, and is further reinforced by secreted mucins (glycocalyx), antimicrobial peptides, and active immune cell migration (leukocytes)[1][5][7]. The unique permeability of this barrier not only allows for immunological defense but also makes it a focus for mucosal drug delivery research[2]. Disruption of epithelial integrity, through hormonal changes, microbiome imbalance, or direct injury, is associated with elevated risk of infection, inflammation, and reproductive tract disease[3][6][7]. The vaginal maturation index, a cytologic marker, is used clinically to assess epithelial health and hormone sensitivity[4]. The term “vaginal epithelial barrier” describes a tissue/functional barrier rather than a discrete molecular target, receptor, enzyme, transporter, or gene product. Although research focuses on proteins within the barrier, such as tight junction molecules, these should be listed as separate canonical targets (e.g., JAM-A, claudin-1) if specific molecular targets are needed. As a result, “Vaginal epithelial barrier” is not considered a canonical therapeutic target and the query is technically incorrect if seeking a molecule/receptor.

Other names

Vaginal epitheliumCervicovaginal epithelial barrierVaginal mucosal barrier