Relationship Between Human β-Defensin 2 and the Vaginal Environment

Area of Science:

• Microbiology
• Immunology
• Gynecology

Background:

• Human beta-defensin 2 (HBD2) is a key antimicrobial peptide in the lower genital tract.
• Bacterial vaginosis (BV) is diagnosed using the Nugent score.
• Understanding HBD2's role in vaginal infections is crucial.

Purpose of the Study:

• To investigate the correlation between Nugent scores, interleukin-6 (IL-6), and HBD2 levels in vaginal secretions.
• To explore the relationship between HBD2 and specific vaginal infections, including bacterial vaginosis and Candida spp.
• To elucidate the in vitro mechanism of HBD2 induction by Candida albicans.

Main Methods:

• Enzyme-linked immunosorbent assays (ELISA) were used to measure HBD2 and IL-6 levels in vaginal wash samples from 98 women.
• Vaginal samples were assessed using the Nugent scoring system.
• In vitro experiments utilized the VK2/E6E7 human vaginal epithelial cell line, heat-killed Candida albicans (HKCA), and luciferase assays.

Main Results:

• A positive correlation was observed between the Nugent score (Lactobacillus morphotypes) and HBD2 levels.
• HBD2 levels were significantly correlated with the presence of Candida spp. (P < 0.01).
• In vitro, heat-killed Candida albicans induced HBD2 expression in VK2/E6E7 cells via Dectin-1 and NF-κB signaling pathways.

Conclusions:

• HBD2 expression is positively associated with the presence of both Lactobacillus and Candida species in vaginal secretions.
• Candida albicans infection stimulates HBD2 production through Dectin-1 and NF-κB activation.
• These findings highlight HBD2's role in modulating the vaginal microenvironment during infection.