7 - Xenobiotic metabolites modify immune output of the cervicovaginal epithelium: potential mechanisms underlying barrier disruption

Xenobiotic metabolites are exogenous biochemicals that can adversely impact reproductive health. We previously identified xenobiotics in cervicovaginal (CV) fluid during pregnancy in association with spontaneous preterm birth (sPTB). Suggesting bioactive potential, in vitro data reveal that these xenobiotics can modify CV epithelial barrier function. We hypothesize that xenobiotics dysregulate epithelial immune output as a mechanism to disrupt the CV barrier.


Study Design:

Vaginal (VK2), ectocervical (Ecto), and endocervical (Endo) cell lines were treated with xenobiotics diethanolamine (DEA, 2.5mM), ethyl glucoside (EG, 5mM), tartrate (TA, 2.5mM) for 24 hours. A 41-plex cytokine Luminex panel and 5-plex matrix metalloproteinase (MMP) Luminex panel were run on cell media (n=3 per condition). Data were analyzed with a five-parameter logistic curve. One-way ANOVAs with Dunnett’s multiple comparisons tests were performed.



Results:

DEA induces inflammatory cytokines while EG and TA generally exert anti-inflammatory effects across all cells (Fig. 1). DEA upregulates IL-6, IL-8, IP-10, MCP-1, GRO, fractalkine, MMP-1, MMP-9, and MMP-10 (p < 0.05 for all), factors involved in acute inflammation and recruitment of monocytes, neutrophils, and lymphocytes. EG and TA downregulate multiple cytokines, including RANTES and MCP-1 (p < 0.05 for all), which serve as chemotactic factors.  VK2 cells exhibit higher inflammatory tone compared to cervical cells, with approximately twice the number of differentially detected cytokines after xenobiotic treatment. Cervical cells demonstrate similar immunologic responses to xenobiotics compared to VK2 cells.



Conclusion:

Xenobiotic metabolites present in the CV space during pregnancy modify epithelial immune output, unveiling potential immunologic pathways through which environmental exposures may contribute to the pathogenesis of cervical remodeling preceding sPTB. Future work identifying exogenous sources of these xenobiotics is warranted and offers potential to modify aspects of the environment to improve pregnancy outcomes. SMFM/AAOGF (KG), 5R01NR014784 (ME)