O02.1 Cervicovaginal microbiota species distinctly modulate the immunometabolic microenvironment in a human three-dimensional cervical model

Abstract

<h3>Background</h3> Bacterial vaginosis-associated bacteria (BVAB) have been linked to gynecologic and obstetric sequalae, including an increased risk of STI acquisition and pre-term birth. However, there is a fundamental gap that exists in understanding the function of these microorganisms in the local microenvironment that contribute to disease. Hence, our objective was to identify immunometabolic signatures of cervicovaginal microbiota species in the context of cervical epithelium that can relate to clinical findings. <h3>Methods</h3> Human three-dimensional (3D) cervical epithelial cell models were infected under anaerobic conditions with Gardnerella vaginalis, Prevotella bivia, Atopobium vaginae, Sneathia amnii, a polymicrobial community of BVAB, or health-associated Lactobacillus crispatus. Cell culture supernatants were collected 24 h post infection and analyzed using multiplex cytometric bead arrays and ultrahigh-performance liquid chromatography-mass spectroscopy. <h3>Results</h3> Lactobacillus and BVAB effectively colonized the surface and crevices of human 3D cervical model visualized by scanning electron microscopy. Immunoproteomics analysis (28 targets) revealed that A. vaginae, S. amnii and polymicrobial community exert the greatest proinflammatory potentials, whereas G. vaginalis and P. bivia mostly altered epithelial barrier targets. S. amnii also induced proteins related to cellular stress and angiogenesis. The metabolomics analysis yielded 418 known metabolites. Random Forest analysis of metabolic profiles highlighted excellent prediction (93.75%) of infections. Furthermore, A. vaginae, S. amnii and the polymicrobial community profiles clustered separately from G. vaginalis, P. bivia, L. crispatus and controls. BVAB induced production of biogenic amines in a species-specific manner. A. vaginae and S. amnii impacted arginine/citrulline metabolism, leading to pro-inflammatory signaling, and induced production of oxidative stress-related metabolites. In contrast, G. vaginalis and P. bivia altered epithelial barrier through mucin and collagen degradation and potential ammonia production. <h3>Conclusions</h3> We demonstrated the utility of our 3D model to recapitulate the cervicovaginal microenvironment and identified unique and species-specific mechanisms by which BVAB contribute to pathophysiological changes favorable for STIs.