Veillonellaceae family members uniquely alter the cervical metabolic microenvironment in a human three-dimensional epithelial model

Abstract

Bacterial vaginosis (BV) is a gynecologic disorder characterized by a shift in cervicovaginal microbiota from Lactobacillus spp. dominance to a polymicrobial biofilm composed of diverse anaerobes. We utilized a well-characterized human three-dimensional cervical epithelial cell model in conjunction with untargeted metabolomics and immunoproteomics analyses to determine the immunometabolic contribution of three members of the Veillonellaceae family: Veillonella atypica, Veillonella montpellierensis and Megasphaera micronuciformis at this site. We found that Veillonella spp. infections induced significant elevation of polyamines. M. micronuciformis infections significantly increased soluble inflammatory mediators, induced moderate levels of cell cytotoxicity, and accumulation of cell membrane lipids relative to Veillonella spp. Notably, both V. atypica and V. montpellierensis infections resulted in consumption of lactate, a key metabolite linked to gynecologic and reproductive health. Collectively our approach and data provide unique insights into the specific contributions of Veillonellaceae members to the pathogenesis of BV and women’s health.

Immunometabolic Analysis of Mobiluncus mulieris and Eggerthella sp. Reveals Novel Insights Into Their Pathogenic Contributions to the Hallmarks of Bacterial Vaginosis

“…Specifically, sphingolipids were significantly elevated exclusively by Eggerthella sp. We also found similar significantly altered glycerolipids and sphingolipids as those reported by Salliss et al., 2021 that were elevated following infection with another BV-related microorganism: Megasphaera micronuciformis ( Salliss et al., 2021 ). Sphingolipids are components of eukaryotic cell membranes and have been related to proinflammatory signaling pathways and apoptosis ( Kolter and Sandhoff, 2006 ; Hannun and Obeid, 2008 ; Hannun and Obeid, 2018 ).…”

“…with the highest fold change (1150-fold) of all the metabolites measured. Although the role of this metabolite in the cervicovaginal microenvironment is still not clear, we have previously observed its accumulation following infections with other vaginal bacteria ( Łaniewski and Herbst-Kralovetz, 2021 ; Salliss et al., 2021 ). The severity of BV has been associated with increased risk of HIV and other STI acquisition ( Allsworth and Peipert, 2011 ); thus, contribution of Eggerthella spp.…”

“…Organotypic 3-D human cervical epithelial cell models recapitulate many features of parental tissue that are not observed in monolayer cell culture models. Our advanced 3-D cell culture model exhibits physiologically relevant features, such as TLR expression, microvilli, intercellular junctional complexes and secretory material that could influence how BV-associated bacteria can colonize the model in a way similar to in vivo tissues ( Gardner et al., 2020 ; Łaniewski and Herbst-Kralovetz, 2021 ; Salliss et al., 2021 ) These features provide a more accurate representation of the in vivo state which is more amenable to translational research efforts and studying host-microbe interactions; however, each model system has its strengths, weaknesses and utility ( Hjelm et al., 2010 ; Radtke and Herbst-Kralovetz, 2012 ; Radtke et al., 2012 ; Herbst-Kralovetz et al., 2016 ). The close relation of 3-D human cervical epithelial cells to cervical tissue allows us to investigate how these pathogens can cause pathophysiological changes to the cervicovaginal microenvironment and epithelia.…”

“…MVA1 from three independent experiments were sent to Metabolon Inc. (Durham, NC) for untargeted global metabolomics analysis. Metabolites were resolved using ultra-performance liquid chromatography with mass spectrometry (UPLC-MS) as described previously ( Ilhan et al., 2020 ; Salliss et al., 2021 ). The sample extracts were dried then reconstituted in solvents compatible to four different methods.…”

Bacterial vaginosis and health-associated bacteria modulate the immunometabolic landscape in 3D model of human cervix

“…Our well-characterized human three-dimensional (3D) cervical epithelial cell model 43 , 44 , based on the rotating wall vessel bioreactor technology 45 , demonstrates a remarkable resemblance to human tissue in vivo, recapitulates several hallmarks of cellular differentiation (such as microvilli, junctional complexes, mucus, and Toll-like receptor profiles), and mount physiologically and clinically relevant responses to microbial products 43 , cervicovaginal microbiota 46 , 47 , and STI pathogens 48 . When coupled with multiplexed immunoassays and metabolomics approaches and the knowledge of human and bacterial metabolism, our infection models are powerful tools for the identification of key immune mediators and metabolites in healthy and diseased microenvironments.…”