Distinct cervical tissue-adherent and luminal microbiome communities correlate with mucosal host gene expression and protein levels in Kenyan sex workers
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ABSTRACT: Background: While the luminal microbiome composition in the human cervicovaginal tract has been defined, the presence and impact of tissue-adherent ectocervical microbiota remain incompletely understood. Studies of luminal and tissue-associated bacteria in the gastrointestinal tract suggest that they may have distinct roles in health and disease. Here, we performed a multi-omics characterization of paired luminal and tissue samples collected from a clinically well-characterized cohort of Kenyan women. Results: We identified a tissue-adherent bacterial microbiome, with a higher alpha diversity than the luminal microbiome, in which dominant genera overall included Gardnerella and Lactobacillus, followed by Prevotella, Atopobium, and Sneathia. About half of the L. iners dominated luminal samples had a corresponding Gardnerella dominated tissue microbiome. Broadly, the tissue-adherent microbiome was associated with fewer differentially expressed host genes than the luminal microbiome. Gene set enrichment analysis revealed that L. crispatus-dominated tissue-adherent communities were associated with protein translation and antimicrobial activity, whereas a highly diverse microbiome was associated with epithelial remodeling and pro-inflammatory pathways. Communities dominated by L. iners and Gardnerella were associated with low host transcriptional activity. Tissue-adherent microbiomes dominated by Lactobacillus and Gardnerella correlated with host protein profiles associated with epithelial barrier stability, and with a more pro-inflammatory profile for the Gardnerella-dominated microbiome group. Tissue samples with a highly diverse composition had a protein profile representing cell proliferation and pro-inflammatory activity. Conclusion: We identified ectocervical tissue-adherent bacterial communities in all study participants. These communities were distinct from cervicovaginal luminal microbiota in a significant proportion of individuals. This difference could possibly explain that L. iners dominant luminal communities have a high probability of transitioning to high diverse bacterial communities including high abundance of Gardnerella. By performing integrative multi-omics analyses we further revealed that bacterial communities at both sites correlated with distinct host gene expression and protein levels. The tissue-adherent bacterial community is similar to vaginal biofilms that significantly impact women’s reproductive and sexual health.
Project description:Cervicovaginal microbiome dysbiosis is associated with increased prevalence and incidence of sexually transmitted infections including HIV. We compared the cervicovaginal proteome as characterised by mass-spectrometry of four groups of African female sex workers (total N=50) grouped by microbiome composition as characterised by 16S rDNA microarray. Group 1 had a Lactobacillus crispatus-dominated microbiome, group 2 a L. iners-dominated microbiome, and groups 3 and 4 had a microbiome containing multiple genera of anaerobic bacteria, with group 3 representing transition to or from dysbiosis and group 4 full dysbiosis. 82 human proteins were differentially abundant among the groups, either showing an increasing or decreasing trend from microbiome groups 1 to 4. Proteins that increased included proteasome subunits and other proteins involved in catabolic metabolism, actin organising proteins and proteins involved in the immune response. Proteins that decreased included antiproteases, keratins, and cornified envelope proteins. We also compared the abundance of pre-defined proteins of interest among microbiome groups: markers of cell type, inflammation, and cell death, and mucins. The dysbiotic groups had increased abundance of proteins unique to lymphocytes and macrophages, pro-inflammatory cytokines, cell death markers, and MUC5B. We conclude that the cervicovaginal human proteome is associated with the cervicovaginal microbiome in a dose-response manner. The changes are likely caused by a pro-inflammatory influx of immune cells and an increase of cell death in dysbiosis. Dysbiosis-associated immune activation, breaches in epithelial integrity, altered mucin balance, and altered protease-antiprotease balance may all contribute to the increased risk of HIV transmission when cervicovaginal dysbiosis is present.
Project description:BACKGROUND: The intestinal microbiota play a key role in the onset, progression, and recurrence of Crohn’s disease (CD). Most microbiome studies assay fecal material, which does not provide region-specific information on mucosally adherent bacteria that directly interact with host systems. Changes in luminal oxygen has been proposed as a contributor to CD dybiosis. METHODS: 16S rRNA data was generated using colonic and ileal mucosal from patients with CD and without inflammatory bowel diseases (nonIBD). We developed profiles reflecting bacterial abundance within defined aerotolerance categories. Bacterial diversity, composition, and aerotolerance profiles were compared across intestinal regions and disease phenotypes. RESULTS: Bacterial diversity decreased in CD in both ileum and colon. Aerotolerance profiles significantly differed between intestinal segments in nonIBD, though both were dominated by obligate anaerobes, as expected. In CD, high relative levels of obligate anaerobes were maintained in the colon and increased in the ileum. Relative abundance of similar and distinct taxa were altered in colon and ileum. Notably, several obligate anaerobes, such as Bacteroides fragilis, dramatically increased in CD in one or both intestinal segments, though specific increasing taxa varied across patients. Increased abundance of taxa from the Proteobacteria phylum was found only in the ileum. Bacterial diversity was significantly reduced in resected pre-operative tissues of patients that developed disease recurrence across two independent cohorts, with common lower abundance of bacteria from the Bacteroides, Streptococcus, and Blautia genera. CONCLUSIONS: Mucosally adherent bacteria in colon and ileum show distinct alterations in CD that provide additional insights not revealed in fecal material.
Project description:Depot medroxyprogesterone acetate (DMPA) is an injectable hormonal contraceptive used by millions of women worldwide. However, experimental studies have associated DMPA use with genital epithelial barrier disruption and mucosal influx of human immunodeficiency virus (HIV) target cells. We explored the underlying molecular mechanisms of these findings. Ectocervical biopsies and cervicovaginal lavage (CVL) specimens were collected from HIV-seronegative Kenyan sex workers using DMPA (n=32) or regularly cycling controls (n=64). Tissue samples were assessed by RNA-sequencing and quantitative imaging analysis, whereas protein levels were measured in CVL samples. The results suggested a DMPA-associated upregulation of genes involved in immune regulation, including genes associated with cytokine-mediated signaling and neutrophil-mediated immunity. A transcription factor analysis further revealed DMPA-associated upregulation of RELA and NFKB1 which are involved in several immune activation pathways. Several genes significantly downregulated in the DMPA versus the control group were involved in epithelial structure and function, including genes encoding keratins, small proline-rich proteins, and cell-cell adhesion proteins. Pathway analyses indicated DMPA use was associated with immune activation and suppression of epithelium development, including keratinization and cornification processes. The cervicovaginal microbiome composition (Lactobacillus dominant and non-Lactobacillus dominant) had no overall interactional impact on the DMPA associated tissue gene expression. Imaging analysis verified that DMPA use was associated with an impaired epithelial layer as illustrated by staining for the selected epithelial junction proteins E-cadherin, desmoglein-1 and claudin-1. Additional staining for CD4+ cells revealed a more superficial location of these cells in the ectocervical epithelium of DMPA users versus controls. Altered protein levels of SERPINB1 and ITIH2 were further observed in the DMPA group. Identification of specific impaired epithelial barrier structures at the gene expression level, which were verified at the functional level by tissue imaging analysis, illustrates mechanisms by which DMPA adversely may affect the integrity of the genital mucosa.
Project description:Introduction: Structural integrity of the cervical epithelial barrier is crucial for defending the female reproductive tract against sexually transmitted infections, including HIV. Female sex hormones, estradiol and progesterone, play an important role in modulating this epithelial barrier. However, the influence of fluctuating estradiol and progesterone on ectocervical tissue gene and protein expression in naturally cycling women at high risk for sexually transmitted infections is not well understood. Methods: Ectocervical biopsies, cervicovaginal lavage fluid, and venous blood samples were collected from naturally cycling Kenyan female sex workers at two time points, separated by 2 weeks. The first time point represented the luteal phase of the menstrual cycle and the second time point represented the follicular phase. Plasma estradiol and progesterone levels were measured at each time point. Ectocervical tissues were analyzed by RNA-sequencing and in situ immunofluorescence staining. Cervicovaginal lavage samples were evaluated using antibody-based protein profiling. Results: Employing a systems biology approach, we demonstrated that high plasma estradiol levels enhanced ectocervical epithelial integrity. These findings were more pronounced in samples from the follicular phase (when progesterone and estradiol levels were significantly lower) and included increased expression, and more intact distribution, of the desmosomal cadherin DSG1. The effects of progesterone on gene and protein levels, as well as on intact tissue (as visualized by in situ staining), were modest throughout the menstrual cycle. Both estradiol and progesterone levels had limited influence on mucosal immune factors. Conclusion: Estradiol levels were associated with modulation of cervical epithelial barrier integrity, including the expression and distribution of DSG1, during the follicular phase of natural menstrual cycles in Kenyan sex workers.
Project description:The anaerobic actinobacterium Gardnerella was first isolated from the bladder by suprapubic aspiration more than fifty years ago. Since then, Gardnerella has been increasingly recognized as a common and often abundant member of the female urinary microbiome (urobiome). Some studies even suggest that the presence of Gardnerella is associated with urological disorders in women. We recently reported that inoculation of Gardnerella into the bladders of mice results in urothelial exfoliation. Here we performed whole bladder RNA-seq in our mouse model to identify additional host pathways involved in the response to Gardnerella bladder exposure. The transcriptional response to Gardnerella reflected the urothelial turnover that is a consequence of exfoliation, while also illustrating the activation pathways involved in inflammation and immunity. Additional timed exposure experiments in mice provided further evidence of a potentially clinically relevant consequence of bladder exposures to Gardnerella -- increased susceptibility to subsequent UTI caused by uropathogenic Escherichia coli. Together these data provide a broader picture of the bladder response to Gardnerella and lay the groundwork for future studies examining the impact of Gardnerella on bladder health.
Project description:The diverse bacterial communities that colonize the gastrointestinal tract play an essential role in maintaining immune homeostasis through the production of critical metabolites such as short chain fatty acids (SCFA), and this can be disrupted by antibiotic use. However, few studies have addressed the effects of specific antibiotics longitudinally on the microbiome and immunity. We evaluated the effects of four specific antibiotics; enrofloxacin, cephalexin, paromomycin, and clindamycin; in healthy female rhesus macaques. All antibiotics disrupted the microbiome, including reduced abundances of fermentative bacteria and increased abundances of potentially pathogenic bacteria, including Enterobacteriaceae in stool, and decreased Helicobacteraceae in the colon. This was associated with decreased SCFAs, indicating altered bacterial metabolism. Importantly, antibiotic use also substantially altered local immune responses, including increased neutrophils and Th17 cells in the colon. Furthermore, we observed increased soluble-CD14 in plasma, indicating microbial translocation. These data provide a longitudinal evaluation of antibiotic-induced changes to the composition and function of colonic bacterial communities, associated with specific alterations in mucosal and systemic immunity.
Project description:Griffithsin (GRFT) is an anti-viral lectin with potent anti-HIV activity. GRFT’s preclinical safety, lack of systemic absorption after topical administration, and lack of cross-resistance with existing products prompted its development for topical HIV pre-exposure prophylaxis. We evaluated safety, pharmacokinetics and pharmacodynamics of PC-6500 (0.1% GRFT in a carrageenan (CG) gel) in healthy, HIV-negative, non-pregnant women following once daily vaginal gel administration for 14 days. No significant adverse events, histopathological changes in cervico-vaginal mucosa, or anti-drug (GRFT) antibodies were detected. No cervicovaginal proinflammatory responses and no changes in the ectocervical transcriptome were evident. Vaginal microbiome remained largely unchanged. Reduced abundance of vaginosis-associated bacteria and decreased levels of proinflammatory chemokines (CXCL8 and CCL20) were observed. GRFT was not detected in plasma. GRFT and GRFT/CG in CVLs dose-dependently inhibited HIV and HPV, respectively, in vitro. The data suggest GRFT/CG is a promising on-demand multipurpose prevention product that warrants further investigation.
Project description:The human gut is colonized by trillions of microorganisms that influence human health and disease through the metabolism of xenobiotics, including therapeutic drugs and antibiotics. The diversity and metabolic potential of the human gut microbiome have been extensively characterized, but it remains unclear which microorganisms are active and which perturbations can influence this activity. Here, we use flow cytometry, 16S rRNA gene sequencing, and metatranscriptomics to demonstrate that the human gut contains distinctive subsets of active and damaged microorganisms, primarily composed of Firmicutes, which display marked temporal variation. Short-term exposure to a panel of xenobiotics resulted in significant changes in the physiology and gene expression of this active microbiome. Xenobiotic-responsive genes were found across multiple bacterial phyla, encoding novel candidate proteins for antibiotic resistance, drug metabolism, and stress response. These results demonstrate the power of moving beyond DNA-based measurements of microbial communities to better understand their physiology and metabolism. RNA-Seq analysis of the human gut microbiome during exposure to antibiotics and therapeutic drugs.
Project description:The experiment was designed to test the interactions of Spartina alterniflora, its microbiome, and the interaction of the plant-microbe relationship with oil from the Deepwater Horizon oil spill (DWH). Total RNA was extracted from leaf and root microbiome of S. alterniflora in soils that were oiled in DWH oil spill with or without added oil, as well as those grown in unoiled soil with or without added oil. The work in its entirety characterizes the transport, fate and catabolic activities of bacterial communities in petroleum-polluted soils and within plant tissues.