Vaginal Lactobacillus crispatus persistence following application of a live biotherapeutic product: colonization phenotypes and genital immune impact.

BACKGROUND: Bacterial vaginosis (BV) increases HIV acquisition risk, potentially by eliciting genital inflammation. After BV treatment, the vaginal administration of LACTIN-V, a live biotherapeutic containing the Lactobacillus crispatus strain CTV-05, reduced BV recurrence and vaginal inflammation; however, 3 months after product cessation, CTV-05 colonization was only sustained in 48% of participants. RESULTS: This nested sub-study in 32 participants receiving LACTIN-V finds that 72% (23/32) demonstrate clinically relevant colonization (CTV-05 absolute abundance > 106 CFU/mL) during at least one visit while 28% (9/32) of women demonstrate colonization resistance, even during product administration. Immediately prior to LACTIN-V administration, the colonization-resistant group exhibited elevated vaginal microbiota diversity. During LACTIN-V administration, colonization resistance was associated with elevated vaginal markers of epithelial disruption and reduced chemokines, possibly due to elevated absolute abundance of BV-associated species and reduced L. crispatus. Colonization permissive women were stratified into sustained and transient colonization groups (31% and 41% of participants, respectively) based on CTV-05 colonization after cessation of product administration. These groups also exhibited distinct genital immune profiles during LACTIN-V administration. CONCLUSIONS: The genital immune impact of LACTIN-V may be contingent on the CTV-05 colonization phenotype, which is in turn partially dependent on the success of BV clearance prior to LACTIN-V administration.

Immunometabolic and potential tumor-promoting changes in 3D cervical cell models infected with bacterial vaginosis-associated bacteria.

Specific bacteria of the human microbiome influence carcinogenesis at diverse anatomical sites. Bacterial vaginosis (BV) is the most common vaginal disorder in premenopausal women that is associated with gynecologic sequelae, including cervical cancer. BV-associated microorganisms, such as Fusobacterium, Lancefieldella, Peptoniphilus, and Porphyromonas have been associated with gynecologic and other cancers, though the pro-oncogenic mechanisms employed by these bacteria are poorly understood. Here, we integrated a multi-omics approach with our three-dimensional (3-D) cervical epithelial cell culture model to investigate how understudied BV-associated bacteria linked to gynecologic neoplasia influence hallmarks of cancer in vitro. Lancefieldella parvulum and Peptoniphilus lacrimalis elicited robust proinflammatory responses in 3-D cervical cells. Fusobacterium nucleatum and Fusobacterium gonidiaformans modulated metabolic hallmarks of cancer corresponding to accumulation of 2-hydroxyglutarate, pro-inflammatory lipids, and signs of oxidative stress and genotoxic hydrogen sulfide. This study provides mechanistic insights into how gynecologic cancer-associated bacteria might facilitate a tumor-promoting microenvironment in the human cervix.

Tilapia Piscidin 4 (TP4) Reprograms M1 Macrophages to M2 Phenotypes in Cell Models of Gardnerella vaginalis-Induced Vaginosis.

Gardnerella vaginalis is associated with bacterial vaginosis (BV). The virulence factors produced by G. vaginalis are known to stimulate vaginal mucosal immune response, which is largely driven by activated macrophages. While Tilapia piscidin 4 (TP4), an antimicrobial peptide isolated from Nile tilapia, is known to display a broad range of antibacterial functions, it is unclear whether TP4 can affect macrophage polarization in the context of BV. In this study, we used the culture supernatants from G. vaginalis to stimulate differentiation of THP-1 and RAW264.7 cells to an M1 phenotype. The treatment activated the NF-κB/STAT1 signaling pathway, induced reactive nitrogen and oxygen species, and upregulated inflammatory mediators. We then treated the induced M1 macrophages directly with a non-toxic dose of TP4 or co-cultured the M1 macrophages with TP4-treated vaginal epithelial VK2 cells. The results showed that TP4 could not only decrease pro-inflammatory mediators in the M1 macrophages, but it also enriched markers of M2 macrophages. Further, we found that direct treatment with TP4 switched M1 macrophages toward a resolving M2c phenotype via the MAPK/ERK pathway and IL-10-STAT3 signaling. Conversely, tissue repair M2a macrophages were induced by TP4-treated VK2 cells; TP4 upregulated TSG-6 in VK2 cells, which subsequently activated STAT6 and M2a-related gene expression in the macrophages. In conclusion, our results imply that TP4 may be able to attenuate the virulence of G. vaginalis by inducing resolving M2c and tissue repair M2a macrophage polarizations, suggesting a novel strategy for BV therapy.

Comparison of Female Genital Tract Cytokine and Microbiota Signatures Induced by Initiation of Intramuscular DMPA and NET-EN Hormonal Contraceptives - a Prospective Cohort Analysis.

Background: Cervicovaginal inflammation, bacterial microbiota and hormonal contraceptives all influence sexual and reproductive health. To date, the effects of intramuscular depo-medroxyprogesterone acetate (DMPA-IM) versus injectable norethisterone enanthate (NET-EN) on vaginal microbiota or cytokines have not been compared back-to-back, although in-vitro data suggest that DMPA-IM and NET-EN have different pharmacokinetic and biologic activities. This study aimed at comparing the effects of DMPA-IM versus NET-EN initiation on cervicovaginal cytokines and microbiota in women at high risk for sexually transmitted infections (STIs) assigned to the respective contraceptives. Methods: We collected socio-demographic characteristics and vaginal samples from women initiating DMPA-IM (ECHO Trial; n = 53) and NET-EN (UChoose Trial; n = 44) at baseline and after two consecutive injections to assess cytokine concentrations by Luminex, vaginal microbiota by 16S rRNA gene sequencing, STIs, bacterial vaginosis (BV) and candidiasis. Results: Cytokine concentrations did not change significantly after initiating DMPA-IM or NET-EN, although NET-EN versus DMPA-IM-associated profiles were distinct. While the abundance of bacterial taxa associated with optimal and non-optimal microbiota fluctuated with DMPA-IM use, overall community composition did not significantly change with either contraceptive. HSV-2 serology, chlamydial infection, gonorrhoea and candidiasis did not influence the associations between contraceptive type and cervicovaginal cytokines or microbiota. Conclusions: Both DMPA-IM and NET-EN use did not lead to broad inflammatory or microbiota changes in the female genital tract of sub-Saharan African women. This suggests that NET-EN is likely a viable option for contraception in African women at high risk of BV and STIs.

Temporal Changes in Vaginal Microbiota and Genital Tract Cytokines Among South African Women Treated for Bacterial Vaginosis.

The standard treatment for bacterial vaginosis (BV) with oral metronidazole is often ineffective, and recurrence rates are high among African women. BV-associated anaerobes are closely associated with genital inflammation and HIV risk, which underscores the importance of understanding the interplay between vaginal microbiota and genital inflammation in response to treatment. In this cohort study, we therefore investigated the effects of metronidazole treatment on the vaginal microbiota and genital cytokines among symptomatic South African women with BV [defined as Nugent score (NS) ≥4] using 16S rRNA gene sequencing and multiplex bead arrays. Among 56 BV-positive women, we observed short-term BV clearance (NS <4) in a proportion of women six weeks after metronidazole treatment, with more than half of these experiencing recurrence by 12 weeks post-treatment. BV treatment temporarily reduced the relative abundance of BV-associated anaerobes (particularly Gardnerella vaginalis and Atopobium vaginae) and increased lactobacilli species (mainly L. iners), resulting in significantly altered mucosal immune milieu over time. In a linear mixed model, the median concentrations of pro-inflammatory cytokines and chemokines were significantly reduced in women who cleared BV compared to pre-treatment. BV persistence and recurrence were strongly associated with mucosal cytokine profiles that may increase the risk of HIV acquisition. Concentrations of these cytokines were differentially regulated by changes in the relative abundance of BVAB1 and G. vaginalis. We conclude that metronidazole for the treatment of BV induced short-term shifts in the vaginal microbiota and mucosal cytokines, while treatment failures promoted persistent elevation of pro-inflammatory cytokine concentrations in the genital tract. These data suggest the need to improve clinical management of BV to minimize BV related reproductive risk factors.

The reproductive tract microbiota in pregnancy.

The reproductive tract microbiota plays a crucial role in maintenance of normal pregnancy and influences reproductive outcomes. Microbe-host interactions in pregnancy remain poorly understood and their role in shaping immune modulation is still being uncovered. In this review, we describe the composition of vaginal microbial communities in the reproductive tract and their association with reproductive outcomes. We also consider strategies for manipulating microbiota composition by using live biotherapeutics, selective eradication of pathogenic bacteria with antibiotics and vaginal microbiota transplantation. Finally, future developments in this field and the need for mechanistic studies to explore the functional significance of reproductive tract microbial communities are highlighted.

Recent Semen Exposure Impacts the Cytokine Response and Bacterial Vaginosis in Women.

Background: The presence of semen in the vagina from unprotected sex may influence the immune and microbial environment of the female genital tract. Inflammatory cytokine concentrations and BV-associated bacteria in female genital secretions may influence HIV risk, although the effect of recent sexual intercourse on incident BV and the cytokine milieu of cervicovaginal secretions has rarely been measured in previous studies. Here, we investigated the extent to which partner semen impacts the cytokine response and incident BV. Methods: At baseline, we assessed the recency of semen exposure in menstrual cup supernatants by quantifying prostate specific antigen (PSA) levels using ELISA in 248 HIV-uninfected women at high risk for HIV infection. Luminex was used to measure 48 cytokines in menstrual cup supernatants and vaginal swabs to diagnose BV by Nugent score. Point-of-care screening for Chlamydia trachomatis and Neisseria gonorrhoeae was conducted using GeneXpert while OSOM was used for Trichomonas vaginalis detection. Multivariable models, adjusted for age, sexually transmitted infections, BV, current contraception use and condom use, were used to assess the impact of semen exposure on biomarkers of inflammation and BV. Results: Presence of PSA, indicating recent semen exposure within 48 hours prior to sampling, was observed in menstrual cup supernatants of 17% (43/248) of women. Of these women, 70% (30/43) had self-reported condom use at their last sex act and 84% (36/43) had BV (Nugent score >7). PSA presence was significantly associated with prevalent BV (Relative Risk (RR), 2.609; 95% Confidence Interval (CI), 1.104 - 6.165; p = 0.029). Furthermore, women with detectable PSA had high median concentrations of macrophage inflammatory protein- beta (MIP-1α, p=0.047) and low median concentration of the stem cell growth factor beta (SCGF-ß, p=0.038) compared to those without PSA. Conclusion: A degree of discordance between self-reports of consistent condom use and PSA positivity was observed. There was also evidence of a relationship between recent semen exposure, BV prevalence and altered cytokine concentrations. These findings suggest that PSA, as a semen biomarker, should be taken into consideration when investigating biological markers in the female genital tract and self-reported condom use in studies on reproductive and sexual health.

Perspectives on Existing and Novel Alternative Intravaginal Probiotic Delivery Methods in the Context of Bacterial Vaginosis Infection.

Bacterial vaginosis (BV) is one of the most common vaginal infections that affects hundreds of millions of women of reproductive age, worldwide. Traditional treatment strategies, such as oral and topical antibiotics, have shown efficacy against BV, but frequent recurrence of infection and the development of antibiotic-resistant bacteria remain as significant challenges. Alternatively, recent progress in understanding immune, microbiological, and metabolic interactions in the vaginal microbiota has prompted the consideration of administering probiotic organisms to restore and maintain vaginal health within the context of BV prevention and treatment. Given this, the objective of this review is to discuss existing and potential alternative approaches to deliver, and to potentially sustain the delivery of probiotics, to prevent and/or treat BV infections. First, a brief overview is provided regarding the probiotic species and combinatorial probiotic strategies that have shown promise in the treatment of BV and in restoring female reproductive health. Additionally, the advantages and challenges associated with current oral and intravaginal probiotic delivery platforms are discussed. Lastly, we present emerging and promising alternative dosage forms, such as electrospun fibers and 3D bioprinted scaffolds, that may be adapted as new strategies to intravaginally deliver probiotic organisms. Graphical abstract.

Differences in Vaginal Microbiota, Host Transcriptome, and Proteins in Women With Bacterial Vaginosis Are Associated With Metronidazole Treatment Response.

BACKGROUND: Bacterial vaginosis (BV) treatment failures and recurrences are common. To identify features associated with treatment response, we compared vaginal microbiota and host ectocervical transcriptome before and after oral metronidazole therapy. METHODS: Women with BV (Bronx, New York and Thika, Kenya) received 7 days of oral metronidazole at enrollment (day 0) and underwent genital tract sampling of microbiome (16S ribosomal RNA gene sequencing), transcriptome (RNAseq), and immune mediator concentrations on day 0, 15, and 35. RESULTS: Bronx participants were more likely than Thika participants to clinically respond to metronidazole (19/20 vs 10/18, respectively, P = .0067) and by changes in microbiota composition and diversity. After dichotomizing the cohort into responders and nonresponders by change in α-diversity between day 35 and day 0, we identified that transcription differences associated with chemokine signaling (q = 0.002) and immune system process (q = 2.5 × 10-8) that differentiated responders from nonresponders were present at enrollment. Responders had significantly lower levels of CXCL9 in cervicovaginal lavage on day 0 (P < .007), and concentrations of CXCL9, CXCL10, and monocyte chemoattractant protein 1 increased significantly between day 0 and day 35 in responders vs nonresponders. CONCLUSIONS: Response to metronidazole is characterized by significant changes in chemokines and related transcripts, suggesting that treatments that promote these pathways may prove beneficial.

HIV susceptibility in women: The roles of genital inflammation, sexually transmitted infections and the genital microbiome.

Given that heterosexual transmission of HIV across the genital mucosa is the most common route of infection in women, an in-depth understanding of the biological mechanisms associated with HIV risk in the female genital tract (FGT) is essential for effective control of the epidemic. Genital pro-inflammatory cytokines are well-described biological co-factors to HIV risk. Increased levels of pro-inflammatory cytokines in the FGT have been associated with a 3-fold higher-risk of acquiring HIV, presumably through involvement in barrier compromise and the recruitment of highly activated HIV target cells to the site of initial viral infection and replication. Sexually transmitted infections (STIs) and bacterial vaginosis (BV) are suggested possible contributors to genital inflammation in the FGT, and this, coupled with the relationship between genital inflammation and HIV risk, underscores the importance of effective treatment of STI and BV in the promotion of women's health. In most low- and middle-income countries, STIs are treated syndromically, a practice providing rapid treatment without identifying the infection source. However, this approach has been associated with over-diagnosis and the overuse of drugs. Further, because many women with STIs are asymptomatic, syndromic management also fails to treat a vast proportion of infected women. Although several studies have explored the role of STIs and the vaginal microbiome on genital inflammation and HIV risk, the impact of STI and BV management on genital inflammation remains poorly understood. This review aimed to collate the evidence on how BV and STI management efforts affect genital inflammation and the genital microbiome in women.

Inflammation Mediators Regulate the Microbiota Resistance to Adverse Factors.

We studied the effects of IL-1ß, IL-8, TNFα, and prostaglandin E2α in concentrations typically observed in health and during inflammation on the growth of vaginal microbiota and its resistance to factors inhibiting the synthesis of proteins, nucleic acids, and peptidoglycans. An increase in the cytokine levels, characteristic of inflammation, inhibits the growth of Lactobacillus population and improves its resistance to adverse factors. The growth of the population of opportunistic microorganisms (S. aureus, E. coli) is stimulated under these conditions, while their resistance to adverse factors decreases. Hence, it seems that the cytokines regulate the behavior of the host cells and of its bacterial symbionts.

Is bacterial vaginosis associated with autoimmune antibody positivity?

OBJECTIVE: To evaluate the association between bacterial vaginosis (BV) and autoimmune antibody positivity. METHOD: We evaluated Papanicolaou-stained cervicovaginal smears of 210 patients with poor obstetric history who were admitted to a special preconception counselling programme. Cytological specimens with various types of microorganisms except for BV, epithelial cell abnormalities and other non-neoplastic findings, including inflammation were excluded from the cohort in addition to patients with autoimmune and chronic inflammatory diseases. The remaining study population (n = 121) was divided into two groups of patients with autoimmune antibody positivity (study group, n = 80) and patients without antibody positivity (control group, n = 41). RESULTS: The rate of BV was demonstrated to be 13.8% and 2.4% in the study and control groups respectively (P = .042). We also demonstrated that the anti-nuclear antibody was positive in 58.3% of the cases with BV. CONCLUSION: BV was found more frequently in patients with autoimmune antibody positivity to a statistically significant degree.

The impact of cervical cytobrush sampling on cervico-vaginal immune parameters and microbiota relevant to HIV susceptibility.

The immunology and microbiota of the female genital tract (FGT) are key determinants of HIV susceptibility. Cervical cytobrush sampling is a relatively non-invasive method permitting the longitudinal assessment of endocervical immune cells, but effects on FGT immunology are unknown. Blood, cervico-vaginal secretions and cervical cytobrushes were collected from sexually transmitted infection (STI)-free women at baseline and after either 6 hours or 48 hours. Endocervical immune cell subsets were assessed by flow cytometry, and pro-inflammatory cytokines by multiplex ELISA. The density of Lactobacillus species and key bacterial vaginosis-associated bacterial taxa were determined by qPCR. Paired changes were assessed before and after cytobrush sampling. After 6 hours there were significant increases in CD4 + T cell, antigen presenting cell (APC) and neutrophil numbers; APC elevations persisted at 48 hours, while neutrophil and CD4 + T cell numbers returned to baseline. In addition, pro-inflammatory cytokine levels were increased at 6 hours and returned to baseline by 48 hours. No significant changes were observed in the absolute abundance of Lactobacillus species or BV-associated bacteria at either time point. Overall, cytobrush sampling altered genital immune parameters at 6 hours, but only APC number increases persisted at 48 hours. This should be considered in longitudinal analyses of FGT immunology.

Inflammatory and antimicrobial properties differ between vaginal Lactobacillus isolates from South African women with non-optimal versus optimal microbiota.

Female genital tract (FGT) inflammation increases HIV infection susceptibility. Non-optimal cervicovaginal microbiota, characterized by depletion of Lactobacillus species and increased bacterial diversity, is associated with increased FGT cytokine production. Lactobacillus species may protect against HIV partly by reducing FGT inflammation. We isolated 80 lactobacilli from South African women with non-optimal (Nugent 4-10; n = 18) and optimal microbiota (Nugent 0-3; n = 14). Cytokine production by vaginal epithelial cells in response to lactobacilli in the presence and absence of Gardnerella vaginalis was measured using Luminex. Adhesion to vaginal epithelial cells, pH, D/L-lactate production and lactate dehydrogenase relative abundance were assessed. Lactobacilli from women with non-optimal produced less lactic acid and induced greater inflammatory cytokine production than those from women with optimal microbiota, with IL-6, IL-8, IL-1α, IL-1ß and MIP-1α/ß production significantly elevated. Overall, lactobacilli suppressed IL-6 (adjusted p < 0.001) and IL-8 (adjusted p = 0.0170) responses to G. vaginalis. Cytokine responses to the lactobacilli were inversely associated with lactobacilli adhesion to epithelial cells and D-lactate dehydrogenase relative abundance. Thus, while cervicovaginal lactobacilli reduced the production of the majority of inflammatory cytokines in response to G. vaginalis, isolates from women with non-optimal microbiota were more inflammatory and produced less lactic acid than isolates from women with optimal microbiota.

Differential Expression of Local Immune Response Genes in the Vagina: Implication for the Diagnosis of Vaginal Infections.

Transcription profiles of genes of local immune response were determined in the vagina of women with bacterial vaginosis, aerobic vaginitis, and vulvovaginal candidosis for detection of the most specific immune markers for these vaginal infections. Laboratory diagnosis of the vaginal infections was performed microscopically; the inflammatory reaction in the vagina (leukorrhea) was defined as the presence of >10 white blood cells per field of view. Transcription profiles of IL1b, IL10, IL18, TNFα, TLR4, GATA3, and CD68 were determined using reverse-transcription quantitative real-time PCR. The strongest predictors of aerobic vaginitis were increased levels of IL1b and IL10 mRNA. Bacterial vaginosis was strongly associated with reduced levels of IL18 and GATA3 mRNA. Increased levels of IL1b and TLR4 transcripts showed significant discriminatory power for vulvovaginal candidosis and leukorrhea. The results of this study suggest differential expression of local immune response genes in the vagina of women with different vaginal infections. Detection of specific immune markers in the vagina using reverse-transcriptase PCR could supplement PCR detection of abnormal vaginal microflora for the diagnosis of vaginal infections.

Vaginal Microbiota and Mucosal Immune Markers in Women With Vulvovaginal Discomfort.

BACKGROUND: Up to 30% of women with vaginal symptoms are not assigned a diagnosis after standard diagnostic assessment. METHODS: We compared premenopausal women with idiopathic vaginitis (IV) or vulvodynia (VVD) to healthy controls. Microbiota were characterized using rRNA sequencing. Cytokines/chemokines (IL-10, IL-1α, IL-1ß, IL-6, IL-8, IL-2, IL-18, IL-4, IL-9, and IL-13) were measured in vaginal lavage fluid using the Meso Scale Discovery platform or ELISA (IL-1ra). Immunoglobulins were measured in vaginal lavage fluid using a bead-based immunoassay (Millipore). Cases and controls were compared using Kruskal-Wallis, analysis of variance, and linear regression or (for microbiome composition) the Bray-Curtis dissimilarity statistic. RESULTS: We compared 20 women with IV, 30 with VVD, and 52 controls. Most (80%) had greater than 90% 16S rRNA gene sequences from Lactobacillus crispatus, L. jensenii, L. gasseri, or L. iners. In analyses adjusted for age and hormonal contraception (HC), Gardnerella vaginalis was less prevalent and abundant in women with VVD (2/30, 7%) versus controls (16/52, 31%) or IV (5/20, 25%) (P = 0.030). Bray-Curtis dissimilarity was not significantly different between IV and controls or VVD. Fungal sequences were only detected in 5 participants: 2 control, 1 IV, 2 VVD. In univariate analysis, cytokines were not associated with diagnosis. Median vaginal concentration of IgE (but not other immunoglobulins) was lower in women with VVD (P = 0.006). CONCLUSIONS: Minimal differences in vaginal microbiota and inflammatory markers between women with IV, VVD or controls suggest no striking association between vaginal bacteria, fungi or inflammation and diagnosis in these women.

Vaginal dysbiosis associated-bacteria Megasphaera elsdenii and Prevotella timonensis induce immune activation via dendritic cells.

Dysbiosis of the vaginal microbiome as a result of overgrowth of anaerobic bacteria leads to bacterial vaginosis (BV) which is associated with increased inflammation in the genital mucosa. Moreover, BV increases susceptibility to sexual transmitted infections (STIs) and is associated with adverse pregnancy outcomes. It remains unclear how specific vaginal aerobic and anaerobic bacteria affect health and disease. We selected different vaginal bacteria ranging from true commensals to species associated with dysbiosis and investigated their effects on activation of dendritic cells (DCs). Commensal Lactobacilli crispatus did not induce DC maturation nor led to production of pro-inflammatory cytokines. In contrast, BV-associated bacteria Megasphaera elsdenii and Prevotella timonensis induced DC maturation and increased levels of pro-inflammatory cytokines. Notably, DCs stimulated with Prevotella timonensis suppressed Th2 responses and induced Th1 skewing, typically associated with preterm birth. In contrast, Lactobacillus crispatus and Megasphaera elsdenii did not affect Th cell polarization. These results strongly indicate that the interaction of vaginal bacteria with mucosal DCs determines mucosal inflammation and we have identified the anaerobic bacterium Prevotella timonensis as a strong inducer of inflammatory responses. Specifically targeting these inflammation-inducing bacteria might be a therapeutic strategy to prevent BV and associated risks in STI susceptibility and preterm birth.

Apoptosis of vaginal epithelial cells in clinical samples from women with diagnosed bacterial vaginosis.

Bacterial vaginosis (BV) is one of the most common vaginal infections among women of childbearing age. Gardnerella vaginalis (G. vaginalis) is a keystone microorganism present in more than 95% of all BV cases. The first step of the infection process in BV is mediated by interaction of microorganisms with epithelial cells (ECs). However, the role of these cells in BV pathogenesis is largely unknown. The present study aimed to investigate the vaginal EC response during BV. Twenty healthy women and 34 women with BV were enrolled in this study. The number of ECs in the vaginal swab was counted and analyzed for intracellular signals and apoptosis by flow cytometry. Cell damage was evaluated by lactate dehydrogenase assay. Compared to that in healthy donors, the percentage of exfoliated vaginal ECs was increased in women with BV, and an absence of neutrophils was observed in both groups. Activation signals, such as p-IκBα and c-Fos were unmodulated in the vaginal ECs of women with BV. Moreover, EC damage and apoptosis were significantly increased in patients with BV. Apoptosis was related to caspase-3 activation and the presence of G. vaginalis. This study provides the first evidence of a direct involvement of G. vaginalis in the apoptotic process of vaginal ECs during BV. This effect was mediated by caspase-3 activation, and G. vaginalis appeared to be one of causes for inducing EC apoptosis in BV. Hence, our findings suggest a possible explanation for the increased exfoliation of ECs in the vagina during BV.

Aberrant cervical innate immunity predicts onset of dysbiosis and sexually transmitted infections in women of reproductive age.

Sexually transmitted infections (STIs) and vaginal dysbiosis (disturbed resident microbiota presenting with abnormal Nugent score or candidiasis) have been associated with mucosal inflammation and risk of HIV-1 infection, cancer and poor reproductive outcomes. To date, the temporal relationships between aberrant cervical innate immunity and the clinical onset of microbial disturbance have not been studied in a large population of reproductive age women. We examined data from a longitudinal cohort of 934 Ugandan and Zimbabwean women contributing 3,274 HIV-negative visits who had complete laboratory, clinical and demographic data. Among those, 207 women later acquired HIV, and 584 women were intermittently diagnosed with C. trachomatis (CT), N. gonorrhoeae (NG), genital herpes (HSV-2), T. vaginalis (TV), candidiasis, and abnormal intermediate (4-6) or high (7-10) Nugent score, i.e. bacterial vaginosis (BV). Immune biomarker concentrations in cervical swabs were analyzed by generalized linear and mixed effect models adjusting for site, age, hormonal contraceptive use (HC), pregnancy, breastfeeding, genital practices, unprotected sex and overlapping infections. High likelihood ratios (1.5-4.9) denoted the values of cervical immune biomarkers to predict onset of abnormal Nugent score and candidiasis at the next visits. When controlling for covariates, higher levels of ß-defensin-2 were antecedent to BV, CT and HSV-2, lower anti-inflammatory ratio IL-1RA:IL-1ß-to intermediate Nugent scores and candida, lower levels of the serine protease inhibitor SLPI-to candida, lower levels of the adhesion molecule ICAM-1 -to TV, and lower levels of the oxidative stress mitigator and endothelial activation marker VEGF-to NG. Changes in innate immunity following onset of dysbiosis and infections were dependent on HC use when controlling for all other covariates. In conclusion, imminent female genital tract dysbiosis or infection can be predicted by distinct patterns of innate immunity. Future research should characterize biotic and abiotic determinants of this pre-existing innate immunity state.

Host-vaginal microbiota interactions in the pathogenesis of bacterial vaginosis.

PURPOSE OF REVIEW: The cause of bacterial vaginosis, the most common cause of vaginal discharge in women, remains controversial. We recently published an updated conceptual model on bacterial vaginosis pathogenesis, focusing on the roles of Gardnerella vaginalis and Prevotella bivia as early colonizers and Atopobium vaginae and other bacterial vaginosis-associated bacteria (BVAB) as secondary colonizers in this infection. In this article, we extend the description of our model to include a discussion on the role of host-vaginal microbiota interactions in bacterial vaginosis pathogenesis. RECENT FINDINGS: Although G. vaginalis and P. bivia are highly abundant in women with bacterial vaginosis, neither induce a robust inflammatory response from vaginal epithelial cells. These early colonizers may be evading the immune system while establishing the bacterial vaginosis biofilm. Secondary colonizers, including A. vaginae, Sneathia spp., and potentially other BVAB are more potent stimulators of the host-immune response to bacterial vaginosis and likely contribute to its signs and symptoms as well as its adverse outcomes. SUMMARY: Elucidating the cause of bacterial vaginosis has important implications for diagnosis and treatment. Our current bacterial vaginosis pathogenesis model provides a framework for key elements that should be considered when designing and testing novel bacterial vaginosis diagnostics and therapeutics.