Inflammation in the female reproductive tract (FRT) is associated with increased HIV transmission. Lactobacillus spp. dominate the vaginal microbiota of many women and their presence is associated ...with reduced HIV acquisition. Here we demonstrate that lactic acid (LA), a major organic acid metabolite produced by lactobacilli, mediates anti-inflammatory effects on human cervicovaginal epithelial cells. Treatment of human vaginal and cervical epithelial cell lines with LA (pH 3.9) elicited significant increases in the production of the anti-inflammatory cytokine IL-1RA. When added simultaneously or prior to stimulation, LA inhibited the Toll-like receptor agonist-elicited production of inflammatory mediators IL-6, IL-8, TNFα, RANTES, and MIP3α from epithelial cell lines and prevented IL-6 and IL-8 production by seminal plasma. The anti-inflammatory effect of LA was mediated by the protonated form present at pH≤3.86 and was observed with both L- and D-isomers. A similar anti-inflammatory effect of LA was observed in primary cervicovaginal cells and in an organotypic epithelial tissue model. These findings identify a novel property of LA that acts directly on epithelial cells to inhibit FRT inflammation and highlights the potential use of LA-containing agents in the lower FRT as adjuncts to female-initiated strategies to reduce HIV acquisition.
Over-the-counter intra-vaginal lactic-acid containing douches are marketed as vaginal hygiene products that support optimal vaginal pH balance. We report the effect of a commercially available douche ...(Etos®) on the vaginal microbiota (VM) in a prospective study.
Twenty-five healthy women were recruited through advertisements in 2015-2017 (ethical approval: METC-2014_413) and followed over three menstrual cycles. The participants had a median age of 24 years IQR: 22-29, were mostly Dutch-Caucasian (88%), and 60% used combined oral contraceptives. All participants douched three times a week during the second cycle, starting on the first day of that cycle. Participants completed a questionnaire at baseline, kept a daily diary to report douching, menses, and sexual activity, self-collected vaginal swabs every other day during the first and third cycle and daily during the second cycle, and measured vaginal pH mid-cycle. A median of 44 vaginal swabs inter-quartile range (IQR): 41-50 were assessed per participant by 16S rRNA gene (V3-V4 region) sequencing and a Candida albicans PCR was done at four time-points. At baseline, 21 participants (84%) had Lactobacillus-dominated VM (Lactobacillus crispatus (n = 14), L. iners (n = 6), or diverse Lactobacillus species (n = 1) and 4 participants (16%) had VM consisting of diverse anaerobes. In multinomial logistic regression models, a trend towards increased odds were observed for having diverse anaerobic VM in the second and third cycle, compared to the first cycle, after adjusting for menses odds ratio (OR) = 1.4 (95% CI: 0.9-2.1) and OR = 1.7 (95% CI: 0.9-3.1), respectively (p = 0.376). Douching did not affect vaginal pH. Menses increased the odds for having VM consisting of diverse anaerobes almost two-fold (OR = 1.7; 95% CI: 1.0-2.8), while douching during menses increased the odds 2.6 fold (OR = 2.6; 95% CI: 1.0-6.5), compared to not menstruating (p = 0.099). Participants were more likely to test positive for C. albicans after cycle 2, compared to cycle 1 OR = 3.0 (95% CI: 1.2-7.2); p = 0.017.
The Etos® douche did not significantly affect the vaginal pH or VM composition, although increased odds for having diverse anaerobic VM was observed, especially when douching during menses. Furthermore, douching may promote C. albicans infections.
Objective
Determine the associations between factors and sexual practices and the composition of the vaginal microbiome (VM) of women treated for bacterial vaginosis (BV).
Design
Prospective cohort ...study.
Setting
The Melbourne Sexual Health Centre, Melbourne, Australia.
Population
Seventy‐five reproductive‐age women diagnosed with clinical BV, treated with first‐line antibiotics and followed for up to 6 months.
Methods
Women self‐collected vaginal swabs and completed questionnaires at enrolment, the day following antibiotics and monthly for up to 6months until BV recurrence or no BV recurrence (n = 430 specimens). Bacterial composition was determined using 16S rRNA gene amplicon sequencing. The effects of ongoing factors on VM composition (utilising 291 monthly specimens) were assessed using generalised estimating equations population‐averaged models, which accounted for repeated measures within individuals.
Main outcome measures
The relative abundance of vaginal bacterial taxa.
Results
Women who reported ongoing sex with a regular sexual partner (RSP) had a VM comprised of increased relative abundance of non‐optimal BV‐associated bacteria (Adjusted co‐efficient Adjusted co‐eff = 11.91, 95% CI 3.39to20.43, P = 0.006) and a decreased relative abundance of optimal, Lactobacillus species (Adjusted co‐eff = −12.76, 95% CI −23.03 to −2.49, P = 0.015). A history of BV was also associated with a decreased relative abundance of Lactobacillus spp. (Adjusted co‐eff = −12.35, 95% CI −22.68, P = 0.019). The relative abundance of Gardnerella, Atopobium and Sneathia spp. increased following sex with an RSP.
Conclusions
Sex with an untreated RSP after BV treatment was associated with a VM comprised of non‐optimal BV‐associated bacteria. BV treatment approaches may need to include partner treatment if they are to achieve a sustained optimal VM associated with improved health outcomes.
Tweetable
Sex drives a return to a ‘non‐optimal’ vaginal microbiota after antibiotics for bacterial vaginosis.
Tweetable
Sex drives a return to a ‘non‐optimal’ vaginal microbiota after antibiotics for bacterial vaginosis.
Emergence of drug resistant strains of human immunodeficiency virus type 1 (HIV-1) is a major hindrance in the long-term treatment of HIV-1 infected individuals. Alternative strategies, including ...those directed to structural elements of viral targets, are needed to combat the growing acquired immune deficiency syndrome (AIDS) pandemic. The HIV-1 reverse transcriptase (RT) dimer interface, critical for dimer stability and catalytic function, is a novel target for designing new anti-HIV-1 drugs. Several existing RT inhibitors are known to impair polymerase function by destabilizing RT dimer stability and can serve as useful leads in this direction. Conversely, studies have shown that potent nonnucleoside reverse transcriptase inhibitors (NNRTIs) can enhance RT subunit interaction, which may contribute in part to the inhibitory effect of these drugs. Interface peptides are reported to suppress enzyme activity by interfering with active RT heterodimer formation. This review focuses on small molecule and peptide inhibitors that interfere with the formation of the active RT heterodimer and also discusses regions in the RT that are critical for RT dimerization that can be considered as potential targets for chemotherapeutic intervention.
The NS2 protein of hepatitis C virus (HCV) plays a critical role in virus morphogenesis and infectivity. The crystal structure of the C‐terminus of the NS2 protein (NS2Pro) from the H77 strain ...indicates that NS2Pro forms a homodimer. In this study, using computational modelling, we identified residues at the NS2Pro dimer interface that have a role in dimerization and confirmed their capacity to influence dimerization by expression studies. Our modelling analysis identified 22 residues at the NS2Pro dimer interface that may be important for dimer formation. Based on the free binding energy, we selected the top five ranked mutations (V162A, M170A, I175A, D186A and I201A) for further study. Western blot analysis revealed that M170A, I175A, I201A, D186A and V162A resulted in a 4.0‐, 3.2‐, 3.0‐, 2.8‐ and 1.5‐fold increase, respectively, in the monomer/dimer ratio compared to wild type, confirming a role in homodimer formation or stability. Japanese Fulminant Hepatitis type 1 mutants expressing M170A, I175A, D186A and I201A demonstrated increasing defects in both RNA replication and the production of infectious virus compared to wild type. This study identified residues at the NS2Pro dimer interface that modulate NS2Pro homodimerization and demonstrated that abrogation of NS2Pro homodimerization results in defects in HCV replication and release of infectious virus.
The non-nucleoside reverse transcriptase (RT) inhibitors (NNRTIs) are a therapeutic class of compounds that are routinely used, in combination with other antiretroviral drugs, to treat HIV-1 ...infection. NNRTIs primarily block HIV-1 replication by preventing RT from completing reverse transcription of the viral single-stranded RNA genome into DNA. However, some NNRTIs, such as efavirenz, have been shown to inhibit the late stages of HIV-1 replication by interfering with HIV-1 Gag-Pol polyprotein processing, while others, such as the pyrimidinediones, have been shown to inhibit both HIV-1 RT-mediated reverse transcription and HIV-1/HIV-2 viral entry. Accordingly, in this review we describe the multiple mechanisms by which NNRTIs inhibit HIV-1 reverse transcription (and in some cases HIV-2 reverse transcription) and other key steps involved in HIV-1/HIV-2 replication.
Bacterial vaginosis (BV) is a common yet poorly understood vaginal condition that has become a major focus of HIV transmission and immunology research. Varied terminologies are used by clinicians and ...researchers to describe microbial communities that reside in the female reproductive tract (FRT), which is driven, in part, by microbial genetic and metabolic complexity, evolving diagnostic and molecular techniques, and multidisciplinary perspectives of clinicians, epidemiologists, microbiologists, and immunologists who all appreciate the scientific importance of understanding mechanisms that underlie BV. This Perspectives article aims to clarify the varied terms used to describe the cervicovaginal microbiota and its "nonoptimal" state, under the overarching term of BV. The ultimate goal is to move toward language standardization in future literature that facilitates a better understanding of the impact of BV on FRT immunology and risk of sexually transmitted infections, including HIV.
Abstract
Background
Women with a cervicovaginal microbiota dominated by
Lactobacillus
spp. are at reduced risk of acquiring sexually transmitted infections including HIV, but the biological ...mechanisms involved remain poorly defined. Here, we performed metaproteomics on vaginal swab samples from young South African women (
n
= 113) and transcriptomics analysis of cervicovaginal epithelial cell cultures to examine the ability of lactic acid, a metabolite produced by cervicovaginal lactobacilli, to modulate genital epithelial barrier function.
Results
Compared to women with
Lactobacillus
-depleted microbiota, women dominated by vaginal lactobacilli exhibit higher abundance of bacterial lactate dehydrogenase, a key enzyme responsible for lactic acid production, which is independently associated with an increased abundance of epithelial barrier proteins. Physiological concentrations of lactic acid enhance epithelial cell culture barrier integrity and increase intercellular junctional molecule expression.
Conclusions
These findings reveal a novel ability of vaginal lactic acid to enhance genital epithelial barrier integrity that may help prevent invasion by sexually transmitted pathogens.
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