A distinct cytokine and chemokine profile at the genital mucosa is associated with HIV-1 protection among HIV-exposed seronegative commercial sex workers

Vitamin D Decreases Susceptibility of CD4+ T Cells to HIV Infection by Reducing AKT Phosphorylation and Glucose Uptake: A Bioinformatic and In Vitro Approach

Activated immune cells are highly susceptible to human immunodeficiency virus (HIV) infection. Vitamin D (VitD) induces antimicrobial responses and reduces cellular activation. We investigated VitD effects on HIV-1 replication, glucose uptake, and gene regulation using computational and in vitro approaches. CD4+ T cells from healthy male donors were treated with VitD and infected with HIV-1. After 72 h, p24 protein was measured to assess viral replication. VitD effects on anti- and pro-HIV genes were analyzed by a Boolean network model based on curated databases and the literature. CCR5 and CXCR4 coreceptor expression, AKT phosphorylation, and glucose uptake were evaluated by flow cytometry, and expression of some model-identified genes was quantified by qPCR. VitD reduced p24 by 53.2% (p = 0.0078). Boolean network modeling predicted that VitD upregulates antiviral, migration, and cell-differentiation related genes, while downregulating genes related to cellular activation, proliferation, glucose metabolism, and HIV replication, notably AKT1, CCNT1, SLC2A1, HIF1A, and PFKL. In vitro, VitD reduced AKT phosphorylation by 26.6% (p = 0.0156), transcription of CCNT1 by 22.7% (p = 0.0391), and glucose uptake by 22.8% (p = 0.0039) without affecting classic antiviral genes or coreceptor expression. These findings suggest an anti-HIV effect of VitD, mediated through AKT and glucose metabolism downmodulation, both involved in cell activation and HIV-1 replication.

Natural Resistance to HIV Infection: Role of Immune Activation

INTRODUCTION

Although repeated exposure to HIV-1 can result in infection, some individuals remain seronegative without clinical or serologic evidence of infection; these individuals are known as HIV-1-exposed seronegative individuals. This population has been extensively studied to understand the mechanisms associated with natural resistance to HIV infection. Two main hypotheses have been proposed to explain this resistance: some researchers associated resistance with a low activation phenotype characterized by a decrease in the activation and proliferation of immune system cells linked with infection control and decreased production of cytokines and pro-inflammatory molecules, whereas others suggest that resistance is related to immune system activation and the expression of high levels of chemokines, pro-inflammatory cytokines and antiviral molecules.

AIMS

Our study aims to review and analyze the most relevant evidence supporting the role of the activation level of the immune system during natural resistance to HIV-1 infection.

METHODS

A search was conducted via the PubMed, SciELO and ScienceDirect databases. The literature search was performed in a nonsystematic manner. Articles published in the last five decades addressing immune activation mechanisms in natural resistance to HIV were reviewed.

RESULTS

A low-activation phenotype, characterized by a high frequency of Treg cells; reduced expression of CD25, CD38, and HLA-DR; and lower production of pro-inflammatory cytokines in peripheral and mucosal tissues, plays a key role in reducing the number of activated cells susceptible to infection, but it minimizes chronic inflammation, facilitating viral entry and spread. In contrast, the activation phenotype is associated with high expression of markers such as CD25, CD38, and HLA-DR, along with elevated high levels of interferon-stimulated genes and pro-inflammatory cytokines. This profile could promote infection control while increasing the number of virus-susceptible cells.

CONCLUSION

The complexity of the immune response during HIV exposure, reflected in the conflicting evidence concerning whether low or high immune activation offers protection against infection, suggests that there may be multiple pathways to HIV-1 resistance, influenced by factors such as the type of viral exposure, the immune environment, and individual genetics. Further research is needed to determine which immune states are protective and how these responses can be modulated to prevent infection.

Vaginal Bacteria and Proinflammatory Host Immune Mediators as Biomarkers of Human Immunodeficiency Virus Acquisition Risk Among African Women

BACKGROUND

Few investigations have assessed contributions of both vaginal bacteria and proinflammatory immune mediators to human immunodeficiency virus (HIV) acquisition risk in a prospective cohort.

METHODS

We conducted a nested case-control study of African women who participated in a randomized placebo-controlled trial of daily oral versus vaginal tenofovir-based preexposure prophylaxis for HIV infection. Vaginal concentrations of 23 bacterial taxa and 16 immune mediators were measured. Relationships between individual bacterial concentrations or immune mediators and HIV risk were analyzed using generalized estimating equations in a multivariable model. Factor analysis assessed relationships between combinations of bacterial taxa, immune mediators, and HIV acquisition risk.

RESULTS

We identified 177 HIV pre-seroconversion visits from 150 women who acquired HIV and 531 visits from 436 women who remained HIV uninfected. Fourteen bacterial taxa and 6 proinflammatory cytokines and chemokines were individually associated with greater HIV risk after adjusting for confounders. Women with all 14 taxa versus <14 taxa (adjusted odds ratio [aOR], 4.45 [95% confidence interval {CI}, 2.20-8.98]; P < .001) or all 6 immune mediators versus <6 mediators (aOR, 1.77 [95% CI, 1.24-2.52]; P < .001) had greater risk for HIV acquisition. Factor analysis demonstrated that a bacterial factor comprised of 14 high-risk bacterial taxa (aOR, 1.57 [95% CI, 1.27-1.93]; P < 0.001) and the interferon gamma-induced protein 10 (highest quartile: aOR, 3.19 [95% CI, 1.32-7.72]; P = 0.002) contributed to the highest HIV risk.

CONCLUSIONS

Bacterial and host biomarkers for predicting HIV acquisition risk identify women at greatest risk for HIV infection and can focus prevention efforts.

HIV-Associated Genital Immune Biomarkers in the Female Sex Worker Population: A Pilot Study

PROBLEM

Female sex workers (FSW) experience a disproportionately high burden of HIV infection, yet characterization of the vaginal immune microenvironment that may impact biological risk is not well studied among FSW in the United States. Additionally, feasible methodology for collecting biological materials has not been evaluated in this population.

METHODS

We enrolled 10 FSW (5 premenopausal, 5 postmenopausal) who participated in a survey and provided vaginal swabs. Biomarkers were assessed by ELISA, and included cytokines, chemokines, and antimicrobial/wound-healing mediators.

RESULTS

One hundred percent of FSW were African American, with a median age of 43.5. The median age when participants started sex work was 17.5, with 60% working 7 days per week and seeing up to 10 clients per night. Eighty percent reported recent unprotected sex and only 30% used some form of contraception. One self-reported sexually transmitted infection at the time of visit and two reported living with HIV. Vaginal secretions showed detectable levels of all biomarkers tested, except MIP3α and MIP1α, which were undetectable in all samples. When stratified by age/menopause status, no significant changes were observed except for Serpin A1 with higher median levels in premenopausal compared to postmenopausal FSW (median 5.79 vs. 5.205 log pg/mL, p = 0.016). Comparison with samples from an existing repository of non-FSW women showed significantly reduced chemokines IL8 (p = 0.045), MIP3α (p ≤ 0.001), and MIP1β (p = 0.015) in the FSW group.

CONCLUSIONS

We report characterization of the vaginal secretome in a cohort of FSW in the United States. Understanding of the genital immune microenvironment can inform future research in HIV prevention and therapeutic options in this population.

Elevated plasma levels of IP-10 and MIG are early predictors of loss of control among elite HIV controllers

Plasma cytokine levels were quantified among 30 persons with HIV (PWH) identified as elite controllers (15 transient controllers [studied a median of 1.38 years before losing viral control] and 15 persistent controllers). Thirty antiretroviral therapy (ART)-naive PWH, 30 ART-treated PWH with undetectable viremia, and 30 HIV-uninfected controls also were studied. Higher levels of cytokines were recognized among PWH than among controls, with EC displaying the highest levels. Elevated levels of IP-10 and MIG were identified among transient controllers as predictors of the loss of viral control. These findings offer feasible biomarkers for predicting virologic outcome and loss of control in EC.

High-fat diet feeding exacerbates HIV-1 rectal transmission

High-fat diet (HFD) is well known to impact various aspects of gut health and has been associated with many diseases and inflammation. However, the impact of HFD feeding on HIV-1 rectal transmission has not yet been well addressed. With an increasing threat of HIV-1 infection in men who have sex with men (MSM), where the rectal route is the primary mode of infection, it is imperative to understand the impact of HFD on gut microbiota and inflammation and consequently, its effect on HIV-1 rectal transmission. Here, we utilized our double humanized bone marrow, liver, thymus (dHu-BLT) mouse model to assess the impact of HFD feeding on the host's susceptibility to HIV-1 rectal transmission. We found that feeding an HFD successfully altered the gut microbial composition within 3 weeks in the dHu-BLT mouse model. In addition, levels of inflammatory mediators, specifically IL-12p70, IP-10, ICAM-1, and fecal calprotectin, were significantly higher in HFD-fed mice compared to control mice on a regular chow diet. We also observed that significantly different inflammatory markers (IL-12p70 and ICAM-1) were negatively correlated with the number of observed ASVs, Shannon diversity, and Faith's diversity in the HFD-fed group. Notably, when repeatedly challenged with a low dose of HIV-1 via a rectal route, mice receiving an HFD were significantly more susceptible to HIV-1 rectal infection than control mice. Together, these results underscore the impact of HFD feeding on the gut microbiota and inflammation and suggest the significance of diet-induced gut microbial dysbiosis and inflammation in promoting viral infection.IMPORTANCEHFD induces gut microbial dysbiosis and inflammation and has been associated with many infections and disease progression; however, its impact on HIV-1 rectal transmission is largely unknown. Given the increasing threat of HIV-1 incidence in men who have sex with men (MSM), it has become crucial to comprehend the impact of factors associated with gut health, like HFD consumption, on host susceptibility to HIV-1 rectal transmission. This is particularly important since anal intercourse remains the primary mode of HIV transmission within the MSM group. In this study, utilizing our unique mouse model, featuring both the human immune system and gut microbiota, we showed that HFD feeding led to gut microbial dysbiosis, induced inflammation, and increased HIV-1 rectal transmission. Collectively, our study highlights the significant impact of HFD on gut microbiota and inflammation and suggests an HFD consumption as a potential risk factor for promoting HIV-1 rectal susceptibility.

Comparison of the Biological Basis for Non-HIV Transmission to HIV-Exposed Seronegative Individuals, Disease Non-Progression in HIV Long-Term Non-Progressors and Elite Controllers

HIV-exposed seronegative individuals (HESIs) are a small fraction of persons who are multiply exposed to human immunodeficiency virus (HIV), but do not exhibit serological or clinical evidence of HIV infection. In other words, they are groups of people maintaining an uninfected status for a long time, even after being exposed to HIV several times. The long-term non-progressors (LTNPs), on the other hand, are a group of HIV-infected individuals (approx. 5%) who remain clinically and immunologically stable for an extended number of years without combination antiretroviral therapy (cART). Meanwhile, elite controllers are comprise a much lower number (0.5%) of HIV-infected persons who spontaneously and durably control viremia to below levels of detection for at least 12 months, even when using the most sensitive assays, such as polymerase chain reaction (PCR) in the absence of cART. Despite the fact that there is no universal agreement regarding the mechanisms by which these groups of individuals are able to control HIV infection and/or disease progression, there is a general consensus that the mechanisms of protection are multifaceted and include genetic, immunological as well as viral factors. In this review, we analyze and compare the biological factors responsible for the control of HIV in these unique groups of individuals.

Distinct cervical tissue-adherent and luminal microbiome communities correlate with mucosal host gene expression and protein levels in Kenyan sex workers

BACKGROUND

The majority of studies characterizing female genital tract microbiota have focused on luminal organisms, while 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 these communities may have distinct roles in health and disease. Here, we performed a multi-omics characterization of paired luminal and tissue samples collected from a cohort of Kenyan female sex workers.

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 microbial community was associated with epithelial remodeling and pro-inflammatory pathways. Tissue-adherent communities dominated by L. iners and Gardnerella were associated with lower host transcriptional activity. Tissue-adherent microbiomes dominated by Lactobacillus and Gardnerella correlated with host protein profiles associated with epithelial barrier stability, although 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 of a female sex worker cohort. These communities were distinct from cervicovaginal luminal microbiota in a significant proportion of individuals. We further revealed that bacterial communities at both sites correlated with distinct host gene expression and protein levels. The tissue-adherent bacterial community could possibly act as a reservoir that seed the lumen with less optimal, non-Lactobacillus, bacteria. Video Abstract.

The role of the genital microbiota in the acquisition and pathogenesis of sexually transmitted infections

PURPOSE OF REVIEW

There are an estimated 374 million new sexually transmitted infections (STIs) worldwide every year. Our review article examines the current evidence of how STI acquisition, transmission, and pathogenesis is impacted upon by the genital microbiota, with a focus on epidemiological, biochemical, and immunological features.

RECENT FINDINGS

At least in women, a genital microbiota dominated by lactobacilli has long been considered optimal for reproductive health, while depletion of lactobacilli may lead to a genital microenvironment dominated by anaerobic pathogens, which can manifest clinically as bacterial vaginosis. Recent research efforts have characterized genital microbiota composition in greater resolution, sometimes at species-level, using proteomics, metabolomics, and deep sequencing. This has enhanced our understanding of how specific microbiota members influence acquisition or clinical manifestation of STI pathogen infection. Other advances include a steady, though still slow, increase in the number of studies that sought to determine the genital (penile or urethral) microbiota of males and how it may impact that of their female partners' genital microbiota and risk of STI acquisition. Altogether, these data enabled us to explore the concept that genital microbiota may be sexually transmitted and influence pathogenesis and clinical presentation of other STI.

SUMMARY

With STI infection rates increasing worldwide, it is important now more than ever to find novel STI prevention strategies. Understanding if and how the genital microbiota is a modifiable risk factor for STI transmission, acquisition, and clinical manifestation may prove to be an important strategy in our efforts to curb morbidity in at risk populations.

Dynamic immune markers predict HIV acquisition and augment associations with sociobehavioral factors for HIV exposure

Prior studies attempting to link biomarkers of immune activation with risk of acquiring HIV have relied on cross sectional samples, most without proximity to HIV acquisition. We created a nested case-control study within the Sabes study in Peru, and assessed a panel of plasma immune biomarkers at enrollment and longitudinally, including within a month of diagnosis of primary HIV or matched timepoint in controls. We used machine learning to select biomarkers and sociobehavioral covariates predictive of HIV acquisition. Most biomarkers were indistinguishable between cases and controls one month before HIV diagnosis. However, levels differed between cases and controls at study entry, months to years earlier. Dynamic changes in IL-2, IL-7, IL-10, IP-10 and IL-12, rather than absolute levels, jointly predicted HIV risk when added to traditional risk factors, and there was modest effect modification of biomarkers on association between sociobehavioral risk factors and HIV acquisition.

Evaluating the impact of three progestin-based hormonal contraceptive methods on immunologic changes in the female genital tract and systemically (CHIME Study): a prospective cohort study protocol

BACKGROUND

Gonadal hormones can modify immune function, which may impact susceptibility to infectious diseases, including Human Immunodeficiency Virus (HIV). There is limited knowledge about how hormonal contraceptives (HC) influence the immune response during the course of use. The CHIME study aims to evaluate the effect of long-acting progestin-based hormonal contraceptives (depot medroxyprogesterone acetate, etonogestrel implant, and levonorgestrel intrauterine device) on immunologic changes in the female genital tract (FGT) and systemic compartment.

METHODS

CHIME is an observational cohort study where participants attend 2 visits prior to initiating the HC method of their choice, and then attend 6 visits over 12 months with biological sampling (vaginal swabs, cervicovaginal lavage, cytobrush and blood) for immunological, bacteriological, and virological analyses at each visit. Immune profiling will be evaluated by multi-color flow cytometry to determine how different T-cell subsets, in particular the CD4 T-cell subsets, change during the course of contraceptive use and whether they have different profiles in the FGT compared to the systemic compartment. The study aims are (1) to characterize the alterations in FGT and systemic immune profiles associated with three long-acting progestin-only HC and (2) to evaluate the vaginal microenvironment, determined by 16 s rRNA sequencing, as an individual-level risk factor and moderator of genital and systemic immune profile changes following exposure to three commonly used HC. Data collection started in March 2019 and is scheduled to be completed in October 2024.

DISCUSSION

The CHIME study aims to contribute to the body of research designed to evaluate the comparative impact of three long-acting progestin-only HC on innate and adaptive immune functions to understand how immunologic effects alter STI and HIV susceptibility.

High level of plasma TILRR protein is associated with faster HIV seroconversion

Background

TILRR (Toll-like Interleukin-1 Receptor Regulator) is a modulator of many genes in NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) signaling. It promotes the production of inflammatory mediators and the migration of immune cells. Recently, we showed that TILRR protein circulates in human blood. Thus, it could influence systemic inflammation. Systemic and mucosal inflammations increase the susceptibility to HIV infection. In this study, we analyzed the TILRR protein levels of the archived plasma samples of women enrolled in the Pumwani cohort to determine whether the plasma TILRR protein levels before seroconversion are correlated with differential risk of HIV seroconversion.

Methods

TILRR protein of 941 archived HIV negative plasma samples from 390 women who were HIV negative at the cohort enrollment was quantified with an in-house developed multiplex bead array method. Proinflammatory cytokines/chemokines were measured using a 14-plex bead array method. Spearman rank correlation analysis was used to determine the correlation between plasma TILRR protein and proinflammatory cytokines/chemokines. Kaplan-Meier survival analysis was conducted to evaluate whether the median plasma TILRR protein levels correlate with increased risk of HIV seroconversion.

Findings

The level of plasma TILRR protein was positively correlated with plasma IL-1β (rho: 0.2593, p<0.0001), MCP-1 (rho: 0.2377, p<0.0001), and IL-17A (rho: 0.1225, p=0.0216). Women with median plasma TILRR protein levels ≥100 ng/ml seroconverted significantly faster than women with plasma TILRR protein levels <100 ng/ml (log-rank= 100.124, p<0.0001; relative risk= 3.72 and odds ratio= 15.29). Furthermore, the factors causing genital inflammation, such as STIs (sexually transmitted infections), vaginal discharge, and genital ulcers were not statistically significantly different among women with different median plasma TILRR protein levels.

Interpretation

The high plasma TILRR protein levels are highly correlated with several plasma proinflammatory cytokines/chemokines. High median plasma TILRR protein (≥100 ng/ml) strongly predicted an increased risk of HIV seroconversion. Reducing plasma TILRR protein levels may reduce the risk of HIV acquisition.

Funding

The study was funded by an operating grant from the Canadian Institutes of Health Research (CIHR), operating grant-PA: CHVI Vaccine Discovery and Social Research (http://www.cihr-irsc.gc.ca/e/193.html), and National Microbiology Laboratory of Canada.

Transient Increases in Inflammation and Proapoptotic Potential Are Associated with the HESN Phenotype Observed in a Subgroup of Kenyan Female Sex Workers

Interferon (IFN) -stimulated genes (ISGs) are critical effectors of IFN response to viral infection, but whether ISG expression is a correlate of protection against HIV infection remains elusive. A well-characterized subcohort of Kenyan female sex workers, who, despite being repeatedly exposed to HIV-1 remain seronegative (HESN), exhibit reduced baseline systemic and mucosal immune activation. This study tested the hypothesis that regulation of ISGs in the cells of HESN potentiates a robust antiviral response against HIV. Transcriptional profile of a panel of ISGs with antiviral function in PBMC and isolated CD4+ T cells from HESN and non-HESN sex worker controls were defined following exogenous IFN-stimulation using relative RT-qPCR. This study identified a unique profile of proinflammatory and proapoptotic ISGs with robust but transient responses to exogenous IFN-γ and IFN-α2 in HESN cells. In contrast, the non-HESN cells had a strong and prolonged proinflammatory ISG profile at baseline and following IFN challenge. Potential mechanisms may include augmented bystander apoptosis due to increased TRAIL expression (16-fold), in non-HESN cells. The study also identified two negative regulators of ISG induction associated with the HESN phenotype. Robust upregulation of SOCS-1 and IRF-1, in addition to HDM2, could contribute to the strict regulation of proinflammatory and proapoptotic ISGs in HESN cells. As reducing IRF-1 in the non-HESN cells resulted in the identified HESN ISG profile, and decreased HIV susceptibility, the unique HESN ISG profile could be a correlate of protection against HIV infection.

Environmental Pollutants, Mucosal Barriers, and Pathogen Susceptibility; The Case for Aflatoxin B1 as a Risk Factor for HIV Transmission and Pathogenesis

HIV transmission risk is dependent on the infectivity of the HIV+ partner and personal susceptibility risk factors of the HIV- partner. The mucosal barrier, as the internal gatekeeper between environment and self, concentrates and modulates the internalization of ingested pathogens and pollutants. In this review, we summarize the localized effects of HIV and dietary toxin aflatoxin B1 (AFB1), a common pollutant in high HIV burden regions, e.g., at the mucosal barrier, and evidence for pollutant-viral interactions. We compiled literature on HIV and AFB1 geographic occurrences, mechanisms of action, related co-exposures, personal risk factors, and HIV key determinants of health. AFB1 exposure and HIV sexual transmission hotspots geographically co-localize in many low-income countries. AFB1 distributes to sexual mucosal tissues generating inflammation, microbiome changes and a reduction of mucosal barrier integrity, effects that are risk factors for increasing HIV susceptibility. AFB1 exposure has a positive correlation to HIV viral load, a risk factor for increasing the infectivity of the HIV+ partner. The AFB1 exposure and metabolism generates inflammation that recruits HIV susceptible cells and generates chemokine/cytokine activation in tissues exposed to HIV. Although circumstantial, the available evidence makes a compelling case for studies of AFB1 exposure as a risk factor for HIV transmission, and a modifiable new component for combination HIV prevention efforts.

Sex Differences in Primary HIV Infection: Revisiting the Role of TLR7-Driven Type 1 IFN Production by Plasmacytoid Dendritic Cells in Women

Plasmacytoid dendritic cells (pDCs) produce type I interferon (IFN-I) during HIV-1 infection in response to TLR7 stimulation. However, IFN-I-signaling has been shown to play opposite effects in HIV-1 and SIV infection. TLR7-driven type I interferon production in pDCs is higher in women than in men due to the cell-intrinsic actions of estrogen and X-chromosome complement. Indeed, TLR7 is encoded on the X-chromosome, and the TLR7 gene escapes the X-chromosome inactivation in immune cells of women which express significantly higher levels of TLR7 protein than male cells. Following HIV infection, women have a lower viremia during acute infection and exhibit stronger antiviral responses than men, which has been attributed to the increased capacity of female pDCs to produce IFN-α upon TLR7-stimulation. However, a deleterious functional impact of an excessive TLR7 response on acute viremia in women has been recently revealed by the analysis of the frequent rs179008 c.32A>T SNP of TLR7. This SNP was identified as a sex-specific protein abundance quantitative trait locus (pQTL) causing a difference in the TLR7 protein dosage and effector function in females only. T allele expression was associated with a lower TLR7 protein synthesis, blunted production of IFN-α by pDCs upon TLR7 stimulation, and an unexpectedly lower viral load during primary HIV-1 infection in women. In the present review, the author will revisit the role of TLR7-driven pDC innate function in the context of HIV-1 infection to discuss at what stage of primary HIV-1 infection the TLR7 rs179008 T allele is likely to be protective in women.

Microbial mismanagement: how inadequate treatments for vaginal dysbiosis drive the HIV epidemic in women

Women and girls represent a key population driving new HIV infections and persistence of the HIV pandemic. A key determinant of HIV susceptibility is the composition of the vaginal microbiome, which can influence the local immune cell population, inflammation status, and HIV prevention drug levels. While a low-diversity composition dominated by Lactobacillus crispatus is associated with a decreased risk of HIV acquisition, high diversity environments associated with bacterial vaginosis increase risk of HIV. Given the important role of the vaginal microbiome in determining HIV susceptibility, altering the microbiome towards a Lactobacillus-dominated state is an attractive complementary strategy to reduce HIV incidence rates. Here, we provide an overview of the mechanisms by which the vaginal microbiome may contribute to HIV acquisition risk. Furthermore, we address the advantages and limitations of historical treatments and emerging technologies under investigation to modify the vaginal microbiome, including: antibiotics, bacteriophages, probiotics, topicals, and engineered bacteria. By addressing the current state of vaginal microbiome knowledge and strategies for manipulation, we hope to amplify the growing calls for increased resources and research into vaginal microbial health, which will be essential to accelerating preventative efforts amongst the world's most vulnerable populations.

HIV-Exposed Seronegative Sex Workers Express Low T-Cell Activation and an Intact Ectocervical Tissue Microenvironment

Immunological correlates of natural resistance to HIV have been identified in HIV-exposed seronegative (HESN) individuals and include a low-inflammatory genital mucosal status. The cervicovaginal epithelium has not been studied for such correlates despite constituting an important barrier against sexual HIV transmission. To fill this gap in knowledge, we collected samples of blood, cervical mononuclear cells, cervicovaginal lavage, and ectocervical tissue from Kenyan HESN sex workers (n = 29) and controls (n = 33). The samples were analyzed by flow cytometry, protein profiling, 16S rRNA gene sequencing, in situ image analysis, and tissue-based RNA sequencing. A significantly higher relative proportion of regulatory T cells in blood (B7⁺CD25^hiFoxP3⁺CD127^loCD4⁺ and B7⁺Helios⁺FoxP3⁺CD4⁺), and a significantly lower proportion of activated cervical T cells (CCR5⁺CD69⁺CD4⁺ and CCR5⁺CD69⁺CD8⁺), were found in the HESN group compared with the controls. In contrast, there were no statistically significant differences between the study groups in cervicovaginal protein and microbiome compositions, ectocervical epithelial thickness, E-cadherin expression, HIV receptor expression, and tissue RNA transcriptional profiles. The identification of an intact ectocervical microenvironment in HESN individuals add new data to current knowledge about natural resistance to sexual transmission of HIV.

Differential Elevation of Inflammation and CD4+ T Cell Activation in Kenyan Female Sex Workers and Non-Sex Workers Using Depot-Medroxyprogesterone Acetate

Background

Depot Medroxyprogesterone (DMPA) is one of the most widely used contraceptives in Sub-Saharan Africa where HIV incidence is high. We explored the effect of DMPA on the activation of HIV cellular targets and inflammation as a possible mechanism of increased HIV risk with DMPA use. Since sex work is known to affect the immune system, this study aimed to understand the effect of DMPA on the immune system among sex workers and non-sex worker women.

Methods

Twenty-seven DMPA-using HIV seronegative female sex workers (FSW) and 30 DMPA-using HIV seronegative non-sex worker (SW) women were enrolled in the study. Twenty-four FSWs and 30 non-sex workers who were not using any hormonal contraception (no HC) were recruited as controls. Blood and cervico-vaginal samples were collected from all participants and assayed for T cell activation and proinflammatory cytokines.

Results

Among no HC users, sex workers had lower expression of CD38 and CD69 on blood-derived CD4⁺ T cells along with lower CD4⁺CCR5⁺ cells frequency in the endocervix. Plasma MCP-1, TNFα and IL-17 also had reduced expression in FSW not using HC. Non-sex workers using DMPA had elevated proportions of blood-derived CD4⁺CD38⁺, CD4⁺CD69⁺ and CD4⁺HLA-DR⁺ T cells relative to non-sex workers who were not taking any HC. DMPA-using non-sex workers also had an increased level of plasma interferon gamma (IFN-γ), monokine induced by interferon-γ (MIG) and sCD40L, alongside higher proportion of CD4⁺CD38⁺ and CD4⁺CD69⁺ T cells at the cervix compared to non-sex workers no-HC controls., Finally, non-sex workers and FSWs using DMPA had similar levels of genital and peripheral CD4⁺ T cell activation and inflammation.

Conclusion

DMPA increased inflammation and expression of activation markers on potential HIV target cells in non-sex workers. These data show that DMPA is a strong immune modulator and its use counteracts the decreased immune activation associated with sex work. These findings suggest that inflammation and increased HIV target cells in blood and at the genital tract may be mechanisms by which DMPA increases susceptibility to HIV.

Vaginal microbiome-hormonal contraceptive interactions associate with the mucosal proteome and HIV acquisition

Alterations to the mucosal environment of the female genital tract, such as genital inflammation, have been associated with increased HIV acquisition in women. As the microbiome and hormonal contraceptives can affect vaginal mucosal immunity, we hypothesized these components may interact in the context of HIV susceptibility. Using previously published microbiome data from 685 women in the CAPRISA-004 trial, we compared relative risk of HIV acquisition in this cohort who were using injectable depot medroxyprogesterone acetate (DMPA), norethisterone enanthate (NET-EN), and combined oral contraceptives (COC). In women who were Lactobacillus-dominant, HIV acquisition was 3-fold higher in women using DMPA relative to women using NET-EN or COC (OR: 3.27; 95% CI: 1.24–11.24, P = 0.0305). This was not observed in non-Lactobacillus-dominant women (OR: 0.95, 95% CI: 0.44–2.15, P = 0.895) (interaction P = 0.0686). Higher serum MPA levels associated with increased molecular pathways of inflammation in the vaginal mucosal fluid of Lactobacillus-dominant women, but no differences were seen in non-Lactobacillus dominant women. This study provides data suggesting an interaction between the microbiome, hormonal contraceptives, and HIV susceptibility.

Alterations to the mucosal environment of the female genital tract have been associated with increased HIV acquisition in women. As both the vaginal microbiome and hormonal contraceptives affect mucosal immunity, we investigated their interaction with HIV susceptibility. We characterized the vaginal microbiomes in 685 women from the CAPRISA-004 trial, who utilized three major types of hormonal contraceptives including injectable depot medroxyprogesterone acetate (DMPA), norethisterone enanthate (NET-EN), and combined oral contraceptives (COC). In the 40% of women with Lactobacillus-depleted microbiomes, HIV acquisition was not different between contraceptive groups. However, in the 60% of women with Lactobacillus as the dominant bacterial taxa, HIV acquisition risk was 3-fold higher (in women using DMPA relative to women using NET-EN and COC). Higher serum medroxyprogesterone acetate levels in Lactobacillus dominant women associated with increased cervicovaginal inflammation pathways in the mucosal proteome, biomarkers of which associated with HIV susceptibility. This study provides data suggesting an interaction between the microbiome, hormonal contraceptives, and HIV susceptibility.

Inflammation, HIV, and Immune Quiescence: Leveraging on Immunomodulatory Products to Reduce HIV Susceptibility

The relationship between inflammation and HIV has been a focus of research over the last decade. In HIV-infected individuals, increased HIV-associated immune activation significantly correlated to disease progression. While genital inflammation (GI) has been shown to significantly increase the risk of HIV acquisition and transmission, immune correlates for reduced risk remain limited. In certain HIV-exposed seronegative individuals, an immune quiescent phenotype characterized reduced risk. Immune quiescence is defined by specific, targeted, highly regulated immune responses that hinder overt inflammation or immune activation. Targeted management of inflammation, therefore, is a plausible strategy to mitigate HIV risk and slow disease progression. Nonsteroidal anti-inflammatory drugs (NSAIDs) such as hydroxychloroquine and aspirin have shown encouraging preliminary results in low-risk women by reducing systemic and genital immune activation. A topical NSAID, containing ibuprofen, is effective in treating vulvovaginal inflammation. Additionally, the glucocorticoids (GCs), prednisolone, and dexamethasone are used to treat HIV-associated immune activation. Collectively, these data inform on immune-modulating drugs to reduce HIV risk. However, the prolonged use of these pharmaceutical drugs is associated with adverse effects, both systemically and to a lesser extent topically. Natural products with their reduced side effects coupled with anti-inflammatory properties render them viable options. Lactic acid (LA) has immunomodulatory properties. LA regulates the genital microbiome by facilitating the growth of Lactobacillus species, while simultaneously limiting bacterial species that cause microbial dysbiosis and GI. Glycerol monolaurate, besides being anti-inflammatory, also inhibited SIV infections in rhesus macaques. The proposed pharmaceutical and natural products could be used in combination with either antiretrovirals for treatment or preexposure prophylaxis for HIV prevention. This review provides a summary on the associations between inflammation, HIV risk, and disease progression. Furthermore, we use the knowledge from immune quiescence to exploit the use of pharmaceutical and natural products as strategic interventions to manage inflammation, toward mitigating HIV infections.

Characterization of Oral Immunity in Cases and Close Household Contacts Exposed to Andes Orthohantavirus (ANDV)

Background: Andes orthohantavirus (ANDV) is the sole etiologic agent of Hantavirus Cardiopulmonary Syndrome in Chile and, until now, the only Hantavirus known to be transmitted by person-to-person route. The main risk of person-to-person transmission is to be a sexual partner of an index case, and deep kissing the main mechanism of infection. Experimental reports suggest that ANDV infection can be inhibited by some saliva components. Therefore, some host factors like saliva quality, could help to explain why some individuals do not become infected even though their exposure to the virus is high.

Aim: To compare some saliva components, such cytokines and mucins, between ANDV-infected cases (exposed-sick), their close household contacts (exposed-not sick) and healthy control not exposed.

Methods: Sixty-nine confirmed ANDV-infected cases, 76 close household contacts exposed to ANDV but not infected (CHC) and 39 healthy control not exposed (HCNE). The following components were measured in saliva: secretory immunoglobulin A (sIgA) by ELISA; cytokines (IL1β, IL12p70, TNFα, INFy, IL10, IL6, VEGF, IP10, and IL8) by Multiplex Assay and mucins MUC7 and MUC5B by Western Blotting.

Results: Among infected cases, CHC and HCNE analyzed 74, 45, and 33% were men, respectively (p ≤ 0.05). The average age for cases, CHC and HCNE was 37.7, 28.7, and 32 years, respectively (p ≤ 0.05). The average concentration of sIgA in infected cases was 4.846 mg/mL, higher than for CHC group, 0.333 mg/mL (p ≤ 0.05). For cytokines, significant differences were found comparing all groups for IFNy, IL12p70, and IL8. Among CHC group, there was a higher frequency of detection of MUC7 isoform (62.6%; 31/49) compared to ANDV-infected cases (40.5%; 17/42) (p < 0.05). Similarly, presence of MUC5B was higher among CHC groups (62.16%; 46/74) than in ANDV-infected cases (44.4%; 28/63) (p < 0.05).

Conclusions: Three salivary components showed differences between infected cases and close household contacts (sIgA, cytokines, and mucins). These differences can be explained by the acute state of the disease in the ANDV-infected cases group. However, the differences in MUC5B and isoforms of MUC7 are not entirely explainable by the infection itself. This work represents a novel description of salivary components in the context of ANDV infection.

Betamethasone induces potent immunosuppression and reduces HIV infection in a PBMC in vitro model

Genital inflammation is an established risk factor for increased HIV acquisition risk. Certain HIV-exposed seronegative populations, who are naturally resistant to HIV infection, have an immune quiescent phenotype defined by reduced immune activation and inflammatory cytokines at the genital tract. Therefore, the aim of this study was to create an immune quiescent environment using immunomodulatory drugs to mitigate HIV infection. Using an in vitro peripheral blood mononuclear cell (PBMC) model, we found that inflammation was induced using phytohemagglutinin and Toll-like receptor (TLR) agonists Pam3CSK4 (TLR1/2), lipopolysaccharide (LPS) (TLR4) and R848 (TLR7/8). After treatment with anti-inflammatory drugs, ibuprofen (IBF) and betamethasone (BMS), PBMCs were exposed to HIV NL4-3 AD8. Multiplexed ELISA was used to measure 28 cytokines to assess inflammation. Flow cytometry was used to measure immune activation (CD38, HLA-DR and CCR5) and HIV infection (p24 production) of CD4+ T cells. BMS potently suppressed inflammation (soluble cytokines, p<0.05) and immune activation (CD4+ T cells, p<0.05). BMS significantly reduced HIV infection of CD4+ T cells only in the LPS (0.98%) and unstimulated (1.7%) conditions (p<0.02). In contrast, IBF had minimal anti-inflammatory and immunosuppressive but no anti-HIV effects. BMS demonstrated potent anti-inflammatory effects, regardless of stimulation condition. Despite uniform immunosuppression, BMS differentially affected HIV infection according to the stimulation conditions, highlighting the complex nature of these interactions. Together, these data underscore the importance of interrogating inflammatory signaling pathways to identify novel drug targets to mitigate HIV infection.

Cervico-Vaginal Inflammatory Cytokine and Chemokine Responses to Two Different SIV Immunogens

Studies have shown that vaccine vectors and route of immunization can differentially activate different arms of the immune system. However, the effects of different HIV vaccine immunogens on mucosal inflammation have not yet been studied. Because mucosal sites are the primary route of HIV infection, we evaluated the cervico-vaginal inflammatory cytokine and chemokine levels of Mauritian cynomolgus macaques following immunization and boost using two different SIV vaccine immunogens. The PCS vaccine delivers 12 20-amino acid peptides overlapping the 12 protease cleavage sites, and the Gag/Env vaccine delivers the full Gag and full Env proteins of simian immunodeficiency virus. We showed that the PCS vaccine prime and boosts induced short-lived, lower level increases of a few pro-inflammatory/chemotactic cytokines. In the PCS-vaccine group only the levels of MCP-1 were significantly increased above the baseline (P = 0.0078, Week 6; P = 0.0078, Week 17; P = 0.0234; Week 51) following multiple boosts. In contrast, immunizations with the Gag/Env vaccine persistently increased the levels of multiple cytokines/chemokines. In the Gag/Env group, higher than baseline levels were consistently observed for IL-8 (P = 0.0078, Week 16; P = 0.0078, Week 17; P = 0.0156, Week 52), IL-1β (P = 0.0234, Week 16; P = 0.0156, Week 17; P = 0.0156, Week 52), and MIP-1α (P = 0.0313, Week 16; P = 0.0156, Week 17; P = 0.0313, Week 52). Over time, repeated boosts altered the relative levels of these cytokines between the Gag/Env and PCS vaccine group. 18 weeks after final boost with a higher dosage, IP-10 levels (P = 0.0313) in the Gag/Env group remained higher than baseline. Thus, the influence of vaccine immunogens on mucosal inflammation needs to be considered when developing and evaluating candidate HIV vaccines.

Impact of Standard Bacterial Vaginosis Treatment on the Genital Microbiota, Immune Milieu, and Ex Vivo Human Immunodeficiency Virus Susceptibility

BACKGROUND

Genital immunology is a key determinant of human immunodeficiency virus (HIV) susceptibility. Both factors are modulated by bacterial vaginosis (BV) and, to some extent, by Lactobacillus iners, the genital Lactobacillus spp. that predominates in African, Caribbean, and other Black (ACB) women. We conducted a clinical trial to assess the impact of oral metronidazole treatment on the genital immune parameters of HIV acquisition risks in Kenyan women with BV.

METHODS

The primary endpoint was ex vivo cervical CD4+ T-cell HIV susceptibility after 1 month; secondary endpoints included genital cytokine/chemokine levels, cervical immune cell populations, and the composition of the cervico-vaginal microbiota by 16S ribosomal RNA gene amplicon sequencing.

RESULTS

BV resolved (Nugent score ≤ 3) at 1 month in 20/45 participants, and cervical CD4+ T-cell HIV entry was moderately reduced in all participants, regardless of treatment outcome. Resolution of BV and reduced abundances of BV-associated gram-negative taxa correlated with reduced genital interleukin (IL)-1α/β. However, BV resolution and the concomitant colonization by Lactobacillus iners substantially increased several genital chemokines associated with HIV acquisition, including interferon-γ inducible protein (IP)-10, macrophage inflammatory protein (MIP)-3α, and monokine induced by gamma interferon (MIG). In an independent cohort of ACB women, most of whom were BV-free, vaginal chemokines were again closely linked with L. iners abundance, though not other Lactobacillus spp.

CONCLUSIONS

BV treatment reduced genital CD4+ T-cell HIV susceptibility and IL-1 levels, but dramatically increased the genital chemokines that may enhance HIV susceptibility; the latter effect was related to the restoration of an Lactobacillus iners-dominated microbiota. Further studies are needed before treatment of asymptomatic BV can be recommended for HIV prevention in ACB communities.

Characterization of the Genital Mucosa Immune Profile to Distinguish Phases of the Menstrual Cycle: Implications for HIV Susceptibility

BACKGROUND

Inflammation and immune activation are key factors in sexual transmission of human immunodeficiency virus (HIV). We sought to define the impact of hormonal cycling on the mucosal immune environment and HIV risk in sex workers with a natural menstrual cycle.

METHODS

We compared soluble mucosal immune factors and cervical mononuclear cells during hormone titer-defined phases of the menstrual cycle among 37 sex workers from Nairobi, Kenya. Systemic and mucosal samples were collected 14 days apart to distinguish the follicular and luteal phases of the menstrual cycle, and phases were confirmed by hormone measurements. Vaginal concentrations of 19 immune modulators and cervical T-cell activation markers were measured.

RESULTS

The follicular phase signature was characterized by an elevated CCL2 level, decreased interleukin 1α and interleukin 1β cervical concentrations, and a significant increase in the proportion of CD4+ T cells that expressed CD69. The genital concentration of CCL2 was the best marker to distinguish the follicular from the luteal phase in univariate and multivariate analyses and remained independent of elevated genital inflammation and bacterial vaginosis.

CONCLUSION

The follicular phase of the menstrual cycle was associated with an elevated CCL2 level and retention of resident memory CD4+ T cells, which has implications for increased susceptibility to HIV infection.

The combination of CXCL9, CXCL10 and CXCL11 levels during primary HIV infection predicts HIV disease progression

Background

Chemokines are small chemotactic cytokines involved in inflammation, cell migration, and immune regulation in both physiological and pathological contexts. Here, we investigated the profile of chemokines during primary HIV infection (PHI).

Methods

Fifty-four participants with blood samples before and during HIV infection and clinical information available were selected from an HIV-negative man who have sex with men (MSM) prospective cohort. Thirty chemokines and 10 cytokines were measured pre- and post-HIV infection in the same individuals using a Bio-Plex Pro™ Human Chemokine Panel.

Results

Levels of 18 chemokines/cytokines changed significantly during PHI relative to pre-HIV infection levels; 14 were up-regulated and 4 down-regulated. Among them, CXCL9, CXCL10, and CXCL11 were the most prominently raised. Levels of CXCL9 and CXCL10 were much higher in the high-set point group (log viral load (lgVL) ≥ 4.5) than those in the low-set point group (lgVL < 4.5) and levels of CXCL9, CXCL10, and CXCL11 were higher in the low-CD4⁺ T-cell count group (CD4⁺ T-cell count ≥ 500). A formula to predict HIV disease progression using a combination panel comprising CXCL9, CXCL10, and CXCL11 was developed, where risk score = 0.007 × CXCL9 + 0.004 × CXCL10 − 0.033 × CXCL11 − 1.724, with risk score values higher than the cutoff threshold (0.5211) indicating more rapid HIV disease progression.

Conclusions

A panel of plasma CXCL9, CXCL10, and CXCL11 measured during primary HIV-1 infection could predict long-term HIV disease prognosis in an MSM group and has potential as a novel biomarker in the clinic.

Impact of Endemic Infections on HIV Susceptibility in Sub-Saharan Africa

Human immunodeficiency virus (HIV) remains a leading cause of global morbidity with the highest burden in Sub-Saharan Africa (SSA). For reasons that are incompletely understood, the likelihood of HIV transmission is several fold higher in SSA than in higher income countries, and most of these infections are acquired by young women. Residents of SSA are also exposed to a variety of endemic infections, such as malaria and various helminthiases that could influence mucosal and systemic immunology. Since these immune parameters are important determinants of HIV acquisition and progression, this review explores the possible effects of endemic infections on HIV susceptibility and summarizes current knowledge of the epidemiology and underlying immunological mechanisms by which endemic infections could impact HIV acquisition. A better understanding of the interaction between endemic infections and HIV may enhance HIV prevention programs in SSA.

Feeding-Related Gut Microbial Composition Associates With Peripheral T-Cell Activation and Mucosal Gene Expression in African Infants

Background

Exclusive breastfeeding reduces the rate of postnatal human immunodeficiency virus (HIV) transmission compared to nonexclusive breastfeeding; however, the mechanisms of this protection are unknown. Our study aimed to interrogate the mechanisms underlying the protective effect of exclusive breastfeeding.

Methods

We performed a prospective, longitudinal study of infants from a high-HIV-prevalence, low-income setting in South Africa. We evaluated the role of any non-breast milk feeds, excluding prescribed medicines on stool microbial communities via 16S rRNA gene sequencing, peripheral T-cell activation via flow cytometry, and buccal mucosal gene expression via quantitative polymerase chain reaction assay.

Results

A total of 155 infants were recruited at birth with mean gestational age of 38.9 weeks and mean birth weight of 3.2 kg. All infants were exclusively breastfed (EBF) at birth, but only 43.5% and 20% remained EBF at 6 or 14 weeks of age, respectively. We observed lower stool microbial diversity and distinct microbial composition in exclusively breastfed infants. These microbial communities, and the relative abundance of key taxa, were correlated with peripheral CD4+ T-cell activation, which was lower in EBF infants. In the oral mucosa, gene expression of chemokine and chemokine receptors involved in recruitment of HIV target cells to tissues, as well as epithelial cytoskeletal proteins, was lower in EBF infants.

Conclusions

These data suggest that nonexclusive breastfeeding alters the gut microbiota, increasing T-cell activation and, potentially, mucosal recruitment of HIV target cells. Study findings highlight a biologically plausible mechanistic explanation for the reduced postnatal HIV transmission observed in EBF infants.

Vitamin D treatment of peripheral blood mononuclear cells modulated immune activation and reduced susceptibility to HIV-1 infection of CD4+ T lymphocytes

INTRODUCTION

Mucosal immune activation, in the context of sexual transmission of HIV-1 infection, is crucial, as the increased presence of activated T cells enhance susceptibility to infection. In this regard, it has been proposed that immunomodulatory compounds capable of modulating immune activation, such as Vitamin D (VitD) may reduce HIV-1 transmission and might be used as a safe and cost-effective strategy for prevention. Considering this, we examined the in vitro effect of the treatment of peripheral blood mononuclear cells (PBMCs) with the active form of VitD, calcitriol, on cellular activation, function and susceptibility of CD4+ T cells to HIV-1 infection.

METHODS

We treated PBMCs from healthy HIV unexposed individuals (Co-HC) and frequently exposed, HIV-1 seronegative individuals (HESNs) from Colombia and from healthy non-exposed individuals from Canada (Ca-HC) with calcitriol and performed in vitro HIV-1 infection assays using X4- and R5-tropic HIV-1 strains respectively. In addition, we evaluated the activation and function of T cells and the expression of viral co-receptors, and select antiviral genes following calcitriol treatment.

RESULTS

Calcitriol reduced the frequency of infected CD4+ T cells and the number of viral particles per cell, for both, X4- and R5-tropic viruses tested in the Co-HC and the Ca-HC, respectively, but not in HESNs. Furthermore, in the Co-HC, calcitriol reduced the frequency of polyclonally activated T cells expressing the activation markers HLA-DR and CD38, and those HLA-DR+CD38-, whereas increased the subpopulation HLA-DR-CD38+. Calcitriol treatment also decreased production of granzyme, IL-2 and MIP-1β by T cells and increased the transcriptional expression of the inhibitor of NF-kB and the antiviral genes cathelicidin (CAMP) and APOBEC3G in PBMCs from Co-HC.

CONCLUSION

Our in vitro findings suggest that VitD treatment could reduce HIV-1 transmission through a specific modulation of the activation levels and function of T cells, and the production of antiviral factors. In conclusion, VitD remains as an interesting potential strategy to prevent HIV-1 transmission that should be further explored.

Natural history, dynamics, and ecology of human papillomaviruses in genital infections of young women: protocol of the PAPCLEAR cohort study

INTRODUCTION

Human papillomaviruses (HPVs) are responsible for one-third of all cancers caused by infections. Most HPV studies focus on chronic infections and cancers, and we know little about the early stages of the infection. Our main objective is to better understand the course and natural history of cervical HPV infections in healthy, unvaccinated and vaccinated, young women, by characterising the dynamics of various infection-related populations (virus, epithelial cells, vaginal microbiota and immune effectors). Another objective is to analyse HPV diversity within hosts, and in the study population, in relation to co-factors (lifestyle characteristics, vaccination status, vaginal microbiota, human genetics).

METHODS AND ANALYSIS

The PAPCLEAR study is a single center longitudinal study following 150 women, aged 18-25 years, for up to 2 years. Visits occur every 2 or 4 months (depending on HPV status) during which several variables are measured, such as behaviours (via questionnaires), vaginal pH, HPV presence and viral load (via qPCR), local concentrations of cytokines (via MesoScale Discovery technology) and immune cells (via flow cytometry). Additional analyses are outsourced, such as titration of circulating anti-HPV antibodies, vaginal microbiota sequencing (16S and ITS1 loci) and human genotyping. To increase the statistical power of the epidemiological arm of the study, an additional 150 women are screened cross-sectionally. Finally, to maximise the resolution of the time series, participants are asked to perform weekly self-samples at home. Statistical analyses will involve classical tools in epidemiology, genomics and virus kinetics, and will be performed or coordinated by the Centre National de la Recherche Scientifique (CNRS) in Montpellier.

ETHICS AND DISSEMINATION

This study has been approved by the Comité de Protection des Personnes Sud Méditerranée I (reference number 2016-A00712-49); by the Comité Consultatif sur le Traitement de l'Information en matière de Recherche dans le domaine de la Santé (reference number 16.504); by the Commission Nationale Informatique et Libertés (reference number MMS/ABD/AR1612278, decision number DR-2016-488) and by the Agence Nationale de Sécurité du Médicament et des Produits de Santé (reference 20160072000007). Results will be published in preprint servers, peer-reviewed journals and disseminated through conferences.

TRIAL REGISTRATION NUMBER

NCT02946346; Pre-results.

Natural Immunity to HIV is associated with Low BLyS/BAFF levels and low frequencies of innate marginal zone like CD1c+ B-cells in the genital tract

BLyS/BAFF is recognized for its role in B-cell ontogenesis, as well as cell fate decision towards the first-line/innate marginal zone (MZ) B-cell pool. Excess BLyS/BAFF is associated with hyperglobulinemia and increased frequencies of activated precursor-like MZ B-cells. Herein, we show that HIV highly-exposed seronegative (HESN) commercial sex workers (CSWs) had lower soluble BLyS/BAFF levels and relative frequencies of BLyS/BAFF expressing cells in their genital mucosa when compared to those from HIV-infected CSWs and HIV-uninfected non-CSWs. Furthermore, we identified genital innate and/or marginal zone (MZ)-like CD1c⁺ B-cells that naturally bind to fully glycosylated gp120, which frequencies were lower in HESNs when compared to HIV-infected CSWs and HIV-uninfected non-CSWs. Although genital levels of total IgA were similar between groups, HESNs had lower levels of total IgG1 and IgG3. Interestingly, HIV-gp41 reactive IgG1 were found in some HESNs. Low genital levels of BLyS/BAFF observed in HESNs may allow for controlled first-line responses, contributing to natural immunity to HIV.

Worldwide, most human immunodeficiency virus (HIV) infections affect women through heterosexual intercourse. We and others have identified African female commercial sex workers (CSWs), who remain seronegative despite high exposition to HIV (HESNs). Innate marginal zone (MZ) B-cells recirculate in humans and have been found in front-line areas such as the sub-epithelial lamina propria of mucosal associated lymphoid tissues. MZ B-cells can bind to fully glycosylated gp120 and produce specific IgG and IgA, and have a propensity for B regulatory potential, which could help both the fight against HIV and maintenance of low inflammatory conditions reported for HESNs. Here we identify genital MZ-like B-cells, which frequencies are lower in the genital tract of HESNs when compared to HIV-infected CSWs and HIV-uninfected non-CSW women. Furthermore, this coincides with significantly lower genital levels of B lymphocyte stimulator (BLyS/BAFF), known to shape the MZ pool and which overexpression leads to MZ deregulation in HIV-infected progressors. HESN individuals provide an exceptional opportunity to determine important clues for the development of protective devices. Here we show that contained BLyS/BAFF levels are concomitant with natural immunity against HIV, and may prevent dysregulated first-line responses. MZ-like B-cells could be harnessed in preventive strategies viewed at soliciting quick first-line to be adjunct to matured long term protection.

A high mucosal blocking score is associated with HIV protection

BACKGROUND

Early steps of HIV infection are mediated by the binding of the envelope to mucosal receptors as α4β7 and the C-type lectins DC-SIGN and langerin. Previously Env-specific B-cell responses have been reported in highly exposed seronegative individuals (HESN).

METHOD

Here, we studied gp120-specific antibodies ability to block HIV interaction with α4β7, DC-SIGN and/or langerinin HESN. New cell-based assays were developed to analyze whether antibodies that can alter gp120 binding to α4β7, DC-SIGN and/or langerin are induced in HESN. A mucosal blocking score (MBS) was defined based on the ability of antibodies to interfere with gp120/α4β7, gp120/DC-SIGN, and gp120/langerin binding. A new MBS was evaluated in a cohort of 86 HESN individuals and compared with HIV+ patients or HIV- unexposed healthy individuals.

RESULTS

Antibodies reducing gp120 binding to both α4β7 and DC-SIGN were present in HESN serum but also in mucosal secretions, whereas antibodies from HIV+ patients facilitated gp120 binding to DC-SIGN. Any correlation was observed between MBS and the capacity of antibodies to neutralize infection of α4β7 CD4+ T cells with primary isolates.

CONCLUSIONS

MBS is significantly associated with protection in HESN and might reflect altered HIV spreading to mucosal-associated lymphoid tissues.

Increased Cervical CD4+CCR5+ T Cells Among Kenyan Sex Working Women Using Depot Medroxyprogesterone Acetate

Depot medroxyprogesterone acetate (DMPA) is the most common hormonal contraceptive used by women in sub-Saharan Africa, however, it has been epidemiologically associated with HIV infections. To assess whether DMPA has an effect on the number and activation of HIV target cells, this study assessed the levels and phenotype of blood- and mucosal-derived HIV target cells among women using DMPA. Thirty-five HIV uninfected women from the Pumwani Sex Worker cohort from Nairobi, Kenya were enrolled in the study (15 using DMPA and 20 not using hormonal contraception). Blood (plasma and peripheral blood mononuclear cells) and cervicovaginal (lavage, cervical cells, and ectocervical biopsies) samples were collected. Cellular phenotype and activation status were determined by flow cytometry, cytokine levels were assessed by bead array and image analysis assessed cell number and phenotype in situ. In blood, the proportion of HIV target cells and activated T cells was lower in DMPA users versus those not using hormonal contraceptives. However, analysis of cervical mononuclear cells showed that DMPA users had elevated levels of activated T cells (CD4⁺CD69⁺) and expressed lower levels of the HIV co-receptor CCR5 on a per cell basis, while tissue samples showed that in the ectocervix, DMPA users had a higher proportion of CD4⁺CCR5⁺ T cells. This study demonstrates that DMPA users had higher levels of activated T cells and HIV target cells in the genital tract. The increased pool of mucosal HIV target cells provides new biological information about the potential impact of DMPA on HIV susceptibility.

A High-throughput Bead-based Affinity Assay Enables Analysis of Genital Protein Signatures in Women At Risk of HIV Infection

Women at high risk of HIV infection, including sex workers and those with active genital inflammation, have molecular signatures of immune activation and epithelial barrier remodeling in samples of their genital mucosa. These alterations in the local immunological milieu are likely to impact HIV susceptibility. We here analyze host genital protein signatures in HIV uninfected women, with high frequency of condom use, living in HIV-serodiscordant relationships. Cervicovaginal secretions from women living in HIV-serodiscordant relationships (n = 62) were collected at three time points over 12 months. Women living in HIV-negative seroconcordant relationships (controls, n = 25) were sampled at one time point. All study subjects were examined for demographic parameters associated with susceptibility to HIV infection. The cervicovaginal samples were analyzed using a high-throughput bead-based affinity assay. Proteins involved in epithelial barrier function and inflammation were increased in HIV-serodiscordant women. By combining several methods of analysis, a total of five proteins (CAPG, KLK10, SPRR3, elafin/PI3, CSTB) were consistently associated with this study group. Proteins analyzed using the affinity set-up were further validated by label-free tandem mass spectrometry in a partially overlapping cohort with concordant results. Women living in HIV-serodiscordant relationships thus had elevated levels of proteins involved in epithelial barrier function and inflammation despite low prevalence of sexually transmitted infections and a high frequency of safe sex practices. The identified proteins are important markers to follow during assessment of mucosal HIV susceptibility factors and a high-throughput bead-based affinity set-up could be a suitable method for such evaluation.

Mucosa: Key Interactions Determining Sexual Transmission of the HIV Infection

In the context of HIV sexual transmission at the genital mucosa, initial interactions between the virus and the mucosal immunity determine the outcome of the exposure. Hence, these interactions have been deeply explored in attempts to undercover potential targets for developing preventative strategies. The knowledge gained has led to propose a hypothetical model for mucosal HIV transmission. Subsequent research studies on this topic further revealed new mechanisms and identified new host-HIV interactions. This review aims at integrating these findings to inform better and update the current model of HIV transmission. At the earliest stage of virus exposure, the epithelial integrity and the presence of antiviral factors are critical in preventing viral entry to the submucosa. However, the virus has been shown to enter to the submucosa in the presence of physical abrasion or via epithelial transmigration using paracellular passage or transcytosis mechanisms. The efficiency of these processes is greater with cell-associated viral inoculums and can be influenced by the presence of viral and immune factors, and by the structure of the exposed epithelium. Once the virus reaches the submucosa, dendritic cells and fibroblasts, as recently described, have been shown in vitro of being capable of facilitating the transfer of viral particles to susceptible cells, leading to viral dissemination, most likely in a trans-infection manner. The presence of activated CD4⁺ T cells in submucosa increases the probability of infection, where the predominant microbiota could be implicated through the modulation of an inflammatory microenvironment. Other factors such as genital fluids and hormones could also play an essential role in HIV transmission. Here, we review the most recent evidence described for mucosal HIV-transmission contributing with the understanding of this phenomenon.

Physiological Changes from Violence-Induced Stress and Trauma Enhance HIV Susceptibility Among Women

PURPOSE OF REVIEW

This theoretical review identifies physiological mechanisms by which violence against women (VAW) may increase women's susceptibility to HIV through trauma, stress, and immune dysfunction.

RECENT FINDINGS

Research documents systemic and local immune responses are related to stress and trauma from abuse across the life course (i.e., childhood, IPV, adulthood re-victimization). Findings are interpreted within a theoretical framework grounded in the Social Stress Theory and the concept of toxic stress, and highlight the current state of the science connecting: (1) VAW to the physiological stress response and immune dysfunction, and (2) the physiological stress response and inflammation to HIV susceptibility and infection in the female reproductive tract. Despite a dearth of research in human subjects, evidence suggests that VAW plays a significant role in creating a physiological environment conducive to HIV infection. We conclude with a discussion of promising future steps for this line of research.

Live attenuated varicella-zoster virus vaccine does not induce HIV target cell activation

BACKGROUND

Varicella-zoster virus (VZV) is under consideration as a promising recombinant viral vector to deliver foreign antigens including HIV. However, new vectors have come under increased scrutiny, since trials with adenovirus serotype 5-vectored (Ad5-vectored) HIV vaccine demonstrated increased HIV risk in individuals with pre-immunity to the vector that was thought to be associated with mucosal immune activation (IA). Therefore, given the prospect of developing an HIV/VZV chimeric vaccine, it is particularly important to define the impact of VZV vaccination on IA.

METHODS

Healthy VZV-seropositive Kenyan women (n = 44) were immunized with high-dose live attenuated VZV vaccine, and we assessed the expression on CD4+ T cells isolated from blood, cervix, and rectum of IA markers including CD38 and HLA-DR and of markers of cell migration and tissue retention, as well as the concentration of genital and intestinal cytokines. A delayed-start group (n = 22) was used to control for natural variations in these parameters.

RESULTS

Although immunogenic, VZV vaccination did not result in significant difference in the frequency of cervical activated (HLA-DR+CD38+) CD4+ T cells (median 1.61%, IQR 0.93%-2.76%) at 12 weeks after vaccination when compared with baseline (median 1.58%, IQR 0.75%-3.04%), the primary outcome for this study. VZV vaccination also had no measurable effect on any of the IA parameters at 4, 8, and 12 weeks after vaccination.

CONCLUSION

This study provides the first evidence to our knowledge about the effects of VZV vaccination on human mucosal IA status and supports further evaluation of VZV as a potential vector for an HIV vaccine.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02514018.

FUNDING

Primary support from the Canadian Institutes for Health Research (CIHR). For other sources, see Acknowledgments.

IP-10 is highly involved in HIV infection

Interferon-γ (IFN-γ)-induced protein 10 (IP-10 or CXCL-10) is a chemokine involved in trafficking immune cells to inflammatory sites. Numerous studies have reported abnormally high plasma IP-10 levels in the context of human immunodeficiency virus (HIV) infection, and IP-10 is considered an important pro-inflammatory factor in the HIV disease process. The data regarding the roles of IP-10 in HIV infection required collation; this review summarizes the biological characteristics of IP-10, the positive association between plasma IP-10 levels and HIV disease progression, the effect of IP-10 on human immune cells, and potential related mechanisms. This review provides important insights into the role of IP-10 in HIV monitoring and treatment.

Natural Killer Cells Adapt to Cytomegalovirus Along a Functionally Static Phenotypic Spectrum in Human Immunodeficiency Virus Infection

Events related to HCMV infection drive accumulation of functionally enhanced CD57^posNKG2C^pos adapted NK cells. We investigated NK cell adaptation to HCMV along a proposed continuum progressing from acute activation through maturation and memory formation towards functional exhaustion. Acute exposure to conditioned medium collected 24 h after HCMV infection (HCMVsn) increased NK cell cytotoxicity for all HCMV-seronegative and seropositive donors tested, with mean 38 and 29% boosts in natural and antibody-dependent cell-mediated cytotoxicity (ADCC), respectively. Increases in NK cell cytotoxicity were completely abrogated by blocking type I interferon (IFN) receptors and equivalent responses occurred with exposure to IFN-α2 alone at the same concentration present in HCMVsn. To study longer term effects of HCMV infection, we focused on three groups of human immunodeficiency virus (HIV)-infected subjects distinguished as HCMV-seronegative or HCMV-seropositive with either high (>20%) or low (<6%) fractions of their NK cells expressing NKG2C. The NK cells of all three HIV-infected groups responded to HCMVsn and IFN-α2 in a manner similar to the NK cells of either HCMV-seronegative or seropositive controls. Neither HCMV status, nor the extent of phenotypic evidence of adaptation to HCMV infection significantly affected mean levels of ADCC or CD16-mediated NK cell degranulation and IFN-γ production compared between the HIV-infected groups. Levels of IFN-γ production correlated significantly with the fraction of NK cells lacking FcεRIγ (FcRγ), but not with the fraction of NK cells expressing NKG2C. There was negligible expression of exhaustion markers Lag-3 and PD-1 on NK cells in any of the groups and no significant difference between groups in the fraction of NK cells expressing Tim-3. The fraction of NK cells expressing Tim-3 was unaffected by CD16 stimulation. Relative to the total NK cell population, responses of Tim-3-expressing cells to CD16 stimulation were variably compromised in HCMV seronegative and seropositive groups. In general, NK cell function in response to signaling through CD16 was well preserved in HIV infection and although HCMV had a clear effect on NK cell FcRγ and NKG2C expression, there was little evidence that the level of adaptation to HCMV infection affected CD16-dependent NK cell signaling in HIV infection.

The immune response to sub-clinical mastitis is impaired in HIV-infected women

Background

Subclinical mastitis (SCM) is relatively common in lactating women and may be associated with HIV shedding in breast milk. The potential association between HIV infection and breast milk immunologic factors and immune response to SCM needs to be addressed.

Methods

In this cross-sectional study, SCM (Na/K ratio > 1) was tested in 165 mature breast milk samples collected from 40 HIV-infected women who didn’t transmit HIV to their child by breastfeeding and 43 HIV-uninfected women enrolled in an interventional cohort in South-Africa (Vertical Transmission Study). The level of 33 immune markers related to Th1/Th2 related response, inflammation and bacterial exposure were compared in ART-naive HIV-infected versus HIV-uninfected women. The associations between HIV infection and SCM on the concentration of immune factors were tested separately by Wilcoxon rank-sum test and corrected for false discovery rate. To control for potential confounder effects and take into account the clustering of breast milk samples from a single woman, multivariate mixed linear models adjusted on child age at the time of sampling were performed for each immune factor.

Results

Subclinical mastitis was detected in 15 (37.5%) HIV-infected women and 10 (23.3%) HIV-uninfected women. In the absence of SCM, the breast milk levels of IP-10 and MIG were higher and IL1-RA lower in HIV-infected women than in HIV-uninfected women (respectively p < 0.001, p = 0.001, p = 0.045). In HIV-uninfected women, SCM was characterized by a robust immune response with higher concentrations of a broad panel of Th1 and inflammatory related immune markers than in samples without SCM. By contrast, in HIV-infected women a limited number of immune markers were increased and lower increases were observed in samples with SCM than without SCM.

Conclusion

HIV infection in ART-naïve women was associated with elevated breast milk levels of IP-10 and MIG, which areTh1-related cytokines induced by IFN-γ. During SCM, a lower and narrower immune response was observed in HIV-infected than HIV-uninfected women, suggesting that HIV infection affects the capacity of the mammary gland to respond to SCM.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1667-4) contains supplementary material, which is available to authorized users.

Ranpirnase Reduces HIV-1 Infection and Associated Inflammatory Changes in a Human Colorectal Explant Model

Ranpirnase (RNP) is a low molecular weight type III endoribonuclease, which demonstrates broad antiviral and antitumor properties. We sought to characterize the antiviral activity of RNP against HIV-1 and to determine whether RNP modulates local inflammatory changes associated with HIV infection in the colorectal explant model. Colorectal explants were incubated for 2 h with HIV-1_BaL, in the presence of increasing concentrations of RNP (0-60 μg/mL). After washing, explants were cultured for 14 days, with supernatant collected at days 3, 7, 10, and 14. All samples were assayed for HIV-1 p24. Additionally, 30 soluble inflammatory biomarkers were assayed in the day 3 supernatant sample. Other biopsies were stimulated with lipopolysaccharides (LPS) (10 μg/mL) in the presence of RNP and soluble biomarkers assayed at day 3. RNP inhibited productive infection of the colorectal explants with HIV-1_BaL and induced a dose-dependent decrease in 15/30 biomarkers. Affected biomarkers included IP-10, MDC, MIP-1α, MIP-1β, TARC, IL12-p40, IL-15, IL-17, IL-1α, IL-7, IFNγ, IL12-p70, IL-1β, IL-4, IL-5, and TNF-β. Similarly, RNP dose-dependent inhibition was demonstrated in 7/30 biomarkers after LPS stimulation, all of which overlapped with HIV-1_BaL-induced biomarker changes. The ability of RNP to inhibit both colorectal explant HIV-1_BaL infection and inflammatory changes associated with HIV-1 infection makes RPN a promising agent for topical rectal pre-exposure prophylaxis.

The relationship between sex hormones, the vaginal microbiome and immunity in HIV-1 susceptibility in women

The role of sex hormones in regulating immune responses in the female genital tract has been recognized for decades. More recently, it has become increasingly clear that sex hormones regulate susceptibility to sexually transmitted infections through direct and indirect mechanisms involving inflammation and immune responses. The reproductive cycle can influence simian/human immunodeficiency virus (SHIV) infections in primates and HIV-1 infection in ex vivo cervical tissues from women. Exogenous hormones, such as those found in hormonal contraceptives, have come under intense scrutiny because of the increased susceptibility to sexually transmitted infections seen in women using medroxyprogesterone acetate, a synthetic progestin-based contraceptive. Recent meta-analyses concluded that medroxyprogesterone acetate enhanced HIV-1 susceptibility in women by 40%. In contrast, estradiol-containing hormonal contraceptives were not associated with increased susceptibility and some studies reported a protective effect of estrogen on HIV/SIV infection, although the underlying mechanisms remain incompletely understood. Recent studies describe a key role for the vaginal microbiota in determining susceptibility to sexually transmitted infections, including HIV-1. While Lactobacillus spp.-dominated vaginal microbiota is associated with decreased susceptibility, complex microbiota, such as those seen in bacterial vaginosis, correlates with increased susceptibility to HIV-1. Interestingly, sex hormones are inherently linked to microbiota regulation in the vaginal tract. Estrogen has been postulated to play a key role in establishing a Lactobacillus-dominated microenvironment, whereas medroxyprogesterone acetate is linked to hypo-estrogenic effects. The aim of this Review is to contribute to a better understanding of the sex-hormone-microbiome-immunity axis, which can provide key information on the determinants of HIV-1 susceptibility in the female genital tract and, consequently, inform HIV-1 prevention strategies.

Using safe, affordable and accessible non-steroidal anti-inflammatory drugs to reduce the number of HIV target cells in the blood and at the female genital tract

INTRODUCTION

At its basic level, HIV infection requires a replication-competent virus and a susceptible target cell. Elevated levels of vaginal inflammation has been associated with the increased risk of HIV infection as it brings highly activated HIV target cells (CCR5+CD4+ T cells; CCR5+CD4+CD161+ Th17 T cells) to the female genital tract (FGT) where they interact with HIV. Decreased HIV risk has been associated with a phenotype of decreased immune activation, called immune quiescence, described among Kenyan female sex workers who were intensely exposed to HIV yet remain uninfected. Current prevention approaches focus on limiting viral access. We took the novel HIV prevention approach of trying to limit the number of HIV target cells in the genital tract by reducing inflammation using safe, affordable and globally accessible anti-inflammatory drugs.

METHODS

We hypothesized that the daily administration of low doses of acetylsalicylic acid (ASA 81 mg) or hydroxychloroquine (HCQ 200 mg) would reduce inflammation thereby decreasing HIV target cells at the FGT. Low-risk HIV seronegative women from Nairobi, Kenya were randomized for six weeks therapy of ASA (n = 37) or HCQ (n = 39) and tested to determine the impact on their systemic and mucosal immune environment.

RESULTS

The results showed that HCQ use was associated with a significant reduction in the proportion of systemic T cells that were CCR5+CD4+ (p = 0.01) and Th17 (p = 0.01). In the ASA arm, there was a 35% and 28% decrease in the proportion of genital T cells that were CD4+CCR5+ (p = 0.017) and Th17 (p = 0.04) respectively. Proteomic analyses of the cervical lavage showed ASA use was associated with significantly reduced amount of proteins involved in the inflammatory response and cell recruitment at the mucosa, although none of the individual proteins passed multiple comparison correction. These changes were more apparent in women with Lactobacillus dominant microbiomes.

CONCLUSION

Together, these data indicate that taking low-dose ASA daily was associated with significant reduction in HIV target cells at the FGT. This study provides proof-of-concept for a novel HIV-prevention approach that reducing inflammation using safe, affordable and globally accessible non-steroidal anti-inflammatory agents is associated with significant reduction in the proportion of HIV-target cells at the FGT.

Natural Immunity to HIV: A Template for Vaccine Strategies

Africa accounts for the majority of global human immunodeficiency virus (HIV) infections, most of which affect women through heterosexual intercourse. Currently, there is no cure for HIV and the development of vaccines and microbicides remains the best solution to eradicate the pandemic. We and others have identified HIV highly-exposed seronegative (HESN) individuals among African female commercial sex workers (CSWs). Analyses of genital samples from HESNs have demonstrated potent innate and anti-inflammatory conditions, HIV-specific CD4⁺ and CD8⁺ T-cells as well as immunoglobulins (Igs), and increased regulatory cell populations, all of which support a delicate balance between strength and control against HIV intrusion. Moreover, we have recently shown that frequencies of innate marginal zone (MZ) B-cells are decreased in the blood of HESNs when compared to HIV-uninfected non-CSW women, suggesting their recruitment to peripheral sites. This coincides with the fact that levels of B lymphocyte stimulator (BLyS/BAFF), known to shape the MZ pool and whose overexpression leads to MZ deregulation in HIV-infected progressors, are significantly lower in the blood of HESNs when compared to both HIV-infected CSWs and HIV-uninfected non-CSW women. Interestingly, MZ B-cells can bind HIV gp120 and produce specific IgG and IgA, and have a propensity for B regulatory potential, which could help both the fight against HIV and maintenance of low inflammatory conditions in HESNs. HESN individuals provide an exceptional opportunity to identify important clues for the development of protective devices, and efforts should aim at soliciting immune responses observed in the context of their natural immunity to HIV.

Implant delivering hydroxychloroquine attenuates vaginal T lymphocyte activation and inflammation

Evidence suggests that women who are naturally resistant to HIV infection exhibit low baseline immune activation at the female genital tract (FGT). This "immune quiescent" state is associated with lower expression of T-cell activation markers, reduced levels of gene transcription and pro-inflammatory cytokine or chemokine production involved in HIV infection while maintaining an intact immune response against pathogens. Therefore, if this unique immune quiescent state can be pharmacologically induced locally, it will provide an excellent women-oriented strategy against HIV infection To our knowledge, this is the first research article evaluating in vivo, an innovative trackable implant that can provide controlled delivery of hydroxychloroquine (HCQ) to successfully attenuate vaginal T lymphocyte activation and inflammation in a rabbit model as a potential strategy to induce an "immune quiescent" state within the FGT for the prevention of HIV infection. This biocompatible implant can deliver HCQ above therapeutic concentrations in a controlled manner, reduce submucosal immune cell recruitment, improve mucosal epithelium integrity, decrease protein and gene expression of T-cell activation markers, and attenuate the induction of key pro-inflammatory mediators. Our results suggest that microbicides designed to maintain a low level of immune activation at the FGT may offer a promising new strategy for reducing HIV infection.

Localized cyclical variations in immunoproteins in the female genital tract and the implications on the design and assessment of mucosal infection and therapies

PROBLEM

Fluctuating hormones regulate reproductive processes in the female genital tract. Consequent changes in the local immunological environment are likely to affect cellular interaction with infectious agents and the assessment of therapies that target mucosal infections.

METHOD OF STUDY

We compared Softcup and Weck-Cel sampling protocols and assessed the changes in the concentrations of 39 soluble proteins with menstrual cycle progression in the mucosal and peripheral compartments.

RESULTS

We demonstrate that the mucosal immunological profile is distinct from serum with inflammatory and migratory signatures that are localized throughout the cycle. The analytes highlighted in the mucosal compartment were generally highest at the follicular phase with a tendency to fall as the cycle progressed through ovulation to the luteal phase.

CONCLUSION

Our results underscore the need to consider these localized cyclical differences in studies aimed at assessing the outcome of disease and the efficacy of mucosal vaccines and other therapies.

High CXCL10/IP-10 levels are a hallmark in the clinical evolution of the HIV infection

The aim of this study was to investigate the modulation of plasma CXCL10, CCL20, CCL22, CCL2, CCL17 and CCL24 levels in HIV-positive patients grouped according to extreme phenotypes of progression to AIDS, and at different stages of HIV infection. HIV-positive individuals with extreme phenotypes of AIDS progression (n=58) at different clinical stages (chronic individuals, both pre-HAART and under-HAART) and HIV-negative controls (n=20) were evaluated. Additionally, HIV-positive individuals that initiated HAART with >350CD4⁺T-cells/mm³ were compared with those who initiated treatment with <350CD4⁺T-cells/mm³. Plasma levels of six chemokines were quantified by a Luminex assay. Higher CXCL10 levels were observed in individuals immediately before their CD4⁺T-cell levels were indicative for HAART (pre-HAART), independently of their progressor status, i.e. slow (SPs) or rapid progressors (RPs). SPs pre-HAART showed higher CXCL10 levels compared to elite controllers and RPs under HAART (p_c=0.009 and p_c=0.007, respectively). CXCL10 levels were higher in SPs HAART CD4<350 (initiated HAART with <350 CD4⁺T-cells) when compared with SPs HAART CD4>350 (initiated HAART with >350 CD4⁺T-cells) (1096 vs. 360.33pg/mL, p=0.0101). Normalisation of CXCL10 levels seems to depend on the CD4⁺T-cell nadir at HAART initiation. CCL20 levels were higher in chronic SPs, SPs pre-HAART, SPs HAART and RPs HAART compared with the HIV-negative controls, indicating persistent CCL20 expression. In conclusion, our results indicate that CXCL10 levels are a hallmark in the clinical evolution of HIV infection. However, our results must be verified in a study evaluating a larger number of AIDS progressors.

Whole genome sequencing of extreme phenotypes identifies variants in CD101 and UBE2V1 associated with increased risk of sexually acquired HIV-1

Host genetic variation modifying HIV-1 acquisition risk can inform development of HIV-1 prevention strategies. However, associations between rare or intermediate-frequency variants and HIV-1 acquisition are not well studied. We tested for the association between variation in genic regions and extreme HIV-1 acquisition phenotypes in 100 sub-Saharan Africans with whole genome sequencing data. Missense variants in immunoglobulin-like regions of CD101 and, among women, one missense/5' UTR variant in UBE2V1, were associated with increased HIV-1 acquisition risk (p = 1.9x10-4 and p = 3.7x10-3, respectively, for replication). Both of these genes are known to impact host inflammatory pathways. Effect sizes increased with exposure to HIV-1 after adjusting for the independent effect of increasing exposure on acquisition risk.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00194519; NCT00557245.

Chemokines and Chemokine Receptors: Accomplices for Human Immunodeficiency Virus Infection and Latency

Chemokines are small chemotactic cytokines that are involved in the regulation of immune cell migration. Multiple functional properties of chemokines, such as pro-inflammation, immune regulation, and promotion of cell growth, angiogenesis, and apoptosis, have been identified in many pathological and physiological contexts. Human immunodeficiency virus (HIV) infection is characterized by persistent inflammation and immune activation during both acute and chronic phases, and the "cytokine storm" is one of the hallmarks of HIV infection. Along with immune activation after HIV infection, an extensive range of chemokines and other cytokines are elevated, thereby generating the so-called "cytokine storm." In this review, the effects of the upregulated chemokines and chemokine receptors on the processes of HIV infection are discussed. The objective of this review was to focus on the main chemokines and chemokine receptors that have been found to be associated with HIV infection and latency. Elevated chemokines and chemokine receptors have been shown to play important roles in the HIV life cycle, disease progression, and HIV reservoir establishment. Thus, targeting these chemokines and receptors and the other proteins of related signaling pathways might provide novel therapeutic strategies, and the evidence indicates a promising future regarding the development of a functional cure for HIV.

Protocol of a randomised controlled trial characterising the immune responses induced by varicella-zoster virus (VZV) vaccination in healthy Kenyan women: setting the stage for a potential VZV-based HIV vaccine

INTRODUCTION

A protective HIV vaccine would be expected to induce durable effector immune responses at the mucosa, restricting HIV infection at its portal of entry. We hypothesise that use of varicella-zoster virus (VZV) as an HIV delivery vector could generate sustained and robust tissue-based immunity against HIV antigens to provide long-term protection against HIV. Given that HIV uniquely targets immune-activated T cells, the development of human vaccines against HIV must also involve a specific examination of the safety of the vector. Thus, we aim to evaluate the effects of VZV vaccination on the recipients' immune activation state, and on VZV-specific circulating humoral and cellular responses in addition to those at the cervical and rectal mucosa.

METHODS AND ANALYSIS

This open-label, randomised, longitudinal crossover study includes healthy Kenyan VZV-seropositive women at low risk for HIV infection. Participants receive a single dose of a commercial live-attenuated VZV_Oka vaccine at either week 0 (n=22) or at week 12 (n=22) of the study and are followed for 48 and 36 weeks postvaccination, respectively. The primary outcome is the change on cervical CD4⁺ T-cell immune activation measured by the coexpression of CD38 and HLA-DR 12 weeks postvaccination compared with the baseline (prevaccination). Secondary analyses include postvaccination changes in VZV-specific mucosal and systemic humoral and cellular immune responses, changes in cytokine and chemokine measures, study acceptability and feasibility of mucosal sampling and a longitudinal assessment of the bacterial community composition of the mucosa.

ETHICS AND DISSEMINATION

The study has ethical approval from Kenyatta National Hospital/University of Nairobi Ethics and Research Committee, the University of Toronto Research Ethics Board and by Kenyan Pharmacy and Poisons Board. Results will be presented at conferences, disseminated to participants and stakeholders as well as published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT02514018. Pre-results.