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

Effect of progestin-based contraceptives on HIV-associated vaginal immune biomarkers and microbiome in adolescent girls

Adolescent girls bear a disproportionate burden of both the HIV epidemic and unintended pregnancies; yet important questions remain unanswered regarding the effects of hormonal contraceptives on the vaginal immune microenvironment, which can impact HIV susceptibility in this group. Multiple studies report genital immune alterations associated with the progestin-based contraceptive Depot medroxyprogesterone acetate (DMPA) in adult women, but there is little available data in adolescents. The objective of this longitudinal cohort study was to evaluate the effects of short-term use of three progestin-based contraceptives, levonorgestrel intrauterine device (LNG-IUD), subdermal etonogestrel (ETNG), and injectable DMPA, on HIV-associated vaginal immune biomarkers and microbiome in adolescent girls. Fifty-nine sexually active, HIV-uninfected girls aged 15-19, were recruited from the Washington DC metro area and self-selected into Control (condoms only), combined oral contraceptive pills, LNG-IUD, ETNG and DMPA groups. Vaginal swabs were collected at baseline prior to contraceptive use and at 3-month follow-up visit. Vaginal secretions were tested for pro-inflammatory (IL-1α, IL-1β, TNF-α, IL-6, IL-8, MIP-3α, IP-10, RANTES, MIP-1α, MIP-1β) and anti-inflammatory/anti-HIV (Serpin-A1, Elafin, Beta-Defensin-2, SLPI) immune biomarkers using ELISA and for anti-HIV activity using TZM-bl assay. Vaginal microbiome was evaluated using 16S rRNA gene sequencing. Data were analyzed using SAS Version 9. Among the 34 participants who completed both visits, no significant changes in median biomarker concentrations, HIV inhibition and microbiome composition were observed between baseline and follow-up visits for any of the contraceptive groups. IL-8 (p<0.01), MIP-3α (0.02), Elafin (p = 0.03) and RANTES (p<0.01) differed significantly by race whereas IL-6 was significantly different by age (p = 0.03). We conclude that 3-month use of LNG-IUD, ETNG and DMPA have minimal effects on adolescent vaginal immune microenvironment, and therefore unlikely to impact HIV risk. Future studies with larger sample size and longer follow-up are recommended to continue to evaluate effects of contraceptives on the lower genital tract immunity and susceptibility to sexually transmitted infections.

The vaginal microbiome and HIV transmission dynamics

PURPOSE OF REVIEW

Among women, having a nonoptimal, highly diverse vaginal microbiome dominated by bacteria other than optimal Lactobacillus species such as L. crispatus or L. jensenii predicts HIV transmission. Reducing HIV acquisition among women requires a better understanding of the mechanisms through which the vaginal microbiome impacts HIV transmission dynamics and how to more effectively treat and intervene. Technological advancements are improving the ability of researchers to fully characterize interacting host-bacteria mechanisms. Consequently, the purpose of this review was to summarize the most innovative research on the vaginal microbiome and its role in HIV transmission in the past year.

RECENT FINDINGS

Studies combining multiomics, experimental, and translational approaches highlight the associations of a nonoptimal microbiome with maladaptive alterations in immune cell functioning, vaginal metabolites, host cell transcription, mucosal immunity, and epithelial barrier integrity. While there are multiple mechanisms proposed to increase HIV acquisition risk, there are virtually zero acceptable and effective treatments to improve the vaginal microbiome and immunity.

SUMMARY

Women-centered solutions to modify the vaginal microbiome and bacterial metabolites should continue to be explored as a mechanism to reduce HIV acquisition.

HIV seroconversion among female sex workers: retrospective cohort study from a large-scale HIV prevention and sexual and reproductive health program in Tanzania

Introduction

In 2016, UNAIDS set ambitious targets to reduce global HIV infections by 75% by 2020 and 90% by 2030, based on the 2.1 million new infections reported in 2010. However, by 2022, new HIV infections had only decreased by 38%, from 2.1 million in 2010 to 1.3 million in 2022, raising concerns about reaching the 2030 goal. Female sex workers (FSWs) in sub-Saharan Africa face a disproportionately high risk of HIV acquisition, contributing 5%-20% of all new infections in several countries in the region. This analysis investigates HIV seroconversion and associated factors among FSWs, offering insights into critical interventions for preventing HIV transmission in this population and advancing the goal of ending the HIV pandemic by 2030.

Methods

We conducted a retrospective cohort study involving 17,977 FSWs who initially tested HIV negative upon enrollment in the Sauti project between October 2016 and September 2018. HIV incidence rates were calculated by dividing the number of new HIV cases by observed person-time within the cohort. Cox regression analysis identified factors associated with seroconversion.

Results

The study revealed an HIV incidence rate of 8.6 per 100 person-years among FSWs [95% confidence interval (CI): 8.1-9.1]. Factors independently associated with HIV seroconversion included age 35 years or older [adjusted hazard ratio (aHR): 2.53; 95% CI: 2.03-3.14], unprotected sex (aHR: 1.27; 95% CI: 1.13-1.42), STI symptoms (aHR: 1.99; 95% CI: 1.67-2.38), and alcohol consumption before sex (aHR: 1.20; 95% CI: 1.07-1.34).

Conclusion

Targeted interventions are vital in curbing HIV transmission among FSWs, with a focus on expanding access to primary HIV prevention services, particularly for older FSWs who face heightened risk. Tailored sexual health education programs are imperative to encourage consistent condom use and enable informed decision-making. Accessible and timely STI screening and treatment services are crucial to mitigate HIV transmission risk. Collaborative partnerships between healthcare providers, community organizations, and government agencies are essential in implementing these interventions among FSWs.

Novel point-of-care cytokine biomarker lateral flow test for the screening for sexually transmitted infections and bacterial vaginosis: study protocol of a multicentre multidisciplinary prospective observational clinical study to evaluate the performance and feasibility of the Genital InFlammation Test (GIFT)

INTRODUCTION

A prototype lateral flow device detecting cytokine biomarkers interleukin (IL)-1α and IL-1β has been developed as a point-of-care test-called the Genital InFlammation Test (GIFT)-for detecting genital inflammation associated with sexually transmitted infections (STIs) and/or bacterial vaginosis (BV) in women. In this paper, we describe the rationale and design for studies that will be conducted in South Africa, Zimbabwe and Madagascar to evaluate the performance of GIFT and how it could be integrated into routine care.

METHODS AND ANALYSIS

We will conduct a prospective, multidisciplinary, multicentre, cross-sectional and observational clinical study comprising two distinct components: a biomedical ('diagnostic study') and a qualitative, modelling and economic ('an integration into care study') part. The diagnostic study aims to evaluate GIFT's performance in identifying asymptomatic women with discharge-causing STIs (Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Trichomonas vaginalis (TV) and Mycoplasma genitalium (MG)) and BV. Study participants will be recruited from women attending research sites and family planning services. Several vaginal swabs will be collected for the evaluation of cytokine concentrations (ELISA), STIs (nucleic acid amplification tests), BV (Nugent score) and vaginal microbiome characteristics (16S rRNA gene sequencing). The first collected vaginal swab will be used for the GIFT assay which will be performed in parallel by a healthcare worker in the clinic near the participant, and by a technician in the laboratory. The integration into care study aims to explore how GIFT could be integrated into routine care. Four activities will be conducted: user experiences and/or perceptions of the GIFT device involving qualitative focus group discussions and in-depth interviews with key stakeholders; discrete choice experiments; development of a decision tree classification algorithm; and economic evaluation of defined management algorithms.

ETHICS AND DISSEMINATION

Findings will be reported to participants, collaborators and local government for the three sites, presented at national and international conferences, and disseminated in peer-reviewed publications.The protocol and all study documents such as informed consent forms were reviewed and approved by the University of Cape Town Human Research Ethics Committee (HREC reference 366/2022), Medical Research Council of Zimbabwe (MRCZ/A/2966), Comité d'Ethique pour la Recherche Biomédicale de Madagascar (N° 143 MNSAP/SG/AMM/CERBM) and the London School of Hygiene and Tropical Medicine ethics committee (LSHTM reference 28046).Before the start, this study was submitted to the Clinicaltrials.gov public registry (NCT05723484).

TRIAL REGISTRATION NUMBER

NCT05723484.

The vaginal microbiota of women living with HIV on suppressive antiretroviral therapy and its relation to high-risk human papillomavirus infection

BACKGROUND

Few studies have investigated the vaginal microbiota (VM) in women living with HIV (WLWH) in the context of high-risk human papillomavirus (HR-HPV) infection, even though WLWH are at an increased risk of HPV-related malignancies, including cervical cancer. To explore the impact of HIV and HPV infection on the VM in WLWH, we determined the prevalence of HR-HPV infection and cervical cytologic abnormalities in a cohort of 44 WLWH and 39 seronegative-women (SNW), characterized the vaginal microbiota by 16S sequencing, assessed genital inflammation and systemic immune activation by multiplex bead assay and flow cytometry, respectively. Finally, we explored relationships between bacterial richness and diversity, the top 20 bacterial genera, genital inflammation and systemic immune activation.

RESULTS

We found that HR-HPV prevalence was similar between WLWH and SNW. High-grade squamous intraepithelial lesions (HSIL) were only detected in WLWH negative for HR-HPV infection. In regression analyses, no risk factors were identified. Women co-infected with HIV and HR-HPV had the highest level of systemic immune activation, and these levels were significantly different compared with SNW without HR-HPV infection. Lactobacillus iners was the dominant Lactobacillus species in WLWH and SNW alike.

CONCLUSION

We found no evidence of differences in vaginal microbial richness and diversity, microbial community structure, and genital inflammation by HIV, HPV, or HIV and HPV status.

Women for science and science for women: Gaps, challenges and opportunities towards optimizing pre-exposure prophylaxis for HIV-1 prevention

Preventing new HIV infections remains a global challenge. Young women continue to bear a disproportionate burden of infection. Oral pre-exposure prophylaxis (PrEP), offers a novel women-initiated prevention technology and PrEP trials completed to date underscore the importance of their inclusion early in trials evaluating new HIV PrEP technologies. Data from completed topical and systemic PrEP trials highlight the role of gender specific physiological and social factors that impact PrEP uptake, adherence and efficacy. Here we review the past and current developments of HIV-1 prevention options for women with special focus on PrEP considering the diverse factors that can impact PrEP efficacy. Furthermore, we highlight the importance of inclusion of female scientists, clinicians, and community advocates in scientific efforts to further improve HIV prevention strategies.

Characterization of the Ovine Vaginal Microbiome and Inflammation Patterns as an Improved Testing Model of Human Vaginal Irritation

The development of therapies targeted to improve the health of women has utilized direct vaginal delivery as a more effective and less toxic method of protection from HIV and other pathogens. Vaginal applicants and delivery devices that provide sustained effects have been met with increasing acceptability, but the efficacy and toxicity outcomes have not been successfully predicted by preclinical in vitro studies and animal modeling. We have explored the utilization of sheep as a model for testing the safety of vaginal applicants and devices based on spatial and structural similarities to the human vagina. As recently noted by the FDA, an additional safety measure is an impact on the vaginal microbiome (VMB) that is known to contribute to vaginal health and influence pathogen susceptibility and drug metabolism. To advance the utility of the sheep vaginal model, we completed a thorough molecular characterization of the ovine VMB utilizing both next-generation sequencing (NGS) and PCR methods. The process also created a custom PCR array to quantify ovine VMB community profiles in an affordable, higher throughput fashion. The results from vaginal swabs (&gt;475 samples) collected from non-pregnant crossbred Dorset and Merino ewes treated with selected vaginal applicants or collected as sham samples established 16 VMB community types (VMB CTs). To associate VMB CTs with eubiosis or dysbiosis, we also completed custom ELISAs for six cytokines identifying IL1B, IL8, TNFa, and CXCL10 as useful markers to support the characterization of ovine vaginal inflammation. The results indicated that Pasteurella, Actinobacillus, Pseudomonas, Bacteroides, Leptotrichia, and E. coli were common markers of eubiosis (low inflammatory marker expression), and that Haemophilus, Ureaplasma, and Corynebacterium were associated with dysbiosis (high cytokine levels). Utilizing the optimized workflow, we also confirmed the utility of three commonly used vaginal applicants for impact on the VMB and inflammatory state, producing a dataset that supports the recommendation for the use of sheep for testing of vaginal applicants and devices as part of preclinical pipelines.