The Impact of Sex Work Interruption on Blood-Derived T Cells in Sex Workers from Nairobi, Kenya

Practical 10-Color T-Cell Panel for Phenotyping Diverse Populations Using Spectral Flow Cytometry: A Beginner's Guide

Flow cytometry stands as the most employed high-throughput single-cell analysis technique, facilitating the profiling of remarkably diverse samples, such as blood, bone marrow and body fluids. In addition, it allows for the discrimination of diverse immune cell subsets, including infrequently encountered types like T regulatory cells and exhausted CD28Null T cells. However, analyzing rare immune cell subsets with conventional flow cytometry poses challenges stemming from factors like fluorophore overlap, compensation issues, and limited flexibility in fluorophore selection. Therefore, spectral flow cytometry offers advantages over traditional flow cytometry. It measures the full emission spectrum and then separates it to identify different fluorochromes. This enables the use of fluorochromes with significant overlap in a single test, allowing for the analysis of more protein markers. Following this, spectral technology employs precise calculations to separate individual fluorochromes, thereby enabling the detection and elimination of autofluorescent signals originating from cells within the entire emission spectrum. This capability is pivotal in achieving deep phenotyping of immune cells with the requisite sensitivity and resolution essential for monitoring the immune systems of patients with compromised immunity, such as cancer and autoimmune disorders. Additionally, it allows for the exploration of interactions between distinct immune subsets. In this context, we introduce an optimized protocol utilizing spectral flow cytometry for precise T-cell characterization and differentiation, encompassing the assessment of their activation states. Furthermore, this protocol extends its applicability to the identification of less common circulating T-cell populations, notably T-regulatory and CD28Null T cells, following autofluorescence correction within the spectrum. This protocol provides a set of steps and reagents for the surface and intracellular staining of human T cells using whole peripheral blood. The spectral-based design of this panel allows for its applicability to other spectral machines, providing a versatile and efficient tool for T-cell analysis. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Achieving optimal staining through effective antibody titration Basic Protocol 2: Single-cell staining Basic Protocol 3: Comprehensive panel staining post-titration and spectral library integration.

Dyspareunia, signs of epithelial disruption, sexual abstinence, and HIV status in female sex workers in Nairobi: a cross-sectional study

BACKGROUND

Epithelial trauma is a risk factor of HIV infection in men who have sex with men (MSM) and female sex workers (FSWs). Painful intercourse may be indicative of epithelial tissue disruption. Previous studies on a cohort of Kenyan FSWs established an association between prolonged sexual abstinence and late HIV seroconversion. Our research objective was to establish whether there is a relationship between HIV serostatus and signs of epithelial disruption and between HIV serostatus and sexual abstinence behaviour.

METHODS

Participants were selected from a Nairobi health facility. A structured questionnaire was administered to 322 FSWs, who provided data on HIV status, sexual behaviour, abstinence intervals and the level of sexual dysfunction. Sexual dysfunction scores were created using parts of the Female Sexual Function Index (FSFI-19). Additional questions addressed epithelial trauma signs. Descriptive data analysis, bivariate and multivariate logistic regression were used to describe the study population and determine factors associated with living with HIV. Potential factors influencing sexual dysfunction were assessed by FSWs via self-rating.

RESULTS

36% of FSWs reported discomfort or pain during vaginal penetration half the time. 44% noticed genital bleeding half the time. Vaginal tenderness was experienced by 70.6% half the time during or after intercourse. Variables predictive of living with HIV on multivariate analysis included a medium and high score of discomfort or pain during and following vaginal penetration (medium: AOR 2.288, p-value 0.032, 95% CI 1.075-4.871; high: AOR 3.044, p-value 0.031, 95% CI 1.110-8.348). No significant association of HIV status with past abstinence durations as reported by participants could be established in the multivariate analysis. A majority of FSWs agreed that steady partnerships (81% agreement), regularity of intercourse (74%), foreplay (72%) and lubricants (65%) alleviated dyspareunia.

CONCLUSIONS

Recurrent exposure to blood during sex was highly prevalent in FSWs, as was sexual dysfunction. Complaint levels were associated with living with HIV, providing evidence that reducing sexual dysfunctions may prevent HIV transmission. Preventive initiatives may be created that address sexual dysfunction in key populations and general populations with a high HIV prevalence. Subjective assessments indicate that prevention may include the promotion of sexual intercourse regularity, foreplay, and lubricant use.

Low-Dose Acetylsalicylic Acid Reduces T Cell Immune Activation: Potential Implications for HIV Prevention

Introduction

Acetylsalicylic acid (ASA) is a well-known and safe anti-inflammatory. At low-dose, it is prescribed to prevent secondary cardiovascular events in those with pre-existing conditions and to prevent preeclampsia. Little is known about how low-dose ASA affects the immune response. In this study, we followed women to assess how ASA use modifies T cells immune phenotypes in the blood and at the genital tract.

Methods

HIV uninfected women from Kenya were enrolled in this study and followed for one month to assess baseline responses including systemic/mucosal baseline immune activation. Participants then received 81mg of ASA daily for 6 weeks to assess changes to T cell immune activation (systemic and mucosal) relative to baseline levels.

Results

The concentration of ASA measured in the blood was 58% higher than the level measured at the female genital tract. In the blood, the level of ASA was inversely correlated with the following: the proportion of Th17 expressing HLA-DR (p=0.04), the proportion of effector CD4⁺ T cells expressing CCR5 (p=0.03) and the proportion of CD8⁺Tc17 expressing CCR5 (p=0.04). At the genital tract, ASA use correlated with a decreased of activated CD4⁺T cells [CD4⁺CCR5⁺CD161⁺ (p=0.02) and CD4⁺CCR5⁺CD95⁺ (p=0.001)].

Conclusion

This study shows that ASA use impacts the immune response in both the systemic and genital tract compartments. This could have major implications for the prevention of infectious diseases such as HIV, in which the virus targets activated T cells to establish an infection. This could inform guidelines on ASA use in women.

Clinical Trial Registration

ClinicalTrials.gov, identifier NCT02079077.

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.

Association of high-risk sexual behaviour with diversity of the vaginal microbiota and abundance of Lactobacillus

Objective

To compare the vaginal microbiota of women engaged in high-risk sexual behaviour (sex work) with women who are not engaged in high-risk sexual behaviour. Diverse vaginal microbiota, low in Lactobacillus species, like those in bacterial vaginosis (BV), are associated with increased prevalence of sexually transmitted infections (STIs) and human immunodeficiency virus (HIV) acquisition. Although high-risk sexual behaviour increases risk for STIs, the vaginal microbiota of sex workers is understudied.

Methods

A retrospective cross-sectional study was conducted comparing vaginal microbiota of women who are not engaged in sex work (non-sex worker controls, NSW, N = 19) and women engaged in sex work (female sex workers, FSW, N = 48), using Illumina sequencing (16S rRNA, V3 region).

Results

Bacterial richness and diversity were significantly less in controls, than FSW. Controls were more likely to have Lactobacillus as the most abundant genus (58% vs. 17%; P = 0.002) and composition of their vaginal microbiota differed from FSW (PERMANOVA, P = 0.001). Six microbiota clusters were detected, including a high diversity cluster with three sub-clusters, and 55% of women with low Nugent Scores fell within this cluster. High diversity was observed by 16S sequencing in FSW, regardless of Nugent Scores, suggesting that Nugent Score may not be capable of capturing the diversity present in the FSW vaginal microbiota.

Conclusions

High-risk sexual behaviour is associated with diversity of the vaginal microbiota and lack of Lactobacillus. These factors could contribute to increased risk of STIs and HIV in women engaged in high-risk sexual behaviour.