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

Abstract

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.

Keywords: DMPA; HIV target cells; T-cell activation; commercial sex workers; endocervix; inflammation.

Figure 1

Study Profile. Flow chart depicting the screening and enrolment process for study participants.

Figure 2

Gating strategy for analysis of CCR5 and activation marker expression on CD4⁺ T cells. Representative plots show gating on singlets, lymphocytes, live cells, internal quality control for consistency in cell flow, CD3+ cells and CD3+CD4+ cells in PBMC (A) and CMC (B). Gating for activation markers and CCR5 was done on the CD4+ T cell fraction of PBMC and CMC. PBMC, Peripheral Blood Mononuclear Cells; CMC, Cervical Mononuclear Cells.

Figure 3

The effect of sex work on T cell activation and CCR5 expression among women not using hormonal contraceptives. (A) Comparison of CMCs among FSW and non-sex workers not using any HC and (B) Comparison of PBMCs among FSW and non-FSW using DMPA. Bars are median, interquartile range. CMC, Cervical Mononuclear Cells; PBMC, Peripheral Blood Mononuclear Cells; FSW, Female Sex Workers; MFI, median fluorescence intensity; DMPA, depot-medroxyprogesterone acetate; HC, hormonal contraception.

Figure 4

The effect of sex work on cytokine expression among women not using any hormonal contraceptives. (A) Genital expression of IFNγ between sex workers and non-sex workers not using any HC and (B) Comparison of plasma cytokines between sex workers and non sex workers using no HC. Bars are median, interquartile range. FSW, Female Sex Workers; DMPA, depot-medroxyprogesterone acetate; HC, hormonal contraception; CVL, Cervicovaginal Lavage.

Figure 5

Immunophenotyping of cervical mononuclear cells (CMCs). (A) Comparison of CMCs of sex workers using DMPA versus no HC and (B) Comparison of CMCs of non-sex workers using DMPA versus no HC. Bars are median, interquartile range. FSW, Female Sex Workers; DMPA, depot-medroxyprogesterone acetate; HC, hormonal contraception; NS, not significant.

Figure 6

Immunophenotyping of peripheral blood mononuclear cells (PBMCs). (A) Comparison of CD4+ T cells of sex workers using DMPA versus no HC and (B) Comparison of CD4+ T cells of non-sex workers using DMPA versus no HC. Bars are median, interquartile range. FSW, Female Sex Workers; MFI, median fluorescence intensity; DMPA, depot-medroxyprogesterone acetate; HC, hormonal contraception; NS, not significant.

Figure 7

The impact of DMPA on plasma cytokine expression. (A) Plasma IL-10 Expression in sex workers using DMPA versus no HC and (B) Levels of plasma cytokines in non-sex workers using DMPA versus no HC. Bars are median, interquartile range. FSW, Female Sex Workers; DMPA, depot-medroxyprogesterone acetate.

Figure 8

T cell activation and CCR5 expression in women using DMPA. (A) Immunophenotyping of CMCs sex workers and non-sex workers using DMPA and (B) Immunophenotyping of PBMCs sex workers and non-sex workers using DMPA. Bars are median, interquartile range. FSW, Female Sex Workers; MFI, median fluorescence intensity; DMPA, depot-medroxyprogesterone acetate; HC, hormonal contraception. NS, not significant.

Figure 9

Comparison of plasma cytokine expression among women using DMPA. Plasma concentration of MCP-1, TNFa and IL-17 between sex workers and non-sex workers not using any HC. Bars are median, interquartile range. FSW, Female Sex Workers; DMPA, depot-medroxyprogesterone acetate.