Exogenous oestrogen inhibits genital transmission of cell‐associated HIV‐1 in DMPA‐treated humanized mice

Abstract

IntroductionHIV affects more women than any other life‐threatening infectious agent, and most infections are sexually transmitted. HIV must breach the female genital tract mucosal barrier to establish systemic infection, and clinical studies indicate virus more easily evades this barrier in women using depot‐medroxyprogesterone acetate (DMPA) and other injectable progestins for contraception. Identifying a potential mechanism for this association, we learned DMPA promotes susceptibility of wild‐type mice to genital herpes simplex virus type 2 (HSV‐2) infection by reducing genital tissue expression of the cell‐cell adhesion molecule desmoglein‐1 (DSG‐1) and increasing genital mucosal permeability. Conversely, DMPA‐mediated increases in genital mucosal permeability and HSV‐2 susceptibility were eliminated in mice concomitantly administered exogenous oestrogen (E). To confirm and extend these findings, herein we used humanized mice to define effects of systemic DMPA and intravaginal (ivag) E administration on susceptibility to genital infection with cell‐associated HIV‐1.MethodsEffects of DMPA or an intravaginal (ivag) E cream on engraftment of NOD‐scid‐IL‐2Rgcnull (NSG) mice with human peripheral blood mononuclear cells (hPBMCs) were defined with flow cytometry. Confocal microscopy was used to evaluate effects of DMPA, DMPA and E cream, or DMPA and the pharmacologically active component of the cream on vaginal tissue DSG‐1 expression and genital mucosal permeability to low molecular weight (LMW) molecules and hPBMCs. In other studies, hPBMC‐engrafted NSG mice (hPBMC‐NSG) received DMPA or DMPA and ivag E cream before genital inoculation with 106 HIV‐1‐infected hPBMCs. Mice were euthanized 10 days after infection, and plasma HIV‐1 load quantified by qRT‐PCR and splenocytes used to detect HIV‐1 p24 antigen via immunohistochemistry and infectious virus via TZM‐bl luciferase assay.ResultsWhereas hPBMC engraftment was unaffected by DMPA or E treatment, mice administered DMPA and E (cream or the pharmacologically active cream component) displayed greater vaginal tissue expression of DSG‐1 protein and decreased vaginal mucosal permeability to LMW molecules and hPBMCs versus DMPA‐treated mice. DMPA‐treated hPBMC‐NSG mice were also uniformly susceptible to genital transmission of cell‐associated HIV‐1, while no animal concomitantly administered DMPA and E cream acquired systemic HIV‐1 infection.ConclusionExogenous E administration reduces susceptibility of DMPA‐treated humanized mice to genital HIV‐1 infection.

Norethisterone Enanthate Increases Mouse Susceptibility to Genital Infection with Herpes Simplex Virus Type 2 and HIV Type 1

“…Likewise, unlike MPA, a portion of NET is aromatized in vivo to ethinyl estradiol, a potent estrogen with high estrogen receptor affinity (58). Because susceptibility of DMPAtreated humanized mice to genital infection with cell-associated HIV-1 is eliminated by concomitant treatment with exogenous estrogen (25), it is possible that aromatic conversion of NET to a more estrogenic compound in vivo makes NET-EN less likely than DMPA to enhance genital pathogen susceptibility.…”

“…As previously described, mice in estrus-and progestin-treated mice were sedated and intravaginally (ivag) administered 10 ml of PBS containing 50 mg of Lucifer yellow CH lithium salt (molecular mass = 457.2 Da) and 62.5 mg of dextran Texas Red (molecular mass = 70 kDa) (both Life Technologies) to assess vaginal permeability to low-molecular mass molecules (23)(24)(25). As already described, human PBMC (hPBMC) were activated and labeled with 5 mM carboxyfluorescein succinimidyl ester (Cell-Trace CFSE; Life Technologies) to evaluate genital leukocyte permeability (25). Briefly, cells were resuspended in RPMI 1640 (10 8 cells per milliliter), and 10 ml of this suspension was ivag administered to sedated animals.…”

“…molecules and activated leukocytes, compromised genital mucosal barrier function, and enhanced susceptibility to genital HSV type 2 (HSV-2) and cell-associated HIV type 1 (HIV-1) infection (24). Guided by mouse model results, we discovered analogous changes in the expression of cell-cell adhesion molecules and mucosal barrier function in ectocervical tissue from women using DMPA or an LNG-releasing intrauterine system (LNG-IUS) (24,25). Based on these earlier results, in this study, we used two mouse models to explore the effects of NET-EN on genital mucosal barrier function and susceptibility to genital infection with HSV-2 or cell-associated HIV-1.…”

Exogenous sex steroids regulate genital epithelial barrier function in female rhesus macaques

“…Evaluation of the barrier function of vaginal mucosal epithelium was performed as previously described [ 12 , 13 , 18 , 19 ]. In summary, fresh vaginal biopsies were placed in chilled transport medium and transferred to sterile 96-well plates.…”

“…We also demonstrated this DMPA-mediated weakening of genital epithelial barrier function respectively increased susceptibility of wildtype and humanized mice to genital infection with herpes simplex virus type 2 (HSV-2) and cell-associated human immunodeficiency virus type 1 (HIV-1) [ 12–14 ]. Conversely, DMPA-mediated effects on genital epithelial barrier function and pathogen susceptibility were obviated in mice administered DMPA and exogenous estrogen [ 12 , 13 ]. Notably, analogous changes in genital epithelial integrity and permeability were identified in DMPA-treated mice and women initiating use of DMPA [ 12 ], comparative findings that established mice appropriately model important elements of the human response to this exogenous progestin [ 12 ].…”