Estrogen reverses progestin-mediated loss of genital mucosal barrier function

摘要 艾滋病毒对妇女的影响比任何其他威胁生命的传染病都要多。它最常见的是性传播， 病毒必须避开生殖器粘膜屏障才能引起全身性感染。临床研究表明艾滋病病毒 在使用注射孕激素储存库-甲羟孕酮的女性中更容易穿透这种防御 醋酸盐(DMPA)。我们的研究小组为这种可能性提供了生物学上的合理性，表明DMPA 通过减少细胞间黏附分子的表达促进小鼠对HSV-2感染的易感性 桥粒芯糖蛋白-1(DSG1)和增加生殖器粘膜通透性。DMPA同样增加了对 人源化小鼠对生殖器艾滋病毒的感染。确定了这些结果的潜在机制，我们发现了DMPA 对小鼠的治疗降低了小鼠阴道内Ephin A3(EFNA3)的水平；雌激素(E)受体靶基因显示 促进上皮组织中DSG1的表达。为我们的发现提供临床相关性，我们向女性展示了 启动DMPA使用时宫颈外膜DSG1表达和粘膜通透性的变化与 在老鼠身上看到的那些。同样，药理上相关的DMPA剂量可相对增强生殖器粘膜 恒河猴通透性(RMS)。这些数据新揭示了DMPA损害了粘膜屏障保护。 然而，使用HIV感染的人源化小鼠模型，我们也发现联合治疗 DMPA和阴道内(IVAG)E通过增强生殖器粘膜完整性来阻止病毒感染。这些结果 从而确定了激素避孕策略结合使用外源激素的意想不到的优势 孕激素和E(即，它们避免了单独使用孕激素造成的屏障保护的丧失)。作为必要的步骤 在建立这一方法时，这一建议将阐明E介导的生殖器增强的机制 粘膜屏障功能和E释放IVR(E-IVR)保护生殖器RMS的能力 SIV变速器。明确地说，我们将使用小鼠来定义E介导的对EFNA3通路的调节 DSG1的表达和促进生殖器粘膜屏障功能(目标1)。我们将制定一个RM大小的E-IVR来 提供药理相关的药物剂量，并使用这些环比较EFNA3和DSG1的表达 DMPA、DMPA和安慰剂IVR或DMPA和E-IVR治疗的RM的粘膜屏障功能(目标2)。 最后，我们将比较服用DMPA、DMPA和安慰剂IVR的RMS中生殖器SIV的传播情况。 DMPA和E-IVR在不断增加接种病毒的情况下面临重复生殖器挑战(目标3)。这部作品 将确定E诱导EFNA3信号通路促进生殖器上皮完整性的机制， 并证明E-IVRs通过消除DMPA介导的生殖器减弱来阻断SIV的传播 粘膜屏障功能。因此，这些研究将在高度相关的临床上提供重要的新信息 模型，并证明在感染艾滋病毒的高危人群中探索类似的避孕策略是合理的。

SUMMARY HIV affects more women than any other life-threatening infectious agent. It is most often sexually transmitted, where virus must evade the genital mucosal barrier to cause systemic infection. Clinical studies suggest HIV more easily penetrates this defense among women using the injectable progestin depot-medroxyprogesterone acetate (DMPA). Offering biological plausibility for this possibility, our research group showed that DMPA promoted mouse susceptibility to HSV-2 infection by reducing expression of the cell-cell adhesion molecule desmoglein-1 (DSG1) and increasing genital mucosal permeability. DMPA similarly boosted susceptibility of humanized mice to genital HIV infection. Identifying a potential mechanism for these results, we found DMPA treatment of mice lowered vaginal levels of ephrin A3 (EFNA3); an estrogen (E) receptor target gene shown to promote DSG1 expression in epithelial tissue. Providing clinical relevance for our findings, we showed women initiating DMPA use display changes in ectocervical DSG1 expression and mucosal permeability identical to those seen in mice. Likewise, pharmacologically relevant DMPA doses comparably enhanced genital mucosal permeability in rhesus macaques (RMs). These data newly reveal DMPA impairs mucosal barrier protection. However, using a humanized mouse model of HIV infection, we also uncovered that combined treatment with DMPA and intravaginal (ivag) E blocks virus acquisition by enhancing genital mucosal integrity. These results thus identified an unexpected advantage of hormonal contraceptive strategies that combine use of exogenous progestin and E (i.e., they avert loss of barrier protection caused by progestin use alone). As necessary steps in establishing this approach, this proposal will elucidate mechanisms of E-mediated enhancement of genital mucosal barrier function and define capacity of an E-releasing ivag ring (E-IVR) to protect RMs from genital SIV transmission. Expressly, we will use mice to define E-mediated regulation of EFNA3 pathways that induce DSG1 expression and boost genital mucosal barrier function (Aim 1). We will formulate a RM-sized E-IVR to deliver pharmacologically relevant drug doses, and use these rings to compare EFNA3 and DSG1 expression and mucosal barrier function in RM treated with DMPA, DMPA and placebo IVR, or DMPA and E-IVR (Aim 2). Finally, we will compare genital SIV transmission in RMs administered DMPA, DMPA and placebo IVR, or DMPA and E-IVR with repetitive genital challenges with escalating inoculums of the virus (Aim 3). This work will identify mechanisms by which E induces EFNA3 signaling pathways promoting genital epithelial integrity, and demonstrate that E-IVRs block SIV transmission by abrogating DMPA-mediated weakening of genital mucosal barrier function. These studies will thus deliver important new information in a highly relevant clinical model, and justify exploration of similar contraceptive strategies in populations at high risk for HIV acquisition.