Mechanisms Underlying the HIV-HSV-2 Syndemic

人类免疫缺陷病毒和单纯疱疹病毒2型是公认的，但其作用的生物学机制还不是很清楚 明白了。最近认识到HSV-2的特点是亚临床脱落频繁 表明该病毒可能有助于持久的免疫激活，并促使我们检查 单纯疱疹病毒2型对外周血T细胞和HIV储备库的影响利用我们的生物资源库 接受抗逆转录病毒治疗的HIV+女性外周血单个核细胞(PBMC) 是或不是HSV-2血清阳性(HIV+/HSV-2+与HIV+/HSV-2-)，我们发现在 HIV+/HSV-2+与HIV+/HSV-2-女性相比，CD4+(但不是CD8+)T细胞的表型。这些变化 包括激活细胞的频率增加，但IL-32的表达却矛盾地下降， 一种被认为与炎症有关的细胞内细胞因子。此外，当分离出CD4+T细胞时 来自病毒抑制的HIV+/HSV-2+的妇女被潜伏期反转剂刺激，添加 重组IL-32可阻断HIV的再激活。这些观察结果表明，IL-32在 在控制艾滋病毒重新激活方面发挥关键作用，并提出了艾滋病毒-单纯疱疹病毒2型综合征的新范式。 我们假设HSV-2在局部(HSV-2生殖器皮肤暴发部位)和 外周血中的CD4+T细胞，包括细胞内IL-32水平的降低，促进了HIV的重新激活。 相反，高水平的IL-32有助于维持艾滋病毒的储备库，这表明IL-32阻断了 可能与重新激活艾滋病毒的战略协同作用，将其作为“休克和杀死”治疗方法的一部分。为了测试这些 假设，我们将分析HIV感染妇女在HSV-2感染前后的PBMC系列样本 从两个独特的队列获得：参加杀微生物剂试验网络(MTN)的妇女-015，纵向 对在参与暴露前预防试验时血清转换为艾滋病毒的非洲妇女的研究，以及 已确定感染艾滋病毒的美国妇女参加了布朗克斯妇女机构间研究(WIHS)。我们会 同时比较感染或未感染HSV-2的HIV感染者的外周血单核细胞。我们将进行表型 免疫细胞亚群来定义与HSV-2感染和HSV-2感染相关的变化 这些变化对血浆病毒载量和艾滋病毒宿主的影响。我们将准备CD4+T细胞库的IL- 32lo细胞，并确定这些亚群是否富含HSV-2和/或HIV反应细胞 IL-32降低是否干扰免疫功能。我们还将利用我们的存储库 生殖器皮肤活检(疱疹病变和健侧)，并分析CD4+T细胞以 确定它们是否对特定表型的细胞进行了原位浓缩。我们将确定IL-32如何 阻断对潜伏期重新激活刺激的反应，以及IL-32拮抗剂如何促进艾滋病毒重新激活。这些 研究将确定可以靶向阻止HIV重新激活的途径和分子 或者相反，加强潜伏期逆转，作为“休克并杀死”艾滋病毒根除战略的一部分。

The HIV and HSV-2 syndemic is well recognized, but the biological mechanisms that contribute are not understood. The recent recognition that HSV-2 is characterized by a frequent state of subclinical shedding suggests that the virus might contribute to persistent immune activation and prompted us to examine the impact of HSV-2 on peripheral blood T cells and on HIV reservoirs. Taking advantage of our biorepository of peripheral blood mononuclear cells (PBMC) from well-characterized HIV+ women on antiretroviral therapy who were or were not HSV-2 seropositive (HIV+/HSV-2+ vs. HIV+/HSV-2-), we found a significant difference in the phenotype of CD4+ (but not CD8+) T cells in HIV+/HSV-2+ compared to HIV+/HSV-2- women. These changes included an increase in the frequency of activated cells, but a paradoxical decrease in the expression of IL-32, an intracellular cytokine presumed to be associated with inflammation. Moreover, when CD4+ T cells isolated from virally suppressed HIV+/HSV-2+ women were stimulated with latency reversal agents, the addition of recombinant IL-32 to the cultures blocked HIV reactivation. These observations suggest that IL-32 plays a pivotal role in controlling HIV reactivation and suggest a new paradigm underlying the HIV-HSV-2 syndemic. We hypothesize that HSV-2 triggers changes in local (at the site of HSV-2 genital skin outbreaks) and peripheral blood CD4+ T cells including a reduction in intracellular IL-32 levels that promote HIV reactivation. Conversely, high levels of IL-32 contribute to the maintenance of HIV reservoirs suggesting that IL-32 blockade may synergize with strategies to reactivate HIV as part of a “shock and kill” approach to cure. To test these hypotheses, we will analyze serial samples of PBMC from HIV infected women before and after HSV-2 acquisition from two unique cohorts: women enrolled in Microbicides Trial Network (MTN)-015, a longitudinal study of African women who seroconverted to HIV while participating in pre-exposure prophylaxis trials, and U.S. women with established HIV infection enrolled in the Bronx Women's Interagency Study (WIHS). We will also compare PBMC in HIV-infected men who are or are not coninfected with HSV-2. We will phenotype immune cell subpopulations to define the changes that occur in association with HSV-2 acquisition and the impact of these changes on plasma viral loads and HIV reservoirs. We will prepare CD4+ T cell libraries of IL- 32lo cells and determine whether these subpopulations are enriched in HSV-2 and/or HIV reactive cells and whether decreased IL-32 interferes with immune functions. We will also take advantage of our repository of genital skin biopsies (herpes lesion and unaffected contralateral side) and analyze the CD4+ T cells to determine whether they are enriched for cells of specific phenotypes in situ. We will determine how IL-32 blocks the response to latency reactivating stimuli and how IL-32 antagonists promote HIV reactivation. These studies will identify pathways and molecules that could be targeted to block HIV reactivation in response to HSV-2 or conversely, enhance latency reversal as part of “shock and kill” HIV eradication strategies.