Immunization with a Novel Single Cycle Flavivirus Particle Vector and Antigenic Peptide Nanofibers as a Prime-boost Vaccine Strategy against HSV-2

 描述（由申请人提供）：目前约16%的14 - 49岁的美国人对2型单纯疱疹病毒（HSV-2）呈血清阳性，全球每年发生2300万例新感染。HSV-2在出生时从母亲传播给新生儿导致严重的发病率或死亡。HSV-2感染是生殖器溃疡疾病的主要原因，这增加了获得其他性传播感染（包括艾滋病毒）的风险。引起全身免疫应答的HSV疫苗在临床试验中失败。动物和人类的临床前研究表明，生殖器HSV-2感染部位的病毒特异性T细胞对于保护至关重要。由先前HSV-2感染产生的生殖道驻留记忆T细胞已显示在HSV-2再攻击的几小时内被激活并迅速清除病毒。诱导这些组织驻留记忆细胞的合理疫苗方法是直接免疫生殖道，但阴道粘膜没有免疫诱导位点，多层生殖器上皮对大多数非感染性细胞提供了屏障。 疫苗。已经测试了替代的免疫位点，目的是激发免疫细胞，这些免疫细胞归巢到生殖器上皮，但这种方法并没有取得一致的成功。据报道，"皮肤归巢"整联蛋白、粘膜整联蛋白和CXCR3趋化因子受体的表达在CD8 + T细胞向阴道上皮的运输中起作用。然而，表达这些分子的免疫细胞向生殖道的运输通常是响应于生殖道中的炎症刺激而实现的，并且许多也迁移到发炎部位的浸润性炎症细胞是HIV的潜在靶标。为了在没有明显炎症的情况下诱导病毒特异性CD8 + T细胞向阴道上皮的特异性运输，我们提出了在"引发和拉动"方法中使用两种新型疫苗平台。这些研究的总体目标是利用趋化因子将疫苗诱导的CD8 + T细胞"拉"入生殖器上皮，以建立生殖道驻留记忆T淋巴细胞群，并确定疫苗的内源性和外源性佐剂化在通过疫苗诱导的T细胞增加CXCR3表达从而促进对趋化因子拉信号的应答中的作用。我们的中心假设是，用我们的新型疫苗平台（用病原体模式受体（PRR）激动剂的内源性和外源性配体作为佐剂）进行的异源初免/加强免疫将诱导大量表达CXCR3的病毒特异性CD8 + T细胞，这些细胞将响应趋化因子配体而运输至阴道粘膜。目的之一是确定由我们的新型单循环黄病毒疫苗引发诱导的个体PRR途径对诱导的CD8 + T细胞的大小、功能和CXCR3表达的影响。目的二将确定与合成疫苗平台一起使用的PRR激动剂佐剂对量级、效应器功能、CXCR3表达和针对HSV-2攻击的保护的作用。总之，这些研究将提供关于佐剂和新的免疫方案的作用的重要信息，以防止性传播病毒。

 DESCRIPTION (provided by applicant): Approximately 16% of Americans aged 14-49 are currently seropositive for Herpes simplex virus type 2 (HSV- 2) and worldwide, 23 million new infections occur each year. Transmission of HSV-2 from mother to neonate at birth results in serious morbidity or death. HSV-2 infections are the leading cause of genital ulcer disease which increases the risk of acquiring other sexually transmitted infections including HIV. HSV vaccines that elicit systemic immune responses have failed in clinical trials. Preclinical studies n animals and humans suggest that virus-specific T cells at the site of genital HSV-2 infection are critical for protection. Genital tract- resident memory T cells resulting from previous HSV-2 infection have been shown to become activated within a few hours of HSV-2 re-challenge and rapidly clear the virus. A rational vaccine approach to induce these tissue-resident memory cells would be direct immunization of the genital tract but the vaginal mucosa does not have immune inductive sites and the multi-layered genital epithelium presents a barrier for most non-infectious vaccines. Alternative immunization sites have been tested with the intent of eliciting immune cells that home to the genital epithelium but this approach has not been uniformly successful. Expression of "skin-homing" integrins, mucosal integrins and CXCR3 chemokine receptor has been reported to play a role in trafficking of CD8+ T cells to the vaginal epithelium. However, trafficking of immune cells expressing these molecules to the genital tract is normally achieved in response to an inflammatory stimulus in the genital tract and many of the infiltrating inflammatory cells that also migrate to the inflamed site are potential targets for HIV. To induce specific trafficking of virus-specific CD8+ T cells to the vaginal epithelium in the absence of overt inflammation, we propose the use of two novel vaccine platforms in a "prime and pull" approach. The overall goals of these studies are to utilize a chemokine "pull" of vaccine-elicited CD8+ T cells into the genital epithelium to establish a population of genital tract-resident memory T lymphocytes and to determine the role of endogenous- and exogenous adjuvanting of the vaccines to increase expression of CXCR3 by vaccine-induced T cells thereby facilitating response to the chemokine pull signal. Our central hypothesis is that heterologous prime/boost immunization with our novel vaccine platforms adjuvanted with endogenous and exogenous ligands for pathogen pattern receptor (PRR) agonists will induce high numbers of CXCR3-expressing, virus-specific CD8+ T cells that will traffic to the vaginal mucosa in response to chemokine ligands. Aim one will determine the influence of individual PRR pathways induced by priming with our novel single cycle flavivirus vaccine on the magnitude, function, and CXCR3 expression of induced CD8+ T cells. Aim two will determine the role of PRR agonist adjuvants used with a synthetic vaccine platform on the magnitude, effector function, CXCR3 expression, and protection against HSV-2 challenge. Together, these studies will provide important information on the role of adjuvants and novel immunization regimens to protect against sexually transmitted viruses.