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)：在14-49岁的美国人中，目前约有16%的人是单纯疱疹病毒2型(HSV-2)血清阳性者，全球每年有2300万新感染病例。HSV-2在出生时从母亲传播给新生儿会导致严重的发病率或死亡。单纯疱疹病毒2型感染是生殖器溃疡疾病的主要原因，这种疾病增加了感染包括艾滋病毒在内的其他性传播疾病的风险。引起全身免疫反应的HSV疫苗在临床试验中失败了。对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细胞对保护至关重要。先前HSV-2感染导致的生殖道驻留记忆T细胞在HSV-2再次攻击后几小时内被激活，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生殖道直接免疫，但阴道粘膜没有免疫诱导部位，多层生殖器上皮对大多数非传染性 疫苗。已经对替代免疫地点进行了测试，目的是激发生殖器上皮所在的免疫细胞，但这种方法并不总是成功的。据报道，“皮肤归巢”整合素、粘膜整合素和CXCR3趋化因子受体的表达在CD8+T细胞向阴道上皮的运输中发挥了作用。然而，表达这些分子的免疫细胞通常是在生殖道中的炎症刺激下实现的，许多也迁移到炎症部位的浸润性炎症细胞是艾滋病毒的潜在目标。为了在没有明显炎症的情况下诱导病毒特异性CD8+T细胞向阴道上皮细胞的特异性运输，我们建议使用两种新的疫苗平台，即“初始和拉动”方法。这些研究的总体目标是利用疫苗诱导的CD8+T细胞进入生殖器上皮来建立生殖道驻留记忆T淋巴细胞的群体，并确定疫苗的内源性和外源性佐剂对疫苗诱导的T细胞增加CXCR3表达的作用，从而促进对趋化因子拉动信号的反应。我们的中心假设是，用我们的新型疫苗平台与病原体模式受体(PRR)激动剂的内源和外源配体进行异种初始/增强免疫，将诱导大量表达CXCR3的病毒特异性CD8+T细胞，这些细胞将在趋化因子配体的作用下运输到阴道粘膜。目的研究新型单环黄病毒疫苗诱导的单个PRR通路对CD8+T细胞数量、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激动剂佐剂在大小、效应器功能、CXCR3表达以及对HSV-2攻击的保护方面的作用。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.