Therapeutic immunization to impact HSV-2 latency and associated pathogenesis

描述（由申请人提供）：大约16%的美国成年人感染了单纯疱疹病毒2型（HSV-2），这是生殖器疱疹的主要原因。病毒形成终身潜伏感染，周期性地重新激活并返回周围，在那里它可以引起复发性疾病或无临床症状地传播，从而有效地传播给新的个体。出生时母亲将2型单纯疱疹病毒传染给新生儿可导致严重的发病率。此外，2型单纯疱疹病毒感染已被证明可使感染艾滋病毒的风险增加2至4倍。免疫是预防生殖器疱疹最有效的方法，但是预防2型单纯疱疹病毒的预防性疫苗在临床试验中失败了。显然，我们需要新的战略。治疗性免疫有可能适应和改善正常的宿主抗病毒免疫反应，并影响与潜伏的HSV-2感染相关的病理后果。因此，我们在本申请中提出的研究解决了一个与RFA直接相关的重要临床问题。在这里，我们将探索使用治疗性免疫来减少潜伏病毒感染的负担，限制潜伏病毒的再激活，或快速限制再激活病毒的复制，从而减少宿主的损伤。豚鼠是唯一具有良好特征的动物模型，在潜伏的HSV-2感染期间经历自发再激活事件，导致反复的病毒脱落和与人类疾病相似的临床症状。因此，它们代表了检验HSV-2潜伏期免疫调节假说的最佳模型。我们的长期目标是开发一种治疗性疫苗方法，以减少潜伏性HSV-2感染的负担和与潜伏性感染相关的发病机制。本应用程序的目的是优化治疗性HSV-2疫苗的递送，以及免疫、成像和分子病毒学技术，以量化HSV-2潜伏的神经元部位和HSV-2再次出现的生殖器组织部位的宿主反应和病毒发病事件。我们的中心假设是，DNA疫苗的治疗性免疫可用于影响HSV-2潜伏期的建立，并将减少复发性生殖器疾病以及HSV-2脱落的程度和频率。目的1将开发强大的新技术来量化HSV-2潜伏期的神经元部位和潜伏期重新出现的生殖器部位的重要细胞介导免疫事件。目的2将利用这些新开发的方法来确定在原发性临床疾病发病时进行治疗性免疫接种是否会提高候选治疗性HSV-2疫苗的疗效，从而显著降低潜伏病毒载量并减少复发性疾病。目的3将建立新的成像技术，以增加我们对HSV-2潜伏期复发后发病机制的理解，并提供重要的定量算法，以准确测量病毒再激活对生殖器上皮的影响。目标4将开发新的疫苗结构，旨在增加细胞介导的免疫应答，并更有效地干扰HSV-2的潜伏期和再激活。

DESCRIPTION (provided by applicant): Approximately 16% of adult Americans have been infected by herpes simplex virus type 2 (HSV-2), the main cause of genital herpes. The virus establishes a lifelong latent infection from which it periodically reactivates and returns to the periphery where it can cause recurrent disease or be shed without clinical symptoms, resulting in efficient transmission to new individuals. Transmission of HSV-2 from mother to neonate at birth results in serious morbidity. Further, HSV-2 infections have been shown to increase the risk of HIV acquisition by 2 to 4- fold. Immunization would be the most effective approach to preventing genital herpes, but prophylactic vaccines to protect against HSV-2 disease have failed in clinical trials. Clearly new strategies are needed. Therapeutic immunization has the potential to adapt and improve normal host antiviral immune responses and impact the pathological consequences associated with a latent HSV-2 infection. Consequently, the studies that we propose in this application address a significant clinical problem which is of direct relevance to this RFA. Here we will explore the use of therapeutic immunization to reduce the burden of latent virus infection, to limit reactivation from latency, or to quickly limit the repliation of reactivated virus reducing damage in the host. Guinea pigs are the only well characterized animal model which experience spontaneous reactivation events during latent HSV-2 infection resulting in recurrent virus shedding and clinical signs similar to human disease. Thus, they represent the best model to test hypotheses of immune modulation of HSV-2 latency. Our long term goal is to develop a therapeutic vaccine approach that will reduce the burden of latent HSV-2 infection and the pathogenesis associated with the latent infection. The objective of this application is to optimize delivery of a therapeutic HSV-2 vaccine and immune, imaging, and molecular virology techniques to quantify host responses and viral pathogenesis events both at the neuronal site of HSV-2 latency and in genital tissue the site of HSV-2 re-emergence. Our central hypothesis is that therapeutic immunization with a DNA vaccine can be used to impact the establishment of HSV-2 latency and will decrease recurrent genital disease as well as the magnitude and frequency of HSV-2 shedding. Aim 1 will develop powerful new techniques to quantify important cell-mediated immune events at the neuronal site of HSV-2 latency and at the genital site of re-emergence from latency. Aim 2 will utilize these newly developed methods to determine if therapeutic immunization at the onset of primary clinical disease will improve the efficacy of a candidate therapeutic HSV-2 vaccine, resulting in significantly lower latent virus load and diminished recurrent disease. Aim 3 will establish new imaging techniques to increase our understanding of the pathogenesis of HSV-2 following re-emergence from latency and to provide important quantitative algorithms to accurately measure the effect of reactivating virus on the genital epithelium. Aim 4 will develop novel vaccine constructs designed to increase cell-mediated immune responses to immunization and to more effectively interfere with HSV-2 latency and reactivation.