Therapeutic Ocular HSV Vaccine in HLA Transgenic Rabbits

描述（由申请人提供）：单纯疱疹病毒1型（HSV-1）感染角膜，然后在三叉神经节（TG）的感觉神经元中建立潜伏期。1型单纯疱疹病毒的散发性自发再激活会导致泪液中病毒的脱落，从而将病毒传播给其他个体，也会引起复发性疱疹基质角膜炎（HSK），这是一种致盲性眼部疾病。我们目前知识的一个主要空白是：“我们如何预防或显著减少泪液中的病毒脱落和由于TG中潜伏病毒的自发再激活而引起的单纯疱疹病毒引起的眼部疾病？”hsv特异性CD8+ t细胞在体外诱导的小鼠TG中HSV-1再激活似乎减少。不幸的是，小鼠体内HSV-1的自发再激活极为罕见，因此这些发现与小鼠体内HSV-1自发再激活的相关性无法确定。我们现在有了一种“人源化”的HLA转基因兔眼HSV-1模型，该模型具有“类人”的CD8 t细胞免疫反应（HLA Tg兔）。在一项初步研究中，我们发现用来自HSV-1 gD的3个人CD8 t细胞表位治疗性免疫潜伏感染的HLA - Tg兔，可使自发再激活降低4倍。这种新的动物模型现在将允许我们第一次验证这样一种假设，即一种治疗性疫苗可以诱导适当的人类t细胞对HSV-1的反应，从而减少自发再激活的影响（眼睛中的病毒脱落和hsv诱导的眼部疾病）。我们的具体目标包括：(1)。验证用HSV-1人CD8+ t细胞表位治疗性免疫可减少HLA转基因兔潜伏感染后的自发再激活的假设。CD4-CD8脂肽疫苗，携带来自糖蛋白B和D （gB和gD）的人CD4+和CD8+ T细胞表位的不同组合，将用于免疫潜伏感染的HLA - Tg兔。将确定防止病毒在眼睛中脱落（由于自发再激活）和单纯疱疹病毒引起的眼部疾病。(2)。在Aim 1中验证HLA转基因兔治疗性疫苗诱导的保护性免疫与TG、结膜和/或引流淋巴结中效应性和记忆性CD8+ t细胞的存在相关的假设。我们将评估体内诱导的HSV和表位特异性CD8+ T细胞的数量/功能是否与泪液和眼部疾病中自发病毒脱落的保护相关。我们将评估与保护相关的CD8+ T细胞机制。(3)。验证潜伏感染HLA - Tg的家兔体内CD8+ T细胞的减少会消除疫苗的效力，同时也会增加未接种的家兔的自发再激活。这些研究将为人类表位特异性CD8+ T细胞在HSV-1自发再激活的免疫控制中的作用提供重要的新信息。这可能会导致针对眼疱疹的免疫治疗策略的新范式的发展。

DESCRIPTION (provided by applicant): Herpes simplex virus 1 (HSV-1) infects the cornea and then establishes latency in sensory neurons of the trigeminal ganglia (TG). Sporadic spontaneous reactivation of HSV-1 causes shedding of virus in tears leading to spread of virus to other individuals, and can also cause recurrent Herpes Stromal Keratitis (HSK), a blinding ocular disease. A major gap in our current knowledge is: "How can we prevent or significantly reduce virus shedding in tears and HSV-induced ocular disease due to spontaneous reactivation of latent virus in the TG?" HSV-specific CD8+ T-cells appear to decrease in vitro induced HSV-1 reactivation in explanted mouse TG. Unfortunately, spontaneous reactivation of HSV-1 in mice is extremely rare so the relevance of these findings to in vivo HSV-1 spontaneous reactivation cannot be determined in mice. We now have a "humanized" HLA transgenic rabbit model of ocular HSV-1 that mounts "human-like" CD8 T-cell immune responses (HLA Tg rabbits). In a Preliminary Study we found that therapeutic immunization of latently infected HLA Tg rabbits with 3 human CD8 T-cell epitopes from HSV-1 gD decreased spontaneous reactivation 4-fold. This novel animal model will now allow us for the first time to test the hypothesis that a therapeutic vaccine that induces appropriate human T-cell responses to HSV-1 can decrease the effects of spontaneous reactivation (virus shedding in eyes and HSV-induced ocular disease). Our specific Aims include: (1). Test the hypothesis that therapeutic immunization with HSV-1 human CD8+ T-cell epitopes can decrease spontaneous reactivation in latently infected HLA Transgenic rabbits. CD4-CD8 lipopeptide vaccines, bearing different combinations of human CD4+ and CD8+ T cell epitopes from glycoprotein B and D (gB & gD), will be used to immunize latently infected HLA Tg rabbits. Protection against virus shedding in eyes (due to spontaneous reactivation) and HSV-induced ocular disease will be determined. (2). Test the hypothesis that the protective immunity induced by the therapeutic vaccination of HLA Transgenic rabbits in Aim 1 correlates with the presence of effector and memory CD8+ T-cells in the TG, conjunctiva, and/or draining lymph nodes. We will assess whether the number/function of HSV- and epitope- specific CD8+ T cells induced in vivo correlates with protection from spontaneous virus shedding in tears and ocular disease. We will assess the CD8+ T cell mechanism that correlates with protection. (3). Test the hypothesis that decreasing CD8+ T cells in latently infected HLA Tg rabbits will abrogate vaccine efficacy and also increase spontaneous reactivation in unvaccinated rabbits. These studies will provide important new information regarding the role of CD8+ T cells specific to human epitopes in immune control of HSV-1 spontaneous reactivation. This may lead to the development of new paradigms for immunotherapeutic strategies against ocular herpes. PUBLIC HEALTH RELEVANCE: This project is aimed at developing a lipopeptide therapeutic vaccine against ocular herpes (a leading cause of blindness in developed countries) using a novel human leukocyte antigen (HLA) transgenic rabbit model.