Therapeutic Ocular HSV Vaccine in HLA Transgenic Rabbits

 描述(申请人提供)：复发性眼部疱疹疾病是全球范围内视力丧失的主要原因，发生于三叉神经节(TG)感觉神经元的潜伏单纯疱疹病毒(HSV-1)重新激活后。我们的长期目标是开发一种安全有效的免疫治疗疫苗，以阻止病毒重新激活和流泪。虽然HSV特异性CD8+T细胞在减少病毒重新激活方面至关重要，但它们似乎也与导致角膜疱疹病变的免疫病理有关。在过去的5年里，我们有了几个重要的发现，形成了这种竞争性更新应用的基础：(1)来自自然保护的血清阳性无症状(ASYMP)患者(那些感染了但从未复发的眼疱疹患者)的HSV特异性记忆CD8+T细胞主要是效应记忆T细胞(TEM细胞)。而单纯疱疹病毒特异性记忆性CD8+T细胞则以中枢记忆T细胞为主。(2)来自ASYMP个体的CD8+T细胞，而不是来自SYMP个体的CD8+T细胞，强烈识别HSV-1糖蛋白和被蛋白的不同且不重叠的表位，反之亦然。(3)HSV-1ASYMP CD8+T细胞表位治疗性免疫能显著提高HSV-1ASYMP CD8+T细胞和组织记忆性CD8 T细胞(TRM细胞)的数量和功能，减少泪液中病毒的自发脱落。(4)未保护的HLATG兔TG中CD8+T细胞表达高水平的PD-1和CTLA-4抑制受体，并出现功能障碍。(5)眼部局部应用表达T细胞趋化因子CXCL10的AAV8载体后，HSV-1潜伏感染的HLATG兔体内CD8+T细胞和组织驻留记忆T细胞(TRM细胞)增多，泪液中病毒脱落减少。基于这些已发表的初步数据，我们假设，通过PRIME/Pull免疫治疗疫苗联合PD-1和CTLA-4免疫检查点阻断，增加抗病毒Tg驻留的TEM/TRM CD8+T细胞的数量和功能，应该会显著减少HSV的自发重新激活(通过泪水脱落来衡量)。我们的具体目标是：1：用人HSV-1 CD8+TEM/TRM细胞表位(PRIME)和表达兔CXCL9、CXCL10和CCL5 T细胞吸引趋化因子(Pull)的嗜神经AAV8载体，验证HSV-1潜伏感染的HLATG兔治疗性Prime/Pull疫苗将增加TG驻留的抗病毒CD8+Tm/TRM细胞的数量，减少HSV-1自发激活和泪液中病毒的脱落。目的：验证一次/拉式治疗性疫苗接种，加上PD-1和CTLA-4免疫检查点的阻断，将在TG中产生更多功能的CD8 TEM/TRM细胞，并对HSV-1的重新激活和泪水中的病毒脱落产生更强大的保护作用。该疫苗与免疫检查点阻断相结合是治疗复发性疱疹致盲的一种创新方法。

 DESCRIPTION (provided by applicant): Recurrent ocular herpetic disease, a major cause of vision loss worldwide, occurs following reactivation of latent herpes simplex virus (HSV-1) from sensory neurons of the trigeminal ganglia (TG). Our long-term goal is to develop a safe and efficient immunotherapeutic vaccine to stop virus reactivation and shedding in tears. While HSV-specific CD8+ T cells are critical in reducing virus reactivations, they also appear to be associated with the immuno-pathology that leads to corneal herpetic lesions. During the last 5 years, we have made several significant findings that form the basis of this competitive renewal application: (1) HSV-specific memory CD8+ T cells from "naturally protected" seropositive asymptomatic (ASYMP) individuals (those who are infected but never develop recurrent ocular herpes) are mainly effector memory T cells (TEM cells). In contrast, HSV-specific memory CD8+ T cells from symptomatic (SYMP) patients (those who often develop recurrent ocular herpes) are mainly central memory T cells (TCM cells). (2) CD8+ T cells from ASYMP individuals, but not CD8+ T-cells from SYMP individuals, strongly recognize distinct and non-overlapping sets of epitopes from HSV-1 glycoproteins and tegument proteins, and vice versa. (3) Therapeutic immunization of latently infected HLA Tg rabbits with HSV-1 ASYMP CD8+ T cell epitopes boosted the number and function of HSV-specific CD8+ TEM and tissue- resident memory CD8 T cells (TRM cells) in TG and decreased spontaneous viral shedding in tears. (4) A significant proportion of CD8+ T cells in TG of non-protected HLA Tg rabbits expressed high levels of PD-1 and CTLA-4 inhibitory receptors and appeared to be dysfunctional. (5) Topical ocular application of an AAV8 vector expressing the T-cell attracting chemokine CXCL10 pulled more CD8+ TEM and tissue-resident memory T cells (TRM cells) into TG of HSV-1 latently infected HLA Tg rabbits and reduced virus shedding in tears. Building on these strong published and preliminary data, we hypothesize that increasing the number and function of anti- viral TG-resident TEM/TRM CD8+ T cells, by prime/pull immunotherapeutic vaccination combined with PD-1 and CTLA-4 immune checkpoints blockade, should significantly decrease HSV spontaneous reactivation (as measured by shedding in tears). Our Specific Aims are: Aim 1: Test the hypothesis that therapeutic prime/pull vaccination of HSV-1 latently infected HLA Tg rabbits, using human HSV-1 CD8+ TEM/TRM cell epitopes (prime) and neurotropic AAV8 vectors expressing rabbit CXCL9, CXCL10, and CCL5 T-cell-attracting chemokines (pull), will increase the number of TG-resident anti-viral CD8+ TEM/TRM cells and reduce HSV-1 spontaneous reactivation and virus shedding in tears. Aim 2: Test the hypothesis that prime/pull therapeutic vaccination, together with blockade of PD-1 and CTLA-4 immune checkpoints will result in even more functional CD8 TEM/TRM cells in the TG, and produce a more robust protection against HSV-1 reactivation and virus shedding in tears. The prime/pull vaccine combined with immune checkpoints blockade is an innovative approach to treat blinding recurrent herpetic disease.