Actively engaging NK cells during virotherapy to induce neoantigen-specific antitumor immunity

项目总结 近年来，溶瘤病毒疗法的发展取得了重大进展，导致FDA批准 一种基于I型单纯疱疹病毒(HSV-1)的溶瘤病毒(Talimogene Laherparepvec或T-VEC)用于 晚期黑色素瘤的治疗。然而，越来越明显的是，有必要进一步 改进当前版本的OV，以获得更好的临床效益。我们实验室已经构建了一株基于溶瘤的HSV-2 病毒-Fuson-H2，通过一种新的机制，这是第一个此类病毒。我们最近的研究表明武装福森- H2具有嵌合的NK激活剂(C-NK-E)，可以与肿瘤的浸润性自然杀伤(NK)细胞结合 细胞可以显著提高这种病毒疗法的效果。此外，我们观察到肿瘤 直接溶瘤和参与的NK细胞共同作用的破坏导致了可测量的激发 新抗原特异性抗肿瘤免疫。基于这些令人振奋的发现，我们建议开发三个- 通过联合免疫溶瘤增强Fuson-H2抗肿瘤效果的分叉策略 病毒疗法(IOV)。这种战略性的三管齐下的IOV的抗肿瘤活性是一波又一波的 秩序。第一波立即到来，它主要来自病毒介导的直接溶瘤作用。这个 第二波来自病毒治疗触发的NK细胞共同启动的NK介导的肿瘤细胞杀伤 从武装病毒的渗透和释放的C-NK-E。第三波是一系列连锁反应的结果 最终导致新抗原特异性T细胞的诱导和归巢的事件。我们的主要假设是 这一三管齐下的战略将以相应和协调的方式采取行动，显著加强 这种人工晶状体的治疗效果。我们设计了三个具体目标来检验我们的主要假设。在目标1中， 我们将剖析C-NK-E-ARM病毒产生新抗原特异性免疫的机制，并 设计其他策略以进一步加强这一效果。新抗原是癌症的诱人靶点 免疫疗法，但缺乏一种简单而有效的方式来提供它们。原则上，OV提供了一种简单的 在个别患者体内释放这些新抗原的方法，我们建议的策略将确保它们的效率 并及时呈现给宿主的免疫系统，而不需要额外的程序。在目标2中，我们 将研究结合使用两种不同激活受体的C-NK-ES是否可以进一步增强 NK细胞杀伤和新抗原特异性T细胞免疫。在目标3中，我们将展示三管齐下的 IOV可通过全身给药途径对转移性疾病产生有效的治疗作用。 我们最近开发了新的战略来克服系统交付的关键障碍-快速 巨噬细胞系统和中和抗体清除。我们假设这个组合 三管齐下IOV的高效性与改进的全身给药将导致有效的 治疗转移性疾病。因此，我们在这项建议中的研究克服了阻碍 相对较弱的治疗活动和缺乏有效的全身给药手段，以及 开发的策略可在不久的将来转化为临床。

PROJECT SUMMARY Significant progress in recent years on the development of oncolytic virotherapy has led to the FDA approval of a type I herpes simplex virus (HSV-1) based oncolytic virus (Talimogene Laherparepvec or T-VEC) for the treatment of advanced melanoma. However, it has become increasingly clear that there is a need to further improve the current version of OV for a better clinical benefit. Our lab has constructed a HSV-2 based oncolytic virus - FusOn-H2, the first of its kind, by a novel mechanism. Our recent studies showed that arming FusOn- H2 with a chimeric NK engager (C-NK-E) that can engage the infiltrated natural killer (NK) cells with tumor cells could significantly enhance the effectiveness of this virotherapy. Moreover, we observed that tumor destruction by the joint effect of the direct oncolysis and the engaged NK cells led to a measurable elicitation of neoantigen-specific antitumor immunity. Based on these exciting findings, we propose to develop a three- pronged strategy to enhance the antitumor efficacy of FusOn-H2 via combinatorial immuno-oncolytic virotherapy (IOV). The antitumor activities from this strategic three-pronged IOV come in waves in a sequential order. The first wave comes immediately and it derives primarily from the virus-mediated direct oncolysis. The second wave comes from the NK-mediated tumor cell killing enabled jointly by the virotherapy-trigged NK cell infiltration and the released C-NK-E from the armed virus. The third wave is the outcome of a series of chain events that ultimately result in induction and homing of neoantigen-specific T cells. Our major hypothesis is that this three-pronged strategy will act in a consequential and concerted way to significantly enhance the therapeutic efficacy of this IOV. We have designed three specific aims to test our major hypothesis. In Aim 1, we will dissect the mechanism of C-NK-E-armed virus in generating neoantigen-specific immunity and to design additional strategies to further potentiate this effect. Neoantigens are attractive targets for cancer immunotherapy, but there lacks a simple and effective way of delivering them. In principle, OV offers a simple means to release these neoantigens in individual patients, and our proposed strategy will ensure their efficient and timely presentation to the host’s immune system without the need for additional procedures. In Aim 2, we will investigate if combining C-NK-Es that engage two different activation receptors can further potentiate the NK cell killing and neoantigen-specific T cell immunity. In Aim 3, we will demonstrate that the three-pronged IOV can produce an efficient therapeutic effect against metastatic diseases by the systemic delivery route. We have recently developed novel strategies to overcome key obstacles for systemic delivery - the rapid clearance by the macrophage system and the neutralizing antibodies. We hypothesize that the combination of the high potency of the three-pronged IOV with the improved systemic delivery will lead to effective treatment of metastatic diseases. Our studies in this proposal thus overcome the two major hurdles hindering OV - the relatively weak therapeutic activity and lack of means for effective systemic delivery, and the developed strategy can be translated into the clinic in the near future.