Project 3: Circumventing extracellular Adenosine barrier to oncolytic virotherapy

项目概要-项目3 溶瘤病毒（OV）治疗是一种很有前途的治疗实体瘤的生物学方法， 单纯病毒-1（oHSV）是最先进的。事实上，FDA已经批准使用oHSV Imlygic® 最近，Daiichi Sankyo销售的G47 Δ获得了有条件批准，用于治疗转移性黑色素瘤。 GBM治疗在日本由于PI之间在该计划上的密切合作， 在项目资助下，我们最近制备了编码PTEN α的oHSV（oHSV-P10）。这种病毒显示出显著的 在小鼠中对颅内胶质瘤的抗肿瘤功效，并且最近已被Mesoblast许可用于GMP 用于1期临床试验的生产和IND使能研究。 最近对oHSV-P10治疗后代谢变化的研究发现， 产生并释放到肿瘤微环境中。而细胞外ATP（eATP）可以作为 免疫系统的刺激物，其分解（通过胞外酶CD39和CD73）产生腺苷 (eAd)最终抑制抗肿瘤免疫。CD73活性代表了一个重要的限速步骤， 将ATP转化为腺苷。本申请的总体目标是评估oHSV 抗肿瘤活性可以通过抑制细胞外ATP（免疫刺激）转化为 eAd（免疫抑制）通过CD73阻断。 在初步结果中，我们已经鉴定了一种新的人抗体，其可以识别并功能性阻断人源性抗体。 CD73活性。虽然我们正在追求这种抗体的翻译发展以外的赠款，在这里 我们建议评估使用该抗体的CD73阻断对oHSV抗肿瘤功效的影响。在这 项目提案，我们假设CD73抑制将协同联合收割机与oHSV治疗， 增强抗肿瘤功效。这项研究将阐明ATP/腺苷平衡在肿瘤中的作用 微环境在目的1中，我们将鉴定有效抑制CD73功能的人抗体片段 与oHSV-P10组合。在目标2中：我们将评估新生成的oHSV-P10-α CD73对 抗肿瘤功效在目标3中，我们将评估oHSV-P10-α CD73单独和与 安维汀（抗VEGF，常用于复发性GBM患者）对疗效和抗肿瘤免疫力的影响。

PROJECT SUMMARY – PROJECT 3 Oncolytic viral (OV) therapy is a promising biological approach for treating solid tumors, with oncolytic herpes simplex virus-1 (oHSV) being the most advanced. Indeed, the FDA has approved the use of the oHSV Imlygic® for metastatic melanoma and more recently, G47Δ, marketed by Daiichi Sankyo, gained conditional approval for GBM treatment in Japan. As a result of the close collaborations developed between the PIs on this program project grant, we have recently made an oHSV that encodes for PTENα (oHSV-P10). This virus shows significant antitumor efficacy against intracranial glioma in mice and has recently been licensed by Mesoblast for GMP production and IND enabling studies for Phase 1 clinical testing. Recent investigations into metabolic changes upon oHSV-P10 treatment led to the discovery of increased ATP production and release into the tumor microenvironment. While the extracellular ATP (eATP) can act as a stimulator of the immune system, its breakdown (via the ectoenzymes CD39 and CD73) produces adenosine (eAd) which eventually dampens anti-tumor immunity. CD73 activity represents a significant rate limiting step in this process by converting ATP to adenosine. The overall goal of this application is to evaluate how oHSV antitumor activity may be improved by suppressing the conversion of extracellular ATP (immune stimulatory) to eAd (immune suppressive) through CD73 blockade. In preliminary results we have identified a novel human antibody that can recognize and functionally block human CD73 activity. While we are pursuing the translational development of this antibody outside of this grant, here we propose to evaluate the impact of CD73 blockade using this antibody on oHSV anti-tumor efficacy. In this project proposal, we hypothesize that CD73 inhibition will synergistically combine with oHSV therapy by enhancing anti-tumor efficacy. This research will elucidate the role of the ATP/adenosine balance in the tumor microenvironment. In Aim 1 we will identify the human antibody fragment that efficiently inhibits CD73 function in combination with oHSV-P10. In Aim 2: we will evaluate the impact of newly generated oHSV-P10-αCD73 on anti tumor efficacy. In Aim 3 we will evaluate the impact of oHSV-P10-αCD73 alone and in combination with Avastin (anti-VEGF, frequently given to recurrent GBM patients) on efficacy and anti-tumor immunity.