Protease Activation of Newcastle Disease Virus for Oncolytic viral therapy

描述（由申请人提供）：溶瘤病毒治疗近年来引起了人们的关注，部分原因是对病毒-宿主相互作用的理解取得了进展，以及由于许多原因，包括产生耐药性，目前可用的化疗并不完全令人满意。流行的主要溶瘤治疗策略主要依赖于某些病毒的天然肿瘤选择性，例如纽卡斯尔病病毒（NDV）和水泡性口炎病毒（VSV）。但是，由于许多类型细胞上的受体的可用性，靶向肿瘤治疗直到现在才成为可能。此外，天然存在的溶瘤菌株的功效有限。随着反向遗传学的出现，从克隆的cDNA中完全回收感染性病毒，重新靶向溶瘤RNA病毒并通过表达治疗性转基因增强其功效，以及假型病毒包膜以逃避宿主抗病毒免疫现在是可能的。靶向的、武装的和隐形的溶瘤RNA病毒将在未来增强癌症治疗。基质金属蛋白酶（MMP）和其他肿瘤特异性蛋白酶在许多恶性细胞中以高水平表达，使其能够传播和转移。NDV是一种非分节段副粘病毒，通过组织特异性胰蛋白酶样酶切割激活病毒融合糖蛋白在体内靶组织中传播。NDV是一种天然的肿瘤选择性和固有的溶瘤病毒。我们建议在这里，改变这种病毒的融合糖蛋白的胰蛋白酶裂解位点的一个网站，易受基质金属蛋白酶，或人中性粒细胞弹性蛋白酶。我们假设，所产生的重组病毒将不再被胰蛋白酶激活，但将需要特定的蛋白酶，并在表达这些蛋白酶的人肿瘤细胞中有效传播。此外，我们还预计病毒在分泌特异性蛋白酶的异种移植肿瘤中广泛传播，而不会传播到正常细胞，从而抑制肿瘤生长。我们的研究结果将证明重组NDV蛋白酶激活突变体选择性靶向和杀伤人类肿瘤细胞的潜力。此外，根据患者中分泌的蛋白酶类型“个体化”溶瘤NDV的能力为该方法提供了最大的灵活性。此外，该方法还可以与目前可用的配体定向靶向方法组合用于特异性靶向和溶瘤。癌症是美国所有死亡的主要原因之一，仅次于心脏病。我们在这里建议遗传修饰纽卡斯尔病病毒，一种固有的溶瘤病毒，以这样一种方式，它的目标是特定的蛋白酶分泌的人类肿瘤细胞。我们的方法将产生一种蛋白酶靶向的溶瘤病毒，可以根据患者的个体化。

DESCRIPTION (provided by applicant): Oncolytic virus therapy is attracting attention in recent years in part due to the progress in understanding virus- host interactions and because currently available chemotherapy is not completely satisfactory for many reasons, including the development of resistance to drugs. The major oncolytic therapeutic strategies in vogue largely rely upon the natural tumor selectivity of certain viruses, such as Newcastle disease virus (NDV), and Vesicular stomatitis virus (VSV). But, due to the availability of receptors on many types of cells, targeted tumor therapy was not possible until now. Besides, naturally occurring oncolytic strains are limited in their efficacy. With the advent of reverse genetics to recover infectious virus completely from cloned cDNA, retargeting the oncolytic RNA viruses and enhancing their efficacy through expression of therapeutic transgenes, and pseudo-typing the viral envelope to evade host antiviral immunity is now possible. Targeted, armed and stealth oncolytic RNA viruses will enhance cancer therapeutics in future. Matrix metalloproteinases (MMPs) and other tumor specific proteases are expressed at high levels in many malignant cells to enable their dissemination and metastasis. NDV, a non-segmented paramyxovirus, spreads in target tissues in vivo via cleavage activation of the viral fusion glycoprotein by tissue-specific trypsin-like enzymes. NDV is a naturally tumor-selective and inherently oncolytic virus. We propose here, to change the tryptic cleavage site of the fusion glycoprotein of this virus to a site susceptible to MMPs, or human neutrophil elastase. We hypothesize that the resultant recombinant virus will no longer be activated by trypsin but will require specific proteases and spread efficiently in human tumor cells that express these proteases. Furthermore, we also expect the virus to spread extensively in specific protease secreting xenotransplanted tumors without disseminating to normal cells, leading to the inhibition of tumor growth. Our results will demonstrate the potential of selective targeting and killing of human tumor cells by recombinant protease activation mutants of NDV. Further, the capability to "individualize" the oncolytic NDV according to the type of protease secreted in the patient offers the greatest flexibility to this approach. In addition, this method can also be combined with currently available ligand-directed targeting approaches for specific targeting and oncolysis. Cancer is one of the leading causes of all deaths in the United States, exceeded only by heart diseases. We propose here to genetically modify Newcastle disease virus, an inherently oncolytic virus, in such a way that it targets specific protease secreting human tumor cells. Our approach will yield a protease-targeted oncolytic virus that can be individualized according to the patient.