Protease Activation of Newcastle Disease Virus for Oncolytic viral therapy

描述(申请人提供)：近年来，溶瘤病毒疗法引起了人们的注意，部分原因是对病毒-宿主相互作用的了解取得了进展，而且由于许多原因，包括耐药性的产生，目前可用的化疗并不完全令人满意。目前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，如新城疫病毒(NDV)和水泡性口炎病毒(VSV)。但是，由于许多类型的细胞上都有受体，靶向肿瘤治疗直到现在才是可能的。此外，自然产生的溶瘤菌株的效力是有限的。随着反向遗传学的出现，从克隆的cDNA中完全恢复感染性病毒，通过表达治疗性转基因来重定位溶瘤RNA病毒并提高其疗效，以及通过假分型病毒包膜来逃避宿主的抗病毒免疫现在已经成为可能。靶向、武装和隐形的溶瘤RNA病毒将在未来加强癌症治疗。基质金属蛋白酶(MMPs)和其他肿瘤特异性蛋白水解酶在许多恶性肿瘤细胞中高水平表达，使其得以扩散和转移。新城疫病毒是一种非节段性副粘病毒，通过组织特异性胰酶样酶对病毒融合糖蛋白的切割激活在体内的靶组织中传播。新城疫病毒是一种天然的肿瘤选择性和天然溶瘤病毒。在这里，我们建议将该病毒融合糖蛋白的胰酶裂解位点改变为对MMPs或人中性粒细胞弹性蛋白酶敏感的部位。我们假设，由此产生的重组病毒将不再被胰酶激活，而是需要特定的蛋白水解酶，并在表达这些蛋白水解酶的人类肿瘤细胞中有效传播。此外，我们还预计病毒将在分泌特定蛋白酶的异种移植瘤中广泛传播，而不会扩散到正常细胞，从而抑制肿瘤生长。我们的结果将证明重组新城疫病毒蛋白酶激活突变体对人肿瘤细胞的选择性靶向和杀伤作用。此外，根据患者体内分泌的蛋白酶类型对溶瘤新城疫病毒进行“个体化”的能力为这种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相结合，用于特定的靶向和溶瘤作用。癌症是美国所有死亡的主要原因之一，仅次于心脏病。我们在这里建议对新城疫病毒进行基因改造，新城疫病毒是一种天生的溶瘤病毒，它以一种针对分泌特定蛋白酶的人类肿瘤细胞的方式。我们的方法将产生一种以蛋白酶为靶点的溶瘤病毒，可以根据患者的情况进行个性化。

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.