Department of Virology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
Department of Virology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
J Virol. 2020 Nov 9;94(23). doi: 10.1128/JVI.01703-20.
Mammalian reovirus (MRV) strain type 3 Dearing (T3D) is a naturally occurring oncolytic virus that has been developed as a potential cancer therapeutic. However, MRV treatment cannot be applied to cancer cells expressing low levels of junctional adhesion molecule A (JAM-A), which is the entry receptor of MRV. In this study, we developed a reverse genetics system for MRV strain T3D-L, which showed high oncolytic potency. To modify the cell tropism of MRV, an arginine-glycine-aspartic acid (RGD) peptide with an affinity to integrin was inserted at the C terminus or loop structures of the viral cell attachment protein σ1. The recombinant RGD σ1-modified viruses induced remarkable cell lysis in human cancer cell lines with marginal JAM-A expression and in JAM-A knockout cancer cell lines generated by a CRISPR/Cas9 system. Pretreatment of cells with anti-integrin antibody decreased cell death caused by the RGD σ1-modified virus, suggesting the infection to the cells was via a specific interaction with integrin αV. By using mouse models, we assessed virulence of the RGD σ1-modified viruses This system will open new avenues for the use of genetically modified oncolytic MRV for use as a cancer therapy. Oncolytic viruses kill tumors without affecting normal cells. A variety of oncolytic viruses are used as cancer therapeutics. Mammalian reovirus (MRV), which belongs to the genus , family , is one such natural oncolytic virus. The anticancer effects of MRV are being evaluated in clinical trials. Unlike other oncolytic viruses, MRV has not been genetically modified for use as a cancer therapeutic in clinical trials. Here, we used a reverse genetic approach to introduce an integrin-affinity peptide sequence into the MRV cell attachment protein σ1 to alter the natural tropism of the virus. The recombinant viruses were able to infect cancer cell lines expressing very low levels of the MRV entry receptor, junctional adhesion molecule A (JAM-A), and cause tumor cell death while maintaining its original tropism via JAM-A. This is a novel report of a genetically modified oncolytic MRV by introducing a peptide sequence into σ1.
哺乳动物呼肠孤病毒（MRV）株 3 型迪林（T3D）是一种天然溶瘤病毒，已被开发为一种潜在的癌症治疗药物。然而，MRV 治疗不能应用于表达低水平连接黏附分子 A（JAM-A）的癌细胞，JAM-A 是 MRV 的进入受体。在这项研究中，我们开发了一种用于具有高溶瘤效力的 MRV 株 T3D-L 的反向遗传学系统。为了修饰 MRV 的细胞嗜性，在病毒细胞附着蛋白 σ1 的 C 末端或环结构中插入了一个对整联蛋白具有亲和力的精氨酸-甘氨酸-天冬氨酸（RGD）肽。重组 RGD σ1 修饰病毒在 JAM-A 表达水平低的人类癌细胞系和由 CRISPR/Cas9 系统产生的 JAM-A 敲除癌细胞系中诱导显著的细胞裂解。用抗整联蛋白抗体预处理细胞可降低 RGD σ1 修饰病毒引起的细胞死亡，表明感染细胞是通过与整联蛋白 αV 的特异性相互作用。通过使用小鼠模型，我们评估了 RGD σ1 修饰病毒的毒力。该系统将为使用遗传修饰的溶瘤性 MRV 作为癌症治疗开辟新途径。溶瘤病毒在不影响正常细胞的情况下杀死肿瘤。多种溶瘤病毒被用作癌症治疗药物。哺乳动物呼肠孤病毒（MRV）属于呼肠孤病毒科，正呼肠孤病毒属，是一种天然溶瘤病毒。MRV 的抗癌作用正在临床试验中进行评估。与其他溶瘤病毒不同，MRV 尚未在临床试验中通过遗传修饰用于癌症治疗。在这里，我们使用反向遗传方法将一个整合素亲和肽序列引入到 MRV 细胞附着蛋白 σ1 中，以改变病毒的天然嗜性。重组病毒能够感染表达极低水平 MRV 进入受体——连接黏附分子 A（JAM-A）的癌细胞系，并通过 JAM-A 引起肿瘤细胞死亡，同时保持其原始嗜性。这是通过在 σ1 中引入肽序列来遗传修饰溶瘤性 MRV 的新报告。
