Oncolytic virus (OV) immunotherapy is characterized by viruses which specifically target cancer cells and cause their cytolysis. They provide a unique and promising new tool for the eradication of cancer as they interact with and affect the tumor microenvironment (TME), vasculature, and immune system. Advancements of genetic engineering have allowed for these viruses to be armed in such a way to have enhanced targeting, strong immunomodulation properties, and an ability to modify the TME. However, there are still major limitations in their use, mostly due to difficulties in delivering the viral particles to the tumors and in ensuring that the immunomodulatory properties are able to stimulate the host immune response to mount a complete response. Using novel delivery systems and using OVs as a complementary therapy in a combinatorial treatment have shown some significant successes. In this review, we discuss the major issues and difficulties in using OVs as anti-tumor agents and some of the strategies put in place so far to overcome these limitations. KEY POINTS: • Oncolytic viruses (OVs) infect cancer cells and cause their cytolysis. • The major limitations in using OVs as anti-tumor therapy were discussed. • The potential strategies to overcome these limitations were summarized.

中文翻译：

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溶瘤病毒免疫疗法的限制因素和克服它们的方法。

溶瘤病毒 (OV) 免疫疗法的特点是病毒特异性靶向癌细胞并导致其细胞溶解。由于它们与肿瘤微环境 (TME)、脉管系统和免疫系统相互作用并对其产生影响，因此它们为根除癌症提供了一种独特且有前景的新工具。基因工程的进步使这些病毒能够以具有增强的靶向性、强大的免疫调节特性和修饰 TME 的能力的方式武装起来。然而，它们的使用仍然存在重大限制，主要是由于难以将病毒颗粒递送至肿瘤以及确保免疫调节特性能够刺激宿主免疫反应以产生完全反应。在联合治疗中使用新的递送系统和使用 OV 作为补充治疗已经取得了一些显着的成功。在这篇综述中，我们讨论了使用 OV 作为抗肿瘤剂的主要问题和困难，以及迄今为止为克服这些限制而采取的一些策略。要点： • 溶瘤病毒 (OV) 感染癌细胞并导致其细胞溶解。• 讨论了使用 OV 作为抗肿瘤疗法的主要限制。• 总结了克服这些限制的潜在策略。• 讨论了使用 OV 作为抗肿瘤疗法的主要限制。• 总结了克服这些限制的潜在策略。• 讨论了使用 OV 作为抗肿瘤疗法的主要限制。• 总结了克服这些限制的潜在策略。