溶瘤病毒正在成为有前途的抗癌剂。尽管 N-糖基化对病毒的重要生物学功能已被广泛接受，但 N-聚糖和聚糖加工酶在溶瘤病毒治疗中的作用仍然难以捉摸。在这里，通过冷冻电镜分析，我们确定了溶瘤病毒 M1 (OVM) 包膜上的三种不同的 N-聚糖是有效受体结合所必需的。 E1-N141-聚糖对MXRA8受体的结合有直接影响，E2-N200-聚糖介导E2从其前体PE2成熟，而PE2不能与MXRA8结合，E2-N262-聚糖轻微促进受体结合。 OVM N-聚糖在受体结合中的必要性使其对于体外和体内溶瘤作用不可或缺。进一步研究发现寡糖转移酶（OST）的关键催化亚基STT3A是OVM N-糖基化的决定因素，肿瘤细胞中STT3A的表达与OVM诱导的溶瘤作用呈正相关。在各种实体瘤中观察到 STT3A 表达增加，表明 OVM 具有广谱抗癌潜力。总的来说，我们的研究支持 STT3A 介导的 N-糖基化在 OVM 受体结合和溶瘤中的重要性，从而为 OVM 提供了一种新颖的预测生物标志物。© 2023。作者，获得 Springer Nature Limited 的独家许可。

Oncolytic viruses are emerging as promising anticancer agents. Although the essential biological function of N-glycosylation on viruses are widely accepted, roles of N-glycan and glycan-processing enzyme in oncolytic viral therapy are remain elusive. Here, via cryo-EM analysis, we identified three distinct N-glycans on the envelope of oncolytic virus M1 (OVM) as being necessary for efficient receptor binding. E1-N141-glycan has immediate impact on the binding of MXRA8 receptor, E2-N200-glycan mediates the maturation of E2 from its precursor PE2 which is unable to bind with MXRA8, and E2-N262-glycan slightly promotes receptor binding. The necessity of OVM N-glycans in receptor binding make them indispensable for oncolysis in vitro and in vivo. Further investigations identified STT3A, a key catalytic subunit of oligosaccharyltransferase (OST), as the determinant of OVM N-glycosylation, and STT3A expression in tumor cells is positively correlated with OVM-induced oncolysis. Increased STT3A expression was observed in various solid tumors, pointing to a broad-spectrum anticancer potential of OVM. Collectively, our research supports the importance of STT3A-mediated N-glycosylation in receptor binding and oncolysis of OVM, thus providing a novel predictive biomarker for OVM.© 2023. The Author(s), under exclusive licence to Springer Nature Limited.