Laboratory of Oncolytic Virus Immuno-Therapeutics, German Cancer Research Centre, Im Neuenheimer Feld 242, 69120 Heidelberg, Germany.
Laboratory of Oncolytic Virus Immuno-Therapeutics, Luxembourg Institute of Health, 84 Val Fleuri, L-1526 Luxembourg, Luxembourg.
Viruses. 2020 Oct 21;12(10):1199. doi: 10.3390/v12101199.
H-1 protoparvovirus (H-1PV) is a self-propagating virus that is non-pathogenic in humans and has oncolytic and oncosuppressive activities. H-1PV is the first member of the family to undergo clinical testing as an anticancer agent. Results from clinical trials in patients with glioblastoma or pancreatic carcinoma show that virus treatment is safe, well-tolerated and associated with first signs of efficacy. Characterisation of the H-1PV life cycle may help to improve its efficacy and clinical outcome. In this study, we investigated the entry route of H-1PV in cervical carcinoma HeLa and glioma NCH125 cell lines. Using electron and confocal microscopy, we detected H-1PV particles within clathrin-coated pits and vesicles, providing evidence that the virus uses clathrin-mediated endocytosis for cell entry. In agreement with these results, we found that blocking clathrin-mediated endocytosis using specific inhibitors or small interfering RNA-mediated knockdown of its key regulator, AP2M1, markedly reduced H-1PV entry. By contrast, we found no evidence of viral entry through caveolae-mediated endocytosis. We also show that H-1PV entry is dependent on dynamin, while viral trafficking occurs from early to late endosomes, with acidic pH necessary for a productive infection. This is the first study that characterises the cell entry pathways of oncolytic H-1PV.
H-1 细小病毒（H-1PV）是一种自我复制的病毒，对人类无致病性，具有溶瘤和抑瘤活性。H-1PV 是作为抗癌药物进行临床测试的第一个家族成员。在胶质母细胞瘤或胰腺癌患者的临床试验结果表明，病毒治疗安全、耐受良好，并与最初的疗效迹象相关。H-1PV 生命周期的特征可能有助于提高其疗效和临床结果。在这项研究中，我们研究了 H-1PV 在宫颈癌 HeLa 和神经胶质瘤 NCH125 细胞系中的进入途径。通过电子和共聚焦显微镜，我们在网格蛋白包被陷窝和小泡内检测到 H-1PV 颗粒，这提供了病毒使用网格蛋白介导的内吞作用进入细胞的证据。与这些结果一致，我们发现使用特定抑制剂或小干扰 RNA 介导的关键调节剂 AP2M1 敲低来阻断网格蛋白介导的内吞作用，可显著减少 H-1PV 的进入。相比之下，我们没有发现病毒通过小窝蛋白介导的内吞作用进入的证据。我们还表明，H-1PV 的进入依赖于胞质动力蛋白，而病毒的运输从早期内体到晚期内体，酸性 pH 值对有效感染是必要的。这是首次描述溶瘤性 H-1PV 细胞进入途径的研究。
