College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China.
Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China.
Viruses. 2022 Jun 27;14(7):1402. doi: 10.3390/v14071402.
Avian metapneumovirus subgroup C (aMPV/C) is highly pathogenic to various avian species with acute respiratory tract clinicopathology and/or drops in egg production. Nucleolin (NCL), an important nucleolar protein, has been shown to regulate multiple viral replication and serve as a functional receptor for viral entry and internalization. Whether NCL is involved in aMPV/C pathogenesis is not known. In this study, we found that aMPV/C infection altered the subcellular localization of NCL in cultured cells. siRNA-targeted NCL resulted in a remarkable decline in aMPV/C replication in Vero cells. DF-1 cells showed a similar response after CRISPR/Cas9-mediated knock out of NCL during aMPV/C infection. Conversely, NCL overexpression significantly increased aMPV/C replication. Pretreatment with AS1411-a aptamer, a guanine (G)-rich oligonucleotide that forms four-stranded structures and competitively binding to NCL, decreased aMPV/C replication and viral titers in cultured cells. Additionally, we found that the aMPV/C fusion (F) protein specifically interacts with NCL through its central domain and that AS1411 disrupts this interaction, thus inhibiting viral replication. Taken together, these results reveal that the aMPV/C F protein interacts with NCL, which is employed by aMPV/C for efficient replication, thereby highlighting the strategic potential for control and therapy of aMPV/C infection.
禽偏肺病毒亚群 C（aMPV/C）对多种禽类具有高致病性，引起急性呼吸道临床病理学和/或产蛋量下降。核仁素（NCL）是一种重要的核仁蛋白，已被证明能调节多种病毒复制，并作为病毒进入和内化的功能性受体。NCL 是否参与 aMPV/C 的发病机制尚不清楚。在本研究中，我们发现 aMPV/C 感染改变了培养细胞中 NCL 的亚细胞定位。siRNA 靶向 NCL 导致 Vero 细胞中 aMPV/C 复制显著下降。CRISPR/Cas9 介导的 NCL 敲除后，DF-1 细胞在 aMPV/C 感染期间也表现出类似的反应。相反，NCL 的过表达显著增加了 aMPV/C 的复制。在用鸟嘌呤（G）丰富的寡核苷酸 AS1411-a 预处理后，该寡核苷酸能形成四链结构并与 NCL 竞争性结合，降低了培养细胞中的 aMPV/C 复制和病毒滴度。此外，我们发现 aMPV/C 融合（F）蛋白通过其中心结构域特异性地与 NCL 相互作用，而 AS1411 破坏了这种相互作用，从而抑制了病毒复制。综上所述，这些结果表明，aMPV/C F 蛋白与 NCL 相互作用，aMPV/C 利用 NCL 进行有效的复制，从而突出了控制和治疗 aMPV/C 感染的战略潜力。
