Jin Xiaohui, Yuan Yixin, Zhang Chi, Zhou Yong, Song Yue, Wei Zhanyong, Zhang Gaiping
The College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou 450002, P. R. China.
Key Laboratory for Animal-derived Food Safety of Henan Province, Zhengzhou 450002, P. R. China.
J Vet Sci. 2020 May;21(3):e50. doi: 10.4142/jvs.2020.21.e50.
Porcine parvovirus (PPV) is a single-stranded DNA virus that causes porcine reproductive failure. It is of critical importance to study PPV pathogenesis for the prevention and control of the disease. NS1, a PPV non-structural protein, is participated in viral DNA replication, transcriptional regulation, and cytotoxicity. Our previous research showed that PPV can activate nuclear factor kappa B (NF-κB) signaling pathway and then up-regulate the expression of interleukin (IL)-6.
Herein, the purpose of this study is to determine whether the non-structural protein NS1 of PPV also has the same function.
Real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR), enzyme-linked immunosorbent assay, western blot, immunofluorescence assay and small interfering RNA (siRNA) were used.
Our findings demonstrated that PPV NS1 protein can up-regulate the expression levels of IL-6 and tumor necrosis factor-alpha in a dose-dependent manner. Moreover, PPV NS1 protein was found to induce the phosphorylation of IκBα, then leading to the phosphorylation and nuclear translocation of NF-κB. In addition, the NS1 protein activated the upstream pathways of NF-κB. Meanwhile, TLR2-siRNA assay showed TLR2 plays an important role in the activation of NF-κB signaling pathway induced by PPV-NS1.
These findings indicated that PPV NS1 protein induced the up-regulated of IL-6 expression through activating the TLR2 and NF-κB signaling pathways. In conclusion, these findings provide a new avenue to study the innate immune mechanism of PPV infection.
猪细小病毒（PPV）是一种单链DNA病毒，可导致猪繁殖障碍。研究PPV发病机制对于疾病的预防和控制至关重要。NS1是PPV的一种非结构蛋白，参与病毒DNA复制、转录调控和细胞毒性作用。我们之前的研究表明，PPV可激活核因子κB（NF-κB）信号通路，进而上调白细胞介素（IL）-6的表达。
本研究旨在确定PPV的非结构蛋白NS1是否也具有相同功能。
采用实时定量逆转录聚合酶链反应（RT-qPCR）、酶联免疫吸附测定、蛋白质免疫印迹法、免疫荧光测定及小干扰RNA（siRNA）技术。
我们的研究结果表明，PPV NS1蛋白可呈剂量依赖性上调IL-6和肿瘤坏死因子-α的表达水平。此外，发现PPV NS1蛋白可诱导IκBα磷酸化，进而导致NF-κB磷酸化并核转位。另外，NS1蛋白激活了NF-κB的上游通路。同时，TLR2-siRNA检测显示TLR2在PPV-NS1诱导的NF-κB信号通路激活中起重要作用。
这些结果表明，PPV NS1蛋白通过激活TLR2和NF-κB信号通路诱导IL-6表达上调。总之，这些结果为研究PPV感染的固有免疫机制提供了一条新途径。
