Ministry of Education Key Laboratory for Ecology of Tropical Islands, College of Life Sciences, Hainan Normal University, Haikou, Hainan, 571158, China.
School of Tropical Agricultural Technology, Hainan College of Vocation and Technique, Haikou, Hainan, 570216, China.
Vet Microbiol. 2018 Dec;227:61-68. doi: 10.1016/j.vetmic.2018.10.025. Epub 2018 Oct 26.
TGEV can induce IFN-β production, which in turn plays a vital role in host antiviral immune responses. Our previous studies showed that TGEV infection activated p53 signaling to induce host cell apoptosis, which might influence virus replication. However, whether there be an interaction between p53 and IFN-β signaling in the process of TGEV infection is unknown. In the present study, we used low dose of TGEV to infect p53 wild-type PK-15 cells (WT PK-15 cells) and p53 deficient cells (p53-/- PK-15 cells), to investigate the modulation of IFN signaling and virus replication by p53. The results showed that the IFN-β expression and production were notably inhibited in p53-/- PK-15 cells compared with that in WT PK-15 cells at early stage of TGEV infection. In addition, TGEV-induced the changes in mRNA levels of TRIF, TRAM, MDA5, RIG-I, IPS-1, IRF9, IRF3, ISG15 and ISG20 were notably hindered in p53-/- PK-15 cells before 36 h post infection (p.i.). Moreover, TGEV genomic RNA and sub genomic mRNA (N gene and ORF7) levels showed significant increase in p53-/- PK-15 cells compared with WT PK-15 cells after TGEV infection. And viral titers were observably enhanced in p53-/- PK-15 cells. Furthermore, exogenous IFN-β and polyinosinic-polycytidylic acid (poly (I:C)) treatment markedly inhibited the mRNA levels of TGEV gRNA, N and ORF7 in WT PK-15 cells and p53-/- PK-15 cells compared to control. Taken together, these results demonstrated that p53 may mediate IFN-β signaling to inhibit viral replication early after TGEV infection.
TGEV 可诱导 IFN-β 的产生，而 IFN-β 在宿主抗病毒免疫反应中起着至关重要的作用。我们之前的研究表明，TGEV 感染激活了 p53 信号通路，诱导宿主细胞凋亡，这可能会影响病毒的复制。然而，在 TGEV 感染过程中，p53 是否与 IFN-β 信号通路相互作用尚不清楚。在本研究中，我们使用低剂量的 TGEV 感染 p53 野生型 PK-15 细胞（WT PK-15 细胞）和 p53 缺失细胞（p53-/- PK-15 细胞），以研究 p53 对 IFN 信号和病毒复制的调节作用。结果表明，在 TGEV 感染早期，与 WT PK-15 细胞相比，p53-/- PK-15 细胞中 IFN-β 的表达和产生明显受到抑制。此外，TGEV 诱导的 TRIF、TRAM、MDA5、RIG-I、IPS-1、IRF9、IRF3、ISG15 和 ISG20 的 mRNA 水平变化在感染后 36 小时之前明显受到抑制。此外，与 WT PK-15 细胞相比，TGEV 感染后 p53-/- PK-15 细胞中的 TGEV 基因组 RNA 和亚基因组 mRNA（N 基因和 ORF7）水平显著增加。并且，p53-/- PK-15 细胞中的病毒滴度明显增加。此外，外源性 IFN-β 和聚肌苷酸-聚胞苷酸（poly（I:C））处理明显抑制了 WT PK-15 细胞和 p53-/- PK-15 细胞中 TGEV gRNA、N 和 ORF7 的 mRNA 水平，与对照组相比。综上所述，这些结果表明，p53 可能在 TGEV 感染后早期通过介导 IFN-β 信号通路抑制病毒复制。
