Journal of Zhejiang University-SCIENCE B

, Volume 19, Issue 7, pp 570–580 | Cite as

Nucleocapsid protein from porcine epidemic diarrhea virus isolates can antagonize interferon-λ production by blocking the nuclear factor-κB nuclear translocation

  • Ying Shan
  • Zi-qi Liu
  • Guo-wei Li
  • Cong Chen
  • Hao Luo
  • Ya-jie Liu
  • Xun-hui Zhuo
  • Xing-fen Shi
  • Wei-huan Fang
  • Xiao-liang LiEmail author


Porcine epidemic diarrhea virus (PEDV) is a highly infectious pathogen that can cause severe diseases in pigs and result in enormous economic losses in the worldwide swine industry. Previous studies revealed that PEDV exhibits an obvious capacity for modulating interferon (IFN) signaling or expression. The newly discovered type III IFN, which plays a crucial role in antiviral immunity, has strong antiviral activity against PEDV proliferation in IPEC-J2 cells. In this study, we aimed to investigate the effect of PEDV nucleocapsid (N) protein on type III IFN-λ. We found that the N proteins of ten PEDV strains isolated between 2013 and 2017 from different local farms shared high nucleotide identities, while the N protein of the CV777 vaccine strain formed a monophyletic branch in the phylogenetic tree. The N protein of the epidemic strain could antagonize type III IFN, but not type I or type II IFN expression induced by polyinosinic-polycytidylic acid (poly(I:C)) in IPEC-J2 cells. Subsequently, we demonstrated that the inhibition of poly(I:C)- induced IFN-λ3 production by PEDV N protein was dependent on the blocking of nuclear factor-κB (NF-κB) nuclear translocation. These findings might help increase understanding of the pathogenesis of PEDV and its mechanisms for evading the host immune response.

Key words

Porcine epidemic diarrhea virus Nucleocapsid protein Interferon-λ (IFN-λ) Nuclear factor-κB (NF-κB) Intestinal epithelial cells 

猪流性腹泻病毒流行毒株核衣壳蛋白能够通过阻断核因子κB 入核拮抗λ 干扰素产生



探索猪流性腹泻病毒(PEDV)核衣壳蛋白(N 蛋白)对III 型λ 干扰素(IFN-λ)的影响。


首次在IPEC-J2 细胞模型中证明PEDV 流行病毒 株的N 蛋白可拮抗由聚肌胞苷酸(poly(I:C))诱 导表达的III 型IFN,但不能拮抗I 型或II 型IFN。 这种拮抗作用是通过阻断核因子κB(NF-κB)入 核来实现的。


利用poly(I:C)刺激IPEC-J2 细胞使其IFN 诱导表 达。实验组转染N 蛋白真核表达载体,对照组转 染空载体;利用定量聚合酶链反应(qPCR)、荧 光素酶报告基因等技术,检测N 蛋白对I 型、II 型及III 型IFN 表达抑制情况。利用间接免疫荧 光技术,检测NF-κB 在细胞内的分布情况,分析 NF-κB 入核与N 蛋白抑制IFN-λ 表达的关系。


2013 年至2017 年间从浙江省不同的农场分离的 10个PEDV毒株的N蛋白具有较高的核苷酸同源 性,而疫苗毒株CV777 的N 蛋白在系统发育树 中形成单系分支(图1)。流行病毒株的N 蛋白 可以在IPEC-J2 细胞中成功表达(图2 和3), 并拮抗由poly(I:C)诱导表达的III 型IFN,但不能 拮抗I 型或II 型IFN(图4 和5)。PEDV N 蛋白 通过阻断NF-ΚB 入核来对poly(I:C) 诱导的 IFN-λ3 产生的抑制作用(图6)。


猪流行性腹泻 核衣壳蛋白 λ 干扰素 核因子κB 肠上皮细胞 

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Copyright information

© Zhejiang University and Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Zhejiang Province Key Lab of Preventive Veterinary Medicine, Institute of Preventive Veterainary Medicine, College of Animal SciencesZhejiang UniversityHangzhouChina
  2. 2.Institute of Parasitic DiseaseZhejiang Academy of Medical SciencesHangzhouChina
  3. 3.Animal Products Quality Testing Center of Zhejiang ProvinceHangzhouChina

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