14-3-3\u03b5 acts as a proviral factor in highly pathogenic porcine reproductive and respiratory syndrome virus infection

Shengliang Cao,Yuzhong Zhao,Sidang Liu,Yihong Xiao,Min Tan,Fangyuan Cong,Li Li,Jiaqi Liu,Guofei Ding

doi:10.1186/s13567-019-0636-0

Abstract

The highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) emerged in 2006 in China and caused great economic losses for the swine industry because of the lack of an effective vaccine. 14-3-3 proteins are generating significant interest as potential drug targets by allowing the targeting of specific pathways to elicit therapeutic effects in human diseases. In a previous study, 14-3-3s were identified to interact with non-structural protein 2 (NSP2) of PRRSV. In the present study, the specific subtype 14-3-3ε was confirmed to interact with NSP2 and play a role in the replication of the HP-PRRSV TA-12 strain. Knockdown of 14-3-3ε in Marc-145 cells and porcine alveolar macrophages (PAMs) caused a significant decrease in TA-12 replication, while stable overexpression of 14-3-3ε caused a significant increase in the replication of TA-12 and low pathogenic PRRSV (LP-PRRSV) CH-1R. The 14-3-3 inhibitor difopein also decreased TA-12 and CH-1R replication in Marc-145 cells and PAMs. These findings are consistent with 14-3-3ε acting as a proviral factor and suggest that 14-3-3ε siRNA and difopein are therapeutic candidates against PRRSV infection.

Highlights

Porcine reproductive and respiratory syndrome (PRRS), caused by the PRRS virus (PRRSV), is one of the more severe diseases affecting the pig industry worldwide
We evaluated the effect of 14-3-3 proteins on HP-PRRSV replication and found that targeting this protein family might be a potential therapeutic strategy against HP-PRRSV infection
Cells and virus Marc-145 (PRRSV-permissive cell line derived from African monkey kidney cells) and 293T cells were obtained from the China Center for Type Culture Collection (Wuhan, China) and cultured in Dulbecco’s modified Eagle’s medium (Gibco, Langley, OK, USA) supplemented with 10% fetal bovine serum (FBS) (Biological Industries, Beit HaEmek, Israel) at 37 °C in 5% CO2 in a humidified incubator

Summary

Introduction

Porcine reproductive and respiratory syndrome (PRRS), caused by the PRRS virus (PRRSV), is one of the more severe diseases affecting the pig industry worldwide. The 14-3-3 proteins play a role in virus infection and are considered to be potential biomarkers for HIVrelated neurodegeneration [19, 20]. The 14-3-3 proteins can enhance porcine circovirus type 2 infection in PK-15 cells in the presence of IFN-γ [21] or promote autophagy by interacting with microRNA-30a-5p [22]. They control innate antiviral immunity by regulating the retinoic acidinducible gene I (RIG-I) translocon, thereby blocking antiviral signaling [23,24,25]. We evaluated the effect of 14-3-3 proteins on HP-PRRSV replication and found that targeting this protein family might be a potential therapeutic strategy against HP-PRRSV infection

Materials and methods

Results

Findings

Discussion