PEDV and PDCoV Pathogenesis: The Interplay Between Host Innate Immune Responses and Porcine Enteric Coronaviruses.

Surapong Koonpaew,Thanathom Chailangkarn,Anan Jongkaewwattana,Samaporn Teeravechyan,Phanramphoei Namprachan Frantz

doi:10.3389/fvets.2019.00034

Abstract

Enteropathogenic porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV), members of the coronavirus family, account for the majority of lethal watery diarrhea in neonatal pigs in the past decade. These two viruses pose significant economic and public health burdens, even as both continue to emerge and reemerge worldwide. The ability to evade, circumvent or subvert the host’s first line of defense, namely the innate immune system, is the key determinant for pathogen virulence, survival, and the establishment of successful infection. Unfortunately, we have only started to unravel the underlying viral mechanisms used to manipulate host innate immune responses. In this review, we gather current knowledge concerning the interplay between these viruses and components of host innate immunity, focusing on type I interferon induction and signaling in particular, and the mechanisms by which virus-encoded gene products antagonize and subvert host innate immune responses. Finally, we provide some perspectives on the advantages gained from a better understanding of host-pathogen interactions. This includes their implications for the future development of PEDV and PDCoV vaccines and how we can further our knowledge of the molecular mechanisms underlying virus pathogenesis, virulence, and host coevolution.

Highlights

Two members of swine enteric coronaviruses, porcine epidemic diarrhea virus (PEDV), and porcine deltacoronavirus (PDCoV), have recently emerged as major causative agents of lethal watery diarrhea in piglets, leading to significant losses within the swine industry worldwide
That the PEDV-mediated mitogen-activated protein kinase (MAPK) activation enhanced the viral replication. These findings argue for the notion that PEDV, to its advantage, could manipulate host intracellular processes including the stimulation of the MAPK cascade and the NF-κB pathway
The results of this study suggest that the interferon regulatory factor 3 (IRF3) signaling pathway is interfered in the suppression of the IFNβ production by PEDV E, M, and N protein

Summary

INTRODUCTION

Two members of swine enteric coronaviruses, porcine epidemic diarrhea virus (PEDV), and porcine deltacoronavirus (PDCoV), have recently emerged as major causative agents of lethal watery diarrhea in piglets, leading to significant losses within the swine industry worldwide. Previous studies have shown that PEDV infection inhibits type I IFN induction in several cell types, such as MARC-145 or porcine IECs [60, 76], and exhibits relative resistance to IFN-α by inducing the proteasome dependent degradation of STAT1 [73] These observations suggest that this virus has developed strategies to prevent the biological activities of IFNs. PDCoV has demonstrated antagonism of IFN production in cell culture [66]. The studies described above accentuate the value and effectiveness of harnessing our knowledge regarding these machineries in antiviral strategies

CONCLUDING REMARKS

Findings

Methods