Comparison of Porcine Airway and Intestinal Epithelial Cell Lines for the Susceptibility and Expression of Pattern Recognition Receptors upon Influenza Virus Infection.

Milton Thomas,Max Pierson,Laihua Zhu,Ben Hause,Dan Wang,Zhiguang Ran,Chithra Sreenivasan,Feng Li,Tirth Uprety,David Francis,Radhey Kaushik

doi:10.3390/v10060312

Milton Thomas, Max Pierson + Show 9 more

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https://doi.org/10.3390/v10060312

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Journal: Viruses	Publication Date: Jun 7, 2018
Citations: 15	License type: CC BY 4.0

Affiliation: South Dakota State University, Brookings Institution

Abstract

Influenza viruses infect the epithelial cells of the swine respiratory tract. Cell lines derived from the respiratory tract of pigs could serve as an excellent in vitro model for studying the pathogenesis of influenza viruses. In this study, we examined the replication of influenza viruses in the MK1-OSU cell line, which was clonally derived from pig airway epithelium. MK1-OSU cells expressed both cytokeratin and vimentin proteins and displayed several sugar moieties on the cell membrane. These cells also expressed both Sial2-3Gal and Sial2-6Gal receptors and were susceptible to swine influenza A, but not to human B and C viruses. Interestingly, these cells were also permissive to infection by influenza D virus that utilized 9-O-acetylated glycans. To study the differences in the expression of pattern recognition receptors (PRRs) upon influenza virus infection in the respiratory and digestive tract, we compared the protein expression of various PRRs in MK1-OSU cells with that in the SD-PJEC cell line, a clonally derived cell line from the porcine jejunal epithelium. Toll-like receptor 7 (TLR-7) and melanoma differentiation-associated protein 5 (MDA5) receptors showed decreased expression in influenza A infected MK1-OSU cells, while only TLR-7 expression decreased in SD-PJEC cells. Further research is warranted to study the mechanism behind the virus-mediated suppression of these proteins. Overall, this study shows that the porcine respiratory epithelial cell line, MK1-OSU, could serve as an in-vitro model for studying the pathogenesis and innate immune responses to porcine influenza viruses.

Highlights

Influenza viruses belong to the Orthomyxoviridae family and are classified as types A, B, C, and D based on the antigenic properties of two structural proteins—matrix1 and nucleocapsid
Cells were stained for cytokeratin, vimentin, α-smooth muscle actin (ASMA), and desmin to determine whether these cells are phenotypically epithelial in nature
PEERdesmin, REVIEW suggesting that MK1-OSU cells possess an epithelial phenotype.8 of 19 stained for 10, ASMA

Summary

Introduction

Influenza viruses belong to the Orthomyxoviridae family and are classified as types A, B, C, and D based on the antigenic properties of two structural proteins—matrix and nucleocapsid (https://www.cdc.gov/flu/about/viruses/types.htm, accessed on 11 February 2018). Pigs are susceptible to A, B, C, Viruses 2018, 10, 312; doi:10.3390/v10060312 www.mdpi.com/journal/viruses. Viruses 2018, 10, 312 and D types of influenza viruses and could serve as excellent models for studying pathogenesis and host factors affecting influenza infection. Swine influenza A virus (SIV) infection is an acute respiratory disease endemic to swine populations world-wide. The pig airway lining possesses both Sial2-3Gal and. Sial2-6Gal receptors [3] and is susceptible to human, avian, and swine influenza A viruses. Co-infection of pigs with human and avian influenza viruses enables the emergence of new strains through gene reassortment. The zoonotic potential has not been confirmed, sero-surveillance and virus isolation studies have indicated that swine herds are susceptible to influenza B [4,5] and

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