Antiviral Responses by Swine Primary Bronchoepithelial Cells Are Limited Compared to Human Bronchoepithelial Cells Following Influenza Virus Infection

Abstract

Swine generate reassortant influenza viruses because they can be simultaneously infected with avian and human influenza; however, the features that restrict influenza reassortment in swine and human hosts are not fully understood. Type I and III interferons (IFNs) act as the first line of defense against influenza virus infection of respiratory epithelium. To determine if human and swine have different capacities to mount an antiviral response the expression of IFN and IFN-stimulated genes (ISG) in normal human bronchial epithelial (NHBE) cells and normal swine bronchial epithelial (NSBE) cells was evaluated following infection with human (H3N2), swine (H1N1), and avian (H5N3, H5N2, H5N1) influenza A viruses. Expression of IFNλ and ISGs were substantially higher in NHBE cells compared to NSBE cells following H5 avian influenza virus infection compared to human or swine influenza virus infection. This effect was associated with reduced H5 avian influenza virus replication in human cells at late times post infection. Further, RIG-I expression was lower in NSBE cells compared to NHBE cells suggesting reduced virus sensing. Together, these studies identify key differences in the antiviral response between human and swine respiratory epithelium alluding to differences that may govern influenza reassortment.

Bovine Mx1 enables resistance against foot-and-mouth disease virus in naturally susceptible cells by inhibiting the replication of viral RNA

“…Tracheal tissue was obtained from a fetal Holstein cow of the age of 4 months gestation under aseptic conditions (Wang et al, 2012). Th e bovine fetal primary tracheal epithelial cells were separated, cultured, and cryopreserved according to the methods described by Hauser et al (2013). 293T cells and BHK-21 cells were obtained from the American Type Culture Collection and grown in Dulbecco's modifi ed Eagle's medium (DMEM) supplemented with 10% fetal bovine serum (FBS).…”

Polymerase Discordance in Novel Swine Influenza H3N2v Constellations Is Tolerated in Swine but Not Human Respiratory Epithelial Cells

“…The PK-1 cell line was acquired from ATCC (#CL-101). The isolation, culturing and differentiation of primary NSBE has been described previously [30] . NSBE cells were verified by University of Georgia Veterinary Medical Diagnostic Laboratory (VMDL) as PCR-negative for influenza, circovirus and porcine reproductive respiratory syndrome virus before use.…”

“…Virus stocks of selected reassortants were analyzed in PK-1 cells, MDCK cells, undifferentiated normal swine bronchoepithelial cells, fully differentiated normal swine bronchoepithelial (dNSBE) cells, and fully-differentiated normal human bronchoepithelial (dNHBE) as described [30] , [39] at an MOI = 0.01 for 24, 48, 56 and 72 hpi. All viral titers were determined by the 50% tissue culture infectious dose (TCID 50 ) assay [40] .…”

“…The pdm09 M gene is linked to increased transmissibility [27] [28] ; therefore, this segment within H3N2v may represent a critical determinant for swine-to-human transmission. To address the reassortment potential of pdm09 and swine H3N2-TRIG viruses to combine as an H3N2v constellation, and generate infectious (compatible) or non-infectious (incompatible) pdm09-based reassortants, swine cells from a porcine kidney epithelial cell line (PK-1) and a primary normal swine bronchoepithelial cell line isolated from euthanized pigs [29] , [30] were co-infected with the pdm09 strain (A/California/04/09) and a recently characterized H3N2-TRIG virus (A/Sw/PA/62170-1/2010). This swine H3N2-TRIG isolate was selected as it has established virulence and contact transmissibility in pigs [31] .…”

Advances and Remaining Challenges in the Study of Influenza and Anthrax Infection in Lung Cell Culture

“…Swine primary lung epithelial cells have also been used to characterize innate immune responses to IAV infection [15] and the reassortment tendencies of IAV in co-infected cells [16]. Previous results have shown that primary swine lung epithelial cells compared to the immortalized porcine kidney epithelial cell line (PK-1) give rise to different reassortment outcomes after co-infection when introducing human pandemic H1N1 and swine H3N2 [16].…”