Novel interacting proteins identified by tandem affinity purification and mass spectrometry associated with IFITM3 protein during PDCoV infection.

Interferon-induced transmembrane 3 (IFITM3) is a membrane-associated protein that exhibits antiviral activities against a wide range of viruses through interactions with other cellular and viral proteins. However, knowledge of the mechanisms of IFITM3 in Porcine deltacoronavirus (PDCoV) infection has been lacking. In this study, we demonstrate that IFN-α treatment induces the upregulation of IFITM3 activity and thus attenuates PDCoV infection. PDCoV replication is inhibited in a dose-dependent manner by IFITM3 overexpression. To clarify the novel roles of IFITM3 during PDCoV infection, proteins that interact with IFITM3 were screened by TAP/MS in an ST cell line stably expressing IFITM3 via a lentivirus. We identified known and novel candidate IFITM3-binding proteins and analyzed the protein complexes using GO annotation, KEGG pathway analysis, and protein interaction network analysis. A total of 362 cellular proteins associate with IFITM3 during the first 24 h post-infection. Of these proteins, the relationship between IFITM3 and Rab9a was evaluated by immunofluorescence colocalization analysis using confocal microscopy. IFITM3 partially colocalized with Rab9a and Rab9a exhibited enhanced colocalization following PDCoV infection. We also demonstrated that IFITM3 interacts specifically with Rab9a. Our results considerably expand the protein networks of IFITM3, suggesting that IFITM3 participates in multiple cellular processes during PDCoV infection.

Novel triple-reassortant H1N1 swine influenza viruses in pigs in Tianjin, Northern China.

Pigs are susceptible to both human and avian influenza viruses and therefore have been proposed to be mixing vessels for the generation of pandemic influenza viruses through reassortment. In this study, for the first time, we report the isolation and genetic analyses of three novel triple-reassortant H1N1 swine influenza viruses from pigs in Tianjin, Northern China. Phylogenetic analysis showed that these novel viruses contained genes from the 2009 pandemic H1N1 (PB2, PB1, PA and NP), Eurasian swine (HA, NA and M) and triple-reassortant swine (NS) lineages. This indicated that the reassortment among the 2009 pandemic H1N1, Eurasian swine and triple-reassortant swine influenza viruses had taken place in pigs in Tianjin and resulted in the generation of new viruses. Furthermore, three human-like H1N1, two classical swine H1N1 and two Eurasian swine H1N1 viruses were also isolated during the swine influenza virus surveillance from 2009 to 2013, which indicated that multiple genetic lineages of swine H1N1 viruses were co-circulating in the swine population in Tianjin, China. The emergence of novel triple-reassortant H1N1 swine influenza viruses may be a potential threat to human health and emphasizes the importance of further continuous surveillance.

[Expression of TLR3 and IL-8, Eotaxin in the airway smooth muscle cells induced by PolyI:C].

AIM: to observe the effect of PolyI:C on the expression of TLR3 and inflammation cytokine in the airway smooth muscle cells ASMCs of rat, to investigate relationship between the expression of Toll-like receptor 3 (TLR3) in the airway smooth muscle cells and airway inflammation. METHODS: airway smooth muscle cells were derived from rat airway tissue and were cultured in vitro, ASMCs were divided into 2 groups: control group and PolyI:C group, PolyI:C group was divided into the different time spots. The mRNA expression of TLR3 was measured by RT-PCR. The level of NF-kappaB was measured by Western blot. The concertration of IL-8 and Eotaxin in ASMCs supernatant were determined by ELISA. RESULTS: the expression of TLR3 mRNA and NF-kappaB protein in the ASMCs in PolyI:C group was significantly higher than those in control group(P<0.05), the concentration of IL-8 and Eotaxin in the ASMCs in PolyI:C group was significantly higher compared to control group (P<0.05); and have time dependent manner. CONCLUSION: poly I:C promoted the expression of TLR3 in ASMCs, activated NF-kappaB, incresead the concentration of IL-8 and Eotaxin, involved in airway inflammation of asthma.