| Summary: | 碩士 === 國立中興大學 === 微生物暨公共衛生學研究所 === 106 === Tumor necrosis factor alpha (TNFα)-induced protein type 2 (TNFAIP2) was originally identified as an inducible gene in TNFα-treated human endothelial cells and thus likely participates in angiogenesis and pro-inflammatory responses. TNFAIP2 expression can be transcriptionally upregulated via activation of the transcription factor NF-κB, which is known to mediate both pro- and antiviral functions. Infection of some viruses has been shown to induce TNFAIP2 expression; however, the functional influence remains largely unknown. In this study, the role of TNFAIP2 in the interplay between influenza A virus (IAV) H1N1 infection and cellular response was characterized in IAV-permissive A549 cells. Infection of A549 cells with IAV H1N1 led to expression of IAV-encoded NS1 protein at 12 and 24 hours post infection, in conjunction with activation of NF-κB and phosphorylation of AKT; however, TNFAIP2 expression was reduced by IAV infection. Depletion of TNFAIP2 expression by siRNA promoted viral NS1 expression and IAV H1N1-induced NF-κB activation. Furthermore, gene knockout of TNFAIP2 using the CRISPR/Cas9 system enhanced expression of viral NS1 and NP respectively at 12 and 24 hours post infection, in conjunction with enhanced activation of NF-κB and AKT in A549 cells. Finally, expression vectors for various truncated forms of TNFAIP2 were constructed, and their expression patterns were verified by western blotting and immunofluorescence staining. As a result, deletion of the N-terminus of TNFAIP2 led to its altered intracellular localization. Collectively, the present data suggest that TNFAIP2 may play an inhibitory role in early phase of IAV H1N1 infection. Further investigations are needed to better elucidate underlying mechanisms.
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