title: Influenza A virus upregulates PRPF8 gene expression to increase virus production.
abstract: A ddRT-PCR analysis was performed to detect cellular genes that are differentially expressed after influenza A virus (H1N1) infection of A549 cells. After ddRT-PCR, eight DNA fragments were identified. PRPF8, one of the cellular genes that were upregulated after virus infection, was further analyzed since it has previously been identified as a cellular factor required for influenza virus replication. The upregulation of PRPF8 gene expression after viral infection was confirmed using real-time RT-PCR for mRNA detection and Western blot analysis for protein detection. Influenza A virus also upregulated the PRPF8 promoter in a reporter assay. In addition to H1N1, influenza A virus H3N2 and influenza B virus could also activate PRPF8 expression. Therefore, upregulation of PRPF8 expression might be important for the replication of different influenza viruses. Indeed, overexpression of PRPF8 gene enhanced virus production, while knockdown of expression of this gene reduced viral production significantly. To determine which viral protein could enhance PRPF8 gene expression, individual viral genes were cloned and expressed. Among the different viral proteins, expression of either the viral NS1 or PB1 gene could upregulate the PRPF8 expression. Our results from this study indicate that influenza A virus upregulates cellular PRPF8 gene expression through viral NS1 and PB1 proteins to increase virus production.
authors.affiliation: Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan.
authors.forename: Chee-Hing
authors.initials: CH
authors.lastname: Yang
authors.affiliation: Department of Biochemistry, School of Medicine, Tzu Chi University, 701, Section 3, Chung Yang Road, Hualien, Taiwan.
authors.forename: Hui-Chun
authors.initials: HC
authors.lastname: Li
authors.affiliation: Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien, Taiwan.
authors.forename: Yu-Ling
authors.initials: YL
authors.lastname: Shiu
authors.affiliation: Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien, Taiwan.
authors.forename: Tzu-Shan
authors.initials: TS
authors.lastname: Ku
authors.affiliation: Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien, Taiwan.
authors.forename: Chia-Wen
authors.initials: CW
authors.lastname: Wang
authors.affiliation: Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien, Taiwan.
authors.forename: Yi-Shuan
authors.initials: YS
authors.lastname: Tu
authors.affiliation: Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien, Taiwan.
authors.forename: Hung-Ling
authors.initials: HL
authors.lastname: Chen
authors.affiliation: Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien, Taiwan.
authors.forename: Cheng-Hao
authors.initials: CH
authors.lastname: Wu
authors.affiliation: Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan. losylo@mail.tcu.edu.tw.|Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien, Taiwan. losylo@mail.tcu.edu.tw.|Department of Laboratory Medicine, Buddhist Tzu Chi General Hospital, Hualien, Taiwan. losylo@mail.tcu.edu.tw.
authors.forename: Shih-Yen
authors.identifier: http://orcid.org/0000-0001-8651-0148
authors.initials: SY
authors.lastname: Lo
mesh_terms: D000072283:A549 Cells; D000818:Animals; D002460:Cell Line; D004285:Dogs; D020869:Gene Expression Profiling; D057809:HEK293 Cells; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification / Q000472:pathogenicity*; D053122:Influenza A Virus, H3N2 Subtype / Q000302:isolation & purification / Q000472:pathogenicity*; D009981:Influenza B virus / Q000302:isolation & purification / Q000472:pathogenicity*; D061985:Madin Darby Canine Kidney Cells; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D016601:RNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation; D017361:Viral Nonstructural Proteins / Q000378:metabolism*; D014764:Viral Proteins / Q000378:metabolism*; D014779:Virus Replication
chemical_list: C085820:INS1 protein, influenza virus; C115374:PRPF8 protein, human; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; D017361:Viral Nonstructural Proteins; D014764:Viral Proteins; C077346:influenza virus polymerase basic protein 1