Zebrafish foxo3b Negatively Regulates Antiviral Response through Suppressing the Transactivity of irf3 and irf7.
Forkhead box O (FOXO)3, a member of the FOXO family of transcription factors, plays key roles in various cellular processes, including development, longevity, reproduction, and metabolism. Recently, FOXO3 has also been shown to be involved in modulating the immune response. However, how FOXO3 regulates immunity and the underlying mechanisms are still largely unknown. In this study, we show that zebrafish (Danio rerio) foxo3b, an ortholog of mammalian FOXO3, is induced by polyinosinic-polycytidylic acid stimulation and spring viremia of carp virus (SVCV) infection. We found that foxo3b interacted with irf3 and irf7 to inhibit ifr3/irf7 transcriptional activity, thus resulting in suppression of SVCV or polyinosinic-polycytidylic acid-induced IFN activation. By suppressing expression of key antiviral genes, foxo3b negatively regulated the cellular antiviral response. Furthermore, upon SVCV infection, the expression of the key antiviral genes was significantly enhanced in foxo3b-null zebrafish larvae compared with wild-type larvae. Additionally, the replication of SVCV was inhibited in foxo3b-null zebrafish larvae, leading to a higher survival rate. Our findings suggest that by suppressing irf3/irf7 activity, zebrafish foxo3b negatively regulates the antiviral response, implicating the vital role of the FOXO gene family in innate immunity.
Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; and.
Xing
0000-0001-9338-7440
X
Liu
Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; and.
Xiaolian
X
Cai
Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; and.
Dawei
D
Zhang
Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; and.
Chenxi
C
Xu
Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China; and w-xiao@ihb.ac.cn.|State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China.
Wuhan
W
Xiao
D000818:Animals; D030801:Animals, Genetically Modified; D002478:Cells, Cultured; D005393:Fish Diseases / Q000276:immunology*; D000071316:Forkhead Box Protein O3 / Q000235:genetics; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism*; D007113:Immunity, Innate / Q000235:genetics; D050838:Interferon Regulatory Factor-3 / Q000235:genetics / Q000378:metabolism; D050835:Interferon Regulatory Factors / Q000235:genetics / Q000378:metabolism; D007814:Larva; D011070:Poly I-C / Q000276:immunology; D012209:Rhabdoviridae / Q000502:physiology*; D018353:Rhabdoviridae Infections / Q000276:immunology*; D015533:Transcriptional Activation; D014779:Virus Replication; D015027:Zebrafish / Q000276:immunology*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors; C588215:Foxo3b protein, zebrafish; C555118:IRF7 protein, zebrafish; D050838:Interferon Regulatory Factor-3; D050835:Interferon Regulatory Factors; C000621812:Irf3 protein, zebrafish; D029961:Zebrafish Proteins; D011070:Poly I-C