Upregulation of galectin-3 in influenza A virus infection promotes viral RNA synthesis through its association with viral PA protein

Journal of Biomedical Science

Research

Hao-Earn Chong¹  Chia-Hsing Leu¹  Yi-Cheng Chen¹  Pin Ling²  Chung-Teng Wang²  Nai-Hui Chung²  Mei-Lin Yang³  Ai-Li Shiau³  Chao-Liang Wu⁴  Michael M. C. Lai⁵  Fu-Tong Liu⁶ 

[1] Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, 1, University Road, 701401, Tainan, Taiwan;Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, 1, University Road, 701401, Tainan, Taiwan;Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, 1, University Road, 701401, Tainan, Taiwan;Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan;Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan;Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, 1, University Road, 701401, Tainan, Taiwan;Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan;Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan;Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan;

关键词: Galectin-3;    Influenza virus;    vRNP import;    RNA-dependent RNA polymerase;    RNA synthesis;    Viral PA;   

DOI  :  10.1186/s12929-023-00901-x

 received in 2022-09-26, accepted in 2023-01-11,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundInfluenza is one of the most important viral infections globally. Viral RNA-dependent RNA polymerase (RdRp) consists of the PA, PB1, and PB2 subunits, and the amino acid residues of each subunit are highly conserved among influenza A virus (IAV) strains. Due to the high mutation rate and emergence of drug resistance, new antiviral strategies are needed. Host cell factors are involved in the transcription and replication of influenza virus. Here, we investigated the role of galectin-3, a member of the β-galactoside-binding animal lectin family, in the life cycle of IAV infection in vitro and in mice.MethodsWe used galectin-3 knockout and wild-type mice and cells to study the intracellular role of galectin-3 in influenza pathogenesis. Body weight and survival time of IAV-infected mice were analyzed, and viral production in mouse macrophages and lung fibroblasts was examined. Overexpression and knockdown of galectin-3 in A549 human lung epithelial cells were exploited to assess viral entry, viral ribonucleoprotein (vRNP) import/export, transcription, replication, virion production, as well as interactions between galectin-3 and viral proteins by immunoblotting, immunofluorescence, co-immunoprecipitation, RT-qPCR, minireplicon, and plaque assays. We also employed recombinant galectin-3 proteins to identify specific step(s) of the viral life cycle that was affected by exogenously added galectin-3 in A549 cells.ResultsGalectin-3 levels were increased in the bronchoalveolar lavage fluid and lungs of IAV-infected mice. There was a positive correlation between galectin-3 levels and viral loads. Notably, galectin-3 knockout mice were resistant to IAV infection. Knockdown of galectin-3 significantly reduced the production of viral proteins and virions in A549 cells. While intracellular galectin-3 did not affect viral entry, it increased vRNP nuclear import, RdRp activity, and viral transcription and replication, which were associated with the interaction of galectin-3 with viral PA subunit. Galectin-3 enhanced the interaction between viral PA and PB1 proteins. Moreover, exogenously added recombinant galectin-3 proteins also enhanced viral adsorption and promoted IAV infection in A549 cells.ConclusionWe demonstrate that galectin-3 enhances viral infection through increases in vRNP nuclear import and RdRp activity, thereby facilitating viral transcription and replication. Our findings also identify galectin-3 as a potential therapeutic target for influenza.

【 授权许可】

CC BY   
© The Author(s) 2023

【 图 表 】

Fig. 5

Fig. 2

Fig. 3

Fig. 1

Fig. 1

Fig. 1

Fig. 8

Fig. 2