scholarly journals A genome wide RNA interference screening method to identify host factors that modulate Influenza A virus replication

Methods ◽  
2013 ◽  
Vol 59 (2) ◽  
pp. 217-224 ◽  
Author(s):  
Christopher R. Chin ◽  
Abraham L. Brass
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Bo Li ◽  
Sara M. Clohisey ◽  
Bing Shao Chia ◽  
Bo Wang ◽  
Ang Cui ◽  
...  

AbstractHost dependency factors that are required for influenza A virus infection may serve as therapeutic targets as the virus is less likely to bypass them under drug-mediated selection pressure. Previous attempts to identify host factors have produced largely divergent results, with few overlapping hits across different studies. Here, we perform a genome-wide CRISPR/Cas9 screen and devise a new approach, meta-analysis by information content (MAIC) to systematically combine our results with prior evidence for influenza host factors. MAIC out-performs other meta-analysis methods when using our CRISPR screen as validation data. We validate the host factors, WDR7, CCDC115 and TMEM199, demonstrating that these genes are essential for viral entry and regulation of V-type ATPase assembly. We also find that CMTR1, a human mRNA cap methyltransferase, is required for efficient viral cap snatching and regulation of a cell autonomous immune response, and provides synergistic protection with the influenza endonuclease inhibitor Xofluza.


mBio ◽  
2015 ◽  
Vol 6 (3) ◽  
Author(s):  
Thomas O. Edinger ◽  
Marie O. Pohl ◽  
Emilio Yángüez ◽  
Silke Stertz

ABSTRACT Human cathepsin W (CtsW) is a cysteine protease, which was identified in a genome-wide RNA interference (RNAi) screen to be required for influenza A virus (IAV) replication. In this study, we show that reducing the levels of expression of CtsW reduces viral titers for different subtypes of IAV, and we map the target step of CtsW requirement to viral entry. Using a set of small interfering RNAs (siRNAs) targeting CtsW, we demonstrate that knockdown of CtsW results in a decrease of IAV nucleoprotein accumulation in the nuclei of infected cells at 3 h postinfection. Assays specific for the individual stages of IAV entry further show that attachment, internalization, and early endosomal trafficking are not affected by CtsW knockdown. However, we detected impaired escape of viral particles from late endosomes in CtsW knockdown cells. Moreover, fusion analysis with a dual-labeled influenza virus revealed a significant reduction in fusion events, with no detectable impact on endosomal pH, suggesting that CtsW is required at the stage of viral fusion. The defect in IAV entry upon CtsW knockdown could be rescued by ectopic expression of wild-type CtsW but not by the expression of a catalytically inactive mutant of CtsW, suggesting that the proteolytic activity of CtsW is required for successful entry of IAV. Our results establish CtsW as an important host factor for entry of IAV into target cells and suggest that CtsW could be a promising target for the development of future antiviral drugs. IMPORTANCE Increasing levels of resistance of influenza viruses to available antiviral drugs have been observed. Development of novel treatment options is therefore of high priority. In parallel to the classical approach of targeting viral enzymes, a novel strategy is pursued: cell-dependent factors of the virus are identified with the aim of developing small-molecule inhibitors against a cellular target that the virus relies on. For influenza A virus, several genome-wide RNA interference (RNAi) screens revealed hundreds of potential cellular targets. However, we have only limited knowledge on how these factors support virus replication, which would be required for drug development. We have characterized cathepsin W, one of the candidate factors, and found that cathepsin W is required for escape of influenza virus from the late endosome. Importantly, this required the proteolytic activity of cathepsin W. We therefore suggest that cathepsin W could be a target for future host cell-directed antiviral therapies.


Viruses ◽  
2013 ◽  
Vol 5 (6) ◽  
pp. 1431-1446 ◽  
Author(s):  
Hong Zhang ◽  
Benjamin Hale ◽  
Ke Xu ◽  
Bing Sun

2011 ◽  
Vol 156 (11) ◽  
pp. 1979-1987 ◽  
Author(s):  
Wanyi Li ◽  
Xiaofan Yang ◽  
Yan Jiang ◽  
Baoning Wang ◽  
Yuan Yang ◽  
...  

2015 ◽  
Vol 89 (7) ◽  
pp. 3671-3682 ◽  
Author(s):  
Shih-Feng Hsu ◽  
Wen-Chi Su ◽  
King-Song Jeng ◽  
Michael M. C. Lai

ABSTRACTInfluenza A virus (IAV) depends on cellular factors to complete its replication cycle; thus, investigation of the factors utilized by IAV may facilitate antiviral drug development. To this end, a cellular transcriptional repressor, DR1, was identified from a genome-wide RNA interference (RNAi) screen. Knockdown (KD) of DR1 resulted in reductions of viral RNA and protein production, demonstrating that DR1 acts as a positive host factor in IAV replication. Genome-wide transcriptomic analysis showed that there was a strong induction of interferon-stimulated gene (ISG) expression after prolonged DR1 KD. We found that beta interferon (IFN-β) was induced by DR1 KD, thereby activating the JAK-STAT pathway to turn on ISG expression, which led to a strong inhibition of IAV replication. This result suggests that DR1 in normal cells suppresses IFN induction, probably to prevent undesired cytokine production, but that this suppression may create a milieu that favors IAV replication once cells are infected. Furthermore, biochemical assays of viral RNA replication showed that DR1 KD suppressed viral RNA replication. We also showed that DR1 associated with all three subunits of the viral RNA-dependent RNA polymerase (RdRp) complex, indicating that DR1 may interact with individual components of the viral RdRp complex to enhance viral RNA replication. Thus, DR1 may be considered a novel host susceptibility gene for IAV replication via a dual mechanism, not only suppressing the host defense to indirectly favor IAV replication but also directly facilitating viral RNA replication.IMPORTANCEInvestigations of virus-host interactions involved in influenza A virus (IAV) replication are important for understanding viral pathogenesis and host defenses, which may manipulate influenza virus infection or prevent the emergence of drug resistance caused by a high error rate during viral RNA replication. For this purpose, a cellular transcriptional repressor, DR1, was identified from a genome-wide RNAi screen as a positive regulator in IAV replication. In the current studies, we showed that DR1 suppressed the gene expression of a large set of host innate immunity genes, which indirectly facilitated IAV replication in the event of IAV infection. Besides this scenario, DR1 also directly enhanced the viral RdRp activity, likely through associating with individual components of the viral RdRp complex. Thus, DR1 represents a novel host susceptibility gene for IAV replication via multiple functions, not only suppressing the host defense but also enhancing viral RNA replication. DR1 may be a potential target for drug development against influenza virus infection.


2018 ◽  
Vol 92 (23) ◽  
Author(s):  
Cha Yang ◽  
Xiaokun Liu ◽  
Qingxia Gao ◽  
Tailang Cheng ◽  
Rong Xiao ◽  
...  

ABSTRACTInfluenza A viral ribonucleoprotein (vRNP) is responsible for transcription and replication of the viral genome in infected cells and depends on host factors for its functions. Identification of the host factors interacting with vRNP not only improves understanding of virus-host interactions but also provides insights into novel mechanisms of viral pathogenicity and the development of new antiviral strategies. Here, we have identified 80 host factors that copurified with vRNP using affinity purification followed by mass spectrometry. LYAR, a cell growth-regulating nucleolar protein, has been shown to be important for influenza A virus replication. During influenza A virus infection, LYAR expression is increased and partly translocates from the nucleolus to the nucleoplasm and cytoplasm. Furthermore, LYAR interacts with RNP subunits, resulting in enhancing viral RNP assembly, thereby facilitating viral RNA synthesis. Taken together, our studies identify a novel vRNP binding host partner important for influenza A virus replication and further reveal the mechanism of LYAR regulating influenza A viral RNA synthesis by facilitating viral RNP assembly.IMPORTANCEInfluenza A virus (IAV) must utilize the host cell machinery to replicate, but many of the mechanisms of IAV-host interaction remain poorly understood. Improved understanding of interactions between host factors and vRNP not only increases our basic knowledge of the molecular mechanisms of virus replication and pathogenicity but also provides insights into possible novel antiviral targets that are necessary due to the widespread emergence of drug-resistant IAV strains. Here, we have identified LYAR, a cell growth-regulating nucleolar protein, which interacts with viral RNP components and is important for efficient replication of IAVs and whose role in the IAV life cycle has never been reported. In addition, we further reveal the role of LYAR in viral RNA synthesis. Our results extend and improve current knowledge on the mechanisms of IAV transcription and replication.


PLoS ONE ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. e0174523 ◽  
Author(s):  
Daniel Tsung-Ning Huang ◽  
Chun-Yi Lu ◽  
Pei-Lan Shao ◽  
Luan-Yin Chang ◽  
Jin-Yuan Wang ◽  
...  

2015 ◽  
Vol 11 (9) ◽  
pp. 2511-2519 ◽  
Author(s):  
Dafei Xie ◽  
Lu Han ◽  
Yifu Luo ◽  
Yang Liu ◽  
Song He ◽  
...  

Genome-wide RNA interference screens have greatly facilitated the identification of essential host factors (EHFs) for viral infections, whose knockdown effects significantly influence virus replication but not host cell viability.


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