Role of oxidants in influenza virus-induced gene expression

Influenza virus-induced epithelial damage may be mediated, in part, by reactive oxygen intermediates (ROIs). In this study, we investigated the role of ROIs in the influenza virus-induced gene expression of antioxidant enzymes and in the activation of nuclear factor-κB (NF-κB), an oxidant-sensitive transcriptional factor. Influenza virus infection increased production of intracellular ROIs in A549 pulmonary epithelial cells. Induction of manganese superoxide dismutase (MnSOD) mRNA correlated with increased MnSOD protein and enzyme activity. Influenza virus infection also activated NF-κB binding as determined by an electrophoretic mobility shift assay. Pretreatment of A549 cells with N-acetyl-l-cysteine attenuated virus-induced NF-κB activation and interleukin (IL)-8 mRNA induction but did not block induction of MnSOD mRNA. In contrast, pyrrolidine dithiocarbamate blocked activation of NF-κB and induction of MnSOD and IL-8 mRNAs. Treatment with pyrrolidine dithiocarbamate also markedly decreased virus-induced cell death. Thus oxidants are involved in influenza virus-induced activation of NF-κB, in the expression of IL-8 and MnSOD, and in virus-induced cell death.

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Polymerase Acidic Subunit of H9N2 Polymerase Complex Induces Cell Apoptosis by Binding to PDCD 7 in A549 Cells

10.21203/rs.3.rs-106350/v1 ◽

2020 ◽

Author(s):

Shaohua Wang ◽

Na Li ◽

Shugang Jin ◽

Ruihua Zhang ◽

Tong Xu

Keyword(s):

Cell Death ◽

Influenza Virus ◽

Cell Apoptosis ◽

Influenza A ◽

A549 Cells ◽

Influenza Virus Infection ◽

Economic Loss ◽

Poultry Production ◽

H9n2 Influenza Virus

Abstract Background: H9N2 influenza virus, a subtype of influenza A virus, can spread across different species and induce the respiratory infectious disease in humans, leading to a severe public health risk and a huge economic loss to poultry production. Increasing studies have shown that polymerase acidic (PA) subunit of RNA polymerase in ribonucleoproteins complex of H9N2 involves in crossing the host species barriers, the replication and airborne transmission of H9N2.Methods: Here, to further investigate the role of PA subunit during the infection of H9N2 influenza virus, we employed mass spectrometry (MS) to search the potential binding proteins of PA subunit of H9N2. Our MS results showed that programmed cell death protein 7 (PDCD7) is a binding target of PA subunit. Co-immunoprecipitation and pull-down assays further confirmed the interaction between PDCD7 and PA subunit. Overexpression of PA subunit in A549 lung cells greatly increased the levels of PDCD7 in the nuclear and induced cell death assayed by MTT assay.Results: Flow cytometry analysis and Western blot results showed that PA subunit overexpression significantly increased the expression of pro-apoptotic protein, bax and caspase 3, and induced cell apoptosis. However, knockout of PDCD7 effectively attenuated the effects of PA overexpression in cell apoptosis.Conclusions: In conclusion, the PA subunit of H9N2 bind with PDCD7 and regulated cell apoptosis, which provide new insights in the role of PA subunit during H9N2 influenza virus infection.

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Influenza virus infection induces translocation of apoptosis-inducing factor (AIF) in A549 cells: role of AIF in apoptosis and viral propagation

Archives of Virology ◽

10.1007/s00705-016-3151-x ◽

2016 ◽

Vol 162 (3) ◽

pp. 669-675 ◽

Cited By ~ 6

Author(s):

Xinyan Qu ◽

Xiaoran Ding ◽

Ming Duan ◽

Jing Yang ◽

Ruxian Lin ◽

...

Keyword(s):

Influenza Virus ◽

Virus Infection ◽

A549 Cells ◽

Influenza Virus Infection ◽

Viral Propagation ◽

Apoptosis Inducing Factor

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Human Staufen1 Protein Interacts with Influenza Virus Ribonucleoproteins and Is Required for Efficient Virus Multiplication

Journal of Virology ◽

10.1128/jvi.00504-10 ◽

2010 ◽

Vol 84 (15) ◽

pp. 7603-7612 ◽

Cited By ~ 30

Author(s):

Susana de Lucas ◽

Joan Peredo ◽

Rosa María Marión ◽

Carmen Sánchez ◽

Juan Ortín

Keyword(s):

Influenza Virus ◽

Virus Infection ◽

Influenza A ◽

Particle Production ◽

Nonstructural Protein ◽

A549 Cells ◽

Influenza Virus Infection ◽

Ns1 Protein ◽

Infected Cells

ABSTRACT The influenza A virus genome consists of 8 negative-stranded RNA segments. NS1 is a nonstructural protein that participates in different steps of the virus infectious cycle, including transcription, replication, and morphogenesis, and acts as a virulence factor. Human Staufen1 (hStau1), a protein involved in the transport and regulated translation of cellular mRNAs, was previously identified as a NS1-interacting factor. To investigate the possible role of hStau1 in the influenza virus infection, we characterized the composition of hStau1-containing granules isolated from virus-infected cells. Viral NS1 protein and ribonucleoproteins (RNPs) were identified in these complexes by Western blotting, and viral mRNAs and viral RNAs (vRNAs) were detected by reverse transcription (RT)-PCR. Also, colocalization of hStau1 with NS1, nucleoprotein (NP), and PA in the cytosol of virus-infected cells was shown by immunofluorescence. To analyze the role of hStau1 in the infection, we downregulated its expression by gene silencing. Human HEK293T cells or A549 cells were silenced using either short hairpin RNAs (shRNAs) or small interfering RNAs (siRNAs) targeting four independent sites in the hStau1 mRNA. The yield of influenza virus was reduced 5 to 10 times in the various hStau1-silenced cells compared to that in control silenced cells. The expression levels of viral proteins and their nucleocytoplasmic localization were not affected upon hStau1 silencing, but virus particle production, as determined by purification of virions from supernatants, was reduced. These results indicate a role for hStau1 in late events of the influenza virus infection, possibly during virus morphogenesis.

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Polymerase acidic subunit of H9N2 polymerase complex induces cell apoptosis by binding to PDCD 7 in A549 cells

Virology Journal ◽

10.1186/s12985-021-01547-7 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Shaohua Wang ◽

Na Li ◽

Shugang Jin ◽

Ruihua Zhang ◽

Tong Xu

Keyword(s):

Cell Death ◽

Influenza Virus ◽

Cell Apoptosis ◽

Influenza A ◽

A549 Cells ◽

Influenza Virus Infection ◽

H9n2 Virus ◽

Poultry Production ◽

H9n2 Influenza Virus

Abstract Background H9N2 influenza virus, a subtype of influenza A virus, can spread across different species and induce the respiratory infectious disease in humans, leading to a severe public health risk and a huge economic loss to poultry production. Increasing studies have shown that polymerase acidic (PA) subunit of RNA polymerase in ribonucleoproteins complex of H9N2 virus involves in crossing the host species barriers, the replication and airborne transmission of H9N2 virus. Methods Here, to further investigate the role of PA subunit during the infection of H9N2 influenza virus, we employed mass spectrometry (MS) to search the potential binding proteins of PA subunit of H9N2 virus. Our MS results showed that programmed cell death protein 7 (PDCD7) is a binding target of PA subunit. Co-immunoprecipitation and pull-down assays further confirmed the interaction between PDCD7 and PA subunit. Overexpression of PA subunit in A549 lung cells greatly increased the levels of PDCD7 in the nuclear and induced cell death assayed by MTT assay. Results Flow cytometry analysis and Western blot results showed that PA subunit overexpression significantly increased the expression of pro-apoptotic protein, bax and caspase 3, and induced cell apoptosis. However, knockout of PDCD7 effectively attenuated the effects of PA overexpression in cell apoptosis. Conclusions In conclusion, the PA subunit of H9N2 virus bind with PDCD7 and regulated cell apoptosis, which provide new insights in the role of PA subunit during H9N2 influenza virus infection.

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Role of Interferon and Partial Immunity in Influenza Virus Infection of Mouse Lung

Experimental Biology and Medicine ◽

10.3181/00379727-119-30302 ◽

1965 ◽

Vol 119 (3) ◽

pp. 790-793 ◽

Cited By ~ 1

Author(s):

R. Pollikoff ◽

M. Lieberman ◽

N. E. Lem

Keyword(s):

Influenza Virus ◽

Virus Infection ◽

Influenza Virus Infection ◽

Mouse Lung ◽

Partial Immunity

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The Role of Antimicrobial Peptides in Influenza Virus Infection and Their Potential as Antiviral and Immunomodulatory Therapy

Pharmaceuticals ◽

10.3390/ph9030053 ◽

2016 ◽

Vol 9 (3) ◽

pp. 53 ◽

Cited By ~ 32

Author(s):

I-Ni Hsieh ◽

Kevan Hartshorn

Keyword(s):

Influenza Virus ◽

Virus Infection ◽

Antimicrobial Peptides ◽

Influenza Virus Infection ◽

Immunomodulatory Therapy

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Role of Host Immune Response and Viral Load in the Differential Outcome of Pandemic H1N1 (2009) Influenza Virus Infection in Indian Patients

PLoS ONE ◽

10.1371/journal.pone.0013099 ◽

2010 ◽

Vol 5 (10) ◽

pp. e13099 ◽

Cited By ~ 54

Author(s):

Vidya A. Arankalle ◽

Kavita S. Lole ◽

Ravi P. Arya ◽

Anuradha S. Tripathy ◽

Ashwini Y. Ramdasi ◽

...

Keyword(s):

Immune Response ◽

Influenza Virus ◽

Viral Load ◽

Virus Infection ◽

Influenza Virus Infection ◽

Host Immune Response ◽

Pandemic H1n1 ◽

Differential Outcome ◽

Pandemic H1n1 2009

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Directed Evolution of an Influenza Reporter Virus To Restore Replication and Virulence and Enhance Noninvasive Bioluminescence Imaging in Mice

Journal of Virology ◽

10.1128/jvi.00593-18 ◽

2018 ◽

Vol 92 (16) ◽

Cited By ~ 4

Author(s):

Hui Cai ◽

Meisui Liu ◽

Charles J. Russell

Keyword(s):

Gene Expression ◽

Influenza Virus ◽

Virus Infection ◽

Directed Evolution ◽

Influenza Virus Infection ◽

Foreign Gene ◽

Reporter Virus ◽

Wild Type ◽

Bioluminescence Signal

ABSTRACTReporter viruses provide a powerful tool to study infection, yet incorporating a nonessential gene often results in virus attenuation and genetic instability. Here, we used directed evolution of a luciferase-expressing pandemic H1N1 (pH1N1) 2009 influenza A virus in mice to restore replication kinetics and virulence, increase the bioluminescence signal, and maintain reporter gene expression. An unadapted pH1N1 virus withNanoLuc luciferaseinserted into the 5′ end of the PA gene segment grew to titers 10-fold less than those of the wild type in MDCK cells and in DBA/2 mice and was less virulent. For 12 rounds, we propagated DBA/2 lung samples with the highest bioluminescence-to-titer ratios. Every three rounds, we comparedin vivoreplication, weight loss, mortality, and bioluminescence. Mouse-adapted virus after 9 rounds (MA-9) had the highest relative bioluminescence signal and had wild-type-like fitness and virulence in DBA/2 mice. Using reverse genetics, we discovered fitness was restored in virus rPB2-MA9/PA-D479N by a combination of PA-D479N and PB2-E158G amino acid mutations andPB2noncoding mutations C1161T and C1977T. rPB2-MA9/PA-D479N has increased mRNA transcription, which helps restore wild-type-like phenotypes in DBA/2 and BALB/c mice. Overall, the results demonstrate that directed evolution that maximizes foreign-gene expression while maintaining genetic stability is an effective method to restore wild-type-likein vivofitness of a reporter virus. Virus rPB2-MA9/PA-D479N is expected to be a useful tool for noninvasive imaging of pH1N1 influenza virus infection and clearance while analyzing virus-host interactions and developing new therapeutics and vaccines.IMPORTANCEInfluenza viruses contribute to 290,000 to 650,000 deaths globally each year. Infection is studied in mice to learn how the virus causes sickness and to develop new drugs and vaccines. During experiments, scientists have needed to euthanize groups of mice at different times to measure the amount of infectious virus in mouse tissues. By inserting a foreign gene that causes infected cells to light up, scientists could see infection spread in living mice. Unfortunately, adding an extra gene not needed by the virus slowed it down and made it weaker. Here, we used a new strategy to restore the fitness and lethality of an influenza reporter virus; we adapted it to mouse lungs and selected for variants that had the greatest light signal. The adapted virus can be used to study influenza virus infection, immunology, and disease in living mice. The strategy can also be used to adapt other viruses.

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