scholarly journals The RNA Binding Domain of Influenza A Virus NS1 Protein Affects Secretion of Tumor Necrosis Factor Alpha, Interleukin-6, and Interferon in Primary Murine Tracheal Epithelial Cells

2007 ◽  
Vol 81 (17) ◽  
pp. 9469-9480 ◽  
Author(s):  
Celeste M. Newby ◽  
Leah Sabin ◽  
Andrew Pekosz
Keyword(s):  
Epithelial Cells ◽  
Influenza A Virus ◽  
Influenza A ◽  
Rna Binding ◽  
Binding Domain ◽  
Wild Type Virus ◽  
Ns1 Protein ◽  
Necrosis Factor Alpha ◽  
Tracheal Epithelial ◽  
Rna Binding Domain

ABSTRACT Primary differentiated respiratory epithelial cell cultures closely model the in vivo environment and allow for studies of innate immune responses generated specifically by epithelial cells, the primary cell type infected by human influenza A virus strains. We used primary murine tracheal epithelial cell (mTEC) cultures to investigate antiviral and cytokine responses to influenza A virus infection, focusing on the contribution of the RNA binding domain of the NS1 protein. rWSN NS1 R38A replication is attenuated in mTEC cultures; however, viral antigen is detected predominantly in ciliated cells, similar to wild-type virus. NS1 and NS1 R38A proteins display a primarily cytoplasmic localization in infected mTEC cultures. Increased production of tumor necrosis factor alpha, interleukin-6, and beta interferon is observed during rWSN NS1 R38A infection, and cytokines are secreted in a directional manner. Cytokine pretreatment of mTEC cultures and Vero cells suggest that rWSN NS1 R38A is more sensitive to the presence of antiviral/inflammatory cytokines than wild-type virus. Our results demonstrate that the RNA binding domain is a critical regulator of both cytokine production and cytokine sensitivity during influenza A virus infection of primary tracheal epithelial cells.

scholarly journals Immunogenicity and Protection Efficacy of Replication-Deficient Influenza A Viruses with Altered NS1 Genes

2004 ◽  
Vol 78 (23) ◽  
pp. 13037-13045 ◽  
Author(s):  
Boris Ferko ◽  
Jana Stasakova ◽  
Julia Romanova ◽  
Christian Kittel ◽  
Sabine Sereinig ◽  
...  
Keyword(s):  
Influenza A ◽  
Rna Binding ◽  
T Cell Response ◽  
Binding Domain ◽  
Wild Type Virus ◽  
Type Virus ◽  
Ns1 Protein ◽  
Wild Type ◽  
Influenza A Viruses ◽  
Rna Binding Domain

ABSTRACT We explored the immunogenic properties of influenza A viruses with altered NS1 genes (NS1 mutant viruses). NS1 mutant viruses expressing NS1 proteins with an impaired RNA-binding function or insertion of a longer foreign sequence did not replicate in murine lungs but still were capable of inducing a Th1-type immune response resulting in significant titers of virus-specific serum and mucosal immunoglobulin G2 (IgG2) and IgA, but with lower titers of IgG1. In contrast, replicating viruses elicited high titers of serum and mucosal IgG1 but less serum IgA. Replication-deficient NS1 mutant viruses induced a rapid local release of proinflammatory cytokines such as interleukin-1β (IL-1β) and IL-6. Moreover, these viruses also elicited markedly higher levels of IFN-α/β in serum than the wild-type virus. Comparable numbers of virus-specific primary CD8+ T cells were determined in all of the groups of immunized mice. The most rapid onset of the recall CD8+-T-cell response upon the wild-type virus challenge was detected in mice primed with NS1 mutant viruses eliciting high levels of cytokines. It is noteworthy that there was one NS1 mutant virus encoding NS1 protein with a deletion of 40 amino acids predominantly in the RNA-binding domain that induced the highest levels of IFN-α/β, IL-6 and IL-1β after infection. Mice that were immunized with this virus were completely protected from the challenge infection. These findings indicate that a targeted modification of the RNA-binding domain of the NS1 protein is a valuable technique to generate replication-deficient, but immunogenic influenza virus vaccines.

scholarly journals Structural Basis of the Influenza A Virus RNA Polymerase PB2 RNA-binding Domain Containing the Pathogenicity-determinant Lysine 627 Residue

2009 ◽  
Vol 284 (11) ◽  
pp. 6855-6860 ◽  
Author(s):  
Takashi Kuzuhara ◽  
Daisuke Kise ◽  
Hiroko Yoshida ◽  
Takahiro Horita ◽  
Yoshimi Murazaki ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Influenza A Virus ◽  
Influenza A ◽  
Rna Binding ◽  
Binding Domain ◽  
Structural Basis ◽  
Virus Rna ◽  
Pathogenicity Determinant ◽  
Rna Binding Domain

scholarly journals A Recombinant Influenza A Virus Expressing anRNA-Binding-Defective NS1 Protein Induces High Levels of BetaInterferon and Is Attenuated inMice

2003 ◽  
Vol 77 (24) ◽  
pp. 13257-13266 ◽  
Author(s):  
Nicola R. Donelan ◽  
Christopher F. Basler ◽  
Adolfo García-Sastre
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Rna Binding ◽  
Mdck Cells ◽  
Binding Activity ◽  
Mutant Virus ◽  
Wild Type Virus ◽  
Ns1 Protein ◽  
Wild Type ◽  
Dsrna Binding

ABSTRACT Previously we found that the amino-terminal region of the NS1 protein of influenza A virus plays a key role in preventing the induction of beta interferon (IFN-β) in virus-infected cells. This region is characterized by its ability to bind to different RNA species, including double-stranded RNA (dsRNA), a known potent inducer of IFNs. In order to investigate whether the NS1 RNA-binding activity is required for its IFN antagonist properties, we have generated a recombinant influenza A virus which expresses a mutant NS1 protein defective in dsRNA binding. For this purpose, we substituted alanines for two basic amino acids within NS1 (R38 and K41) that were previously found to be required for RNA binding. Cells infected with the resulting recombinant virus showed increased IFN-β production, demonstrating that these two amino acids play a critical role in the inhibition of IFN production by the NS1 protein during viral infection. In addition, this virus grew to lower titers than wild-type virus in MDCK cells, and it was attenuated in mice. Interestingly, passaging in MDCK cells resulted in the selection of a mutant virus containing a third mutation at amino acid residue 42 of the NS1 protein (S42G). This mutation did not result in a gain in dsRNA-binding activity by the NS1 protein, as measured by an in vitro assay. Nevertheless, the NS1 R38AK41AS42G mutant virus was able to replicate in MDCK cells to titers close to those of wild-type virus. This mutant virus had intermediate virulence in mice, between those of the wild-type and parental NS1 R38AK41A viruses. These results suggest not only that the IFN antagonist properties of the NS1 protein depend on its ability to bind dsRNA but also that they can be modulated by amino acid residues not involved in RNA binding.

scholarly journals The NS1 Protein of Influenza A Virus Blocks RIG-I-Mediated Activation of the Noncanonical NF-κB Pathway and p52/RelB-Dependent Gene Expression in Lung Epithelial Cells

2012 ◽  
Vol 86 (18) ◽  
pp. 10211-10217 ◽  
Author(s):  
Andrea Rückle ◽  
Emanuel Haasbach ◽  
Ilkka Julkunen ◽  
Oliver Planz ◽  
Christina Ehrhardt ◽  
...  
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Influenza A Virus ◽  
Influenza A ◽  
Target Gene ◽  
Lung Epithelial Cells ◽  
Ns1 Protein ◽  
Antiviral Immune Response ◽  
Lung Epithelial ◽  
Infected Cells

Influenza A virus (IAV) infection of epithelial cells activates NF-κB transcription factors via the canonical NF-κB signaling pathway, which modulates both the antiviral immune response and viral replication. Since almost nothing is known so far about a function of noncanonical NF-κB signaling after IAV infection, we tested infected cells for activation of p52 and RelB. We show that the viral NS1 protein strongly inhibits RIG-I-mediated noncanonical NF-κB activation and expression of the noncanonical target gene CCL19.

Crystal structure of the unique RNA-binding domain of the influenza virus NS1 protein

1997 ◽  
Vol 4 (11) ◽  
pp. 896-899 ◽  
Author(s):  
Jinsong Liu ◽  
Patricia A. Lynch ◽  
Chen-ya Chien ◽  
Gaetano T. Montelione ◽  
Robert M. Krug ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Influenza Virus ◽  
Rna Binding ◽  
Binding Domain ◽  
Ns1 Protein ◽  
Rna Binding Domain

scholarly journals The accumulation of influenza A virus segment 7 spliced mRNAs is regulated by the NS1 protein

2012 ◽  
Vol 93 (1) ◽  
pp. 113-118 ◽  
Author(s):  
Nicole C. Robb ◽  
Ervin Fodor
Keyword(s):  
Influenza Virus ◽  
Viral Infection ◽  
Influenza A Virus ◽  
Influenza A ◽  
Rna Binding ◽  
Mrna Splicing ◽  
Ns1 Protein ◽  
Binding Ability ◽  
Alternatively Spliced ◽  
Transcription And Replication

The influenza A virus M1 mRNA is alternatively spliced to produce M2 mRNA, mRNA3, and in some cases, M4 mRNA. Splicing of influenza mRNAs is carried out by the cellular splicing machinery and is thought to be regulated, as both spliced and unspliced mRNAs encode proteins. In this study, we used radioactively labelled primers to investigate the accumulation of spliced and unspliced M segment mRNAs in viral infection and ribonucleoprotein (RNP) reconstitution assays in which only the minimal components required for transcription and replication to occur were expressed. We found that co-expression of the viral NS1 protein in an RNP reconstitution assay altered the accumulation of spliced mRNAs compared with when it was absent, and that this activity was dependent on the RNA-binding ability of NS1. These findings suggest that the NS1 protein plays a role in the regulation of splicing of influenza virus M1 mRNA.

Sign in / Sign up

Export Citation Format

Share Document