scholarly journals Easily Accessible Polycyclic Amines that Inhibit the Wild-Type and Amantadine-Resistant Mutants of the M2 Channel of Influenza A Virus

2014 ◽  
Vol 57 (13) ◽  
pp. 5738-5747 ◽  
Author(s):  
Matias Rey-Carrizo ◽  
Marta Barniol-Xicota ◽  
Chunlong Ma ◽  
Marta Frigolé-Vivas ◽  
Eva Torres ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Wild Type ◽  
Resistant Mutants

scholarly journals Protective role for the N-terminal domain of α-dystroglycan in Influenza A virus proliferation

2019 ◽  
Vol 116 (23) ◽  
pp. 11396-11401 ◽  
Author(s):  
Jessica C. de Greef ◽  
Bram Slütter ◽  
Mary E. Anderson ◽  
Rebecca Hamlyn ◽  
Raul O’Campo Landa ◽  
...  
Keyword(s):  
Puerto Rico ◽  
Basement Membrane ◽  
Influenza A Virus ◽  
Influenza A ◽  
Protective Role ◽  
Wild Type ◽  
Terminal Domain ◽  
Bodily Fluids ◽  
Control Virus

α-Dystroglycan (α-DG) is a highly glycosylated basement membrane receptor that is cleaved by the proprotein convertase furin, which releases its N-terminal domain (α-DGN). Before cleavage, α-DGN interacts with the glycosyltransferase LARGE1 and initiates functional O-glycosylation of the mucin-like domain of α-DG. Notably, α-DGN has been detected in a wide variety of human bodily fluids, but the physiological significance of secreted α-DGN remains unknown. Here, we show that mice lacking α-DGN exhibit significantly higher viral titers in the lungs after Influenza A virus (IAV) infection (strain A/Puerto Rico/8/1934 H1N1), suggesting an inability to control virus load. Consistent with this, overexpression of α-DGN before infection or intranasal treatment with recombinant α-DGN prior and during infection, significantly reduced IAV titers in the lungs of wild-type mice. Hemagglutination inhibition assays using recombinant α-DGN showed in vitro neutralization of IAV. Collectively, our results support a protective role for α-DGN in IAV proliferation.

scholarly journals New polycyclic dual inhibitors of the wild type and the V27A mutant M2 channel of the influenza A virus with unexpected binding mode

2015 ◽  
Vol 96 ◽  
pp. 318-329 ◽  
Author(s):  
Matias Rey-Carrizo ◽  
Sabrina Gazzarrini ◽  
Salomé Llabrés ◽  
Marta Frigolé-Vivas ◽  
Jordi Juárez-Jiménez ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Binding Mode ◽  
Wild Type ◽  
Dual Inhibitors

scholarly journals The Influenza A Virus M2 Cytoplasmic Tail Is Required for Infectious Virus Production and Efficient Genome Packaging

2005 ◽  
Vol 79 (6) ◽  
pp. 3595-3605 ◽  
Author(s):  
Matthew F. McCown ◽  
Andrew Pekosz
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Infectious Virus ◽  
Virus Production ◽  
Cytoplasmic Tail ◽  
Host Cells ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Virus Particles

ABSTRACT The M2 integral membrane protein encoded by influenza A virus possesses an ion channel activity that is required for efficient virus entry into host cells. The role of the M2 protein cytoplasmic tail in virus replication was examined by generating influenza A viruses encoding M2 proteins with truncated C termini. Deletion of 28 amino acids (M2Stop70) resulted in a virus that produced fourfold-fewer particles but >1,000-fold-fewer infectious particles than wild-type virus. Expression of the full-length M2 protein in trans restored the replication of the M2 truncated virus. Although the M2Stop70 virus particles were similar to wild-type virus in morphology, the M2Stop70 virions contained reduced amounts of viral nucleoprotein and genomic RNA, indicating a defect in vRNP packaging. The data presented indicate the M2 cytoplasmic tail plays a role in infectious virus production by coordinating the efficient packaging of genome segments into influenza virus particles.

scholarly journals Functional Replacement of the Carboxy-Terminal Two-Thirds of the Influenza A Virus NS1 Protein with Short Heterologous Dimerization Domains

2002 ◽  
Vol 76 (24) ◽  
pp. 12951-12962 ◽  
Author(s):  
Xiuyan Wang ◽  
Christopher F. Basler ◽  
Bryan R. G. Williams ◽  
Robert H. Silverman ◽  
Peter Palese ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Influenza A Virus ◽  
Influenza A ◽  
Rna Binding ◽  
Influenza Viruses ◽  
Ns1 Protein ◽  
Wild Type ◽  
Dimerization Domain ◽  
Carboxy Terminal

ABSTRACT The NS1 protein of influenza A/WSN/33 virus is a 230-amino-acid-long protein which functions as an interferon alpha/beta (IFN-α/β) antagonist by preventing the synthesis of IFN during viral infection. In tissue culture, the IFN inhibitory function of the NS1 protein has been mapped to the RNA binding domain, the first 73 amino acids. Nevertheless, influenza viruses expressing carboxy-terminally truncated NS1 proteins are attenuated in mice. Dimerization of the NS1 protein has previously been shown to be essential for its RNA binding activity. We have explored the ability of heterologous dimerization domains to functionally substitute in vivo for the carboxy-terminal domains of the NS1 protein. Recombinant influenza viruses were generated that expressed truncated NS1 proteins of 126 amino acids, fused to 28 or 24 amino acids derived from the dimerization domains of either the Saccharomyces cerevisiae PUT3 or the Drosophila melanogaster Ncd (DmNcd) proteins. These viruses regained virulence and lethality in mice. Moreover, a recombinant influenza virus expressing only the first 73 amino acids of the NS1 protein was able to replicate in mice lacking three IFN-regulated antiviral enzymes, PKR, RNaseL, and Mx, but not in wild-type (Mx-deficient) mice, suggesting that the attenuation was mainly due to an inability to inhibit the IFN system. Remarkably, a virus with an NS1 truncated at amino acid 73 but fused to the dimerization domain of DmNcd replicated and was also highly pathogenic in wild-type mice. These results suggest that the main biological function of the carboxy-terminal region of the NS1 protein of influenza A virus is the enhancement of its IFN antagonist properties by stabilizing the NS1 dimeric structure.

ADVANTAGE OF LIVE ATTENUATED COLD-ADAPTED INFLUENZA A VIRUS OVER INACTIVATED VACCINE FOR A/WASHINGTON/80 (H3N2) WILD-TYPE VIRUS INFECTION

The Lancet ◽  
1984 ◽  
Vol 323 (8379) ◽  
pp. 705-708 ◽  
Author(s):  
MaryLou Clements ◽  
RobertF Betts ◽  
BrianR Murphy
Keyword(s):  
Virus Infection ◽  
Influenza A Virus ◽  
Influenza A ◽  
Wild Type Virus ◽  
Inactivated Vaccine ◽  
Type Virus ◽  
Wild Type ◽  
Cold Adapted

scholarly journals Codon Deletions in the Influenza A Virus PA Gene Generate Temperature-Sensitive Viruses

2016 ◽  
Vol 90 (7) ◽  
pp. 3684-3693 ◽  
Author(s):  
Léa Meyer ◽  
Alix Sausset ◽  
Laura Sedano ◽  
Bruno Da Costa ◽  
Ronan Le Goffic ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Rna Polymerase ◽  
Influenza A Virus ◽  
Influenza A ◽  
Wild Type Virus ◽  
Deletion Mutants ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Wild Type

ABSTRACTThe influenza virus RNA-dependent RNA polymerase, which is composed of three subunits, PB1, PB2, and PA, catalyzes genome replication and transcription within the cell nucleus. The PA linker (residues 197 to 256) can be altered by nucleotide substitutions to engineer temperature-sensitive (ts), attenuated mutants that display a defect in the transport of the PA–PB1 complex to the nucleus at a restrictive temperature. In this study, we investigated the ability of the PA linker to tolerate deletion mutations for furtherin vitroandin vivocharacterization. Four viable mutants with single-codon deletions were generated; all of them exhibited atsphenotype that was associated with the reduced efficiency of replication/transcription of a pseudoviral reporter RNA in a minireplicon assay. Using fluorescently tagged PB1, we observed that the deletion mutants did not efficiently recruit PB1 to reach the nucleus at a restrictive temperature (39.5°C). Mouse infections showed that the four mutants were attenuated and induced antibodies that were able to protect mice from challenge with a lethal homologous wild-type virus. Serialin vitropassages of two deletion mutants at 39.5°C and 37°C did not allow the restoration of a wild-type phenotype among virus progeny. Thus, our results identify codons that can be deleted in the PA gene to engineer genetically stabletsmutants that could be used to design novel attenuated vaccines.IMPORTANCEIn order to generate genetically stable live influenza A virus vaccines, we constructed viruses with single-codon deletions in a discrete domain of the RNA polymerase PA gene. The four rescued viruses exhibited a temperature-sensitive phenotype that we found was associated with a defect in the transport of the PA–PB1 dimer to the nucleus, where viral replication occurs. Thesetsdeletion mutants were shown to be attenuated and to be able to produce antibodies in mice and to protect them from a lethal challenge. Assays to select revertants that were able to grow efficiently at a restrictive temperature failed, showing that these deletion mutants are genetically more stable than conventional substitution mutants. These results are of interest for the design of genetically stable live influenza virus vaccines.

scholarly journals CD83 Expression Regulates Antibody Production in Response to Influenza A Virus Infection

2020 ◽  
Author(s):  
Madhav Akauliya ◽  
Avishekh Gautam ◽  
Sony Maharjan ◽  
Byoung Kwon Park ◽  
Jinsoo Kim ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
Virus Infection ◽  
Influenza A Virus ◽  
Cell Population ◽  
Peritoneal Cavity ◽  
Antibody Production ◽  
Influenza A ◽  
Wild Type ◽  
Influenza A Virus Infection

Abstract Background: CD83 is known to regulate lymphocyte maturation, activation, homeostasis, and antibody response to immunization and infection. While CD83 has a major part in B cell function, its role in influenza A virus infection has not yet been investigated. Methods: We investigated the role of CD83 using C57BL/6J wild type mice and CD83 knockout (KO) mice after intraperitoneal administration of the influenza A/WSN/1933 virus. We analyzed cells of the peritoneal cavity, splenocytes, and cells of the bone marrow with FACS to investigate CD83 expression and cell population change in response to the virus infection. ELISA was performed with sera and peritoneal cavity fluids to detect A/WSN/1933 virus-specific IgG and the subclasses of IgG. Results: FACS analysis data showed a transient but distinct induction of CD83 expression in the peritoneal B cells of wild type mice. CD83 KO mice exhibited a delayed recovery of B cells in the bone marrow after influenza virus infection and overall, a smaller T cell population compared to wild type mice. The peritoneal cavity and serum of the wild type mice contained a high titer of IgG within 14 days after infection, whereas the CD83 KO mice had a very low titer of IgG. Conclusions: These results show the importance of CD83 in lymphocytes homeostasis and antibody production during influenza A virus infection.

scholarly journals Favipiravir-resistant influenza A virus shows potential for transmission

2020 ◽  
Author(s):  
Daniel H. Goldhill ◽  
Ada Yan ◽  
Rebecca Frise ◽  
Jie Zhou ◽  
Jennifer Shelley ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Genetic Background ◽  
Influenza A ◽  
Resistance Mutation ◽  
Polymerase Activity ◽  
Resistant Virus ◽  
Wild Type ◽  
Fitness Advantage

AbstractFavipiravir is a nucleoside analogue which has been licensed to treat influenza in the event of a new pandemic. We previously described a favipiravir resistant influenza A virus generated by in vitro passage in presence of drug with two mutations: K229R in PB1, which conferred resistance at a cost to polymerase activity, and P653L in PA, which compensated for the cost of polymerase activity. However, the clinical relevance of these mutations is unclear as the mutations have not been found in natural isolates and it is unknown whether viruses harbouring these mutations would replicate or transmit in vivo. Here, we infected ferrets with a mix of wild type p(H1N1) 2009 and corresponding favipiravir-resistant virus and tested for replication and transmission in the absence of drug. Favipiravir-resistant virus successfully infected ferrets and was transmitted by both contact transmission and respiratory droplet routes. However, sequencing revealed the mutation that conferred resistance, K229R, decreased in frequency over time within ferrets. Modelling revealed that due to a fitness advantage for the PA P653L mutant, reassortment with the wild-type virus to gain wild-type PB1 segment in vivo resulted in the loss of the PB1 resistance mutation K229R. We demonstrated that this fitness advantage of PA P653L in the background of our starting virus A/England/195/2009 was due to a maladapted PA in first wave isolates from the 2009 pandemic. We show there is no fitness advantage of P653L in more recent pH1N1 influenza A viruses. Therefore, whilst favipiravir-resistant virus can transmit in vivo, the likelihood that the resistance mutation is retained in the absence of drug pressure may vary depending on the genetic background of the starting viral strain.Author SummaryIn the event of a new influenza pandemic, drugs will be our first line of defence against the virus. However, drug resistance has proven to be particularly problematic to drugs against influenza. Favipiravir is a novel drug which might be used against influenza virus in the event of a new pandemic. Is resistance likely to be a problem for the use of favipiravir? Our previous work has shown that resistance to favipiravir can be generated in cell culture but we don’t know whether there will be a cost preventing the spread of resistance in whole organisms. Here, we used a mix of wild-type and resistant influenza viruses from early in the 2009 pandemic to test whether viruses resistant to favipiravir could transmit between ferrets. We found that the resistant viruses could transmit but that the resistance mutation was selected against within some ferrets. Using modelling and in vitro experiments, we found that the resistant mutation was selected against in the influenza strain from our experiment but not in more recently evolved strains. Our results show that favipiravir resistant viruses could spread if resistance is generated but the probability will depend on the genetic background of the virus.

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