scholarly journals Strain-dependent effects of PB1-F2 of triple-reassortant H3N2 influenza viruses in swine

2012 ◽  
Vol 93 (10) ◽  
pp. 2204-2214 ◽  
Author(s):  
Lindomar Pena ◽  
Amy L. Vincent ◽  
Crystal L. Loving ◽  
Jamie N. Henningson ◽  
Kelly M. Lager ◽  
...  
Keyword(s):  
Virus Replication ◽  
Influenza A ◽  
Reverse Genetics ◽  
Influenza Viruses ◽  
Dependent Manner ◽  
Lung Pathology ◽  
Influenza A Viruses ◽  
Virus Shedding ◽  
The Impact ◽  
Strain Dependent

The PB1-F2 protein of the influenza A viruses (IAVs) can act as a virulence factor in mice. Its contribution to the virulence of IAV in swine, however, remains largely unexplored. In this study, we chose two genetically related H3N2 triple-reassortant IAVs to assess the impact of PB1-F2 in virus replication and virulence in pigs. Using reverse genetics, we disrupted the PB1-F2 ORF of A/swine/Wisconsin/14094/99 (H3N2) (Sw/99) and A/turkey/Ohio/313053/04 (H3N2) (Ty/04). Removing the PB1-F2 ORF led to increased expression of PB1-N40 in a strain-dependent manner. Ablation of the PB1-F2 ORF (or incorporation of the N66S mutation in the PB1-F2 ORF, Sw/99 N66S) affected the replication in porcine alveolar macrophages of only the Sw/99 KO (PB1-F2 knockout) and Sw/99 N66S variants. The Ty/04 KO strain showed decreased virus replication in swine respiratory explants, whereas no such effect was observed in Sw/99 KO, compared with the wild-type (WT) counterparts. In pigs, PB1-F2 did not affect virus shedding or viral load in the lungs for any of these strains. Upon necropsy, PB1-F2 had no effect on the lung pathology caused by Sw/99 variants. Interestingly, the Ty/04 KO-infected pigs showed significantly increased lung pathology at 3 days post-infection compared with pigs infected with the Ty/04 WT strain. In addition, the pulmonary levels of interleukin (IL)-6, IL-8 and gamma interferon were regulated differentially by the expression of PB1-F2. Taken together, these results indicate that PB1-F2 modulates virus replication, virulence and innate immune responses in pigs in a strain-dependent fashion.

scholarly journals International Laboratory Comparison of Influenza Microneutralization Assays for A(H1N1)pdm09, A(H3N2), and A(H5N1) Influenza Viruses by CONSISE

2015 ◽  
Vol 22 (8) ◽  
pp. 957-964 ◽  
Author(s):  
Karen L. Laurie ◽  
Othmar G. Engelhardt ◽  
John Wood ◽  
Alan Heath ◽  
Jacqueline M. Katz ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Incubation Time ◽  
Influenza A ◽  
Influenza Viruses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Influenza A Viruses ◽  
H5n1 Influenza ◽  
The World ◽  
International Laboratory ◽  
The Impact

ABSTRACTThe microneutralization assay is commonly used to detect antibodies to influenza virus, and multiple protocols are used worldwide. These protocols differ in the incubation time of the assay as well as in the order of specific steps, and even within protocols there are often further adjustments in individual laboratories. The impact these protocol variations have on influenza serology data is unclear. Thus, a laboratory comparison of the 2-day enzyme-linked immunosorbent assay (ELISA) and 3-day hemagglutination (HA) microneutralization (MN) protocols, using A(H1N1)pdm09, A(H3N2), and A(H5N1) viruses, was performed by the CONSISE Laboratory Working Group. Individual laboratories performed both assay protocols, on multiple occasions, using different serum panels. Thirteen laboratories from around the world participated. Within each laboratory, serum sample titers for the different assay protocols were compared between assays to determine the sensitivity of each assay and were compared between replicates to assess the reproducibility of each protocol for each laboratory. There was good correlation of the results obtained using the two assay protocols in most laboratories, indicating that these assays may be interchangeable for detecting antibodies to the influenza A viruses included in this study. Importantly, participating laboratories have aligned their methodologies to the CONSISE consensus 2-day ELISA and 3-day HA MN assay protocols to enable better correlation of these assays in the future.

scholarly journals Impact of oseltamivir treatment on influenza A and B dynamics in human volunteers

2020 ◽  
Author(s):  
Kyla L. Hooker ◽  
Vitaly V. Ganusov
Keyword(s):  
Clinical Trials ◽  
Influenza Virus ◽  
Influenza A ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Influenza B ◽  
Virus Shedding ◽  
Viral Shedding ◽  
Human Volunteers ◽  
The Impact

AbstractInfluenza viruses infect millions of humans every year causing an estimated 400,000 deaths globally. Due to continuous virus evolution current vaccines provide only limited protection against the flu. Several antiviral drugs are available to treat influenza infection, and one of the most most commonly used drugs is oseltamivir (Tamiflu). While the mechanism of action of oseltamivir as a neuraminidase inhibitor is well understood, the impact of oseltamivir on influenza virus dynamics in humans has been controversial. Many clinical trials with oseltamivir have been done by pharmaceutical companies such as Roche but the results of these trials until recently have been reported as summary reports or papers. Typically, such reports included median virus shedding curves for placebo and drug-treated influenza virus infected volunteers often indicating high efficacy of the early treatment. However, median shedding curves may be not accurately representing drug impact in individual volunteers. Importantly, due to public pressure clinical trials data testing oseltamivir efficacy has been recently released in the form of redacted PDF documents. We digitized and re-analyzed experimental data on influenza virus shedding in human volunteers from three previously published trials: on influenza A (1 trial) or B viruses (2 trials). Given that not all volunteers exposed to influenza viruses actually start virus shedding we found that impact of oseltamivir on the virus shedding dynamics was dependent on i) selection of volunteers that were infected with the virus, and ii) the detection limit in the measurement assay; both of these details were not well articulated in the published studies. By assuming that any viral measurement is above the limit of detection we could match previously published data on median influenza A virus (flu A study) shedding but not on influenza B virus shedding (flu B study B) in human volunteers. Additional analyses confirmed that oseltamivir had an impact on the duration of shedding and overall shedding (defined as area under the curve) but this result was varied by the trial. Interestingly, treatment had no impact on the rates at which shedding increased or declined with time in individual volunteers. Additional analyses showed that oseltamivir impacted the kinetics of the start and end of viral shedding and in about 20-40% of volunteers treatment had no impact on viral shedding duration. Our results suggest an unusual impact of oseltamivir on influenza viruses shedding kinetics and caution about the use of published median data or data from a few individuals for inferences. Furthermore, we call for the need to publish raw data from critical clinical trials that can be then independently analyzed.

scholarly journals High expression levels of influenza virus receptors in airway of the HBV-transgenic mice

2019 ◽  
Vol 147 ◽  
Author(s):  
Jiajun Yang ◽  
Hao Li ◽  
Liyuan Jia ◽  
Xianchun Lan ◽  
Yuhui Zhao ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Transgenic Mice ◽  
Chronic Diseases ◽  
Influenza A ◽  
Respiratory Illness ◽  
Influenza Viruses ◽  
Influenza A Viruses ◽  
Expression Levels ◽  
Virus Receptors ◽  
The Impact

Abstract In the human population, influenza A viruses are associated with acute respiratory illness and are responsible for millions of deaths annually. Avian and human influenza viruses typically have a different α2-3- and α2-6-linked sialic acid (SA) binding preference. Only a few amino acid changes in the haemagglutinin on the surface of avian influenza viruses (AIV) can cause a switch from avian to human receptor specificity, and the individuals with pathognostic chronic diseases might be more susceptible to AIV due to the decreased expression level of terminal α2-3-linked SA in their saliva. Here, using lectin and virus histochemical staining, we observed the higher expression levels of α2-3/6-linked SA influenza virus receptors in the airway of HBV-transgenic mice compared with that of control mice due to the significant decrease in control mice during ageing, which imply that this is also a risk factor for individuals with pathognostic chronic diseases susceptible to influenza viruses. Our findings will help understand the impact on influenza virus pathogenesis and transmission.

scholarly journals Establishment of Vero cell RNA polymerase I-driven reverse genetics for Influenza A virus and its application for pandemic (H1N1) 2009 influenza virus vaccine production

2013 ◽  
Vol 94 (6) ◽  
pp. 1230-1235 ◽  
Author(s):  
Min-Suk Song ◽  
Yun Hee Baek ◽  
Philippe Noriel Q. Pascua ◽  
Hyeok-il Kwon ◽  
Su-Jin Park ◽  
...  
Keyword(s):  
Vero Cell ◽  
Influenza A ◽  
Reverse Genetics ◽  
Vero Cells ◽  
Influenza Virus Vaccine ◽  
Influenza Viruses ◽  
Vaccine Production ◽  
Influenza A Viruses ◽  
Alternative Means ◽  
Polymerase I

The constant threat of newly emerging influenza viruses with pandemic potential requires the need for prompt vaccine production. Here, we utilized the Vero cell polymerase I (PolI) promoter, rather than the commonly used human PolI promoter, in an established reverse-genetics system to rescue viable influenza viruses in Vero cells, an approved cell line for human vaccine production. The Vero PolI promoter was more efficient in Vero cells and demonstrated enhanced transcription levels and virus rescue rates commensurate with that of the human RNA PolI promoter in 293T cells. These results appeared to be associated with more efficient generation of A(H1N1)pdm09- and H5N1-derived vaccine seed viruses in Vero cells, whilst the rescue rates in 293T cells were comparable. Our study provides an alternative means for improving vaccine preparation by using a novel reverse-genetics system for generating influenza A viruses.

scholarly journals Influenza A Viruses Control Expression of Proviral Human p53 Isoforms p53β and Δ133p53α

2012 ◽  
Vol 86 (16) ◽  
pp. 8452-8460 ◽  
Author(s):  
Olivier Terrier ◽  
Virginie Marcel ◽  
Gaëlle Cartet ◽  
David P. Lane ◽  
Bruno Lina ◽  
...  
Keyword(s):  
Virus Infection ◽  
Cell Fate ◽  
Influenza A ◽  
Influenza Virus Infection ◽  
Influenza Viruses ◽  
Lung Epithelial Cells ◽  
Dependent Manner ◽  
Influenza A Viruses ◽  
P53 Isoforms

Previous studies have described the role of p53 isoforms, including p53β and Δ133p53α, in the modulation of the activity of full-length p53, which regulates cell fate. In the context of influenza virus infection, an interplay between influenza viruses and p53 has been described, with p53 being involved in the antiviral response. However, the role of physiological p53 isoforms has never been explored in this context. Here, we demonstrate that p53 isoforms play a role in influenza A virus infection by using silencing and transient expression strategies in human lung epithelial cells. In addition, with the help of a panel of different influenza viruses from different subtypes, we also show that infection differentially regulates the expressions of p53β and Δ133p53α. Altogether, our results highlight the role of p53 isoforms in the viral cycle of influenza A viruses, with p53β and Δ133p53α acting as regulators of viral production in a p53-dependent manner.

scholarly journals Cloning of the Chicken RNA Polymerase I Promoter and Use for Reverse Genetics of Influenza A Viruses in Avian Cells

2005 ◽  
Vol 79 (21) ◽  
pp. 13811-13816 ◽  
Author(s):  
Pascale Massin ◽  
Pierre Rodrigues ◽  
Monica Marasescu ◽  
Sylvie van der Werf ◽  
Nadia Naffakh
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Reverse Genetics ◽  
Promoter Sequence ◽  
Influenza Viruses ◽  
Rna Polymerase I ◽  
Influenza A Viruses ◽  
Virus Research ◽  
Influenza Vaccine Production ◽  
Polymerase I

ABSTRACT Reverse genetics techniques to rescue influenza viruses have thus far been based on the use of a human polymerase I (PolI) promoter to direct the synthesis of the eight viral RNAs. They can only be used on cells from primate origin due to the species specificity of the PolI promoter. Here we report the cloning of the chicken PolI promoter sequence and the generation of recombinant influenza virus upon transfection of bidirectional PolI/PolII plasmids in avian cells. Potential contributions of this new reverse genetics system in the fields of influenza virus research and influenza vaccine production are discussed.

scholarly journals Characterization of a porcine intestinal epithelial cell line for influenza virus production

2012 ◽  
Vol 93 (9) ◽  
pp. 2008-2016 ◽  
Author(s):  
Zhi Sun ◽  
Victor C. Huber ◽  
Kara McCormick ◽  
Radhey S. Kaushik ◽  
Adrianus C. M. Boon ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Cell Line ◽  
Influenza A ◽  
Reverse Genetics ◽  
Mdck Cells ◽  
Influenza Viruses ◽  
Epithelial Cell Line ◽  
Influenza B ◽  
Specific Cell ◽  
Influenza A Viruses

We have developed a porcine intestine epithelial cell line, designated SD-PJEC for the propagation of influenza viruses. The SD-PJEC cell line is a subclone of the IPEC-J2 cell line, which was originally derived from newborn piglet jejunum. Our results demonstrate that SD-PJEC is a cell line of epithelial origin that preferentially expresses receptors of oligosaccharides with Sia2-6Gal modification. This cell line is permissive to infection with human and swine influenza A viruses and some avian influenza viruses, but poorly support the growth of human-origin influenza B viruses. Propagation of swine-origin influenza viruses in these cells results in a rapid growth rate within the first 24 h post-infection and the titres ranged from 4 to 8 log10 TCID50 ml−1. The SD-PJEC cell line was further tested as a potential alternative cell line to Madin–Darby canine kidney (MDCK) cells in conjunction with 293T cells for rescue of swine-origin influenza viruses using the reverse genetics system. The recombinant viruses A/swine/North Carolina/18161/02 (H1N1) and A/swine/Texas/4199-2/98 (H3N2) were rescued with virus titres of 7 and 8.25 log10 TCID50 ml−1, respectively. The availability of this swine-specific cell line represents a more relevant substrate for studies and growth of swine-origin influenza viruses.

scholarly journals Influenza A Viruses with Mutations in the M1 Helix Six Domain Display a Wide Variety of Morphological Phenotypes

2005 ◽  
Vol 79 (2) ◽  
pp. 1262-1270 ◽  
Author(s):  
Laura M. Burleigh ◽  
Lesley J. Calder ◽  
John J. Skehel ◽  
David A. Steinhauer
Keyword(s):  
Nuclear Export ◽  
Influenza A ◽  
Matrix Protein ◽  
Reverse Genetics ◽  
Virus Assembly ◽  
Single Amino Acid ◽  
Dependent Manner ◽  
Influenza A Viruses ◽  
Binding Function ◽  
Wide Range

ABSTRACT Several functions required for the replication of influenza A viruses have been attributed to the viral matrix protein (M1), and a number of studies have focused on a region of the M1 protein designated “helix six.” This region contains an exposed positively charged stretch of amino acids, including the motif 101-RKLKR-105, which has been identified as a nuclear localization signal, but several studies suggest that this domain is also involved in functions such as binding to the ribonucleoprotein genome segments (RNPs), membrane association, interaction with the viral nuclear export protein, and virus assembly. In order to define M1 functions in more detail, a series of mutants containing alanine substitutions in the helix six region were generated in A/WSN/33 virus. These were analyzed for RNP-binding function, their capacity to incorporate into infectious viruses by using reverse genetics, the replication properties of rescued viruses, and the morphological phenotypes of the mutant virus particles. The most notable effect that was identified concerned single amino acid substitution mutants that caused significant alterations to the morphology of budded viruses. Whereas A/WSN/33 virus generally forms particles that are predominantly spherical, observations made by negative stain electron microscopy showed that several of the mutant virions, such as K95A, K98A, R101A, and K102A, display a wide range of shapes and sizes that varied in a temperature-dependent manner. The K102A mutant is particularly interesting in that it can form extended filamentous particles. These results support the proposition that the helix six domain is involved in the process of virus assembly.

scholarly journals Protective porcine influenza virus-specific monoclonal antibodies recognize similar haemagglutinin epitopes as humans

2021 ◽  
Vol 17 (3) ◽  
pp. e1009330
Author(s):  
Barbara Holzer ◽  
Pramila Rijal ◽  
Adam McNee ◽  
Basudev Paudyal ◽  
Veronica Martini ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Influenza A ◽  
Virus Evolution ◽  
Influenza Viruses ◽  
Antigenic Drift ◽  
Lung Pathology ◽  
Influenza A Viruses ◽  
Vaccine Recommendations ◽  
Natural Hosts ◽  
Zoonotic Strains

Pigs are natural hosts for the same subtypes of influenza A viruses as humans and integrally involved in virus evolution with frequent interspecies transmissions in both directions. The emergence of the 2009 pandemic H1N1 virus illustrates the importance of pigs in evolution of zoonotic strains. Here we generated pig influenza-specific monoclonal antibodies (mAbs) from H1N1pdm09 infected pigs. The mAbs recognized the same two major immunodominant haemagglutinin (HA) epitopes targeted by humans, one of which is not recognized by post-infection ferret antisera that are commonly used to monitor virus evolution. Neutralizing activity of the pig mAbs was comparable to that of potent human anti-HA mAbs. Further, prophylactic administration of a selected porcine mAb to pigs abolished lung viral load and greatly reduced lung pathology but did not eliminate nasal shedding of virus after H1N1pdm09 challenge. Hence mAbs from pigs, which target HA can significantly reduce disease severity. These results, together with the comparable sizes of pigs and humans, indicate that the pig is a valuable model for understanding how best to apply mAbs as therapy in humans and for monitoring antigenic drift of influenza viruses in humans, thereby providing information highly relevant to making influenza vaccine recommendations.

scholarly journals Role of Quail in the Interspecies Transmission of H9 Influenza A Viruses: Molecular Changes on HA That Correspond to Adaptation from Ducks to Chickens

2003 ◽  
Vol 77 (5) ◽  
pp. 3148-3156 ◽  
Author(s):  
Daniel R. Perez ◽  
Wilina Lim ◽  
Jon P. Seiler ◽  
Guan Yi ◽  
Malik Peiris ◽  
...  
Keyword(s):  
Influenza A ◽  
Reverse Genetics ◽  
Influenza Viruses ◽  
Interspecies Transmission ◽  
Influenza A Viruses ◽  
Species Barrier ◽  
Ha Gene ◽  
Novel Variants ◽  
Efficient Replication

ABSTRACT H9 influenza viruses have become endemic in land-based domestic poultry in Asia and have sporadically crossed to pigs and humans. To understand the molecular determinants of their adaptation to land-based birds, we tested the replication and transmission of several 1970s duck H9 viruses in chickens and quail. Quail were more susceptible than chickens to these viruses, and generation of recombinant H9 viruses by reverse genetics showed that changes in the HA gene are sufficient to initiate efficient replication and transmission in quail. Seven amino acid positions on the HA molecule corresponded to adaptation to land-based birds. In quail H9 viruses, the pattern of amino acids at these seven positions is intermediate between those of duck and chicken viruses; this fact may explain the susceptibility of quail to duck H9 viruses. Our findings suggest that quail provide an environment in which the adaptation of influenza viruses from ducks generates novel variants that can cross the species barrier.

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