Increased inducible nitric oxide synthase expression in organs is associated with a higher severity of H5N1 influenza virus infection.

BACKGROUND: The mechanisms of disease severity caused by H5N1 influenza virus infection remain somewhat unclear. Studies have indicated that a high viral load and an associated hyper inflammatory immune response are influential during the onset of infection. This dysregulated inflammatory response w...

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Main Authors: Simon Burggraaf, John Bingham, Jean Payne, Wayne G Kimpton, John W Lowenthal, Andrew G D Bean
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2011-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC3023712?pdf=render
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author Simon Burggraaf
John Bingham
Jean Payne
Wayne G Kimpton
John W Lowenthal
Andrew G D Bean
author_facet Simon Burggraaf
John Bingham
Jean Payne
Wayne G Kimpton
John W Lowenthal
Andrew G D Bean
author_sort Simon Burggraaf
collection DOAJ
description BACKGROUND: The mechanisms of disease severity caused by H5N1 influenza virus infection remain somewhat unclear. Studies have indicated that a high viral load and an associated hyper inflammatory immune response are influential during the onset of infection. This dysregulated inflammatory response with increased levels of free radicals, such as nitric oxide (NO), appears likely to contribute to disease severity. However, enzymes of the nitric oxide synthase (NOS) family such as the inducible form of NOS (iNOS) generate NO, which serves as a potent anti-viral molecule to combat infection in combination with acute phase proteins and cytokines. Nevertheless, excessive production of iNOS and subsequent high levels of NO during H5N1 infection may have negative effects, acting with other damaging oxidants to promote excessive inflammation or induce apoptosis. METHODOLOGY/PRINCIPAL FINDINGS: There are dramatic differences in the severity of disease between chickens and ducks following H5N1 influenza infection. Chickens show a high level of mortality and associated pathology, whilst ducks show relatively minor symptoms. It is not clear how this varying pathogenicty comes about, although it has been suggested that an overactive inflammatory immune response to infection in the chicken, compared to the duck response, may be to blame for the disparity in observed pathology. In this study, we identify and investigate iNOS gene expression in ducks and chickens during H5N1 influenza infection. Infected chickens show a marked increase in iNOS expression in a wide range of organs. Contrastingly, infected duck tissues have lower levels of tissue related iNOS expression. CONCLUSIONS/SIGNIFICANCE: The differences in iNOS expression levels observed between chickens and ducks during H5N1 avian influenza infection may be important in the inflammatory response that contributes to the pathology. Understanding the regulation of iNOS expression and its role during H5N1 influenza infection may provide insights for the development of new therapeutic strategies in the treatment of avian influenza infection.
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spelling doaj.art-b0d9401417f041dca54c34ec3e8d26992022-12-21T18:46:41ZengPublic Library of Science (PLoS)PLoS ONE1932-62032011-01-0161e1456110.1371/journal.pone.0014561Increased inducible nitric oxide synthase expression in organs is associated with a higher severity of H5N1 influenza virus infection.Simon BurggraafJohn BinghamJean PayneWayne G KimptonJohn W LowenthalAndrew G D BeanBACKGROUND: The mechanisms of disease severity caused by H5N1 influenza virus infection remain somewhat unclear. Studies have indicated that a high viral load and an associated hyper inflammatory immune response are influential during the onset of infection. This dysregulated inflammatory response with increased levels of free radicals, such as nitric oxide (NO), appears likely to contribute to disease severity. However, enzymes of the nitric oxide synthase (NOS) family such as the inducible form of NOS (iNOS) generate NO, which serves as a potent anti-viral molecule to combat infection in combination with acute phase proteins and cytokines. Nevertheless, excessive production of iNOS and subsequent high levels of NO during H5N1 infection may have negative effects, acting with other damaging oxidants to promote excessive inflammation or induce apoptosis. METHODOLOGY/PRINCIPAL FINDINGS: There are dramatic differences in the severity of disease between chickens and ducks following H5N1 influenza infection. Chickens show a high level of mortality and associated pathology, whilst ducks show relatively minor symptoms. It is not clear how this varying pathogenicty comes about, although it has been suggested that an overactive inflammatory immune response to infection in the chicken, compared to the duck response, may be to blame for the disparity in observed pathology. In this study, we identify and investigate iNOS gene expression in ducks and chickens during H5N1 influenza infection. Infected chickens show a marked increase in iNOS expression in a wide range of organs. Contrastingly, infected duck tissues have lower levels of tissue related iNOS expression. CONCLUSIONS/SIGNIFICANCE: The differences in iNOS expression levels observed between chickens and ducks during H5N1 avian influenza infection may be important in the inflammatory response that contributes to the pathology. Understanding the regulation of iNOS expression and its role during H5N1 influenza infection may provide insights for the development of new therapeutic strategies in the treatment of avian influenza infection.http://europepmc.org/articles/PMC3023712?pdf=render
spellingShingle Simon Burggraaf
John Bingham
Jean Payne
Wayne G Kimpton
John W Lowenthal
Andrew G D Bean
Increased inducible nitric oxide synthase expression in organs is associated with a higher severity of H5N1 influenza virus infection.
PLoS ONE
title Increased inducible nitric oxide synthase expression in organs is associated with a higher severity of H5N1 influenza virus infection.
title_full Increased inducible nitric oxide synthase expression in organs is associated with a higher severity of H5N1 influenza virus infection.
title_fullStr Increased inducible nitric oxide synthase expression in organs is associated with a higher severity of H5N1 influenza virus infection.
title_full_unstemmed Increased inducible nitric oxide synthase expression in organs is associated with a higher severity of H5N1 influenza virus infection.
title_short Increased inducible nitric oxide synthase expression in organs is associated with a higher severity of H5N1 influenza virus infection.
title_sort increased inducible nitric oxide synthase expression in organs is associated with a higher severity of h5n1 influenza virus infection
url http://europepmc.org/articles/PMC3023712?pdf=render
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