Cargando…

Distribution of sialic acid receptors and influenza A virus of avian and swine origin in experimentally infected pigs

BACKGROUND: Pigs are considered susceptible to influenza A virus infections from different host origins because earlier studies have shown that they have receptors for both avian (sialic acid-alpha-2,3-terminal saccharides (SA-alpha-2,3)) and swine/human (SA-alpha-2,6) influenza viruses in the upper...

Descripción completa

Detalles Bibliográficos
Autores principales: Trebbien, Ramona, Larsen, Lars E, Viuff, Birgitte M
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3177912/
https://www.ncbi.nlm.nih.gov/pubmed/21902821
http://dx.doi.org/10.1186/1743-422X-8-434
_version_ 1782212354690252800
author Trebbien, Ramona
Larsen, Lars E
Viuff, Birgitte M
author_facet Trebbien, Ramona
Larsen, Lars E
Viuff, Birgitte M
author_sort Trebbien, Ramona
collection PubMed
description BACKGROUND: Pigs are considered susceptible to influenza A virus infections from different host origins because earlier studies have shown that they have receptors for both avian (sialic acid-alpha-2,3-terminal saccharides (SA-alpha-2,3)) and swine/human (SA-alpha-2,6) influenza viruses in the upper respiratory tract. Furthermore, experimental and natural infections in pigs have been reported with influenza A virus from avian and human sources. METHODS: This study investigated the receptor distribution in the entire respiratory tract of pigs using specific lectins Maackia Amurensis (MAA) I, and II, and Sambucus Nigra (SNA). Furthermore, the predilection sites of swine influenza virus (SIV) subtypes H1N1 and H1N2 as well as avian influenza virus (AIV) subtype H4N6 were investigated in the respiratory tract of experimentally infected pigs using immunohistochemical methods. RESULTS: SIV antigen was widely distributed in bronchi, but was also present in epithelial cells of the nose, trachea, bronchioles, and alveolar type I and II epithelial cells in severely affected animals. AIV was found in the lower respiratory tract, especially in alveolar type II epithelial cells and occasionally in bronchiolar epithelial cells. SA-alpha-2,6 was the predominant receptor in all areas of the respiratory tract with an average of 80-100% lining at the epithelial cells. On the contrary, the SA-alpha-2,3 was not present (0%) at epithelial cells of nose, trachea, and most bronchi, but was found in small amounts in bronchioles, and in alveoli reaching an average of 20-40% at the epithelial cells. Interestingly, the receptor expression of both SA-alpha-2,3 and 2,6 was markedly diminished in influenza infected areas compared to non-infected areas. CONCLUSIONS: A difference in predilection sites between SIV and AIV virus was found, and this difference was in accordance with the distribution of the SA-alpha-2,6 and SA-alpha-2,3 receptor, respectively. The results indicated that the distribution of influenza A virus receptors in pigs are similar to that of humans and therefore challenge the theory that the pig acts as a mixing vessel between human and avian influenza viruses. Furthermore, it was shown that AIV prefers to infect alveolar type II epithelial cells in pigs. This corresponds with findings in humans emphasising the resemblance between the two species.
format Online
Article
Text
id pubmed-3177912
institution National Center for Biotechnology Information
language English
publishDate 2011
publisher BioMed Central
record_format MEDLINE/PubMed
spelling pubmed-31779122011-09-22 Distribution of sialic acid receptors and influenza A virus of avian and swine origin in experimentally infected pigs Trebbien, Ramona Larsen, Lars E Viuff, Birgitte M Virol J Research BACKGROUND: Pigs are considered susceptible to influenza A virus infections from different host origins because earlier studies have shown that they have receptors for both avian (sialic acid-alpha-2,3-terminal saccharides (SA-alpha-2,3)) and swine/human (SA-alpha-2,6) influenza viruses in the upper respiratory tract. Furthermore, experimental and natural infections in pigs have been reported with influenza A virus from avian and human sources. METHODS: This study investigated the receptor distribution in the entire respiratory tract of pigs using specific lectins Maackia Amurensis (MAA) I, and II, and Sambucus Nigra (SNA). Furthermore, the predilection sites of swine influenza virus (SIV) subtypes H1N1 and H1N2 as well as avian influenza virus (AIV) subtype H4N6 were investigated in the respiratory tract of experimentally infected pigs using immunohistochemical methods. RESULTS: SIV antigen was widely distributed in bronchi, but was also present in epithelial cells of the nose, trachea, bronchioles, and alveolar type I and II epithelial cells in severely affected animals. AIV was found in the lower respiratory tract, especially in alveolar type II epithelial cells and occasionally in bronchiolar epithelial cells. SA-alpha-2,6 was the predominant receptor in all areas of the respiratory tract with an average of 80-100% lining at the epithelial cells. On the contrary, the SA-alpha-2,3 was not present (0%) at epithelial cells of nose, trachea, and most bronchi, but was found in small amounts in bronchioles, and in alveoli reaching an average of 20-40% at the epithelial cells. Interestingly, the receptor expression of both SA-alpha-2,3 and 2,6 was markedly diminished in influenza infected areas compared to non-infected areas. CONCLUSIONS: A difference in predilection sites between SIV and AIV virus was found, and this difference was in accordance with the distribution of the SA-alpha-2,6 and SA-alpha-2,3 receptor, respectively. The results indicated that the distribution of influenza A virus receptors in pigs are similar to that of humans and therefore challenge the theory that the pig acts as a mixing vessel between human and avian influenza viruses. Furthermore, it was shown that AIV prefers to infect alveolar type II epithelial cells in pigs. This corresponds with findings in humans emphasising the resemblance between the two species. BioMed Central 2011-09-08 /pmc/articles/PMC3177912/ /pubmed/21902821 http://dx.doi.org/10.1186/1743-422X-8-434 Text en Copyright ©2011 Trebbien et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research
Trebbien, Ramona
Larsen, Lars E
Viuff, Birgitte M
Distribution of sialic acid receptors and influenza A virus of avian and swine origin in experimentally infected pigs
title Distribution of sialic acid receptors and influenza A virus of avian and swine origin in experimentally infected pigs
title_full Distribution of sialic acid receptors and influenza A virus of avian and swine origin in experimentally infected pigs
title_fullStr Distribution of sialic acid receptors and influenza A virus of avian and swine origin in experimentally infected pigs
title_full_unstemmed Distribution of sialic acid receptors and influenza A virus of avian and swine origin in experimentally infected pigs
title_short Distribution of sialic acid receptors and influenza A virus of avian and swine origin in experimentally infected pigs
title_sort distribution of sialic acid receptors and influenza a virus of avian and swine origin in experimentally infected pigs
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3177912/
https://www.ncbi.nlm.nih.gov/pubmed/21902821
http://dx.doi.org/10.1186/1743-422X-8-434
work_keys_str_mv AT trebbienramona distributionofsialicacidreceptorsandinfluenzaavirusofavianandswineorigininexperimentallyinfectedpigs
AT larsenlarse distributionofsialicacidreceptorsandinfluenzaavirusofavianandswineorigininexperimentallyinfectedpigs
AT viuffbirgittem distributionofsialicacidreceptorsandinfluenzaavirusofavianandswineorigininexperimentallyinfectedpigs