tetano
Editor, Senior Moderator
J Virol. 2015 Mar 25. pii: JVI.02537-14. [Epub ahead of print]
[h=1]Pandemic swine H1N1 influenza viruses with almost undetectable neuraminidase activity do not transmit via aerosols in ferrets and are inhibited by human mucus, but not swine mucus.[/h] Zanin M[SUP]1[/SUP], Marathe B[SUP]1[/SUP], Wong SS[SUP]1[/SUP], Yoon SW[SUP]1[/SUP], Collin E[SUP]2[/SUP], Oshansky C[SUP]3[/SUP], Jones J[SUP]1[/SUP], Hause B[SUP]4[/SUP], Webby R[SUP]5[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] A balance between the functions of the influenza virus surface proteins hemagglutinin (HA) and neuraminidase (NA) is thought to be important for the transmission of viruses between humans. Here we describe two pandemic H1N1 viruses, A/swine/Virginia/1814-1/2012 and A/swine/Virginia/1814-2/2012 (pH1N1[SUB]low[/SUB]-1 and -2, respectively) that were isolated from swine symptomatic for influenza. The enzymatic activity of the NA of these viruses was almost undetectable whilst the HA binding affinity for α2,6 sialic acids was greater than that of highly homologous pH1N1 viruses, A/swine/Pennsylvania/2436/2012 and A/swine/Minnesota/2499/2012 (pH1N1-1 and -2), which exhibited better balanced HA and NA activities. In vitro growth kinetics of pH1N1[SUB]low[/SUB] and pH1N1 viruses were similar but aerosol transmission of pH1N1[SUB]low[/SUB]-1 was abrogated and transmission via direct contact was significantly impaired in ferrets compared to pH1N1-1, which transmitted by direct and aerosol contact. In normal human bronchial epithelial cells, pH1N1[SUB]low[/SUB]-1 was significantly inhibited by mucus but pH1N1-1 was not. In Madin-Darby canine kidney cell cultures overlaid with human or swine mucus, human mucus inhibited pH1N1[SUB]low[/SUB]-1 but swine mucus did not. These data shows that the interaction between viruses and mucus may be an important factor in viral transmissibility and could be a barrier for interspecies transmission between humans and swine for influenza viruses.
[h=4]IMPORTANCE:[/h] A balance between the function of the influenza virus surface proteins hemagglutinin (HA) and neuraminidase (NA) is thought to be important for transmission of viruses from swine to humans. Here we show that a swine virus with extremely functionally mismatched HA and NAs (pH1N1[SUB]low[/SUB]-1) cannot transmit via aerosol in ferrets, whilst another highly homologous virus with HA and NAs that are better matched functionally (pH1N1-1) can transmit via aerosol. These viruses show similar growth kinetics in Madin Darby canine kidney (MDCK) cells but pH1N1[SUB]low[/SUB]-1 is significantly inhibited by mucus in normal human bronchial epithelial cells whilst pH1N1-1 is not. Further, human mucus could inhibit these viruses but swine mucus could not. These data shows that the interaction between viruses and mucus may be an important factor in viral transmissibility and could be a species barrier between humans and swine for influenza viruses.
Copyright ? 2015, American Society for Microbiology. All Rights Reserved.
PMID: 25810540 [PubMed - as supplied by publisher]
[h=1]Pandemic swine H1N1 influenza viruses with almost undetectable neuraminidase activity do not transmit via aerosols in ferrets and are inhibited by human mucus, but not swine mucus.[/h] Zanin M[SUP]1[/SUP], Marathe B[SUP]1[/SUP], Wong SS[SUP]1[/SUP], Yoon SW[SUP]1[/SUP], Collin E[SUP]2[/SUP], Oshansky C[SUP]3[/SUP], Jones J[SUP]1[/SUP], Hause B[SUP]4[/SUP], Webby R[SUP]5[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] A balance between the functions of the influenza virus surface proteins hemagglutinin (HA) and neuraminidase (NA) is thought to be important for the transmission of viruses between humans. Here we describe two pandemic H1N1 viruses, A/swine/Virginia/1814-1/2012 and A/swine/Virginia/1814-2/2012 (pH1N1[SUB]low[/SUB]-1 and -2, respectively) that were isolated from swine symptomatic for influenza. The enzymatic activity of the NA of these viruses was almost undetectable whilst the HA binding affinity for α2,6 sialic acids was greater than that of highly homologous pH1N1 viruses, A/swine/Pennsylvania/2436/2012 and A/swine/Minnesota/2499/2012 (pH1N1-1 and -2), which exhibited better balanced HA and NA activities. In vitro growth kinetics of pH1N1[SUB]low[/SUB] and pH1N1 viruses were similar but aerosol transmission of pH1N1[SUB]low[/SUB]-1 was abrogated and transmission via direct contact was significantly impaired in ferrets compared to pH1N1-1, which transmitted by direct and aerosol contact. In normal human bronchial epithelial cells, pH1N1[SUB]low[/SUB]-1 was significantly inhibited by mucus but pH1N1-1 was not. In Madin-Darby canine kidney cell cultures overlaid with human or swine mucus, human mucus inhibited pH1N1[SUB]low[/SUB]-1 but swine mucus did not. These data shows that the interaction between viruses and mucus may be an important factor in viral transmissibility and could be a barrier for interspecies transmission between humans and swine for influenza viruses.
[h=4]IMPORTANCE:[/h] A balance between the function of the influenza virus surface proteins hemagglutinin (HA) and neuraminidase (NA) is thought to be important for transmission of viruses from swine to humans. Here we show that a swine virus with extremely functionally mismatched HA and NAs (pH1N1[SUB]low[/SUB]-1) cannot transmit via aerosol in ferrets, whilst another highly homologous virus with HA and NAs that are better matched functionally (pH1N1-1) can transmit via aerosol. These viruses show similar growth kinetics in Madin Darby canine kidney (MDCK) cells but pH1N1[SUB]low[/SUB]-1 is significantly inhibited by mucus in normal human bronchial epithelial cells whilst pH1N1-1 is not. Further, human mucus could inhibit these viruses but swine mucus could not. These data shows that the interaction between viruses and mucus may be an important factor in viral transmissibility and could be a species barrier between humans and swine for influenza viruses.
Copyright ? 2015, American Society for Microbiology. All Rights Reserved.
PMID: 25810540 [PubMed - as supplied by publisher]