Full genome comparison and characterization of avian H10 viruses with different pathogenicity in Mink (Mustela vison) reveals genetic and functional differences in the non-structural gene.
BACKGROUND
The unique property of some avian H10 viruses, particularly the ability to cause severe disease in mink without prior adaptation, enabled our study. Coupled with previous experimental data and genetic characterization here we tried to investigate the possible influence of different genes on the virulence of these H10 avian influenza viruses in mink.


RESULTS
Phylogenetic analysis revealed a close relationship between the viruses studied. Our study also showed that there are no genetic differences in receptor specificity or the cleavability of the haemagglutinin proteins of these viruses regardless of whether they are of low or high pathogenicity in mink. In poly I:C stimulated mink lung cells the NS1 protein of influenza A virus showing high pathogenicity in mink down regulated the type I interferon promoter activity to a greater extent than the NS1 protein of the virus showing low pathogenicity in mink.


CONCLUSIONS
Differences in pathogenicity and virulence in mink between these strains could be related to clear amino acid differences in the non structural 1 (NS1) protein. The NS gene of mink/84 appears to have contributed to the virulence of the virus in mink by helping the virus evade the innate immune responses.
Zohari
Siamak
S
Swedish University of Agricultural Sciences (SLU), Department of Biomedical Sciences and Public Health, Section of Virology, SLU, SE-751 89 Uppsala, Sweden. Siamak.zohari@sva.se
Metreveli
Giorgi
G
Kiss
István
I
Belák
Sándor
S
Berg
Mikael
M
D000818:Animals; D016679:Genome, Viral; D009980:Influenza A virus / Q000145:classification / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity*; D008907:Mink / Q000821:virology*; D008969:Molecular Sequence Data; D009976:Orthomyxoviridae Infections / Q000662:veterinary* / Q000821:virology; D010802:Phylogeny; D017361:Viral Nonstructural Proteins / Q000235:genetics* / Q000378:metabolism; D014774:Virulence
C085820:INS1 protein, influenza virus; D017361:Viral Nonstructural Proteins