TITLE:
Receptor binding specificity and sequence comparison of a novel avian-origin H7N9 virus in China
AUTHORS:
Wei Hu
KEYWORDS:
H7N9; Influenza; Receptor Specificity;Mutation
JOURNAL NAME:
Journal of Biomedical Science and Engineering,
Vol.6 No.5,
May
25,
2013
ABSTRACT:
Avian
influenza such as H5N1 could infect humans and cause great health concern due
to its high mortality rate. In March 2013, a novel reassortant avian-origin
influenza A (H7N9) virus was found in several patients with severe respiratory
illness in China. Since then, at least 82 people in China have been infected
with this new virus and 17 have died from this virus. The question of how these
people were infected with this virus and whether this virus will spread among
people remains an urgent topic for research. This study took an early
investigation of this virus by comparing
the collected viral genome sequences of
2013 H7N9 inChinaagainst
those of previous avian H7N9 and examined the receptor binding specificity of
this new virus. This virus was found to be very different from the previous
avian H7N9 viruses and surprisingly many of the internal proteins of 2013 H7N9
from the avian and human hosts in China were either identical or similar. Our
analysis of the HA protein of this virus implied that the current strains of
2013 H7N9 inChina
displayed avian type receptors as their primary binding preference and human
type receptors as secondary. For pandemic risk assessment, we also detected 23
mutations, including a few well known for host adaptation, in the HA1 domain
of the HA protein from this virus. Each mutation was quantified for its impact
on the recaptor binding selection using a bioinformatics approach. Collectively
these current mutations tended to decrease the HA binding affinity for avian
type recaptors and increase that for human type receptors, which could
enhance the ability of this virus to infect humans.