Emergence of truncated PB1-F2 protein of H3N2 influenza virus during its epidemic period in Jiangsu Province, China.
BACKGROUND
PB1-F2 protein has been proven to increase the pathogenicity of influenza A virus (IAV) strains in primary infection and in secondary bacterial infection. It can also regulate the activity of viral polymerase. However, it was shown in another retrospective study that a portion of IAVs do not express full-length PB1-F2 protein during virus development; different kinds of stop codons cause exits in the open reading frames and form PB1-F2 gene products with the corresponding genotypes. Truncated PB1-F2 in human H3N2 IAVs has long been detected in North America but its evolution in China is still unclear.


METHODS
Influenza-like illnesses (ILIs) from the whole of Jiangsu Province were collected and inspected to determine the type and subtype of the viruses. A portion of isolates collected in the epidemic period were selected as samples for later whole-genome sequencing, and the exact sequences were determined and analyzed.


RESULTS
H3N2 influenza virus was one of the epidemical strains which had been prevalent during 2009-2010, in Jiangsu. Five H3N2 isolates with truncated PB1-F2 protein (25aa) were detected in influenza samples from Nanjing and Xuzhou, while seven similar H3N2 isolates were also reported in Niigata, Japan.


CONCLUSIONS
This emergence indicates the possibility that there has been transmission of the H3N2 virus between the two countries.
Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, Jiangsu 210009, China.
Pingmin
P
Wei
Department of Acute Infectious Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, Jiangsu 210009, China.
Pengfei
P
Luo
Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, Jiangsu 210009, China.
Wei
W
Li
Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, Jiangsu 210009, China.
Hairong
H
Zi
Department of Acute Infectious Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, Jiangsu 210009, China. Email: qixiansyc@hotmail.com).
Xian
X
Qi
Department of Acute Infectious Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, Jiangsu 210009, China.
Fei
F
Deng
Department of Acute Infectious Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, Jiangsu 210009, China.
Yuanfang
Y
Qin
Department of Acute Infectious Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, Jiangsu 210009, China.
Bin
B
Wu
Department of Acute Infectious Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, Jiangsu 210009, China.
Fenyang
F
Tang
D002681:China / Q000453:epidemiology; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype / Q000235:genetics / Q000378:metabolism*; D007251:Influenza, Human / Q000821:virology*; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
C442816:PB1-F2 protein, Influenza A virus; D014764:Viral Proteins