[Antigenic and genetic characterizations of group A influenza viruses H3N2 circulated in men in China during 2000-2002].
OBJECTIVE
To understand the antigenic and genetic characteristics of influenza A H3N2 viruses circulated in man in China from 2000 to 2002.


METHODS
Embryonated chicken eggs inoculated with virus for amplification of viral yield. The harvesting egg allantoic fluids with influenza viruses were provided for testing antigen and RNA extraction. Virion RNA was transcribed into cDNA by reverse transcriptase, cDNA amplified by PCR, and the product of PCR was purified. Afterward RNA sequence analysis was performed by the dideoxynucleotide chain termination method using synthetic oligodeoxynucleotide primers. Finally the phylogenetic tree was analyzed with MegAlign software.


RESULTS
The H3N2 viruses isolated during 2000-2002 were different in amino acid sequences on HA1 domain protein molecule from those of A/Wuhan359/1995 H3N2 as well as those of A/Sydney/7/1997 H3N2 strains. There were four different positions of amino acid sequence on HA1 domain protein molecule among the H3N2 viruses isolated in 2000 and during 2001-2002. They located at 83, 186, 202, 222 and 225 position, respectively. Of them 83 and 186 were in antigenic determinant E and B, respectively. The others located at left wall of the receptor binding site (RBS).


CONCLUSIONS
From the end of 2001 to the beginning of 2002, the influenza epidemic in Northern China caused by H3N2 virus was due to occurrence of antigenic and genetic changes of influenza A(H3N2) virus.
Zhang
Ye
Y
National Institute of Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 100052, China.
Wen
Le-ying
LY
Li
Zi
Z
Guo
Jun-feng
JF
Wang
Min
M
Guo
Yuan-ji
YJ
D000595:Amino Acid Sequence; D000940:Antigenic Variation; D001483:Base Sequence; D002681:China / Q000453:epidemiology; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype / Q000235:genetics* / Q000276:immunology* / Q000302:isolation & purification; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology; D008969:Molecular Sequence Data; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction
D019267:Hemagglutinin Glycoproteins, Influenza Virus