Analysis of the characteristics of hemagglutinin gene of influenza H3N2 virus in 2014-2016 in Nanjing
10.3760/cma.j.cn112866-20200326-00091
- VernacularTitle:2014—2016年南京市甲型H3N2流感病毒HA基因的进化分析
- Author:
Min HE
1
;
Limin SHI
;
Mengkai QIAO
;
Xuan WANG
;
Wei YONG
;
Xuefei DU
Author Information
1. 南京市疾病预防控制中心微生物检验科 210003
- Keywords:
H3N2 influenza A viruses;
Hemagglutintin gene;
Genetic evolution;
Antigenic epitope
- From:
Chinese Journal of Experimental and Clinical Virology
2020;34(5):490-494
- CountryChina
- Language:Chinese
-
Abstract:
Objective:The hemagglutintin (HA) gene of human influenza viruses of H3N2 subtype circulating in Nanjing from 2014 to 2016 was sequenced, and the genetic variation and evolution characteristics of HA gene were analyzed.Methods:Among the positive H3N2 influenza virus, a total of 27 strains were randomly selected according to the time period for virus isolation in MDCK cells. Viral RNA was extracted, HA gene of influenza virus was amplified by reverse transcritase polymerase chain reaction (RT-PCR) and sequenced. The molecular sequence characteristics were analyzed, and genetic evolution characteristics and important functional sites were further analyzed.Results:The HA nucleotide length of H3N2 Nanjing strains was 1 701 bp, encoding 566 amino acids. Highly homologous with WHO recommended vaccine strains in the same year, with sequence similarity of 97.9%-99.5%. Evolutionary analysis showed that the Nanjing strains from 2014 to 2016 were divided into two branches in the evolutionary tree, and realized the transformation from genotype 3c.3a to 3c.2a. Multiple epitope amino acid variations occurred in different years of Nanjing strains.Conclusions:The prevalent strains of H3N2 influenza virus in Nanjing from 2014 to 2016 have high homology with the vaccine strains, the vaccine can provide a certain protective effect. HA gene antigen variation and molecular genetic evolution are active, so it is necessary to continuously monitor the antigen site changes and genetic evolution characteristics of the virus, so as to prepare for the epidemic of H3N2 in the next influenza virus season.
