Epitope identification of HA1 protein of avian influenza virus H5N8 subtype
In order to confirm the new epitopes of avian influenza virus H5N8 subtype,the prokaryotic HA1 protein of H5N8 influenza virue QH448 strain was used as immunogen to immunize mice.A total of five stable hybridoma cell lines were eventually obtained by secreting monoclonal antibodies against QH448 HA1 protein.The 1H12B9,8A12D10,and 9H10F5 antibodies were IgG1 type,and the 2A9D11 and 7E9G6 antibodies were IgG2b type,while the light chains of all antibodies were κ chain.The 5 monoclonal antibodies could specifically recognize the HA protein of avian influenza virus H5 subtype.By using HA1 protein truncations,it was confirmed that the 1H12B9 and 7E9G6 recognized the epitope 330ATGLRNSPLREKRRKR345 of HA protein of H5N8 avian influenza virus,the 2A9D11 recognized epitope 310IHPLTIGECPKYVKSN325,the 8A12D10 recognizedepitope 271KIVKKGDSTIMKSEV285,and the 9H10F5 recognized epitope 121LSRINHFEKILIIPKS136.Homology comparison showed that the four screened antigenic epitopes were highly conserved in the H5-HA proteins.These results indicated that five monoclonal antibodies were developed and characterized,which can recognize four different epitopes of H5-HA protein.The findings provided new antibodies for the diagnosis of H5N8 avian influenza.