Construction The Panel Of H5 Subtype Influenza Virus Hemagglutinin (H5 HA) Specific Monoclonal Antibodies And Preliminary Study On HA Antigenic Drift Of H5 Subtype Influenza Virus

H5N1 subtype Avian Influenza which had been attacked the southern Asian countries has recently spread to many Asian, European, African countries by the migratory birds. The H5N1 virus severely impacted the agricultural economy, led heavy loss of national economy in these countries, and even caused fatal disease on human, therefore threatening all the people in the world. H5N1, likes other influenza virus, usually mutants quickly, and is difficult to be monitered for their spreading. Nowadays the study of the rule of H5 subtype AIV mutant is popular, and it is important for the forecast of the big global influenza.The purpose of this study is to construct a panel of anti-H5 HA monoclonal antibodies (mAbs), and to analyze the rule of H5 subtype influenza hemaggglutinin (H5 HA) antigen drifting.First of all, we chose a representative H5N1 strain A/Ck/HK/Yu22/02 as antigen to immunize mice. After screening, 144 anti-H5 HA mAbs were obtained. Based on these mAbs we construct a anti-H5 mAb panel.Meanwhile, we analyzed various H5N1 virus specimens isolated from southeast Asia countries with a phylogenetic method. 33 virus strains which overlap the most mutant lineages of H5 AIV in the world were selected as evaluating viruses.By using the 33 virus strains we evaluated the mAb panel with hemagglutinin inhibition test (HI) and found there were 10 epitope zones on the H5 HA, which could be correspondingly recognized by 10 groups (M1-M10) of mAbs in the mAb panel. Based on HI test result of 114 mAbs, 16 mAbs was selected for neutralization test (NT). It is found that H5 HA has 4 different neutralizing epitope zones which were recognized by 4 types of neutralizating mAbs (N1-N4).On the other hand, we developed a new method to analyze the antigen drift of H5 subtype influenza according to our HI test map and NT test map. We found some rules existed in the current H5 subtype influenza: (1) H5N1 virus is highly mutable, as 8 variations are spreading at the same time; (2) All H5N1 virus strains contain an universal conservative epitope; (3) H5N1 viruses isolated from different geographic regions have different mutant rules. Therefore, our study provides a new method for the selection and evaluation of H5 subtype influenza vaccine virus strains by using the anti-H5 HA neutralizing mAbs.Finally, we found that the application of a mAb-8H5 could greatly improve the sensitivity of current anti-H5 test after further evaluation of the mAb.