Antigenic diversity of H5 highly pathogenic avian influenza viruses of clade 2.3.4.4 isolated in Asia

Abstract

H5 highly pathogenic avian influenza viruses (HPAIV) have spread in both poultry and wild birds since late 2003. Continued circulation of HPAIV in poultry in several regions of the world has led to antigenic drift. In the present study, we analyzed the antigenic properties of H5 HPAIV isolated in Asia using four neutralizing mAbs recognizing hemagglutinin, which were established using A/chicken/Kumamoto/1-7/2014 (H5N8), belonging to clade 2.3.4.4 and also using polyclonal antibodies. Viruses of clades 1.1, 2.3.2.1, 2.3.4, and 2.3.4.4 had different reactivity patterns to the panel of mAbs, thereby indicating that the antigenicity of the viruses of clade 2.3.4.4 were similar but differed from the other clades. In particular, the antigenicity of the viruses of clade 2.3.4.4 differed from those of the viruses of clades 2.3.4 and 2.3.2.1, which suggests that the recent H5 HPAIV have further evolved antigenically divergent. In addition, reactivity of antiserum suggests that the antigenicity of viruses of clade 2.3.4.4 differed slightly among groups A, B, and C. Vaccines are still used in poultry in endemic countries, so the antigenicity of H5 HPAIV should be monitored continually to facilitate control of avian influenza. The panel of mAbs established in the present study will be useful for detecting antigenic drift in the H5 viruses that emerge from the current strains.

Isolation and characterization of avian influenza viruses from raw poultry products illegally imported to Japan by international flight passengers

“…MAbs of Dk/Pen/84 (H5N2) recognize amino acid residue at position 88 (D101/1), 145 (A310/39), 157 (64/1), 168 (B220/1) and 205 (25/2) based on the H3 numbering system (Soda et al., ). MAbs of CK/Kum/14 (H5N8) recognize amino acid residue at position 160 (A32/2), 50 (A262/2), 47 and 287 (B3/2) and 124 (B157/1) based on the H3 numbering system (Ohkawara et al., ). Each MAb of Dk/Pen/84 (H5N2) bound low pathogenic AIV, Mal/Hok/09 (H5N1), while most of the MAbs did not bind Gs/GD‐like HPAIVs, including H5 isolates.…”

“… Location of amino acid substitutions in antigenic variants selected in the presence of respective neutralizing monoclonal antibodies (Ohkawara et al., ; Soda et al., ). …”

“…For the fluorescent antibody assay, Madin‐Darby canine kidney (MDCK) cells infected with representative AIV were fixed with cold 100% acetone 8 hr post‐inoculation. The reactivity patterns of neutralizing MAbs with viruses were investigated via immunofluorescence with a fluorescein isothiocyanate (FITC)‐conjugated goat IgG to mouse IgG (ICN Biomedicals, Inc., Costa Mesa, CA, USA) (Ohkawara et al., ; Soda et al., ). Fluorescence was visualized with an Axiovert 200 inverted microscope (Carl Zeiss MicroImaging, Thornwood, NY, USA).…”

“…T A B L E 3 Antigenic analysis of H5 influenza viruses with anti-sera using haemagglutination inhibition test Location of amino acid substitutions in antigenic variants selected in the presence of respective neutralizing monoclonal antibodies (Ohkawara et al, 2017;Soda et al, 2008). b Viruses isolated in this study.…”

Rapid and broad detection of H5 hemagglutinin by an immunochromatographic kit using novel monoclonal antibody against highly pathogenic avian influenza virus belonging to the genetic clade 2.3.4.4

“…Two MAbs, A64/1 and A32/2, were used in the New Linjudge Flu A/H5. The MAb, A64/1, was previously produced using a hybridoma cell line against an H5 low pathogenic avian influenza virus (LPAIV), A/duck/Pennsylvania/10218/1984 (H5N2) [ 22 ], and a novel MAb, A32/2, was prepared in a similar method against a clade 2.3.4.4 H5 HPAIV, A/chicken/Kumamoto/1-7/2014 (H5N8) [ 23 ]. The improved H5 IC kit was manufactured as described previously [ 10 ].…”