Generation of a recombinant chickenized monoclonal antibody against the neuraminidase of H9N2 avian influenza virus

Fei Wang,Zhimin Wan,Yajuan Wang,Hongxia Shao,Jianqiang Ye,Aijian Qin,Kun Qian

doi:10.1186/s13568-020-01086-4

Abstract

We previously reported a monoclonal antibody (mAb), 1G8, against the neuraminidase (NA) of H9N2 avian influenza virus (AIV) with significant NA inhibitory activity. To generate a recombinant chickenized mAb (RCmAb) against the NA of H9N2 AIV for passive immunization in poultry, the gene of the fragment of antigen binding (Fab) of mAb 1G8 was cloned and fused with the fragment crystallizable (Fc) gene of chicken IgY. The RCmAb 1G8 was expressed in COS-1 cells and could be detected in cell culture supernatant. The results of NA inhibitory activity tests of the RCmAb 1G8 in an enzyme-linked lectin assay (ELLA) and a microneutralization (MN) assay showed that the RCmAb 1G8 maintained significant NA inhibitory activity and neutralizing ability. This is the first chickenized antibody against AIV, which would be a good candidate for passive immunization in poultry.

Highlights

H9N2 avian influenza virus (AIV) has been prevalent in China since the first outbreak in Guangdong Province in 1992
We previously reported a mouse-derived monoclonal antibody (mAb) 1G8, that has a significant inhibitory effect on the NA enzyme activity of H9N2 AIV (Wan et al 2016)
The virus was propagated in 9-day-old embryonated chicken eggs and preserved at − 70 °C. 1G8 hybridoma cells were screened from sp2/0 cells fused with spleen cells from BALB/C mice immunized with X1 virus, as previously reported (Wan et al 2016)

Summary

Introduction

H9N2 avian influenza virus (AIV) has been prevalent in China since the first outbreak in Guangdong Province in 1992. H9N2, a low-pathogenicity virus in domestic poultry, causes mainly respiratory symptoms, immunosuppression and a decline in egg production. Great economic losses can be caused when poultry are co-infected with other pathogenic organisms (Horwood et al 2018; Pan et al 2012). One is haemagglutinin (HA), and the other is neuraminidase (NA) Both of them can induce neutralizing antibodies in chickens. Specific antibodies induced by NA contribute mainly to immunity by limiting viral replication and disease severity (Eichelberger et al 2014). NA inhibitors, such as oseltamivir, zanamivir, Wang et al AMB Expr (2020) 10:151 peramivir, laninamivir, and a recently approved polymerase acidic (PA) inhibitor, baloxavir marboxil, are currently used to treat influenza virus infections. The emergence of antiviral drug resistance is a major concern for these inhibitors (Hussain et al 2017)

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Conclusion