Development and Characterization of Neutralizing Monoclonal Antibodies Against the S1 Subunit Protein of QX-like Avian Infectious Bronchitis Virus Strain Sczy3

Abstract

Infectious bronchitis (IB) is a highly contagious disease in chickens caused by infectious bronchitis virus (IBV). The present study was carried out with the aim to develop anti-spike 1 (S1) subunit monoclonal antibodies (MAbs) that could react with IBV strains of different genotypes. The high antigenicity region of S1 gene of an QX-like IBV strain Sczy3 was amplified and ligated into the prokaryotic expression vector pET-32a(+), and the recombinant His-S1 fusion proteins were expressed and purified. The purified whole viral antigen of Sczy3 strain was used to immunize BALB/c mice to produce hybridoma-secreting anti-IBV MAbs. Eleven anti-IBV MAbs were generated, and two MAbs 1C8 and 2C10 were positive in indirect ELISA against both His-S1 protein and the purified whole viral antigen. These two MAbs showed positive reaction with IBV in Western blot, and the isotype were both IgM. These two MAbs react specifically with IBV but not with Newcastle disease virus (NDV) or avian influenza virus (AIV) subtype H9 or H5, and could cross-react with other 10 IBV strains in five different genotypes. End-point neutralizing assay performed in chicken embro kidney (CEK) cells revealed that the neutralization titer of 1C8 and 2C10 against Sczy3 reached 1:2.82 and 1:4.70, respectively. The anti-S1 MAbs produced in the present work may be valuable in developing an antigen-capture ELISA test for antigen detection or a competitive ELISA test for antibody detection or therapeutic medicine for IB in poultry.

Molecular Modeling of Major Structural Protein Genes of Avian Coronavirus: Infectious Bronchitis Virus Mass H120 and Italy02 Strains

“…That is, as a cofactor for the synthesis of immunoglobulins, C 0 3 convertase, immune cell adhesion, antibody-dependent cytolysis, IgM lymphocyte binding, macrophage response to lymphokines, and the adhesion of helper T lymphocytes (Tam et al, 2003). These data are in accordance with the results described above (Zou et al, 2015). These authors have demonstrated that this molecule promotes more antigenic and immunogenic power around this active site, giving an immune response of 100% neutralizing antibodies.…”

“…The S1 gene is now commonly used as a marker of the IBV classification. Although it is highly variable, it remains the first choice for the development of subunits of vaccines against IB (Zou et al, 2015). Furthermore, since there are still relatively conserved regions or epitopes in the S1 subunit, S1 could also be used as a targeted antigen in the development of diagnostic agents (Zou et al, 2015).…”

“…Although it is highly variable, it remains the first choice for the development of subunits of vaccines against IB (Zou et al, 2015). Furthermore, since there are still relatively conserved regions or epitopes in the S1 subunit, S1 could also be used as a targeted antigen in the development of diagnostic agents (Zou et al, 2015). However, there is little information on the structure of the S1 gene protein in 3D, which is carried out to predict epitopes on this gene, hence the objective of this paper, which aimed to predict and identify the most immunogenic antigenic sites are critical for vaccine development.…”

Infectious Bronchitis Virus Evolution, Diagnosis and Control

“…The majority of the available ELISA kits are designed to detect polyclonal antibodies against the whole virion and do not allow serotypization. Several alternatives to commercially available ELISA kits have been developed [ 52 , 53 , 54 , 55 , 56 ], some of which are based on serotype- or strain-specific monoclonal antibodies [ 57 , 58 , 59 ], but their use in routine diagnostics is currently limited.…”

Metodologia Para Expressão Da Glicoproteína S1 Do Vírus Da Bronquite Infecciosa Das Galinhas Em Sistemas Procarioto E Eucarioto

“…A glicoproteína S possui segmentos S1 e S2, sendo que a porção S1 fica exposta no envelope viral, o que a torna um importante indutor da produção de anticorpos neutralizantes e, consequentemente, o principal alvo para o sistema imune do hospedeiro (CAVANAGH, 1983(CAVANAGH, , 2007. Devido a sua imunogenicidade, a proteína S1 pode ser um antígeno adequado para utilização em diagnóstico sorológico e monitoramento vacinal das aves (IGNJATOVIC; GALLI, 1994;ZOU et al, 2015).…”