Generation Of A Monoclonal Antibody Against Porcine Reproductive And Respiratory Syndrome Virus GP3Protein And Characterization Of Its Epitopes

Porcine reproductive and respiratory syndrome virus (PRRSV) was classified in the family Arteriviridae in the newly created order Nidovirales. Typical clinical symptom of PRRS were fever, abortion, prematurity, stillbirths and respiratory disease in pigs of any age. GP3protein is part of the virion envelop and is one of the minor structural proteins expressed by porcine reproductive and respiratory syndrome virus (PRRSV).GP3is a heavily glycosylated glycoprotein which is encoded by the viral open reading frame (ORF)3, in a small amount, GP3able to induce neutralizing antibodies. GP3Also significant in cell receptor recognition of virus particles, as well as in other aspects of virus mutation. The research of epitopes by phage display technology not only prove the structure and function of antigen-specific molecule, but also reveal the mechanism of antigen-antibody reaction, and can be widely used in a variety of peptide vaccines and the development of new drugs. Therefore, this experiment, with PRRSV HH08isolate as the model virus, was carried to prepare monoclonal antibody against GP3and study its epitopes.In this experiment, PRRSV-GP3protein which expression in prokaryotic expression system as immune protein was used to immunize mice, then cell fusion by a conventional technique, after three rounds of subclone successfully and achieve an anti-PRRSV GP3protein monoclonal antibody of IgG2a subclass. It has better stability and specificity, IFA and western blot showed that it can react with recombinant GP3protein and total PRRSV.Using phage random peptide library panning1F7monoclonal antibody for4rounds, screend10phage clones. Sequencing results showed that7phage clones had consensus sequences ATPLSSTTWLWR, which shared similarity with amino acid64-70in PRRSV GP3protein. Phage-based ELISA and antigen competitive inhibition test confirmed that the phage displayed epitopes were similar with the natural epitopes in the PRRSV GP3protein, therefore, they can be used to detect PRRSV antibody and can also be used to develop epitope vaccines. This study is helpful for PRRSV diagnosis and prevention.