Monoclonal Antibody Development and Antigenic Epitope Identification of Infectious Bursal Disease Virus Vp5

Abstract

Infectious bursal disease (IBD) is an important immunosuppressive disease of chicken caused by infectious bursal disease virus (IBDV) infection. VP5 is a nonessential protein for IBDV replication, but plays an important role in IBDV pathogenesis, and the deeper understanding of VP5 biological functions is not yet sufficient. This study used a prokaryotic system to express and purify the soluble VP5 of the dominant epidemic strain of IBDV, and constructed a hybridoma cell line capable of secreting IBDV VP5 monoclonal antibody (MAb). This VP5 MAb not only has good specificity for IBDV VP5, but also can discriminatively detect IBDV and its VP5-deleted strain. The corresponding antigen epitope of 137RRDLPKPE145 of IBDV VP5 was further identified, which is the first report of IBDV VP5 antigen epitope. This antigen epitope locates at the C-terminus of VP5 and is conserved among various IBDV strains of serotype 1. This study is valuable for further exploration of gene function and differential detection of VP5.

Keywords: Infectious bursal disease virus, VP5, Soluble expression, Monoclonal antibody, Antigen epitope