Antigenic epitope characterization of matrix protein of Newcastle disease virus using monoclonal antibody approach: Contrasting variability amongst NDV strains

Abstract

A panel of 15 monoclonal antibodies (MABs) against matrix (M) protein of Newcastle disease virus (NDV) was obtained and the specificity towards the M protein was proven by radioimmunoprecipitation assay and antigen capture enzyme-linked immunosorbent assay (ELISA). Further studies were directed to antigenic epitope mapping of the M protein by means of this panel. The epitope characterization was performed by competitive antibody-binding assay by means of labelling each MAB with biotin [3]. At least three clear non-overlapping and two partially overlapping groups were determined, each including four, one, eight, one, and one MAB, respectively. All the above MABs appeared to be induced by structural epitopes formed in conditions of tertiary structure of the native M antigen. Twelve reference and 51 recently isolated local NDV strains have been studied by means of this MAB panel, several lineages having been revealed. The high stability of some epitopes and different variability of the others was demonstrated. No correlation between the above lineages and some other properties of the studied NDV strains (host specificity, date and place of isolation) has been found.