Production and characterization of monoclonal antibodies to plum pox virus and their use in differentiation of Mediterranean isolates

Monoclonal antibodies (MAbs) specific to plum pox virus (PPV) were prepared by fusing myeloma cell lines to spleen cells of mice immunized with purified virus, including virus prepared with protease inhibitors to preserve the integrity of the coat protein (CP). The characterized MAbs could be used in ELISA to differentiate several Mediterranean PPV isolates differing in their geographical origin and CP size. At least seven antigenic sites could be established based on the recognition pattern and competition binding analysis, and the epitopes could be classified in three groups by Western blot analysis of intact and trypsin digested virus particles. By means of electron microscopy the epitopes could be seen to be located on the surface of the virus particles.

Diagnostic methods for African horsesickness virus using monoclonal antibodies to structural and non-structural proteins

A panel of 32 hybridoma cell lines secreting monoclonal antibodies (MAbs) reactive with African horsesickness virus serotype 4 (AHSV-4) has been developed. Four of the MAbs recognized the major core antigen VP7, twenty recognized the outer capsid protein VP2 and eight reacted with the non-structural protein NS1. With the VP7-specific MAbs a rapid and sensitive double antibody sandwich immunoassay has been developed to detect viral antigen in infected Vero cells and in spleen tissue from AHSV-infected horses. The sensitivity of the assay is 10 ng viral antigen per 100 microliters. The NS1-specific MAbs allowed visualization by immunofluorescence of tubule-like structures in the cytoplasm of infected Vero cells. This can be very useful as a confirmatory diagnostic procedure. The antigenic map of the outer capsid VP2 protein with MAbs is also reported.