Identification of antigenic epitopes on the foot and mouth disease virus isolate O1/Manisa/Turkey/69 using monoclonal antibodies.

A panel of mouse monoclonal antibodies (MAbs) was produced against a strain of type O foot and mouth disease virus (FMDV) from the Middle East, O1/Manisa/Turkey/69. Seven neutralising MAbs were fully characterised and all were found to react with conformational epitopes. Monoclonal antibody neutralisation-resistant mutants (MARMs) were generated from the parental virus stock and the complete capsid sequences of these MARMs were determined. Sequence analysis revealed that five of the MARMs had amino acid substitutions at either residue 72 or 73 of VP2 (beta B-beta C loop), indicating that five of the MAbs were directed against antigenic site 2. The sixth MARM contained a single amino acid substitution at position 198 of VP1 (carboxy-terminal region). The seventh MARM contained two amino acid substitutions, at position 72 of VP2 and position 149 of VP1 (beta G-beta H loop). These findings indicate that MAbs directed against a type O FMDV from the Middle East recognise residues in the same structural features to those raised against strains from Europe of the same serotype.