Identification of antigenic epitopes on the foot and mouth disease virus isolate O-1/Manisa/Turkey/69 using monoclonal antibodies

A panel of mouse monoclonal antibodies (MAbs) was produced against a strain of type 0 foot and mouth disease virus (FMDV) from the Middle East, O-1/Ma nisa/Turkey/69. Seven neutralising MAbs were fully characterised and all we re found to react with conformational epitopes. Monoclonal antibody neutral isation-resistant mutants (MARMs) were generated from the parental virus st ack and the complete capsid sequences of these MARMs were determined. Seque nce analysis revealed that five of the MARMs had amino acid substitutions a t either residue 72 or 73 of VP2 (betaB-betaC loop), indicating that five o f 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 positi on 72 of VP2 and position 149 of VPI (PG-PH loop). These findings indicate that MAbs directed against a type 0 FMDV from the Middle East recognise res idues in the same structural features to those raised against strains from Europe of the same serotype.