OmpA-FMDV VP1 fusion proteins: production, cell surface exposure and immune responses to the major antigenic domain of foot-and-mouth disease virus.

Exposure at the bacterial outer surface of the major antigenic epitope of the foot-and-mouth disease (FMDV) viral protein VP1 was studied using protein fusion with outer membrane protein A (OmpA) of Shigella dysenteriae for production and transport of the foreign polypeptide to the outer membrane of Escherichia coli. Fusion constructs with VP1 peptide insertions of up to 56 amino acids in the third outer domain of OmpA could be demonstrated on the bacterial surface by indirect immunofluorescence and immunogold labelling. OmpA fusion proteins with large insertions from sequences of the FMDV protein VP1 were shown to elicit virus-specific immune responses in rabbits.