Use of outer membrane protein PhoE as a carrier for the transport of a foreign antigenic determinant to the cell surface of Escherichia coli K-12

PhoE protein is an abundant transmembrane protein from the Escherichia coli K-12 outer membrane. A synthetic oligodeoxynucleotide corresponding to an antigenic determinant of the C-terminal part of the VP1 protein of foot-and-mouth disease virus was inserted into the phoE gene in an area corresponding to a cell surface-exposed region of the PhoE protein. The level of expression of the hybrid protein was normal and the protein was incorporated into the outer membrane. The VP1-epitope was exposed at the cell surface since intact cells were recognized by a monoclonal antibody which was raised against the virus.