CONSTRUCTION OF AN EPITOPE VECTOR UTILIZING THE DIPHTHERIA-TOXIN B-SUBUNIT

An immunogenic loop within the diphtheria toxin has been deleted from the B-subunit by a modification of the inverse polymerase chain reacti on (IPCR) and replaced by a unique restriction endonuclease site. An o ligonucleotide encoding an identified epitope sequence from the major outer membrane protein of Neisseria meningitidis of similar size and s tructure to that deleted has been introduced into the restriction site . Expression of the resulting chimeric B-subunit from Escherichia coil yielded a protein that was recognised by a panel of antibodies specif ic for the meningococcal epitope. Initial immunisation data suggest th at this protein could elicit an antibody response against both diphthe ria toxin and meningococcal proteins.