Active antitoxic immunization by a diphtheria toxin synthetic oligopeptide

Abstract

The loop of 14 amino acids subtended by the disulfide bridge nearer the NH2 terminus of the toxin molecule was synthesized. This loop may be involved in the toxicity and immunological specificity of the molecule. The tetradecapeptide (residues 188-201), when linked covalently with 2 different carriers, elicits in guinea-pigs antibodies which not only bind specifically with the toxin but neutralize its dermonecrotic and lethal effects. These results may constitute the 1st example of successful active immunization against a lethal bacterial toxin using a synthetic antigen.