ENHANCED IMMUNOGENICITY OF RECOMBINANT PEPTIDE FUSIONS CONTAINING MULTIPLE COPIES OF A HETEROLOGOUS T-HELPER EPITOPE

We have examined the immune response against the nonimmunogenic heatstable enterotoxin (STa) of enterotoxigenic Escherichia coli using recombinant fusion proteins containing the STa‐peptide linked to an IgG‐binding analogue of protein A and varying numbers of the T helper epitope 323–339 from ovalbumin (ova). By immunization of inbred strains of mice with a series of STa fusion proteins, containing up to four copies of ova tandemly multiplied, we demonstrated that the anti‐STa antibody response is controlled by ova‐specific T helper cells in a genetically restricted manner. In the responding mouse strains (2 out of 3 tested), the level of antibody production was increased by addition of multiple ova epitopes, the anti‐STa response being considerably higher to fusion proteins containing four than one or two ova epitopes. Copyright © 1990 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim