Effect of peptide-carrier coupling on peptide-specific immune responses

Synthetic peptides are covalently linked to immunogenic carrier proteins to enhance the anti-peptide immune response. To investigate whether the method of conjugation influences the immune response, we evaluated two distinctly different choices of linker for a peptide-carrier construct. HPG-30, a synthetic peptide derived from the p17 gag protein of human immunodeficiency virus 1, was covalently linked to keyhole limpet hemocyanin by either glutaraldehyde or a maleimide ester. Glutaraldehyde linkage enhanced the anti-peptide antibody and native protein response compared to maleimide. The maleimide-linked conjugate was more effective at inducing a peptide-specific cellular response. Thus, manipulation of the conjugation method can modify the magnitude and character of the immune response to a synthetic peptide vaccine.