Masking terminal neo-epitopes of linear peptides through glycosylation favours immune responses towards core epitopes producing parental protein bound antibodies

Abstract

Glycosylation of hydrophobic peptides at one terminus effectively increases their water-solubility, and conjugation through the opposing end to a carrier protein, renders them more immunogenic. Moreover, the glycosylation minimizes antibody responses to potentially deleterious, non-productive terminal neo-epitope regions of the peptides, and consequently shifts peptide immunogenicity towards the core amino acid residues. As proof of concept, glycopeptide-protein conjugates related to influenza hemagglutinin (HA), neuraminidase (NA), and the dimerization loop region of human epidermal growth factor receptor 2 (Her2), demonstrated a favorable production of core peptide specific antibodies as determined by ELISA studies. Furthermore, glycosylated Her2 peptide conjugate antisera were also shown to recognize full length Her2 protein by ELISA and at the cell surface through flow cytometry analysis. In contrast, unmasked peptide conjugates generated significant antibody populations that were specific to the terminal neo-epitope of the peptide immunogen that are notably absent in parental proteins. Antibodies generated in this manner to peptides in the dimerization loop of Her2 are also functional as demonstrated by the growth inhibition of Her2 expressing SKBR3 carcinoma cells. This method provides a technique to tailor-make epitope-specific antibodies that may facilitate vaccine, therapeutic and diagnostic antibody development.

Sulfated Lactosyl Archaeol Archaeosome-Adjuvanted Vaccine Formulations Targeting Rabbit Hemorrhagic Disease Virus Are Immunogenic and Efficacious

“…However, the waning of responses over time in our rabbit study could indicate that some optimization of the RHDV conjugates may be required. It would be interesting to determine if altered peptide loading per CRM 197 molecule or the masking of terminal neo-epitopes on the linear peptides would enhance longevity of responses [ 43 ]. An altered peptide loading profile on the carrier could potentially reduce the induction of anti-carrier antibodies, which have been previously shown to reduce the levels of responses following subsequent vaccinations with conjugate antigens using the same carrier [ 44 ].…”

Challenges in Detection of Serum Oncoprotein: Relevance to Breast Cancer Diagnostics

“… 55 Applications of this concept in recent reports demonstrated that masking the terminal amino acids of peptide antigens with weakly immunogenic glycosylation can shift the immune response toward central residues, providing a path toward the generation of effective domain-specific mAbs using peptide fragments. 56 , 57 …”

Production of monoclonal antibody of heat-labile toxin A subunit to identify enterotoxigenic Escherichia coli by epitope mapping using synthetic peptides

“…Notably, synthetic peptides are increasingly replacing biological molecules in diagnostic tests ( 14 , 15 ). Moreover, unequivocally characterized peptide antigens can display enhanced specificity for recognition, thereby eliminating or minimizing potential cross-reactivity between structurally homologous protein epitopes ( 16 – 18 ). Individual antigenic epitope mapping of native proteins provides useful information that can assist in the design of peptide-based diagnostic tests and peptide libraries for monitoring specific cellular immunity in patients ( 19 – 21 ).…”