Keyhole Limpet Hemocyanin-Conjugated Peptides from Hepatitis C Virus Glycoproteins Elicit Neutralizing Antibodies in BALB/c Mice

Abstract

Currently, no vaccine to prevent hepatitis C virus (HCV) infection is available. A major challenge in developing an HCV vaccine is the high diversity of HCV sequences. The purpose of immunization with viral glycoproteins is to induce a potent and long-lasting cellular and humoral immune response. However, this strategy only achieves limited protection, and antigen selection plays a crucial role in vaccine design. In this study, we investigated the humoral immune responses induced by intraperitoneal injection of keyhole limpet hemocyanin conjugated with 4 highly conserved peptides, including amino acids [aa]317-325 from E1 and aa418-429, aa502-518, and aa685-693 from E2, or 3 peptides from hypervariable region 1 (HVR1) of E2, including the N terminus of HVR1 (N-HVR1, aa384-396), C terminus of HVR1 (C-HVR1, aa397-410), and HVR1 in BALB/c mice. The neutralizing activity against HCV genotypes 1-6 was assessed using the cell culture HCV (HCVcc) system. The results showed that the 4 conserved peptides efficiently induced antibodies with potent neutralizing activity against 3 or 4 genotypes. Antibodies induced by aa685-693 conferred potent protection (>50%) against genotypes 2, 4, and 5. Peptide N-HVR1 elicited antibodies with the most potent neutralization activities against 3 HCV genotypes: TNcc(1a), S52(3a), and ED43(4a). These findings suggested that peptides within HCV glycoproteins could serve as potent immunogens for vaccine design and development.

Design Principles for Immunomodulatory Biomaterials

“…A good rule of thumb is that molecules from an organism are nonimmunogenic to the same organism, are weakly immunogenic to organisms of the same species or phylogenetically close organisms, but strongly immunogenic to phylogenetically distant organisms. For example, a contributing factor to the potent immunogenicity of the keyhole limpet hemocyanin (KLH), a nonheme protein used as a carrier protein in antibody production, − is its “foreignness”. Hemocyanin is found in arthropods and mollusks, with KLH being derived from the hemolymph of the giant keyhole limpet, a mollusk that is phylogenetically distant from humans. , Also, bovine serum albumin is nonimmunogenic in cows but elicits a strong immune response in mice and rabbits. ,− However, it is important to note that immune responsiveness being predicated on self-vs foreign contrast is overly simplistic because some evolutionarily conserved biomolecules, such as collagen, are weakly immunogenic in organisms where they are “foreign”. − On the other hand, spermatozoa are strongly immunogenic in the same organisms where they are “self”. − Nevertheless, designing biomaterials with biomolecules from phylogenetically distant organisms to the target organism is another principle to impart immunomodulatory properties.…”

Comprehending B-Cell Epitope Prediction to Develop Vaccines and Immunodiagnostics

“…Nevertheless, BCEP can support the development of vaccines and immunodiagnostics provided that its limitations are adequately comprehended and addressed. be produced from peptides comprising disordered BCEs of selected target proteins (e.g., pathogen virulence factors), to elicit production of antipeptide antibodies (i.e., peptide antibodies (22)) that can neutralize the biological activity of the proteins (4,(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36). Such an approach is viable where the BCEs are disordered in both the peptides and the proteins; but if the BCEs are conformationally constrained (e.g., folded) in the proteins, their binding by the antipeptide antibodies may fail to occur, as is thought to be the case among unsuccessful attempts at peptide-based vaccine development (16).…”

An Epitope-Focused Trypanosome-Derived Vaccine Platform Elicits High-Affinity Antibodies and Immunity Against Fentanyl Effects

“…to facilitate CD4+ T cell-dependent B cell activation, and combined with adjuvants prior to injection to prompt antigen recognition and increase immunogenicity. Classical hapten-carrier systems have been extensively tested in animals (Baruffaldi et al ., 2019; Sen-Kilic et al ., 2019; Deng et al ., 2021). More recently, the desire to elicit antibodies to small molecule drugs of abuse has propelled implementation of classical hapten-carrier systems to humans with very limited success, and some prominent failures mostly due to the high individual variability in polyclonal antibody responses (Hoogsteder et al ., 2012; Kosten et al ., 2014).…”

“…) to facilitate CD4+ T cell-dependent B cell activation, and combined with adjuvants prior to injection to prompt antigen recognition and increase immunogenicity. Classical hapten-carrier systems have been extensively tested in animals (Baruffaldi et al, 2019;Sen-Kilic et al, 2019;Deng et al, 2021).…”