Optimization of a multivalent peptide vaccine for nicotine addiction

Abstract

We have been optimizing the design of a conjugate vaccine for nicotine addiction that employs a peptide-based hapten carrier. This peptide, which is produced by solid-phase protein synthesis, contains B cell and T cell epitope domains and eliminates the non-relevant, but highly immunogenic sequences in microbial carriers. In this report, the amino acid sequences in the T cell domain were optimized for improved vaccine activity and multivalent formulations containing structurally distinct haptens were tested for the induction of additive antibody responses. Trivalent vaccines produced antibody concentrations in mice that were 100 times greater than the amount of nicotine measured in smokers, and significantly reduced acute nicotine toxicity in rats. Two additional features were explored that distinguish the peptide from traditional recombinant carriers. The first is the minimal induction of an anti-carrier response, which can suppress nicotine vaccine activity. The second employs solid-phase synthesis to manufacture haptenated peptide. This approach obviates conventional conjugation chemistries and streamlines production of a more potent vaccine antigen.

Epitope targeting with self-assembled peptide vaccines

“…Previously, we reported the in vivo activity of several peptide carriers with different TCE combinations for smoking cessation vaccines; the peptides used in these studies (P8, P10, and P15) were subjected to a standard battery of physical characterization techniques. 14 We confirmed by CD analysis that P8 has an α-helical secondary structure and assumes a stable coiled-coil assembly based on the 222/208 nm peak ratio. 19,20 However, above 65 °C, the coils undergo a conformational change that could reflect fraying of the non-heptad TCE terminus or other disruptions of the coiled-coil assembly.…”

“…In addition to P8, we have tested the carrier activity of two peptides containing different universal TCEs: P10 contains epitopes isolated from measles virus fusion 2 and Hepatitis B surface antigen proteins and P15 contains three overlapping TCEs isolated from tetanus toxoid protein (Supplementary Table 1). 14 However, unlike P8, no trimer peaks were detected for these peptides by AUC and DLS (Fig. 2a–c).…”

“…In addition, the P10 vaccine showed enhanced immunogenicity relative to its P15 analog, which is consistent with our anti-nicotine vaccines experiments. 14 Future experiments will determine whether the elevated potency of P10 TCEs is retained in larger animals. A second therapeutic experiment targeted the mouse IgE heavy chain epitope analogous to omalizumab’s IgE-binding site.…”

“…9–12 We have used this carrier to produce a nicotine vaccine for smoking cessation and have shown that the Ab concentrations induced in mice and rats can bind supraphysiological doses of nicotine and prevent nicotine-induced toxicity. 8,13,14…”

Enhancing the Immune Response of a Nicotine Vaccine with Synthetic Small “Non-Natural” Peptides

“…The preparation of the adjuvant system, which we have coined bacterial derived adjuvant (BDA), was previously described by our group [28,29]. Importantly, our nicotine vaccine is unlike previous vaccines [31][32][33][34][35] and has been designed to be administered via an intranasal (IN) route. The BDA vaccine delivery system generates a robust immune response by stimulating IL-1β production through Toll-like receptor 4 (TLR4), a potent mechanism for mucosal immunity [28], resulting in high mucosal and systemic antibody levels in mice [28,29].…”