title: Prescreening of Nicotine Hapten Linkers in Vitro To Select Hapten-Conjugate Vaccine Candidates for Pharmacokinetic Evaluation in Vivo.
abstract: Since the demonstration of nicotine vaccines as a possible therapeutic intervention for the effects of tobacco smoke, extensive effort has been made to enhance nicotine specific immunity. Linker modifications of nicotine haptens have been a focal point for improving the immunogenicity of nicotine, in which the evaluation of these modifications usually relies on in vivo animal models, such as mice, rats or nonhuman primates. Here, we present two in vitro screening strategies to estimate and predict the immunogenic potential of our newly designed nicotine haptens. One utilizes a competition enzyme-linked immunoabsorbent assay (ELISA) to profile the interactions of nicotine haptens or hapten-protein conjugates with nicotine specific antibodies, both polyclonal and monoclonal. Another relies on computational modeling of the interactions between haptens and amino acid residues near the conjugation site of the carrier protein to infer linker-carrier protein conjugation effect on antinicotine antibody response. Using these two in vitro methods, we ranked the haptens with different linkers for their potential as viable vaccine candidates. The ELISA-based hapten ranking was in an agreement with the results obtained by in vivo nicotine pharmacokinetic analysis. A correlation was found between the average binding affinity (IC50) of the haptens to an anti-Nic monoclonal antibody and the average brain nicotine concentration in the immunized mice. The computational modeling of hapten and carrier protein interactions helps exclude conjugates with strong linker-carrier conjugation effects and low in vivo efficacy. The simplicity of these in vitro screening strategies should facilitate the selection and development of more effective nicotine conjugate vaccines. In addition, these data highlight a previously under-appreciated contribution of linkers and hapten-protein conjugations to conjugate vaccine immunogenicity by virtue of their inclusion in the epitope that binds and activates B cells.
authors.forename: Viswanath
authors.initials: V
authors.lastname: Arutla
authors.forename: Joseph
authors.initials: J
authors.lastname: Leal
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Liu
authors.forename: Sriram
authors.initials: S
authors.lastname: Sokalingam
authors.affiliation: Minneapolis Medical Research Foundation , Minneapolis, Minnesota 55404, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Raleigh
authors.forename: Adejimi
authors.initials: A
authors.lastname: Adaralegbe
authors.affiliation: Department of Biomedical Informatics, College of Health Solutions, Arizona State University , Scottsdale, Arizona 85259, United States.
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.affiliation: Minneapolis Medical Research Foundation , Minneapolis, Minnesota 55404, United States.
authors.forename: Paul R
authors.initials: PR
authors.lastname: Pentel
authors.forename: Sidney M
authors.initials: SM
authors.lastname: Hecht
authors.forename: Yung
authors.identifier: 0000-0002-3480-4563
authors.initials: Y
authors.lastname: Chang
mesh_terms: D000818:Animals; D000906:Antibodies / Q000737:chemistry* / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology; D001402:B-Lymphocytes / Q000378:metabolism; D003198:Computer Simulation; D004797:Enzyme-Linked Immunosorbent Assay; D006241:Haptens / Q000737:chemistry* / Q000276:immunology; D006801:Humans; D008807:Mice, Inbred BALB C; D009538:Nicotine / Q000737:chemistry* / Q000276:immunology / Q000493:pharmacokinetics; D019809:Streptavidin / Q000737:chemistry; D018074:Vaccines, Conjugate / Q000737:chemistry / Q000276:immunology
chemical_list: D000906:Antibodies; D000911:Antibodies, Monoclonal; D006241:Haptens; D018074:Vaccines, Conjugate; D009538:Nicotine; D019809:Streptavidin
keywords: B cells; computational modeling; nicotine hapten linkers; pharmacokinetics; vaccine candidates