title: Development of a novel adjuvanted nasal vaccine: C48/80 associated with chitosan nanoparticles as a path to enhance mucosal immunity.
abstract: In a time in which mucosal vaccines development has been delayed by the lack of safe and effective mucosal adjuvants, the combination of adjuvants has started to be explored as a strategy to obtain potent vaccine formulations. This study describes a novel adjuvant combination as an effective approach for a nasal vaccine - the association of the mast cell activator compound 48/80 with chitosan based nanoparticles. It was hypothesized that mucoadhesive nanoparticles would promote the cellular uptake and prolong the antigen residence time on nasal cavity. Simultaneously, mast cell activation would promote a local microenvironment favorable to the development of an immune response. To test this hypothesis, two different C48/80 loaded nanoparticles (NPs) were prepared: Chitosan-C48/80 NP (Chi-C48/80 NP) and Chitosan/Alginate-C48/80 NP (Chi/Alg-C48/80 NP). The potential as a vaccine adjuvant of the two delivery systems was evaluated and directly compared. Both formulations had a mean size near 500nm and a positive charge; however, Chi-C48/80 NP was a more effective adjuvant delivery system when compared with Chi/Alg-C48/80 NP or C48/80 alone. Chi-C48/80 NP activated mast cells at a greater extent, were better internalized by antigen presenting cells than Chi/Alg-C48/80 NP and successfully enhanced the nasal residence time of a model antigen. Superiority of Chi-C48/80 NP as adjuvant was also observed in vivo. Therefore, nasal immunization of mice with Bacillus anthracis protective antigen (PA) adsorbed on Chi-C48/80 NP elicited high levels of serum anti-PA neutralizing antibodies and a more balanced Th1/Th2 profile than C48/80 in solution or Chi/Alg-C48/80 NP. The incorporation of C48/80 within Chi NP also promoted a mucosal immunity greater than all the other adjuvanted groups tested, showing that the combination of a mast cell activator and chitosan NP could be a promising strategy for nasal immunization.
authors.affiliation: Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal.
authors.forename: D
authors.initials: D
authors.lastname: Bento
authors.affiliation: Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: H F
authors.initials: HF
authors.lastname: Staats
authors.affiliation: Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; Institute of Microbiology, Faculty of Medicine, University of Coimbra, 3004-504 Coimbra, Portugal.
authors.forename: T
authors.initials: T
authors.lastname: Gonçalves
authors.affiliation: Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal. Electronic address: olga@ci.uc.pt.
authors.forename: O
authors.initials: O
authors.lastname: Borges
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage* / Q000737:chemistry; D000281:Administration, Intranasal; D000464:Alginates / Q000008:administration & dosage / Q000737:chemistry; D000818:Animals; D000881:Anthrax / Q000097:blood / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D022122:Anthrax Vaccines / Q000008:administration & dosage* / Q000737:chemistry / Q000276:immunology; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000008:administration & dosage* / Q000737:chemistry / Q000276:immunology; D001427:Bacterial Toxins / Q000008:administration & dosage* / Q000737:chemistry / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D002626:Chemistry, Pharmaceutical; D048271:Chitosan / Q000008:administration & dosage* / Q000737:chemistry / Q000276:immunology; D004305:Dose-Response Relationship, Drug; D004337:Drug Carriers; D005260:Female; D020723:Glucuronic Acid / Q000008:administration & dosage / Q000737:chemistry; D006603:Hexuronic Acids / Q000008:administration & dosage / Q000737:chemistry; D006801:Humans; D018928:Immunity, Mucosal / Q000187:drug effects*; D007114:Immunization; D008407:Mast Cells / Q000187:drug effects / Q000276:immunology / Q000382:microbiology; D051379:Mice; D008810:Mice, Inbred C57BL; D050997:Nanomedicine; D053758:Nanoparticles; D009297:Nasal Mucosa / Q000187:drug effects* / Q000276:immunology; D010316:Particle Size; D000067996:RAW 264.7 Cells; D013499:Surface Properties; D006377:T-Lymphocytes, Helper-Inducer / Q000187:drug effects / Q000276:immunology / Q000382:microbiology; D013678:Technology, Pharmaceutical / Q000379:methods; D013997:Time Factors; D003189:p-Methoxy-N-methylphenethylamine / Q000008:administration & dosage* / Q000737:chemistry / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000464:Alginates; D022122:Anthrax Vaccines; D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D015415:Biomarkers; D004337:Drug Carriers; D006603:Hexuronic Acids; C030325:anthrax toxin; D003189:p-Methoxy-N-methylphenethylamine; D020723:Glucuronic Acid; D048271:Chitosan
keywords: Alginate; Anthrax protective antigen; Chitosan; Compound 48/80; Mast cell activator; Mucosal immunity; Nanoparticles; Nasal vaccination