title: Novel immunoadjuvants based on cationic lipid: Preparation, characterization and activity in vivo.
abstract: The interactions between three different protein antigens and dioctadecyldimethylammonium bromide (DODAB) dispersed in aqueous solutions from probe sonication or adsorbed as one bilayer onto particles was comparatively investigated. The three model proteins were bovine serum albumin (BSA), purified 18 kDa/14 kDa antigens from Taenia crassiceps (18/14-Tcra) and a recombinant, heat-shock protein hsp-18 kDa from Mycobacterium leprae. Protein-DODAB complexes in water solution were characterized by dynamic light scattering for sizing and zeta-potential analysis. Cationic complexes (80-100 nm of mean hydrodynamic diameter) displayed sizes similar to those of DODAB bilayer fragments (BF) in aqueous solution and good colloid stability over a range of DODAB and protein concentrations. The amount of cationic lipid required for attaining zero of zeta-potential at a given protein amount depended on protein nature being smaller for 18 kDa/14 kDa antigens than for BSA. Mean diameters for DODAB/protein complexes increased, whereas zeta-potentials decreased with NaCl or protein concentration. In mice, weak IgG production but significant cellular immune responses were induced by the complexes in comparison to antigens alone or carried by aluminum hydroxide as shown from IgG in serum determined by ELISA, delayed type hypersensitivity reaction from footpad swelling tests and cytokines analysis. The novel cationic adjuvant/protein complexes revealed good colloid stability and potential for vaccine design at a reduced DODAB concentration.
authors: Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Caixa Postal 26077, 05513-970 São Paulo, Brazil.
authors: Nilton
authors: N
authors: Lincopan
authors: Noelí M
authors: NM
authors: Espíndola
authors: Adelaide J
authors: AJ
authors: Vaz
authors: Maria Helena B
authors: MH
authors: da Costa
authors: Eliana
authors: E
authors: Faquim-Mauro
authors: Ana M
authors: AM
authors: Carmona-Ribeiro
mesh_terms: D000276:Adjuvants, Immunologic / Q000737:chemistry*; D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D000947:Antigens, Helminth / Q000276:immunology; D002412:Cations / Q000737:chemistry / Q000276:immunology; D002417:Cattle; D002478:Cells, Cultured; D002626:Chemistry, Pharmaceutical; D016207:Cytokines / Q000032:analysis; D004355:Drug Stability; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006968:Hypersensitivity, Delayed / Q000276:immunology; D008055:Lipids / Q000737:chemistry* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009166:Mycobacterium leprae / Q000276:immunology; D053758:Nanoparticles; D010316:Particle Size; D000644:Quaternary Ammonium Compounds / Q000737:chemistry* / Q000276:immunology; D012710:Serum Albumin, Bovine / Q000276:immunology; D013621:Taenia / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000942:Antigens, Bacterial; D000947:Antigens, Helminth; D002412:Cations; D016207:Cytokines; D008055:Lipids; D000644:Quaternary Ammonium Compounds; C015831:dimethyldioctadecylammonium; D012710:Serum Albumin, Bovine