title: Characterization of cationic liposomes based on dimethyldioctadecylammonium and synthetic cord factor from M. tuberculosis (trehalose 6,6'-dibehenate)-a novel adjuvant inducing both strong CMI and antibody responses.
abstract: Incorporation of the glycolipid trehalose 6,6'-dibehenate (TDB) into cationic liposomes composed of the quaternary ammonium compound dimethyldioctadecylammonium (DDA) produce an adjuvant system which induces a powerful cell-mediated immune response and a strong antibody response, desirable for a high number of disease targets. We have used differential scanning calorimetry (DSC) to investigate the effect of TDB on the gel-fluid phase transition of DDA liposomes and to demonstrate that TDB is incorporated into DDA liposome bilayers. Transmission Electron Microscopy (TEM) and cryo-TEM confirmed that liposomes were formed when a lipid film of DDA containing small amounts of TDB was hydrated in an aqueous buffer solution at physiological pH. Furthermore, time development of particle size and zeta potential of DDA liposomes incorporating TDB during storage at 4 degrees C and 25 degrees C, indicates that TDB effectively stabilizes the DDA liposomes. Immunization of mice with the mycobacterial fusion protein Ag85B-ESAT-6 in DDA-TDB liposomes induced a strong, specific Th1 type immune response characterized by substantial production of the interferon-gamma cytokine and high levels of IgG2b isotype antibodies. The lymphocyte subset releasing the interferon-gamma was identified as CD4 T cells.
authors.affiliation: Vaccine Development, Adjuvant Research, Statens Serum Institut, DK-2300 Copenhagen, Denmark.
authors.forename: Jesper
authors.initials: J
authors.lastname: Davidsen
authors.forename: Ida
authors.initials: I
authors.lastname: Rosenkrands
authors.forename: Dennis
authors.initials: D
authors.lastname: Christensen
authors.forename: Anil
authors.initials: A
authors.lastname: Vangala
authors.forename: Daniel
authors.initials: D
authors.lastname: Kirby
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Perrie
authors.forename: Else Marie
authors.initials: EM
authors.lastname: Agger
authors.forename: Peter
authors.initials: P
authors.lastname: Andersen
mesh_terms: D000217:Acyltransferases / Q000276:immunology; D000276:Adjuvants, Immunologic / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D000917:Antibody Formation / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology; D002152:Calorimetry, Differential Scanning; D003311:Cord Factors / Q000737:chemistry / Q000494:pharmacology*; D020285:Cryoelectron Microscopy; D005260:Female; D006017:Glycolipids / Q000737:chemistry / Q000494:pharmacology*; D007111:Immunity, Cellular / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood*; D007371:Interferon-gamma / Q000032:analysis / Q000378:metabolism; D008027:Light; D008081:Liposomes; D051379:Mice; D046529:Microscopy, Electron, Transmission; D009169:Mycobacterium tuberculosis; D000644:Quaternary Ammonium Compounds / Q000737:chemistry / Q000494:pharmacology*; D011993:Recombinant Fusion Proteins / Q000276:immunology; D012542:Scattering, Radiation; D018417:Th1 Cells / Q000276:immunology* / Q000378:metabolism; D032581:Tuberculosis Vaccines / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D003311:Cord Factors; C093276:ESAT-6 protein, Mycobacterium tuberculosis; D006017:Glycolipids; D007074:Immunoglobulin G; D008081:Liposomes; D000644:Quaternary Ammonium Compounds; D011993:Recombinant Fusion Proteins; D032581:Tuberculosis Vaccines; C507803:trehalose 6,6'-dibehenate; C015831:dimethyldioctadecylammonium; D007371:Interferon-gamma; D000217:Acyltransferases; C121433:antigen 85B, Mycobacterium tuberculosis