Content area
Full text
Figure 1. Structures and IUPAC names of DOTAP, DC-Chol and DDA.
(Figure omitted. See article PDF.)
Figure 2. Dimethyldioctadecylammonium (DDA) liposomes enhance uptake and presentation of antigen by dendritic cells. (A) Antigen-loaded DDA liposomes associate with antigen-presenting cells thus enhancing the uptake of antigen. (B) This can be visualized by confocal microscopy: antigen is shown in green, the actin filaments of a dendritic cell in red. It is not yet known whether the antigen is internalized alone (as depicted) or together with the liposomes. (B-C) The enhanced uptake leads to enhanced presentation of antigen by the dendritic cells. This results in increased proliferation of antigen-specific T cells and their subsequent release of IFN-γ as demonstrated by incorporation of radioactively labeled thymidine and detection of IFN-γ by ELISA after 2 days of coculture. Previously published in [47]. Ag: Antigen.
(Figure omitted. See article PDF.)
Figure 3. Incorporation of glycolipids into dimethyldioctadecylammonium (DDA) liposomes can stabilize the particle size distribution and avoid aggregation. (A) The particle size of liposomes formed by DDA, DDA/TDB and DDA/LAcCer. Furthermore, (B) shows the synergistic effect between DDA and TDB, on their own generating a very low immune response, but together generating a strong immune response. However, not all glycolipids obtain as powerful an adjuvant effect upon incorporation into the DDA liposomes as TDB; this is illustrated with LacCer showing antigen-specific IFN-γ levels in blood (pg/ml) after three immunizations with Ag85B-ESAT-6. *After 28 days, DDA is too aggregated to measure the particle size. LacCer: :actocylceramide; TDB: Trehalose 6,6´-dibehenate.
(Figure omitted. See article PDF.)
Figure 4. Immune responses generated by DDA/TDB liposomes and Al(OH)3 . (A) Dimethyldioctadecylammonium/trehalose 6,6´-dibehenate (DDA/TDB) induces high levels of the Th1 cytokine IFN-γ and (B) low levels of the Th2 cytokine IL-5, which is diametrical opposite to the induction obtained by Al(OH)3 . (C) DDA/TDB induces IgG1 levels similar to Al(OH)3 , but (D) higher levels of IgG2b . Previously published in [31]
(Figure omitted. See article PDF.)
Figure 5. Formulation of immunomodulators together with cationic liposomes is a promising method to enhance and modulate the immune response in a desirable direction and can be used when designing tailor-made adjuvants for specific disease targets. CTL: Cytotoxic T lymphocyte; MDP: Muramyl dipeptide; MPL: Monophosphoryl...