Preparation, Characterisation and Entrapment of a Non-glycosidic Threitol Ceramide into Liposomes for Presentation to Invariant Natural Killer T Cells

• Published in: Journal of pharmaceutical sciences 2011-07, Vol.100 (7), p.2724-2733
• Main Authors: Kaur, Randip, Chen, Jili, Dawoodji, Amina, Cerundolo, Vincenzo, Garcia-Diaz, Yoel R., Wojno, Justyna, Cox, Liam R., Besra, Gurdyal S., Moghaddam, Behfar, Perrie, Yvonne
• Format: Article
• Language: English
• Subjects: Adjuvants, Immunologic - administration & dosage; Adjuvants, Immunologic - chemistry; Adjuvants, Immunologic - pharmacology; bilayer; Biological and medical sciences; cationic lipids; Cells, Cultured; Chemistry, Pharmaceutical; dendritic cells; Dendritic Cells - drug effects; Dendritic Cells - immunology; Drug Compounding; Drug Stability; Galactosylceramides - administration & dosage; Galactosylceramides - chemistry; Galactosylceramides - pharmacology; General pharmacology; Humans; Interferon-gamma - metabolism; invariant natural killer T-cells; Killer Cells, Natural - drug effects; Killer Cells, Natural - immunology; Kinetics; Liposomes; Medical sciences; monolayer studies; Particle Size; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Phosphatidylcholines - chemistry; Quaternary Ammonium Compounds - chemistry; Solubility; stability; Sugar Alcohols - administration & dosage; Sugar Alcohols - chemistry; Sugar Alcohols - pharmacology; Technology, Pharmaceutical - methods; threitol ceramide
• ISSN: 0022-3549; 1520-6017
• DOI: 10.1002/jps.22500

Dendritic cells (DCs) are able to present glycolipids to invariant natural killer T (iNKT) cells in vivo. Very few compounds have been found to stimulate iNKT cells, and of these, the best characterised is the glycolipid α-galactosylceramide, which stimulates the production of large quantities of interferon-gamma (IFN-γ) and interleukin-4 (IL-4). However, αGalCer leads to overstimulation of iNKT cells. It has been demonstrated that the αGalCer analogue, threitol ceramide (ThrCer 2), successfully activates iNKT cells and overcomes the problematic iNKT cell activation-induced anergy. In this study, ThrCer 2 has been inserted into the bilayers of liposomes composed of a neutral lipid, 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), or dimethyldioctadecylammonium bromide (DDA), a cationic lipid. Incorporation efficiencies of ThrCer within the liposomes was 96% for DSPC liposomes and 80% for DDA liposomes, with the vesicle size (large multilamellar vs. small unilamellar vesicles) making no significant difference. Langmuir–Blodgett studies suggest that both DSPC and DDA stack within the monolayer co-operatively with the ThrCer molecules with no condensing effect. In terms of cellular responses, IFN-γ secretion was higher for cells treated with small DDA liposomes compared with the other liposome formulations, suggesting that ThrCer encapsulation in this liposome formulation resulted in a higher uptake by DCs.