A novel positively-charged lipid 1,2-bis(hexadecylcycloxy)-3-trimethyl aminopropane (BisHOP) enhances the adjuvant effect of liposomes on encapsulated tetanus toxoid.
A novel positively charged lipid, 1,2-bis(hexadecylcycloxy)-3-trimethylaminopropane-HCl (BisHOP), when incorporated into the bilayers of phosphatidylcholine (PC) and distearoyl phosphatidylcholine (DSPC) dehydration-rehydration vesicles (DRV), was shown to have a powerful effect in enhancing the IgG1 response to tetanus toxoid encapsulated within the liposomes. The adjuvant effect was significantly greater when 20% BisHOP was incorporated as compared to 10% incorporation and to control PC and DSPC DRV. Plain, uncharged DSPC DRV were found to have a greater adjuvant effect than plain PC DRV on the entrapped tetanus toxoid after a single intramuscular injection. Even though antibody levels at 8 weeks post-injection were similar for 20% BisHOP PC and DSPC DRV, the rate of rise of antibody titres was more rapid for 20% BisHOP DSPC than for 20% BisHOP PC DRV. These results suggest that faster and higher titers of antibodies may be obtained by optimal manipulation of the charged and non-charged lipid components of liposomes.
Tan
L
L
Department of Pharmacology, Faculty of Medicine, National University of Singapore, Kent Ridge.
Gregoriadis
G
G
D000276:Adjuvants, Immunologic; D000818:Animals; D002214:Capsules; D004337:Drug Carriers; D007074:Immunoglobulin G / Q000276:immunology; D008055:Lipids / Q000008:administration & dosage*; D008081:Liposomes; D051379:Mice; D008807:Mice, Inbred BALB C; D000644:Quaternary Ammonium Compounds / Q000008:administration & dosage*; D013745:Tetanus Toxoid / Q000008:administration & dosage / Q000276:immunology*
D000276:Adjuvants, Immunologic; D002214:Capsules; D004337:Drug Carriers; D007074:Immunoglobulin G; D008055:Lipids; D008081:Liposomes; D000644:Quaternary Ammonium Compounds; D013745:Tetanus Toxoid; C072780:1,2-bis(hexadecyloxy)-3-trimethylaminopropane