Surface-Linked Liposomal Antigen Induces IgE-Selective Unresponsiveness Regardless of the Lipid Components of Liposomes

Abstract

We have previously reported that antigen coupled with liposomes induced antigen-specific and IgE-selective unresponsiveness in mice. This antigen preparation was investigated for application in a novel vaccine protocol to induce minimal IgE synthesis. In this study, ovalbumin (OVA)-liposome conjugates were made using liposomes of four different lipid components, including unsaturated carrier lipid and three different saturated carrier lipids, after which the induction of anti-OVA antibody production was investigated in mice. All of the OVA-liposome conjugates induced IgE-selective unresponsiveness. The membrane fluidity of liposomes, as measured by detecting changes in the fluorescence polarization of a 1,6-diphenyl-1,3,5-hexatriene (DPH) probe located in the bilayers, was significantly higher in liposomes consisting of unsaturated carrier lipids than those of the other liposomes consisting of saturated carrier lipids. The highest titer of anti-OVA IgG was observed in mice immunized with OVA-liposomes made using liposomes consisting of unsaturated carrier lipids. In addition, among these OVA-liposomes, the one possessing the longest carbon chain induced the lowest IgG antibody production. These results suggest that the membrane fluidity of liposomes might affect the adjuvant effect of liposomes but not the induction of IgE-selective unresponsiveness in immunizations with surface-linked liposomal antigens.

Highly Efficient Antiviral CD8+T-Cell Induction by Peptides Coupled to the Surfaces of Liposomes

“…The oleoyl liposomes consisted of dioleoyl phosphatidylcholine, dioleoyl phosphatidylethanolamine, dioleoyl phosphatidylglycerol acid, and cholesterol in a 4:3:2:7 molar ratio (29). Each peptide was coupled to the surfaces of the liposomes by the use of disuccinimidyl suberate, as described previously (42).…”

“…The inducibility of Ag-specific IgG production was found to vary among liposome preparations: the greater that the membrane mobility in the liposomes is, the greater that the antibody production induced by Ag-liposome conjugates is (29). In our previous study, we have reported that ovalbumin (OVA) coupled to liposomes made with unsaturated fatty acids was presented to both CD4 ϩ and CD8…”

Application of Surface-Linked Liposomal Antigens to the Development of Vaccines That Induce Both Humoral and Cellular Immunity

“…2). The results suggest that the membrane fluidity of liposomes might affect the adjuvant effect of liposomes but not the induction of IgE-selective unresponsiveness in immunizations with surface-linked liposomal antigens (16).…”

Harnessing Nanoparticles for Immune Modulation

“…By contrast, intramuscularly injected fluid-state liposomes are rapidly removed, do not appear to stimulate positive costimulation, and are much less capable of stimulating a T cell response [28]. Whether the intramuscular fluid liposome-antigen combination induced peripheral immune tolerance was not tested, but intraperitoneal (IP) administration of fluid OVA-decorated liposomes can induce antigen-specific IgE non-responsiveness [31,32]. While this was argued to occur in a T cell-independent fashion, the increased levels of IgG after IP administration suggest immune deviation [33].…”