Liposomes as vehicle for allergen presentation in the immunotherapy of allergic diseases

Liposomes are non-toxic, biodegradable and weakly immunogenic lipid vesicles which can be used as immunomodulating agents. In the present study, multilamellar vesicles (MLV) and small unilamellar vesicles (SUV) were used to incorporate an allergenic protein from Artemisia scoparia pollen. MLV incorporated more allergenic protein than SUV. To assess the immunomodulating effect of allergen entrapped in liposomes, Swiss strain mice (made IgE responders) were injected with either free allergen or liposome-entrapped allergen (LEA) and their immune response was measured in terms of specific IgG and specific IgE levels. Results indicated that specific IgE response was significantly lower in mice injected LEA (P less than 0.02) than in mice injected free allergenic protein. Although specific IgG response was higher in mice injected LEA, there was no statistically significant difference between the two groups. Potential use of liposomes as non-immunogenic biocompatible vehicle for antigen presentation in immunotherapy will be discussed.