title: Modulation of the specific allergic response by mite allergens encapsulated into liposomes.
abstract: Liposomes are non toxic and biodegradable lipid vesicles, which are safe and effective adjuvants to induce Th1-skewed immune response. Therefore, the encapsulation of allergens into liposomes could be an attractive alternative for specific allergy immunotherapy. Previously, we obtained DPPC iposomes encapsulating purified allergens from Dermatophagoides siboney, with suitable stability and extremely reduced allergenicity. In this study, Balb/c mice were immunized with allergens ncapsulated into liposomes (LP) and the induced immune response was evaluated in comparison with allergens dissolved in PBS (PBSA) or adsorbed in Alum (AL). The use of Alum or Liposomes induced a strong allergen specific IgG response. However, total IgE serum levels in the AL group were very high, while levels found in LP group were not significantly different from the control group receiving only PBS. The IgG2a/IgG1 subclass ratio was raised in the LP group. Allergen specific IgE, as measured by PCA assay, was similar for LP and PBSA groups, and approximately the half of the reaction size found in AL group. After allergen challenge by inhalation route, peripheral blood and airway eosinophil counts increased significantly in AL, but not in LP group. Additionally, histopathological analysis of lung tissue sections obtained from challenged mice indicated a reduced cellular infiltration in mice immunized with liposomes. These results support the potential use of liposomal formulations for allergen vaccines.
authors.affiliation: Centro de Estudio de Proteínas, Fac. Biología, U.H., C. Habana, Cuba. leslycd@fbio.uh.cu
authors.forename: Lesly
authors.initials: L
authors.lastname: Calderón
authors.forename: Elisa
authors.initials: E
authors.lastname: Facenda
authors.forename: Liuber
authors.initials: L
authors.lastname: Machado
authors.forename: Keiko
authors.initials: K
authors.lastname: Uyema
authors.forename: Dunia
authors.initials: D
authors.lastname: Rodríguez
authors.forename: Eliane
authors.initials: E
authors.lastname: Gomez
authors.forename: Yohanka
authors.initials: Y
authors.lastname: Martínez
authors.forename: Bárbara
authors.initials: B
authors.lastname: González
authors.forename: Virgilio
authors.initials: V
authors.lastname: Bourg
authors.forename: Carlos
authors.initials: C
authors.lastname: Alvarez
authors.forename: Anselmo
authors.initials: A
authors.lastname: Otero
authors.forename: Momtchilo
authors.initials: M
authors.lastname: Russo
authors.forename: Alexis
authors.initials: A
authors.lastname: Labrada
authors.forename: María E
authors.initials: ME
authors.lastname: Lanio
mesh_terms: D000534:Alum Compounds; D000818:Animals; D039741:Antigens, Dermatophagoides / Q000008:administration & dosage / Q000276:immunology*; D006967:Hypersensitivity / Q000276:immunology*; D008081:Liposomes / Q000008:administration & dosage; D051379:Mice; D008807:Mice, Inbred BALB C
chemical_list: D000534:Alum Compounds; D039741:Antigens, Dermatophagoides; D008081:Liposomes; C041524:aluminum sulfate