ADJUVANT FORMULATION BASED ON AN ASCORBYL PALMITATE NANOSTRUCTURE AND CPG-ODN ENHANCES IFN-γ+ T CELL RESPONSE AND ANTIBODY AVIDITY

CHIODETTI, A; SANCHEZ-VALLECILLO,MF; ULLO, G; CRESPO, MI; MORÓN, G; PISTORESI, MC; ALLEMANDI, D; MALETTO, B

Los Cocos. Cordoba

Congreso; LXI Reunión de la Sociedad Argentina de Inmunología.; 2013

Sociedad Argentina de Inmunologia

Previously we have shown that CpG-ODN formulated in a 6-O-ascorbyl palmitate nanostructure (Coa-ASC16) was more efficient as adjuvant than CpG-ODN solution using OVA as an antigen model. Particularly, immunization of mice with OVA/CpG-ODN/Coa-ASC16 resulted in a significant increase of OVA-specific antibody titers and kinetics of apparition (IgG, IgG1, and IgG2a) and IFN-γ and IL-17 secretion compared with OVA/CpG-ODN immunized mice. In order to evaluate the quality of the immune response induced by this adjuvant strategy, we determined the frequency of IFN-γ+ T cells (intracellular staining and flow cytometry) and the binding avidity of plasma antibodies (IgG) for OVA (KSCN elution assay). Mice were subcutaneously immunizated on days 0, 7 and 14 with OVA/CpG-ODN/Coa-ASC16 or OVA/CpG-ODN (dose/mice: OVA:60μg, CpG-ODN:75 μg). On day 21, mice were sacrificed and plasma and spleen were obtained. Spleen cell suspensions were cultured with medium or OVA (100μg/ml). We observed that splenocytes from mice immunized with OVA/CpG-ODN/Coa-ASC16 presented a higher frequency of OVA-specific IFN-γ-producing CD4+ (0.60±0.40 vs 4.60±0.04) and CD8+ (1.9±1.0 vs 5.5±0.7) T cells than splenocytes from mice immunized with OVA/CpG-ODN (p