- FORMULATION OF ANTIGEN AND CpG-ODN WITH Coa-ASC16 OPTIMIZES HUMORAL RESPONSE INDEPENDENTLY OF TYPE I INTERFERONS SIGNALING

Tucumán

Congreso; LXVII Reunión Científica Anual de la Sociedad Argentina de Inmunología; 2019

Background: the new vaccines constituted by antigenic subunits are safe and less expensive, but are not very immunogenic, so they require the incorporation of a vigorous adjuvant. Recently, CpG-ODN was approved by FDA for a human vaccine. Our vaccine strategy is a nanoformulation where the ovalbumin antigen (OVA) and CpG-ODN are formulated with a liquid crystal bilamellar nanostructure (Coa-ASC16) formed by self-assembly of 6-O-ascorbyl palmitate. Previously, we demonstrated that this nanoformulation (OCC) elicited antibodies (IgG1 and IgG2a) and cellular (Th1/Th17 and CD8+ T-cells) responses superior to those induced by a solution of OVA and CpG-ODN (OC) under a three-dose immunization scheme. The CD8+ T-cell response induced by OCC was dependent of type I interferons (IFN-I) signaling. Here, we study if the IFN-I pathways have an impact on the antibodies response. Methods: wild-type C57BL/6 and Ifnar1-/- mice were subcutaneously immunized with a single-dose of OCC, OC and OVA and CpG-ODN in solution heated at 80ºC for 15 min and then cooled down to room temperature in order to simulate the conditions of preparation of the nanostructured formulation (OCø). OVA-specific IgG, IgG2c, and IgG1 titers were evaluated by ELISA. Results: the magnitude and quality of OVA-specific humoral response were similar between wild-type and Ifnar1-/- mice. The immunization with OCC and OCø induced higher IgG, IgG2c and IgG1 titers than OC (p<0.05) in wild-type and Ifnar1-/- mice. In conclusion, unlike the CD8+ T cell response, the positive effects on humoral responses induced by Coa-ASC16 were not affected by the absence of IFN-I signaling.