- EARLY EVENTS OF INNATE IMMUNITY ARE MODIFIED BY THE NANOFORMULATION OF VACCINE COMPONENTS

Tucumán

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

Subunit vaccines are often poorly immunogenic and require a strong adjuvant. Therefore, new adjuvant strategies are demanded to develop new vaccines. We formulated OVA and CpG-ODN with a nanostructure (Coa-ASC16) formed by self-assembly of 6-O-ascorbyl palmitate. This nanoformulation (OCC) elicited strong humoral and cellular (CD4+ and CD8+) responses, which are superior to those induced by a solution of OVA and CpG-ODN (OC). Nonetheless, some characteristics about action mechanism of Coa-ASC16 remain to be elucidated. In this work we study some aspects about early immune events. Mice were subcutaneously immunized with OC or OCC formulation. Cytokines/chemokines were quantified in lymph nodes and serum at 0.33, 2, 24 and 48 hours post-immunization by LEGENDplex Mouse Inflammation Panel 13-plex. We further determined by flow cytometry, OVA and CpG-ODN cellular uptake in lymph nodes 24 hours post-immunization. Lymph nodes of OCC immunized mice showed higher levels of IFN-γ, IL-12p70, IL-1β, IL-10, IL-6, IL-27, IL-17A and IFN-β than mice immunized with OC (p<0.05). In contrast, OC immunized mice display higher levels of IFN-γ, TNF-α, MCP-1, IL-12p70 and IL-6 in serum than OCC immunized mice (p<0.05). Moreover, mice immunized with OCC showed a higher absolute number of OVA+, CpG-ODN+ and OVA+CpG-ODN+ monocytes (Ly6ChighLy6G-CD11b+) and dendritic cells (Ly6C-Ly6G-CD11c+) than mice immunized with OC (p<0.05). In conclusion, the nanoformulation of vaccine components modifies the cytokines/chemokines profile and promotes the co-uptake of antigen and immunostimulant by cells that infiltrate the lymph node.