NANOVACCINE PLATFORM CONTAINING TLR9 AGONIST IMPROVES GERMINAL CENTER RESPONSE

FEDERICO RUIZ MORENO; CONSTANZA MARIN; MARIA ESPERANZA FELICI; DANIEL ALBERTO ALLEMANDI; SANTIAGO PALMA; MARIA CRISTINA PISTORESI PALENCIA; GABRIEL MORON; BELKYS MALETTO

Congreso; LXIX REUNIÓN SAI; 2021

We have previously reported that the nanoformulation of OVA and CpG-ODN with a nanostructure (Coa-ASC16) formed by self-assembly of 6-O-ascorbyl palmitate (ASC16) elicited an OVA-specific antibody response sustained for over 160 days and cellular immune response superior in magnitude and quality to those induced by vaccine components in solution. Here, we study the effect of various vaccine components formulations in the antigen-specific CD8+ T cells, germinal center B cells, and Tfh cells. We also evaluate the effect of ASC16 sterilization (gamma irradiation) on the immune response. Mice were subcutaneously immunized with a single dose of OVA and CpG-ODN nanoformulated with Coa-ASC16 (OCC), an OVA and CpG-ODN solution heated and then cooled down to RT (OCø), an OVA solution heated and then cooled down to RT plus a CpG-ODN solution at RT (øO/C), or with an OVA solution at RT plus a CpG-ODN solution heated and then cooled down to RT (O/øC). Heating and cooling processes recreated the conditions of the nanoformulation preparation. ELISA and flow cytometry techniques were used. In the group of mice immunized with OCC we found a response higher than the response elicited in the other groups of antigen-specific CD8+ T cells (CD3+ CD8+ SIINFEKL-Kb tetramer+) in blood 7-days post-immunization (p