Antibody and cd8+ t-cell responses in immunized mice with different vaccination strategies

RUIZ MORENO FEDERICO NAHUEL, CONSTANZA MARIN, MARIA FERNANDA SANCHEZ VALLECILLO, ANA LAURA CHIODETTI, FLORENCIA RIVELLI , GABRIEL MORON, DANIEL ALLEMANDI, MARIA CRISTINA PISTORESI PALENCIA, SANTIAGO DANIEL PALMA, BELKYS ANGELICA MALETTO

Mar del Plata

Congreso; Reunión Conjunta - Sociedad Argentina de Investigación Clínica (SAIC) - Sociedad Argentina de Inmunología (SAI) - Sociedad Argentina de Fisiología (SAFIS); 2018

SAI

Subunit-vaccines require the development of new adjuvant strategies. Recently, CpG-ODN was approved by FDA for a human vaccine. However, the free CpG-ODN present some limitations that restrict its bioavailability. In this context, we nanoformulated CpG-ODN with a nanostructure (Coa-ASC16) formed by self-assembly of 6-O-ascorbyl palmitate. Here, we investigated the effect of various formulations on antigen-specific response. Mice were subcutaneously immunized with a single-dose of OVA and CpG-ODN in solution (OC), OVA and CpG-ODN nanoformulated with Coa-ASC16 (OCC), OVA and CpG-ODN in solution heated at 80ºC for 15 min and then cooled down to room temperature to simulate the conditions of preparation of the nanostructured formulation (OCø), and OVA formulated with Montanide Gel 01 PR (reference adjuvant) (OM). OVA-specific IgG and IgG2a titers were evaluated by ELISA in all groups and SIINFEKL-Kb tetramer+ CD8+ T-cells by flow cytometry in OCC and OCø groups. Antibody response: OCø developed IgG response faster than other groups (day 8: 2.40±0.17), OCC and OC seroconverted on day 10 (2.00±0.66 and 1.35±0.19), and OM on day 13 (1.43±0.54). OCC induced higher IgG titers than OC and OM (p