Combining a sub-immunizing dose of inactivated Foot and Mouth Disease Virus (FMDV) and plasmids encoding P12A3C or VP1 protein enhances DNA vaccine potency.

PEREYRA E; GNAZZO V; SORIA I; LANGELLOTTI C; BELLUSCI C; D´ANTUONO A; MATTION N; QUATTROCCHI V; ZAMORANO P; MONGINI C

Milán

Congreso; 15th International Congress of Immunolog; 2013

IUIS International Union of Immunological Societie

In this study we evaluated the ability to induce protective immune responses using formulations including plasmids encoding the secreted form of VP1 protein (pVP1s) or the polyprotein P12A3C (pP1)of FMDV in combination or not with pCD40L and pIL15 or a sub-immunizing dose of inactivated FMDV (iFMDV). BALB/c mice were inoculated id with pP1 or pVP1s vaccines in combination or not with a chemical adjuvant and one sub-immunizing dose of iFMDV. Negative controls were inoculated with empty plasmids, or adjuvant. No difference in antibody titers was found among the pP1 groups. On day 7 after the last immunization, vaccinated mice were challenged with 104.5 TCID50 of FMDV. 75% and 50 % of animals were protected when received pP12A3C and pIL15 or pCD40L and the chemical adjuvant, respectively. Animals vaccinated with pVP1s alone or with adjuvant with a single sub-immunizing dose of iFMDV enhanced dramatically the antibodies titers and were protected against the viral challenge, while negative controls were infected. Our results demonstrated that pP1vaccines were effective at priming and suggest that IL15 and CD40L can contribute to immune-enhancement and protection against FMDV challenge. Besides, an inoculation with pVP1 or pP1 and a sub-immunizing dose of iFMDV leads to complete protection and consequently, may be a useful strategy for improving the potency and efficacy of FMDV-DNA vaccines.