IVIT   27842
INSTITUTO DE VIROLOGIA E INNOVACIONES TECNOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Comparison of the immune responses induced by FMD-Vaccines formulated with 146s and 75S particles in mice and cattle
Autor/es:
DI GIACOMO, S.; SCHAMMAS, J.; BUCAFUSCO, D.; BARRIONUEVO, F.; PÉREZ FILGUEIRA, M.; MIRAGLIA, M. CRUZ; SALA, J. M.; CAPOZZO, A.
Lugar:
Bangkok
Reunión:
Congreso; Global Foot-and-Mouth Disease Research Alliance 2019 Scientific Meeting; 2019
Institución organizadora:
Global Foot-and-Mouth Disease Research Alliance
Resumen:
Vaccination against foot-and-mouth disease virus (FMDV) is the main control measure to prevent incursions of the disease. Conventional vaccine production, however, presents significant biological risks in disease-free countries and increases control-related indirect expenses. Empty viral capsids are postulated as safe alternative antigens as they preserve all the epitopes of the native virus but eliminate the infectious capacity due to their lack of genomic RNA. In this work, we aim to identify potential differences in the immune response generated by oil-adjuvanted vaccines formulated with FMDV A24/Cruzeiro natural sucrose-gradient purified empty capsids (75S) or whole-virus particles (146S). To this end, immunization experiments with both antigens were performed in mice and cattle, and adaptive humoral and cellular responses were assessed at different times post-vaccination. Groups of mice (n=5 each) were immunized with oil-adjuvanted FMD vaccines formulated with different amounts of 146S or 75S antigens (1, 0.3 or 0.15 µg/dose). Analysis of the anti-FDMV antibodies did not show significant differences between vaccines formulated with the highest dose of 146S or 75S antigens. Total antibody responses, however, were higher for the 146S formulations in the other two concentrations, starting at 21 days post-vaccination (dpv). Qualitative differences in the IgG isotype composition were found for all three antigen doses, although they were more evident with the highest payload. As a general trend, a significantly higher proportion of IgG2a to IgG1 titers were found in the 146S formulations starting from 14 dpv until 28 dpv. All vaccinated groups were protected to the virus challenge at 28 dpv with the homologous strain.Experiments in bovines also involved oil-vaccines, formulated with 10 ug/dose (n=3 each group) or 3 µg/dose (n=4 each group) of 146S and 75S FMDV antigens. The highest antigenic dose induced significantly higher total and neutralizing antibody titers in the 146S than in the 75S experimental groups at 21, 28 and 63 dpv. With this same payload, antigen-specific interferon-gamma (IFN-γ) production was also higher in cattle vaccinated with 146S formulations than in those receiving the 75S vaccines, but only at 14 dpv and coinciding with peak values. Using the lower antigenic concentration (3 µg/dose), total antibody responses were also significantly higher in the 146S vaccinated group than in the 75S counterpart at 28, 45 and 70 dpv. IFN-γ production did not show significant differences between both experimental groups, except for an early onset of production at 7 dpv only observed in the 146S vaccinated group.As a whole, these results in both animal models indicated the existence of quantitative and qualitative differences in the adaptive immune responses induced by FMD oil vaccines formulated with 146S or 75S antigens. Further investigations will clarify the actual correlation of these results with their corresponding protective capacity in target species.