DEVELOPMENT OF DETECTION ASSAYS TO MEASURE INTERFERON-GAMMA INDUCED BY FOOT-AND-MOUTH DISEASE (FMD) VACCINES IN CATTLE

BUCAFUSCO, DANILO; PEGA, JUAN FRANCO; STAFFORINI, GUILLERMINA; COMPAIRED, DIEGO; OLIVERA, VALERIA; GUINZBURG, MARIELA; ZAMORANO, PATRICIA; SMITSAART, ELIANA; PÉREZ FILGUEIRA, MARIANO

CABA

Congreso; Practical Alternatives to Reduce Animal Testing in Quality Control of Veterinary Biologicals in the America; 2010

PROSAIA

Interferon-gamma (IFN-γ) detection may be used as an indicator of cellular immunity specifically elicited after FMD vaccination. Measurement of IFN-γ has been proposed as a marker for previous infections and FMDV-specific cellular immune responses. In this sense, it may also be used to complement the information provided by anti-FMDV antibody detection tests and to allow a better prediction of the protection and putative viral persistence after virus infection. Following this idea an ELISpot assay and an ELISA based on a commercial kit, were set up to detect IFN-γ from peripheral mononuclear blood cells and whole blood obtained from naïve and vaccinated animals. Different parameters, including antigen preparation, incubation times, cellular concentration and dilution of detecting antibodies, were studied to establish the assay’s working conditions. Finally, blood samples from animals (n=19) enrolled in a FMD vaccine potency test were evaluated. Each sample was tested for anti-FMDV antibody titres by liquid phase blocking ELISA at 60 days-post vaccination (dpv) and viral sero-neutralization capacity and IFN-γ levels at 90 dpv. Animals were challenged at 90 dpv and clinical signs were recorded. Analysis of this preliminary set of data indicates that measurement of IFN-γ can constitute a valuable tool, with a positive association between IFN-γ production and protection against the homologous virus challenge.