Fig. 5.

Quantification of IFN-γ production assessed by ELISA in response to in vitro restimulation with FMDV vaccine antigen. Five calves were vaccinated with commercial BHV-1 vaccine, and subsequently vaccinated with O1 Manisa FMD commercial vaccine (6 weeks later). Post-FMD vaccination, PBMC (a), PBMC depleted of CD4⁺ T-cells (b) and purified CD4⁺ T-cells+APCs (c) were cultured in vitro in the presence of medium alone or optimal concentrations of PWM, heat-inactivated BHV-1, EBTr cell lysate (EBTr), inactivated O1 Manisa FMDV vaccine antigen (FMDV, 0.1 µg ml⁻¹) or BHK-21 cell lysate (BHK-21, 0.1 µg ml⁻¹). After 5 days, supernatants were harvested and assayed for IFN-γ by sandwich ELISA. Results are expressed as the mean IFN-γ concentration (ng ml⁻¹) of duplicate determinations±sd for each of the five vaccinated calves. For each culture condition, the five columns represent animals FMD 6–FMD 10.