Intracellular IFN-γ and IL-10 expression by bovine T-cell subsets. Blood from tuberculin reactor cattle (n = 12) was collected 3-days post skin-test. ICS expression of IFN-γ and IL-10 by CD4, CD8 and TcR-δ T-cell subsets was determined using lysed whole blood cultures stimulated with either PPD-B or PWM. The percentage of CD4⁺, CD8⁺ and TcR-δ⁺ cells expressing IFN-γ or IL-10 are shown in panels (A) and (B) respectively. PPD-B induced responses (no-antigen response subtracted) as represented by grey bars and PWM responses black bars (mean ± standard error).