Fig. 2.

Effect of the CD4⁺ T-cell depletion on VNT and proliferation to FMDV vaccine antigen. Two groups of three calves were treated as described in Fig. 1. (a) VNTs are shown for anti-CD4 mAb (triangles) and TRT3 mAb-(squares) treated calves at time points pre- and post-vaccination. Results are expressed as the mean of determinations (log₂ titres) from individual calves in each group±sem. (b) Total PBMC proliferative responses are shown for TRT3 mAb-treated calves to A22 FMDV vaccine antigen (0.1 µg ml⁻¹, black bars) or BHK-21 cell lysate (0.1 µg ml⁻¹, grey bars) at time points pre- and post-vaccination, as assessed by [methyl-³H] thymidine incorporation. Results are expressed as the mean of determinations from individual calves in each group±sem. (c) Similar to (b), but showing the antigen-specific proliferation of PBMC from CD4 mAb-treated calves. Results are expressed as the mean of determinations from individual calves in each group±sem.