FIG. 6.

Proliferation of bursal and splenic cells following stimulation by purified virus ex vivo. Spleen (Spl) and bursal (BF) cells were prepared from both virus-free and IBDV-infected chickens at 7 days p.i. The cells were stimulated with various concentrations of purified IM-IBDV for 48 h and pulsed with [³H]TdR for 5 h (A); to determine the specificity of lymphoproliferation, purified FPV (25 μg/ml) and NDV (25 μg/ml) were included with IBDV (25 μg/ml) (B). The results are presented as mean counts of three pools in each group ± SD (P < 0.02).