Characterization of CSB-induced PBMC proliferation. (A) PBMC were cultured as described in Materials and Methods, and CSB was added at the indicated concentrations. (B) PBMC were treated with CSB (1 mg/mL) in the absence or presence of rTGFβ1 (1 ng/mL). (C) Total PBMC or monocyte-depleted PBMC (nonadherent) were incubated with CSB (1 mg/mL) for 6 days. Monocytes were depleted by adherence to tissue culture flasks and nonadherent cells were collected, counted, and plated. Data shown are [³H]-thymidine incorporation during the final 16 hours of a 6-day culture period. In each case, the results shown are representative of at least three similar experiments.