The upregulation of mMCP-1 supplemented with TGF-β₁ is dose–dependant. mBMMC were grown for 7 days in WEHI/rrSCF, transferred into 48-well plates at 5 × 10⁵mBMMC/mL, and supplemented with WEHI/rrSCF/rmIL-9 to which was added, in quadruplicate wells, WEHI/rrSCF/rmIL-9 alone (□) or 0.01 (○), 0.1 (▵), 1 (◊), or 5 (▴) ng/mL rhTGF-β₁. (A) shows the percentage of mMCP-1⁺ mast cells. Counts from all the TGF-β₁–supplemented cultures were significantly higher than the WEHI/rrSCF/rm IL-9 controls on days 4 and 7 (P < .03). (B) shows the total numbers of mast cells per culture. The counts from cultures supplemented with 1 or 5 ng/mL rhTGF-β₁were significantly lower than in the controls on day 4 (P < .03). (C) shows the concentrations of mMCP-1 in culture supernatants (in nanograms per milliliter). The mMCP-1 concentrations from all the TGF-β₁–supplemented cultures were significantly higher than the controls on days 4 and 7 (P < .03). (D) shows the concentration of mMCP-1 detected in culture supernatants on day 4 plotted against concentrations of TGF-β₁.