PRT-treated platelets induce TGF-β production in splenic monocytes. The responses of monocytes and Mϕ were examined at 4 hours (day 0) and at days 1, 2, and 6. (A) Cells were gated for monocytes by selecting for CD19^- CD11b^Hi F4/80^{low(and)intermediate} NK1.1⁻ and CD11c⁻ events or gated for macrophages by selecting for CD19⁻ CD11b^intermediate/F4/80^Hi events. (B) Frequency of CD86⁺, CD80⁺, MHCII⁺, and TGF-β⁺ events were determined for monocytes with fold change compared with nontransfused group plotted. (C) For macrophages, measurements of median fluorescent intensities for CD86, CD80, and MHCII and frequency of TGF-β⁺ events were made, with fold change compared with nontransfused group plotted. The frequency of total monocytes and macrophages were derived from total live events and the frequencies of CD86⁺, CD80⁺, MHCII⁺, and TGF-β⁺ events were derived from total monocytes or macrophages, respectively. “X” labels time points where <2 sets of data are available. Data are combined from 2 or 3 independent experiments (n = 5 per group). *P < .05, **P < .01, ***P < .001.