Expression of complement regulators on microparticles. Microparticles from O157LPS-stimulated whole blood were incubated with mouse anti–human CD35:FITC (CR1; A), CD55:APC (DAF; B), or CD46:RPE (MCP; C), showing binding of the antibodies to platelet-, monocyte-, and neutrophil-derived microparticles. Data are presented as the mean fluorescence intensity (MFI) ± SD from 5 independent experiments.