Effects of soluble SIRPα IgV fusion proteins in leukocyte transmigration.
Leukocyte transmigration across matrix (collagen)-coated filters (transwell) using neutrophil-like differentiated HL-60 cells were performed as described in the methods. In these experiments, HL-60 cells (2.5x106) in the upper chambers of the transwells in 150μl HBSS with or without SIRP fusion proteins (40μg/ml), or mAbs (20μg/ml) against CD47 (C5D5) or SIRPα (SE5A5), were induced to migrate into fMLP (1μM) containing lower chambers at 37ºC. Cells that migrated into the lower chamber after 1hr were quantified by MPO assay. Data represents one of three experiments with three individual transwells in each condition + SD.