Signal Regulatory Protein Alpha Is Present in Several Neutrophil Granule Populations and Is Rapidly Mobilized to the Cell Surface to Negatively Fine-Tune Neutrophil Accumulation in Inflammation

Signal regulatory protein alpha (SIRP alpha) is a cell surface glycoprotein with inhibitory functions, which may regulate neutrophil transmigration. SIRPa is mobilized to the neutrophil surface from specific granules, gelatinase granules, and secretory vesicles following inflammatory activation in vitro and in vivo. The lack of SIRPa signaling and the ability to up-regulate SIRPa to the cell surface promote neutrophil accumulation during inflammation in vivo. (C) 2014 S. Karger AG, Basel