Calcium-dependent secretion in human neutrophils: A proteomic approach

Bactericidal, proteolytic and signal proteins released by activated neutrop hils play a major role in infection fighting and inflammatory processes. Th ese proteins are mainly stored in organelles called granules until inductio n of their controlled exocytosis. The present work deals with the character ization of the proteins which are secreted upon activation of human neutrop hils by ionomycin and calcium. Proteins were separated by two-dimensional g el electrophoresis and identified by peptide mass fingerprinting. Almost al l the previously described soluble components of neutrophil granules could be identified. Moreover, several additional proteins were shown to be secre ted by activated neutrophils, namely calgranulins, human cartilage glycopro tein of 39 kDa (HC gp-39), chitotriosidase, and annexin XI. Their subcellul ar localization and possible functions are discussed.