title: Mechanism of extracellular release of human neutrophil calprotectin complex.
abstract: Calprotectin is an abundant cytosolic protein complex of human neutrophils with in vitro extracellular antimicrobial activity. Studies suggest that calprotectin may be actively secreted from intact HL-60 cells and that it can be translocated to polymorphonuclear neutrophil (PMN) cell membranes. To examine whether calprotectin is secreted extracellularly, we incubated soluble and particulate stimuli, including live and heat-inactivated Candida albicans, with whole blood and measured calprotectin levels in the plasma. We compared the release of calprotectin to that of lactoferrin, a protein known to be secreted by PMNs. Extracellular lactoferrin was detected after incubation with any of the particulate stimuli. In contrast, a significant increase in extracellular calprotectin was found only after incubation with live C. albicans. Specifically, the increase in extracellular calprotectin correlated directly with a proportional decrease in PMN viability. Our results indicate that human PMN calprotectin is not secreted extracellularly except as a result of cell disruption or death.
authors: Section of Oral Biology, School of Dentistry, University of California, Los Angeles, USA.
authors: A
authors: A
authors: Voganatsi
authors: A
authors: A
authors: Panyutich
authors: K T
authors: KT
authors: Miyasaki
authors: R K
authors: RK
authors: Murthy
mesh_terms: D002176:Candida albicans / Q000276:immunology; D002470:Cell Survival / Q000502:physiology; D006801:Humans; D007781:Lactoferrin / Q000097:blood / Q000378:metabolism; D039841:Leukocyte L1 Antigen Complex; D008070:Lipopolysaccharides / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000097:blood / Q000378:metabolism*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D019006:Neural Cell Adhesion Molecules / Q000097:blood / Q000378:metabolism*; D009504:Neutrophils / Q000378:metabolism*
chemical_list: D039841:Leukocyte L1 Antigen Complex; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D019006:Neural Cell Adhesion Molecules; D009240:N-Formylmethionine Leucyl-Phenylalanine; D007781:Lactoferrin