Karsten Lollike

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The traditional classification of neutrophil granules as peroxidase-positive (azurophil, or primary) and peroxidase-negative (specific or secondary) has proven to be too simple to explain the differential exocytosis of granule proteins and incorporation of granule membrane into the plasma membrane which is an important aspect of neutrophil activation.(More)
We measured capacitance changes in cell attached patches of human neutrophils using a high frequency lock-in method. With this technique the noise level is reduced to 0.025 fF such that capacitance steps of 0.1 fF are clearly detected corresponding to exo- and endocytosis of single 60 nm vesicles. It is thus possible to detect almost all known exocytotic(More)
Cell membranes behave like electrical capacitors and changes in cell capacitance therefore reflect changes in the cell area. Monitoring capacitance can thus be used to study dynamic cellular phenomenon involving rapid changes in cell surface, such as exo- and/or endocytosis. In this review focus is on the use of capacitance techniques to study exocytosis in(More)
Grancalcin is a recently described Ca(2+)-binding protein especially abundant in human neutrophils. Grancalcin belongs to the penta-EF-hand subfamily of EF-hand proteins, which also comprises calpain, sorcin, peflin, and ALG-2. Penta-EF-hand members are typified by two novel types of EF-hands: one that binds Ca(2+) although it has an unusual Ca(2+)(More)
The extent of mobilization of four different intracellular compartments was measured during in vivo exudation of neutrophils into skin chambers and compared with resting neutrophils obtained from blood. Exudation of neutrophils induced increased surface expression of alkaline phosphatase, complement receptor 1, and Mac-1, and a complete loss of L-selectin.(More)
Human neutrophils are of prime importance for the immune defense. Recent data from eosinophils and pancreatic beta cells have indicated that granules, upon exocytosis, occasionally fuse with each other in the cytosol prior to their subsequent fusion with the plasma membrane. This is termed compound exocytosis. We therefore studied exocytosis of single(More)
Biosynthesis of 3 human granule proteins, myeloperoxidase, defensin and lysozyme, all present in azurophil granules, was investigated in normal bone marrow cells and in the promyelocytic cell line HL-60 to see whether differences in timing of biosynthesis could explain the well established differences in their subcellular localization in the mature(More)
Lysozyme was found to be present in all three types of human neutrophil granules (azurophil-, specific- and gelatinase granules) as determined by subcellular fractionation, employing a three-layer Percoll gradient and measurement of lysozyme by a novel ELISA. The content of lysozyme was also measured in plasma. In contrast to other neutrophil granule(More)
We recently confirmed the existence of gelatinase granules as a subpopulation of peroxidase-negative granules by double-labeling immunogold electron microscopy on intact cells and by subcellular fractionation. Further characterization of gelatinase granules has been hampered by poor separation of specific and gelatinase granules on both two-layer Percoll(More)