Expression of granzyme B in peripheral blood polymorphonuclear neutrophils (PMN), myeloid cell lines and in PMN derived from haemotopoietic stem cells in vitro.
Granzyme B and perforin are the major protagonists of cytotoxicity mediated by natural killer (NK) cells or cytotoxic T cells. More recent we described the presence of granzyme B and perforin in polymorphonuclear neutrophils (PMN), a finding in discrepancy with the credo that granzyme B and perforin expression is restricted to cytotoxic T cells and NK cells. In extension of our previous study, we now provide evidence that granzyme B is not only present in mature PMN, but also in the myeloid cell lines HL-60 and U937, in CD34+ stem cells, and in PMN derived from CD34+ cells in vitro. In agreement with the "targeting by time" hypothesis we found the bulk of granzyme B in association with primary granules, in addition to a minor membrane expression. Granzyme B, on one hand might, enhance the cytotoxic potential of PMN, on the other, it may provide PMN with additional means to degrade extracellular matrices.
Wagner
Christof
C
Institut für Immunologie der Universität Heidelberg, Im Neuenheimer Feld 305, 60120 Heidelberg, Germany.
Stegmaier
Sabine
S
Hänsch
Gertrud Maria
GM
D018952:Antigens, CD34 / Q000378:metabolism; D002478:Cells, Cultured; D003594:Cytoplasmic Granules / Q000201:enzymology*; D053804:Granzymes / Q000097:blood / Q000378:metabolism*; D006801:Humans; D007694:Killer Cells, Natural / Q000201:enzymology*; D022423:Myeloid Cells / Q000201:enzymology; D009504:Neutrophils / Q000201:enzymology*; D013234:Stem Cells / Q000201:enzymology
D018952:Antigens, CD34; D053804:Granzymes