Increased cell-associated IL-8 in human exudative and A23187-treated peripheral blood neutrophils.
IL-8 is a potent neutrophil chemoattractant that has been detected in high concentrations at acutely inflamed sites in vivo. Many cell types, including peripheral blood neutrophils, produce IL-8 that can be released by a variety of pro-inflammatory stimuli. However, the functional importance of neutrophil IL-8 during exudation is not yet known. We now report that neutrophils, harvested from skin lesions on the forearms of normal human volunteers (exudative neutrophils), expressed 100-fold higher levels of cell-associated IL-8 and spontaneously released up to 50-fold more IL-8 than freshly isolated peripheral blood neutrophils from the same donor. Furthermore, cell-associated IL-8 in peripheral blood neutrophils increased 20-fold during incubation at 37 degrees C in vitro and was increased over 200-fold after treatment with the Ca2+ ionophore A23187. More than 35% of the cell-associated IL-8 could be released by stimulation with either Ca2+ ionophore A23187 or phorbol myristate acetate. IL-8 was localized by sucrose gradient centrifugation to a subcellular fraction of heterogeneous, light membranous organelles. The accumulation of IL-8 within these organelles is inhibited by cycloheximide but not actinomycin D, suggesting that IL-8 accumulation is under translational, rather than transcriptional control. These studies indicate that peripheral blood neutrophils are capable of synthesis of large amounts of IL-8. Subsequent release of IL-8 during exudation may regulate neutrophil migration into sites of inflammation.
Kuhns
D B
DB
SAIC Frederick, Frederick Cancer Research and Development Center, MD 21702, USA.
Gallin
J I
JI
D001773:Blood Cells / Q000187:drug effects / Q000276:immunology / Q000502:physiology; D000001:Calcimycin / Q000494:pharmacology; D002634:Chemotaxis, Leukocyte; D015936:Complement C5a / Q000494:pharmacology; D005122:Exudates and Transudates / Q000166:cytology / Q000276:immunology; D006801:Humans; D066298:In Vitro Techniques; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology* / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013347:Subcellular Fractions / Q000276:immunology; D013696:Temperature
D016209:Interleukin-8; D012333:RNA, Messenger; D000001:Calcimycin; D009240:N-Formylmethionine Leucyl-Phenylalanine; D015936:Complement C5a