Temporal adaptation of human neutrophil metabolic responsiveness to the peptide formylmethionyl-leucyl phenylalanine: A comparison between human neutrophils and granule-depleted neutrophil cytoplasts
✍ Scribed by Claes Dahlgren
- Publisher
- John Wiley and Sons
- Year
- 1990
- Tongue
- English
- Weight
- 603 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0263-6484
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✦ Synopsis
When polymorphonuclear leukocytes (neutrophils) and soluble or particulate matter interact, the cells produce superoxide anions (02-) and hydrogen peroxide (H202). The chemotactic peptide formylmethionyl-leucylphenylalanine (FMLP) induced a very weak response in normal neutrophils. The cellular response was changed, however, as a result of in vitro aging of the cells, i.e. the magnitude of the response was increased following storage of the cells at 22°C for up to 120min, in the absence of any stimulus, and before the addition of the peptide. When phorbol myristate acetate was used as a stimulus, there was a pronounced production of 02and H202, but no change in magnitude as a result of in vitro aging. When neutrophil cytoplasts (granule-free vesicles of cytoplasm enclosed by plasmalemma) were exposed to the peptide FMLP of PMA, the vesicles produced both 02and H202. There was, however, no increase in oxidative metabolite production in cytoplasts as a result of in vitro aging when either FMLP or PMA was used as a stimulus. The results thus indidate that mere incubation at room temperature primed the cells to increase their production of oxidative metabolites as a result of spontaneous exposure of hidden receptors. The fact that no such effects were observed with cytoplasts indicates that spontaneous receptor recruitment is a granule-dependent process.