Maintenance and down-regulation of primed neutrophil chemiluminescence activity in human whole blood

Priming of polymorphonuclear neutrophils (PMN) in whole blood (by tumor necrosis factor α and interleukin‐8 for enhancement of luminoldependent chemiluminescence induced by human complement‐opsonized zymosan) was stable for 120 min. In contrast, priming of isolated PMN in plasma‐free suspension for responses to opsonized zymosan, formyl‐methionyl‐leucyl‐phenylalanine, and phorbol myristate acetate was markedly less stable. Decay of priming was not due to irreversible inactivation of the terminal CL production machinery because PMN could be reprimed by platelet‐activating factor or leukotriene B4. The tumor necrosis factor‐α‐primed state of isolated PMN was stabilized by host plasma in a concentration‐dependent fashion. We conclude that PMN priming results in a dynamic state that is reversible. Our findings suggest the existence of blood‐borne components that may act to stabilize or modify PMN priming. J. Leukoc. Biol. 62: 837–844; 1997.