To investigate the effects of Platelet release products (PRPr) and their phagocytosis activators including ATP, ADP, and macromolecular activators of phagocytosis (MAPPs) on phagocytosis and oxidative burst activity by neutrophils in human whole blood.Methods:
A whole blood-based flow cytometric assay was used to assess neutrophilic activity. Escherichia coli were used as the target organisms.Results:
Phagocytosis and oxidative burst by neutrophils were markedly increased after treatment with PRPr or MAPPs + ATP + ADP. The phagocytosis activation was more prominent in the first minute, and displayed a maximum enhancement of 4-fold. The maximum augmentation of oxidative burst was 5-fold which occurred at 5 mins. A striking finding was that the effect of MAPPs was evident from 5 mins onwards and increased with further incubation in both the phagocytosis and oxidative burst assays.Conclusion:
These data suggest that the neutrophilic activity enhanced by PRPr depends more on ATP and ADP during the early phase and on MAPPs during the later phase of the phagocytic process. The present study reveals an important role for PRPr and their phagocytosis activators in the enhancement of neutrophilic activity in human whole blood.