Eosinophils do respond to fMLP
M Yazdanbakhsh, CM Eckmann, L Koenderman, AJ Verhoeven and D Roos
Eosinophils were isolated from normal human blood by separation over
Percoll gradients, which resulted in eosinophil suspensions of a purity
higher than 95% and recoveries of about 65%. Normal human eosinophils were
found to respond to formyl-methionyl-leucyl-phenylalanine (fMLP) at
concentrations greater than 10(-7) mol/L with an increase in the
concentration of intracellular free calcium, oxygen consumption, nitroblue
tetrazolium reduction, and chemiluminescence. The maximal response of
eosinophils to fMLP was lower than that of neutrophils isolated from the
same blood samples and required at least ten times as much fMLP as was
needed for neutrophils. Low fMLP concentrations (approximately 10(-8)
mol/L), which in themselves did not stimulate O2 consumption by either
eosinophils or neutrophils, primed these cells to respond to a suboptimal
concentration of another stimulus. Purification of eosinophils after
treatment of whole blood with fMLP showed that these eosinophils had lost
their ability to respond to fMLP. We conclude that normal eosinophils do
respond to fMLP and that therefore fMLP should not be used to isolate
eosinophils.
Volume 70,
Issue 2,
pp. 379-383,
08/01/1987
Copyright © 1987 by The American Society of Hematology
