AJP - Cell Physiology, Vol 263, Issue 1 C78-C85, Copyright © 1992 by American Physiological Society
Activation of permeabilized neutrophils: role of anions
S. Grinstein, W. Furuya and G. P. Downey
Division of Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada.
Activation of neutrophils was recently reported to be accompanied by large
changes in their Cl- content [J. B. Myers, H. F. Cantiello, J. H. Schwartz,
and A. I. Tauber. Am. J. Physiol. 259 (Cell Physiol. 28): C531-C540, 1990].
The significance of these ionic changes to the immune response has not been
studied. To evaluate the role of intracellular [Cl-], the anionic
composition of the cytosol was varied in human neutrophils permeabilized by
electroporation or by treatment with streptolysin O. In Cl(-)-rich media,
permeabilized but otherwise untreated cells remained quiescent, resembling
unstimulated intact cells. In contrast, suspension of permeabilized cells
in Cl(-)-depleted media elicited protein phosphorylation, actin
polymerization, secretion of lysozyme, and a respiratory burst. The latter
was demonstrated by several criteria to be mediated by the NADPH oxidase.
The responses observed in Cl(-)-depleted media were insensitive to
pretreatment of the cells with pertussis toxin but were inhibited by
addition of GDP or by omission of ATP. The data suggest that an early event
in signal transduction, common to several effectors, is sensitive to the
ionic composition of the cytosol. This component, possibly a GTP-binding
protein, may be affected by the anion concentration changes reported to
occur during physiological stimulation of neutrophils.
