A role for sulfhydryl groups in granulocyte aggregation
EH Kraut and AL Sagone
Polymorphonuclear leukocytes (PMN) stimulated by high concentrations of the
complement component C5A form cellular aggregates, and both the rate and
degree of aggregation are influenced by changes in the PMN plasma membrane
and cytoskeleton. Since sulfhydryls are important constituents of the
plasma membrane and cytoskeleton, we investigated the effect of agents that
oxidize and bind sulfhydryls on C5A-induced aggregation. PMN incubated with
diamide, a nonspecific sulfhydryl- oxidizing agent, had a marked increase
in their aggregation response to C5A. Tertiary butyl hydroperoxide (BHP),
which reacts specifically with the soluble sulfhydryl glutathione (GSH),
had no effect on aggregation. The enhancement of PMN aggregation by
diamide, but not BHP, suggested that oxidation of non-GSH sulfhydryls
contributes to the aggregation response. To test the requirement for
sulfhydryls in PMN aggregation, PMN were treated with the
sulfhydryl-binding agent N-ethylmaleimide (NEM). NEM markedly impaired
aggregation without affecting resting or methylene blue-stimulated
[14C]-L-glucose oxidation of the granulocytes. P-chloromercuriphenyl
sulfonic acid (PCMPSA), an external sulfhydryl-binding agent, had no effect
on aggregation. These studies suggest that cellular sulfhydryls are
required for optimal PMN aggregation and that oxidation of these
sulfhydryls may be one of the biochemical changes that contributes to
aggregation.
Volume 63,
Issue 5,
pp. 1056-1059,
05/01/1984
Copyright © 1984 by The American Society of Hematology
