Abstract
Exposure of guinea-pig eosinophils to leukotriene B4 (LTB4; 1 μM) resulted in a rapid generation of H2O2 (index of NADPH oxidase activation), stimulated [3H]arachidonic acid (AA) release (index of phospholipase A2 activity), and promoted CD18-dependent homotypic aggregation. Under similar conditions, LTB4 (1 μM) induced a rapid activation of extracellular- regulated kinases-1 and 2 (ERK- 1/4 ) but not c-jun N-terminal kinases 46 and 54 (JNK-46/54) or p38 mitogen-activated protein kinase (p38 MAP kinase). To examine the role of ERK- 1/4 in the mechanism of eosinophil activation, a selective inhibitor of MAP kinase kinase- 1/4 (MEK- 1/4 ), PD098059, was employed. However, PD 098059 at concentrations that attenuated ERK- 1/4 activation had no significant affect on eosinophil activation. In contrast, a role for tyrosine kinases in LTB4-induced eosinophil activation was suggested by studies with the tyrosine kinase inhibitors, herbimycin A and lavendustin A. However, the results of those experiments implied divergent pathways for the control of eosinophil responses because the inhibitors were more effective at attenuating H2O2 generation than [3H]AA release, and had little effect on homotypic aggregation.
Original language | English |
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Pages (from-to) | 555-562 |
Number of pages | 8 |
Journal | Journal of Leukocyte Biology |
Volume | 64 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1 Oct 1998 |
Keywords
- Homotypic aggregation
- NADPH oxidase
- Phospholipase A
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology
- Cell Biology