|
|
||||||||
The Journal of Immunology, Vol 148, Issue 8 2483-2488, Copyright © 1992 by American Association of Immunologists
ARTICLES |
JB Klein, JA Scherzer and KR McLeish
Department of Medicine, University of Louisville Health Sciences Center, KY 40292.
Exposure to IFN-gamma increases the respiratory burst of polymorphonuclear leukocytes stimulated by the chemoattractant FMLP. However, the mechanism by which IFN-gamma alters the response to FMLP is unclear. We addressed the hypothesis that IFN-gamma enhances the response to FMLP by regulating the expression of elements of the formyl peptide receptor transmembrane-signaling pathway. HL-60 granulocytes were used as a model of FMLP transmembrane signaling. Formyl peptide receptor number and affinity were studied in isolated plasma membranes prepared from control HL-60 cells (CM) and cells exposed to IFN-gamma 100 U/ml for 24 h (IFN-M). Formyl peptide receptors were significantly increased on IFN-M compared with CM (1473 +/- 300 vs 3209 +/- 924). FMLP stimulates increased guanine nucleotide-binding protein (G protein) activation in IFN-M as evidenced by enhanced guanosine 5'- [gamma-thio]triphosphate binding and GTPase activity. Gi sub-unit content was increased in IFN-M as measured by pertussis toxin-catalyzed ADP-ribosylation and immunoblotting with antibodies against alpha i2 and alpha i3 G protein subunits. Guanosine 5'-[gamma-thio]triphosphate equilibrium binding demonstrated an increased number of G proteins coupled to formyl peptide receptors on IFN-M. We conclude that IFN- gamma increases expression of both formyl peptide receptors and G proteins coupled to these receptors, thereby enhancing FMLP-stimulated transmembrane signaling. Regulation of transmembrane signaling element expression may be a significant mechanism by which IFN-gamma regulates cellular functions.
This article has been cited by other articles:
![]() |
M. Thivierge, J.-L. Parent, J. Stankova, and M. Rola-Pleszczynski Modulation of Formyl Peptide Receptor Expression by IL-10 in Human Monocytes and Neutrophils J. Immunol., March 15, 1999; 162(6): 3590 - 3595. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Wenzel-Seifert, C. M. Hurt, and R. Seifert High Constitutive Activity of the Human Formyl Peptide Receptor J. Biol. Chem., September 11, 1998; 273(37): 24181 - 24189. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |