The expression of cytokine-induced neutrophil chemoattractants (CINC-1 and CINC-2) in rat peritoneal macrophages is triggered by Fc gamma receptor activation: study of the signaling mechanism.
The expression of cytokine-induced neutrophil chemoattractants (CINC-1 and CINC-2) mRNA was studied in rat peritoneal cells stimulated with insoluble IgG/ovalbumin immune complexes. A dose- and time-dependent induction was observed in adherent cells, which was more prominent than that induced by the lipid mediator platelet-activating factor (PAF), comparable to that observed in response to 10 micrograms endotoxin in the absence of lipopolysaccharide (LPS)-binding protein, but lower than that produced by 1 mM dibutyryl cyclic AMP, a compound which stabilized transiently expressed genes containing AU-rich sequences in the 3' untranslated region. Analysis of CINC-1 protein by specific enzyme-linked immunosorbent assay confirmed the presence of CINC-1 in the supernatants at concentrations of approximately 4 nM, 4 h after addition of 100 micrograms/ml immune complexes. CINC-2 beta protein was detectable at a lower concentration (approximately 0.3 nM) under the same conditions. Attempts to relate CINC-1 induction with the pathways for cytoplasmic signaling showed a dissociation of Ca2+ mobilization and protein kinase C activation as judged from the small effect of thapsigargin and the lack of effect of phorbol ester. In contrast, these agents produced a marked mobilization of arachidonate linked to the MAP kinase-dependent activation of cytosolic phospholipase A2. The possible dependence of CINC-1 induction on the autocrine generation of lipid mediators was ruled out by a set of experiments including the use of the PAF receptor antagonist BB823, and the analysis of the effect of free arachidonate and leukotriene B4 on CINC-1 induction. Surprisingly, the inhibitor of leukotriene synthesis MK-886 in the range of concentration 1-10 microM inhibited CINC-1 induction by a mechanism that appears to be independent of its effect on eicosanoid production. Interestingly, CINC-1 induction appeared to be related to protein tyrosine phosphorylation reactions on the basis of both the appearance of several tyrosine-phosphorylated protein bands in lysates from adherent peritoneal cells treated with immune complexes and the complete blockade of CINC-1 induction by treatment with 1 microM herbimycin A, an inhibitor of src protein tyrosine kinases.
Alonso
A
A
Instituto de Biología y Genética Molecular, CSIC-Universidad de Valladolid, Spain.
Bayón
Y
Y
Crespo
M S
MS
D000818:Animals; D000936:Antigen-Antibody Complex / Q000502:physiology; D001094:Arachidonate 5-Lipoxygenase / Q000502:physiology; D016718:Arachidonic Acid / Q000378:metabolism; D001483:Base Sequence; D054360:Chemokine CXCL1; D019743:Chemokines, CXC; D002630:Chemotactic Factors / Q000096:biosynthesis*; D006133:Growth Substances / Q000096:biosynthesis*; D036341:Intercellular Signaling Peptides and Proteins; D017737:Macrophages, Peritoneal / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D010766:Phosphorylation; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D017452:Receptors, IgG / Q000502:physiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014443:Tyrosine / Q000378:metabolism
D000936:Antigen-Antibody Complex; D054360:Chemokine CXCL1; D019743:Chemokines, CXC; D002630:Chemotactic Factors; C513297:Cxcl1 protein, rat; C513294:Cxcl3 protein, rat; D006133:Growth Substances; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D017452:Receptors, IgG; D016718:Arachidonic Acid; D014443:Tyrosine; D001094:Arachidonate 5-Lipoxygenase; D013755:Tetradecanoylphorbol Acetate