CCL20/macrophage inflammatory protein-3alpha production in LPS-stimulated neutrophils is enhanced by the chemoattractant formyl-methionyl-leucyl-phenylalanine and IFN-gamma through independent mechanisms.
We have recently demonstrated that polymorphonuclear neutrophils (PMN), when cultured with LPS or TNF-alpha, have the capacity to release CCL20, a chemokine primarily chemotactic for immature dendritic cells and specific lymphocyte subsets. Here, we report that the chemoattractant formyl-methionyl-leucyl-phenylalanine (fMLP), as well as the immunoregulatory cytokine IFN-gamma, can significantly up-modulate the production of neutrophil-derived CCL20 through entirely unrelated mechanisms. We found that fMLP dramatically up-regulates CCL20 mRNA expression and synthesis in neutrophils stimulated with LPS for 2-3 h, and that its effect takes place through CCL20 mRNA stabilization. In contrast, IFN-gamma potentiates CCL20 gene expression and production only after 21 h of LPS treatment, its effect being mediated by endogenous TNF-alpha in an autocrine fashion, as revealed using neutralizing anti-TNF-alpha antibodies added to IFN-gamma plus LPS-treated PMN. Finally, we demonstrate that activation of p38 mitogen-activated protein kinase (MAPK) plays an important role in mediating the production of CCL20 induced by LPS (with or without IFN-gamma), whereas activation of p42/44 extracellular signal-regulated kinases (ERK) is involved in the enhancing effect of fMLP. Taken together, these findings identify novel biological actions exerted by fMLP and IFN-gamma, potentially involved in the orchestration of inflammatory and immune responses within epithelial and mucosal tissue.
Scapini
Patrizia
P
Department of Pathology, Section of General Pathology, University of Verona, Verona, Italy.
Crepaldi
Luca
L
Pinardi
Cristina
C
Calzetti
Federica
F
Cassatella
Marco A
MA
D054418:Chemokine CCL20; D019742:Chemokines, CC / Q000096:biosynthesis* / Q000235:genetics; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D019402:Macrophage Inflammatory Proteins / Q000096:biosynthesis* / Q000235:genetics; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology*; D009504:Neutrophils / Q000187:drug effects* / Q000276:immunology*; D011725:Pyridines / Q000494:pharmacology; D020871:RNA Stability / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D054399:Receptors, CCR6; D019707:Receptors, Chemokine; D011994:Recombinant Proteins; D015398:Signal Transduction / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects
C108355:CCL20 protein, human; C106311:CCR6 protein, human; D054418:Chemokine CCL20; D019742:Chemokines, CC; D004791:Enzyme Inhibitors; D005419:Flavonoids; D007093:Imidazoles; D008070:Lipopolysaccharides; D019402:Macrophage Inflammatory Proteins; D011725:Pyridines; D012333:RNA, Messenger; D054399:Receptors, CCR6; D019707:Receptors, Chemokine; D011994:Recombinant Proteins; D009240:N-Formylmethionine Leucyl-Phenylalanine; D007371:Interferon-gamma; D020928:Mitogen-Activated Protein Kinases; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one