TNFalpha-induced macrophage chemokine secretion is more dependent on NF-kappaB expression than lipopolysaccharides-induced macrophage chemokine secretion.
The transcription factor NF-kappaB is a pivotal intracellular regulator of many inflammatory responses and it has been proposed that it represents a potential therapeutic target. As chemokines are important for the progress of an inflammatory response by the recruitment of immuno-competent cells, the role NF-kappaB plays in TNFalpha- or lipopolysaccharides (LPS)-induced chemokine secretion by human monocyte-derived macrophages was examined. Secretion of the CXC chemokines IL-8, GROalpha and ENA-78, induced by TNFalpha, was significantly suppressed by inhibiting NF-kappaB, using overexpression of IkappaBalpha. However, when induced by LPS the expression of these chemokines was unaffected. In contrast, expression of the CC chemokines MIP-1alpha, MCP-1 and RANTES inducedby TNFalpha or LPS was significantly inhibited by the overexpression of IkappaBalpha. Therefore, there appear to be different mechanisms regulating CC and CXC chemokine secretion by macrophages, depending on the stimulus and that TNFalpha and LPS can use different signaling mechanisms in macrophages to regulate chemokine synthesis.
Kennedy Institute of Rheumatology Division, Imperial College Faculty of Medicine, London, GB.
Cathleen J
CJ
Ciesielski
Evangelos
E
Andreakos
Brian M J
BM
Foxwell
Marc
M
Feldmann
D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000378:metabolism; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D018946:Chemokine CCL5 / Q000378:metabolism; D054360:Chemokine CXCL1; D054357:Chemokine CXCL10; D054365:Chemokine CXCL5; D019742:Chemokines, CC / Q000378:metabolism*; D019743:Chemokines, CXC / Q000378:metabolism*; D002630:Chemotactic Factors / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000276:immunology; D015870:Gene Expression; D006133:Growth Substances / Q000378:metabolism; D006801:Humans; D020672:I-kappa B Proteins; D036341:Intercellular Signaling Peptides and Proteins; D016209:Interleukin-8 / Q000031:analogs & derivatives* / Q000378:metabolism; D008070:Lipopolysaccharides / Q000276:immunology* / Q000494:pharmacology; D019402:Macrophage Inflammatory Proteins / Q000378:metabolism; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology* / Q000494:pharmacology
C475829:CXCL1 protein, human; C486263:CXCL5 protein, human; D018932:Chemokine CCL2; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D018946:Chemokine CCL5; D054360:Chemokine CXCL1; D054357:Chemokine CXCL10; D054365:Chemokine CXCL5; D019742:Chemokines, CC; D019743:Chemokines, CXC; D002630:Chemotactic Factors; D004268:DNA-Binding Proteins; D006133:Growth Substances; D020672:I-kappa B Proteins; D036341:Intercellular Signaling Peptides and Proteins; D016209:Interleukin-8; D008070:Lipopolysaccharides; D019402:Macrophage Inflammatory Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D014409:Tumor Necrosis Factor-alpha; D000072000:NF-KappaB Inhibitor alpha