Polarized monocyte response to cytokine stimulation.
BACKGROUND
Mononuclear phagocytes (MPs) stand at the crossroads between the induction of acute inflammation to recruit and activate immune effector cells and the downmodulation of the inflammatory process to contain collateral damage. This decision is extensively modulated by the cytokine microenvironment, which includes a broad array of cytokines whose direct effect on MPs remains largely unexplored. Therefore, we tested whether polarized responses of MPs to pathogens are related to the influence of selected cytokines or represent a mandatory molecular switch through which most cytokines operate.


RESULTS
Circulating CD14+ MPs were exposed to bacterial lipopolysaccharide (LPS) followed by exposure to an array of cytokines, chemokines and soluble factors involved in the immune response. Gene expression was studied by global transcript analysis. Two main classes of cytokines were identified that induced a classical or an alternative pathway of MP activation. Expression of genes affected by NFkappaB activation was most predictive of the two main classes, suggesting that this pathway is a fundamental target of cytokine regulation. As LPS itself induces a classical type of activation, the most dramatic modulation was observed toward the alternative pathway, suggesting that a broad array of cytokines may counteract the pro-inflammatory effects of bacterial components.


CONCLUSIONS
This analysis is directly informative of the primary effect of individual cytokines on the early stages of LPS stimulation and, therefore, may be most informative of the way MP maturation may be polarized at the early stages of the immune response.
Nagorsen
Dirk
D
Immunogenetics Section, Department of Transfusion Medicine, Clinical Center, National Institutes of Health, Bethesda, MD 20892-1502, USA. dirk.nagorsen@charite.de
Deola
Sara
S
Smith
Kina
K
Wang
Ena
E
Monsurro
Vladia
V
Zanovello
Paola
P
Marincola
Francesco M
FM
Panelli
Monica C
MC
D000328:Adult; D016207:Cytokines / Q000145:classification / Q000494:pharmacology*; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006801:Humans; D007700:Kinetics; D018950:Lipopolysaccharide Receptors / Q000032:analysis; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D020782:Matrix Metalloproteinases / Q000235:genetics / Q000378:metabolism; D008875:Middle Aged; D009000:Monocytes / Q000187:drug effects / Q000276:immunology*; D016328:NF-kappa B / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction / Q000379:methods; D014158:Transcription, Genetic / Q000187:drug effects
D016207:Cytokines; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D016328:NF-kappa B; D020782:Matrix Metalloproteinases