title: Polarized monocyte response to cytokine stimulation.
abstract: 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.
authors.affiliation: Immunogenetics Section, Department of Transfusion Medicine, Clinical Center, National Institutes of Health, Bethesda, MD 20892-1502, USA. dirk.nagorsen@charite.de
authors.forename: Dirk
authors.initials: D
authors.lastname: Nagorsen
authors.forename: Sara
authors.initials: S
authors.lastname: Deola
authors.forename: Kina
authors.initials: K
authors.lastname: Smith
authors.forename: Ena
authors.initials: E
authors.lastname: Wang
authors.forename: Vladia
authors.initials: V
authors.lastname: Monsurro
authors.forename: Paola
authors.initials: P
authors.lastname: Zanovello
authors.forename: Francesco M
authors.initials: FM
authors.lastname: Marincola
authors.forename: Monica C
authors.initials: MC
authors.lastname: Panelli
mesh_terms: 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
chemical_list: D016207:Cytokines; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D016328:NF-kappa B; D020782:Matrix Metalloproteinases