title: Different pathways of macrophage activation and polarization.
abstract: Monocytes are short-lived cells and undergo spontaneous apoptosis every day. Inflammatory responses may induce dramatic up-regulation of monocyte survival and differentiation. When monocytes are recruited to an area of infection they may differentiate into macrophages. In different microenvironments macrophages polarize into two types. The M1 or classically activated macrophages are characterized by the high ability to produce pro-inflammatory cytokines and the production of NO through the induced synthesis of iNOS. The M2 or alternatively activated macrophages are divided into 3 subtypes, M2 a, b and c, and they have anti-inflammatory properties. Mediators of M1 macrophage TLR-dependent polarization include transcription factors such as NF-κB, AP-1, PU.1, CCAAT/enhancer-binding protein α (C/EBP-α), STAT1 as well as interferon regulatory factor 5 (IRF5), while the transcription factors which promote M2 activation include IRF4, C/EBP-β, Krüppel-like factor 4 (KLF4), STAT6 and PPARγ receptor.
authors.affiliation: Department of Immunology, Medical University of Gdańsk.
authors.forename: Ulana
authors.initials: U
authors.lastname: Juhas
authors.affiliation: Department of Immunology, Medical University of Gdańsk.
authors.forename: Monika
authors.initials: M
authors.lastname: Ryba-Stanisławowska
authors.affiliation: Department of Immunology, Medical University of Gdańsk.
authors.forename: Patryk
authors.initials: P
authors.lastname: Szargiej
authors.affiliation: Department of Immunology, Medical University of Gdańsk.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Myśliwska
mesh_terms: D016207:Cytokines / Q000502:physiology; D006801:Humans; D000090062:Kruppel-Like Factor 4; D008262:Macrophage Activation; D009000:Monocytes / Q000276:immunology / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism
chemical_list: D016207:Cytokines; C000715467:KLF4 protein, human; D000090062:Kruppel-Like Factor 4; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II