Murray PJ, Wynn TAObstacles and opportunities for understanding macrophage polarization. J Leukoc Biol 89: 557-563

Department of Infectious Diseases, St. Jude Children's Research Hospital, 262 Danny Thomas Pl., Memphis, TN 38105, USA.
Journal of leukocyte biology (Impact Factor: 4.29). 03/2011; 89(4):557-63. DOI: 10.1189/jlb.0710409
Source: PubMed


Macrophages are now routinely categorized into phenotypic subtypes based on gene expression induced in response to cytokine and pathogen-derived stimulation. In the broadest division, macrophages are described as being CAMs (M1 macrophages) or AAMs (M2 macrophages) based on their exposure to TLR and IFN signals or Th2 cytokines, respectively. Despite the prolific use of this simple classification scheme, little is known about the precise functions of effector molecules produced by AAMs, especially how representative the CAM and AAM subtypes are of tissue macrophages in homeostasis, infection, or tissue repair and how plasticity in gene expression regulates macrophage function in vivo. Furthermore, correlations between mouse and human tissue macrophages and their representative subtypes are lacking and are a major barrier to understanding human immunity. Here, we briefly summarize current features of macrophage polarization and discuss the roles of various macrophage subpopulations and macrophage-associated genes in health and disease.

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    • "Further subtypes of macrophage/microglia exist, including the predominantly proinflammatory M1 cell (iNOS+) which secretes cytokines including TNF-í µí»¼ and IL-1í µí»½ and the M2 cell (Arg1+), which is anti-inflammatory in nature and is associated with the secretion of IL-10 [175] [176] [177]. Unique stimuli endow macrophages/microglia with their phenotype and effector function. "
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    ABSTRACT: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system characterised by widespread areas of focal demyelination. Its aetiology and pathogenesis remain unclear despite substantial insights gained through studies of animal models, most notably experimental autoimmune encephalomyelitis (EAE). MS is widely believed to be immune-mediated and pathologically attributable to myelin-specific autoreactive CD4+ T cells. In recent years, MS research has expanded beyond its focus on CD4+ T cells to recognise the contributions of multiple immune and glial cell types to the development, progression, and amelioration of the disease. This review summarises evidence of T and B lymphocyte, natural killer cell, macrophage/microglial, astrocytic, and oligodendroglial involvement in both EAE and MS and the intercommunication and influence of each cell subset in the inflammatory process. Despite important advances in the understanding of the involvement of these cell types in MS, many questions still remain regarding the various subsets within each cell population and their exact contribution to different stages of the disease.
    10/2014; 2014:285245. DOI:10.1155/2014/285245
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    • "Different subtype macrophages are involved in the inflammatory micro-environment, including classically activated macrophages (M1 macrophages), which mediate host defense and antitumor immunity; alternatively activated macrophages (M2 macrophages), which suppress inflammatory responses and promote wound healing; tumor-associated macrophages (TAM), which suppress tumor immunity; the monocytic subset of myeloid-derived suppressor cells (MDSCs, which are functionally similar to TAMs) and regulatory macrophages, which predominantly secrete IL-10, and many other different cytokines, play differential roles in viral infection and tumor formation. Although there are some differences among the M2, TAM, MDSC and regulatory subsets of macrophages, each of these populations has a predominant immunosuppressive activity [13]. However, under the liver micro-environment, the role of HCV core protein interaction with macrophages remains largely unclear. "
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    PLoS ONE 09/2014; 9(9):e108278. DOI:10.1371/journal.pone.0108278 · 3.23 Impact Factor
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    • "Neutrophils contribute to the initial defense against foreign microbes and their ultimate removal (resolution) is essential for optimal tissue repair (Martin and Feng, 2009; Novoa and Figueras, 2012). Macrophages, comprising distinct subpopulations of M1 or M2 subtypes, secrete growth factors and cytokines that may attract keratinocytes and fibroblasts to trigger either tissue repair or scar formation (Leibovich and Ross, 1975; Serhan and Savill, 2005; Sica and Mantovani, 2012; Murray and Wynn, 2011). Neutrophils and macrophages can have pro-or anti-repair effects after injury, depending on the tissue and injury context (Dovi et al., 2003; Brancato and Albina, 2011; Marrazzo et al., 2011; Walters et al., 2009). "
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    Development 07/2014; 141(13):2581-91. DOI:10.1242/dev.098459 · 6.46 Impact Factor
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