Blog
About

269
views
0
recommends
+1 Recommend
0 collections
    8
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      From Monocytes to M1/M2 Macrophages: Phenotypical vs. Functional Differentiation

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Studies on monocyte and macrophage biology and differentiation have revealed the pleiotropic activities of these cells. Macrophages are tissue sentinels that maintain tissue integrity by eliminating/repairing damaged cells and matrices. In this M2-like mode, they can also promote tumor growth. Conversely, M1-like macrophages are key effector cells for the elimination of pathogens, virally infected, and cancer cells. Macrophage differentiation from monocytes occurs in the tissue in concomitance with the acquisition of a functional phenotype that depends on microenvironmental signals, thereby accounting for the many and apparently opposed macrophage functions. Many questions arise. When monocytes differentiate into macrophages in a tissue (concomitantly adopting a specific functional program, M1 or M2), do they all die during the inflammatory reaction, or do some of them survive? Do those that survive become quiescent tissue macrophages, able to react as naïve cells to a new challenge? Or, do monocyte-derived tissue macrophages conserve a “memory” of their past inflammatory activation? This review will address some of these important questions under the general framework of the role of monocytes and macrophages in the initiation, development, resolution, and chronicization of inflammation.

          Related collections

          Most cited references 225

          • Record: found
          • Abstract: found
          • Article: not found

          Exploring the full spectrum of macrophage activation.

          Macrophages display remarkable plasticity and can change their physiology in response to environmental cues. These changes can give rise to different populations of cells with distinct functions. In this Review we suggest a new grouping of macrophage populations based on three different homeostatic activities - host defence, wound healing and immune regulation. We propose that similarly to primary colours, these three basic macrophage populations can blend into various other 'shades' of activation. We characterize each population and provide examples of macrophages from specific disease states that have the characteristics of one or more of these populations.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            The chemokine system in diverse forms of macrophage activation and polarization.

            Plasticity and functional polarization are hallmarks of the mononuclear phagocyte system. Here we review emerging key properties of different forms of macrophage activation and polarization (M1, M2a, M2b, M2c), which represent extremes of a continuum. In particular, recent evidence suggests that differential modulation of the chemokine system integrates polarized macrophages in pathways of resistance to, or promotion of, microbial pathogens and tumors, or immunoregulation, tissue repair and remodeling.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Macrophage plasticity and polarization: in vivo veritas.

              Diversity and plasticity are hallmarks of cells of the monocyte-macrophage lineage. In response to IFNs, Toll-like receptor engagement, or IL-4/IL-13 signaling, macrophages undergo M1 (classical) or M2 (alternative) activation, which represent extremes of a continuum in a universe of activation states. Progress has now been made in defining the signaling pathways, transcriptional networks, and epigenetic mechanisms underlying M1-M2 or M2-like polarized activation. Functional skewing of mononuclear phagocytes occurs in vivo under physiological conditions (e.g., ontogenesis and pregnancy) and in pathology (allergic and chronic inflammation, tissue repair, infection, and cancer). However, in selected preclinical and clinical conditions, coexistence of cells in different activation states and unique or mixed phenotypes have been observed, a reflection of dynamic changes and complex tissue-derived signals. The identification of mechanisms and molecules associated with macrophage plasticity and polarized activation provides a basis for macrophage-centered diagnostic and therapeutic strategies.
                Bookmark

                Author and article information

                Contributors
                Journal
                Front Immunol
                Front Immunol
                Front. Immunol.
                Frontiers in Immunology
                Frontiers Media S.A.
                1664-3224
                23 September 2014
                17 October 2014
                2014
                : 5
                Affiliations
                1Laboratory of Innate Immunity and Cytokines, Institute of Protein Biochemistry, National Research Council , Napoli, Italy
                Author notes

                Edited by: Klaus Ley, La Jolla Institute for Allergy and Immunology, USA

                Reviewed by: Fulvio D’Acquisto, Queen Mary University of London, UK; Gaurav K. Gupta, Harvard Medical School, USA

                *Correspondence: Paola Italiani, Laboratory of Innate Immunity and Cytokines, Institute of Protein Biochemistry, National Research Council, Via Pietro Castellino 111, Napoli 80131, Italy e-mail: italianipaola@ 123456gmail.com

                This article was submitted to Inflammation, a section of the journal Frontiers in Immunology.

                Article
                10.3389/fimmu.2014.00514
                4201108
                Copyright © 2014 Italiani and Boraschi.

                This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

                Page count
                Figures: 4, Tables: 3, Equations: 0, References: 226, Pages: 22, Words: 20250
                Categories
                Immunology
                Review Article

                Comments

                Comment on this article