title: FcγRI (CD64): an identity card for intestinal macrophages.
abstract: Macrophages are becoming increasingly recognized as key cellular players in intestinal immune homeostasis. However, differentiating between macrophages and dendritic cells (DCs) is often difficult, and finding a specific phenotypic signature for intestinal macrophage identification has remained elusive. In this issue of the European Journal of Immunology, Tamoutounour et al. [Eur. J. Immunol. 2012. 42: 3150-3166] identify CD64 as a specific macrophage marker that can be used to discriminate DCs from macrophages in the murine small and large intestine, under both steady-state and inflammatory conditions. The authors also propose a sequential 'monocyte-waterfall' model for intestinal macrophage differentiation, with implications for immune tolerance and inflammation at the gut mucosal interface. This Commentary will discuss the advantages and potential limitations of CD64 as a marker for intestinal macrophages.
authors.affiliation: Gastrointestinal Unit, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Jaime
authors.initials: J
authors.lastname: De Calisto
authors.forename: Eduardo J
authors.initials: EJ
authors.lastname: Villablanca
authors.forename: J Rodrigo
authors.initials: JR
authors.lastname: Mora
mesh_terms: D000818:Animals; D003092:Colitis / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology*; D006801:Humans; D007413:Intestinal Mucosa / Q000276:immunology*; D008198:Lymph Nodes / Q000276:immunology*; D008264:Macrophages / Q000276:immunology*; D008643:Mesentery / Q000276:immunology*; D017452:Receptors, IgG / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology*
chemical_list: D017452:Receptors, IgG