title: A new way to keep immune cells in check.
abstract: To avoid being attacked by the immune system, normal cells carry proteins on their surfaces that mark them as "self." Until now, researchers have identified only one type of self marker: so-called class I major histocompatibility complex proteins. Now, on page 2051, a team reports that macrophages, the immune system's scavenger cells, recognize a different inhibitory signal--a protein called CD47. The findings also shed light on the role of CD47, a surface protein present on basically every cell type--and long a molecule in search of a function.
authors.forename: M
authors.initials: M
authors.lastname: Hagmann
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D000943:Antigens, Differentiation; D051928:CD47 Antigen; D002352:Carrier Proteins / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D017707:Erythrocyte Transfusion; D004912:Erythrocytes / Q000276:immunology*; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D039842:Neural Cell Adhesion Molecule L1; D019006:Neural Cell Adhesion Molecules / Q000378:metabolism*; D010587:Phagocytosis; D011971:Receptors, Immunologic; D017634:Self Tolerance; D013154:Spleen / Q000276:immunology
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D051928:CD47 Antigen; D002352:Carrier Proteins; C497895:Cd47 protein, mouse; D008562:Membrane Glycoproteins; D039842:Neural Cell Adhesion Molecule L1; D019006:Neural Cell Adhesion Molecules; D011971:Receptors, Immunologic