title: TARM1 Is a Novel Leukocyte Receptor Complex-Encoded ITAM Receptor That Costimulates Proinflammatory Cytokine Secretion by Macrophages and Neutrophils.
abstract: We identified a novel, evolutionarily conserved receptor encoded within the human leukocyte receptor complex and syntenic region of mouse chromosome 7, named T cell-interacting, activating receptor on myeloid cells-1 (TARM1). The transmembrane region of TARM1 contained a conserved arginine residue, consistent with association with a signaling adaptor. TARM1 associated with the ITAM adaptor FcRγ but not with DAP10 or DAP12. In healthy mice, TARM1 is constitutively expressed on the cell surface of mature and immature CD11b(+)Gr-1(+) neutrophils within the bone marrow. Following i.p. LPS treatment or systemic bacterial challenge, TARM1 expression was upregulated by neutrophils and inflammatory monocytes and TARM1(+) cells were rapidly recruited to sites of inflammation. TARM1 expression was also upregulated by bone marrow-derived macrophages and dendritic cells following stimulation with TLR agonists in vitro. Ligation of TARM1 receptor in the presence of TLR ligands, such as LPS, enhanced the secretion of proinflammatory cytokines by macrophages and primary mouse neutrophils, whereas TARM1 stimulation alone had no effect. Finally, an immobilized TARM1-Fc fusion protein suppressed CD4(+) T cell activation and proliferation in vitro. These results suggest that a putative T cell ligand can interact with TARM1 receptor, resulting in bidirectional signaling and raising the T cell activation threshold while costimulating the release of proinflammatory cytokines by macrophages and neutrophils.
authors: Division of Immunology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom;
authors: Valeria
authors: V
authors: Radjabova
authors: Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, United Kingdom;
authors: Piero
authors: P
authors: Mastroeni
authors: Department of Cancer and Inflammation, Institute for Molecular Medicine, University of Southern Denmark, DK-5000 Odense, Denmark;
authors: Karsten
authors: K
authors: Skjødt
authors: Division of Immunology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom;
authors: Paola
authors: P
authors: Zaccone
authors: Centre for Health Informatics and Multiprofessional Education, University College London, London NW1 2DA, United Kingdom;
authors: Bernard
authors: B
authors: de Bono
authors: Department of Medicine, University of Cambridge, Cambridge CB2 0SP, United Kingdom; and.
authors: Jane C
authors: JC
authors: Goodall
authors: Department of Medicine, University of Cambridge, Cambridge CB2 0SP, United Kingdom; and.
authors: Edwin R
authors: ER
authors: Chilvers
authors: Department of Medicine, University of Cambridge, Cambridge CB2 0SP, United Kingdom; and.
authors: Jatinder K
authors: JK
authors: Juss
authors: Division of Immunology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom;
authors: Des C
authors: DC
authors: Jones
authors: Division of Immunology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom; jt233@cam.ac.uk alexanderbarrow@hotmail.com.
authors: John
authors: J
authors: Trowsdale
authors: Division of Immunology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom; Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110.
authors: Alexander David
authors: AD
authors: Barrow
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D016207:Cytokines / Q000378:metabolism*; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D005260:Female; D006098:Granulocytes / Q000276:immunology / Q000378:metabolism; D057809:HEK293 Cells; D006680:HLA Antigens / Q000235:genetics; D006801:Humans; D007249:Inflammation / Q000276:immunology; D008024:Ligands; D008070:Lipopolysaccharides / Q000276:immunology; D008213:Lymphocyte Activation / Q000235:genetics / Q000276:immunology; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D016688:Mice, Inbred NOD; D008969:Molecular Sequence Data; D009504:Neutrophils / Q000276:immunology* / Q000378:metabolism; D021381:Protein Transport / Q000276:immunology; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology
chemical_list: D016207:Cytokines; D006680:HLA Antigens; D008024:Ligands; D008070:Lipopolysaccharides; D011971:Receptors, Immunologic; D011993:Recombinant Fusion Proteins; C000604578:TARM1 protein, human; C000604579:TARM1 protein, mouse