title: Plasmacytoid dendritic cell-specific receptor ILT7-Fc epsilonRI gamma inhibits Toll-like receptor-induced interferon production.
abstract: Immunoglobulin-like transcripts are a family of inhibitory and stimulatory cell surface immune receptors. Transcripts for one member of this family, ILT7, are selectively expressed in human plasmacytoid dendritic cells (pDCs). We demonstrate here that ILT7 protein associates with the signal adapter protein Fc epsilonRI gamma to form a receptor complex. Using an anti-ILT7 monoclonal antibody, we show that ILT7 is expressed specifically on human pDCs, but not on myeloid dendritic cells or other peripheral blood leukocytes. Cross-linking of ILT7 resulted in phosphorylation of Src family kinases and Syk kinase and induced a calcium influx in freshly isolated pDCs, which was blocked by Src family and Syk kinases inhibitors, thus indicating the activation of an immunoreceptor-based tyrosine activation motif-mediated signaling pathway. ILT7 cross-linking on CpG or influenza virus-stimulated primary pDCs inhibited the transcription and secretion of type I interferon and other cytokines. Therefore, the ILT7-Fc epsilonRI gamma receptor complex negatively regulates the innate immune functions of human pDCs.
authors.affiliation: Department of Immunology, University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA. wcao@mdacc.tmc.edu
authors.forename: Wei
authors.initials: W
authors.lastname: Cao
authors.forename: David B
authors.initials: DB
authors.lastname: Rosen
authors.forename: Tomoki
authors.initials: T
authors.lastname: Ito
authors.forename: Laura
authors.initials: L
authors.lastname: Bover
authors.forename: Musheng
authors.initials: M
authors.lastname: Bao
authors.forename: Gokuran
authors.initials: G
authors.lastname: Watanabe
authors.forename: Zhengbin
authors.initials: Z
authors.lastname: Yao
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Lewis L
authors.initials: LL
authors.lastname: Lanier
authors.forename: Yong-Jun
authors.initials: YJ
authors.lastname: Liu
mesh_terms: D003713:Dendritic Cells / Q000276:immunology*; D006801:Humans; D007372:Interferons / Q000096:biosynthesis*; D017455:Receptors, IgE / Q000276:immunology*; D011971:Receptors, Immunologic / Q000276:immunology*; D051193:Toll-Like Receptors / Q000037:antagonists & inhibitors / Q000276:immunology*
chemical_list: C488262:LILRA4 protein, human; D017455:Receptors, IgE; D011971:Receptors, Immunologic; D051193:Toll-Like Receptors; D007372:Interferons