Signaling and ligand interaction of ILT7: receptor-mediated regulatory mechanisms for plasmacytoid dendritic cells.
Plasmacytoid dendritic cells (pDCs) are specialized dendritic cells (DCs) that produce large amounts of type I interferon (IFN) after Toll-like receptor (TLR) activation. Human pDCs preferentially express immunoglobulin-like transcript 7 (ILT7; LILRA4), which couples with a signaling adapter to activate a prominent immunoreceptor tyrosine-based activation motif (ITAM)-mediated signaling pathway. ILT7 protein directly binds to and can be activated by bone marrow stromal cell antigen 2 (BST2; CD317) protein, the expression of which is found on cells pre-exposed to IFN or on the surface of human cancer cells. The interaction between ILT7 and BST2 functions to assure an appropriate TLR response by pDCs during viral infection and likely participates in pDC-tumor crosstalk. Two opposing modes of receptor-mediated regulatory mechanisms work jointly to fine tune the innate immunity of pDCs.
Cao
Wei
W
Department of Immunology, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA. wcao@mdacc.tmc.edu
Bover
Laura
L
D000818:Animals; D015703:Antigens, CD / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology*; D058851:GPI-Linked Proteins; D006801:Humans; D007113:Immunity, Innate; D007370:Interferon Type I / Q000276:immunology; D008024:Ligands; D008562:Membrane Glycoproteins / Q000276:immunology*; D011971:Receptors, Immunologic / Q000276:immunology*; D015398:Signal Transduction / Q000276:immunology; D051193:Toll-Like Receptors / Q000276:immunology; D014777:Virus Diseases / Q000276:immunology / Q000821:virology; D000074010:Bone Marrow Stromal Antigen 2
D015703:Antigens, CD; D058851:GPI-Linked Proteins; D007370:Interferon Type I; D008024:Ligands; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; D051193:Toll-Like Receptors; C094572:BST2 protein, human; D000074010:Bone Marrow Stromal Antigen 2; C488262:LILRA4 protein, human