title: Downregulation of inflammatory microRNAs by Ig-like transcript 3 is essential for the differentiation of human CD8(+) T suppressor cells.
abstract: We have investigated the mechanism underlying the immunoregulatory function of membrane Ig-like transcript 3 (ILT3) and soluble ILT3Fc. microRNA (miRNA) expression profile identified genes that were downregulated in ILT3-induced human CD8(+) T suppressor cells (Ts) while upregulated in T cells primed in the absence of ILT3. We found that miR-21, miR-30b, and miR-155 target the 3'-untranslated region of genes whose expression was strongly increased in ILT3Fc-induced Ts, such as dual specificity phosphatase 10, B cell CLL/lymphoma 6, and suppressor of cytokine signaling 1, respectively. Transfection of miRNA mimics or inhibitors and site-specific mutagenesis of their 3'-untranslated region binding sites indicated that B cell CLL/lymphoma 6, dual specificity phosphatase 10, and suppressor of cytokine signaling 1 are direct targets of miR-30b, miR-21, and miR-155. Primed CD8(+) T cells transfected with miR-21&30b, miR-21&155, or miR-21&30b&155 inhibitors displayed suppressor activity when added to autologous CD3-triggered CD4 T cells. Luciferase reporter assays of miR-21 and miR-155 indicated that their transcription is highly dependent on AP-1. Analysis of activated T cells showed that ILT3Fc inhibited the translocation to the nucleus of the AP-1 subunits, FOSB and c-FOS, and the phosphorylation of ZAP70 and phospholipase C-γ 1. In conclusion, ILT3Fc inhibits T cell activation and induces the generation of Ts targeting multiple inflammatory miRNA pathways.
authors.affiliation: Division of Immunogenetics and Cellular Immunology, Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA.
authors.forename: Chih-Chao
authors.initials: CC
authors.lastname: Chang
authors.forename: Qing-Yin
authors.initials: QY
authors.lastname: Zhang
authors.forename: Zhuoru
authors.initials: Z
authors.lastname: Liu
authors.forename: Raphael A
authors.initials: RA
authors.lastname: Clynes
authors.forename: Nicole
authors.initials: N
authors.lastname: Suciu-Foca
authors.forename: George
authors.initials: G
authors.lastname: Vlad
mesh_terms: D020413:3' Untranslated Regions; D021581:Active Transport, Cell Nucleus; D001665:Binding Sites / Q000235:genetics; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology; D002454:Cell Differentiation; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D015536:Down-Regulation; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D007249:Inflammation / Q000235:genetics / Q000276:immunology; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins; D035683:MicroRNAs / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D021122:Protein Subunits; D051560:Proto-Oncogene Proteins c-bcl-6; D034741:RNA, Small Interfering / Q000494:pharmacology; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D011971:Receptors, Immunologic; D011993:Recombinant Fusion Proteins / Q000502:physiology; D015398:Signal Transduction; D050378:T-Lymphocytes, Regulatory / Q000166:cytology* / Q000276:immunology; D014162:Transfection
chemical_list: D020413:3' Untranslated Regions; C084103:BCL6 protein, human; D004268:DNA-Binding Proteins; C107907:LILRB4 protein, human; D008562:Membrane Glycoproteins; D035683:MicroRNAs; D021122:Protein Subunits; D051560:Proto-Oncogene Proteins c-bcl-6; D034741:RNA, Small Interfering; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D011993:Recombinant Fusion Proteins