title: MicroRNAs in CD4(+) T cell subsets are markers of disease risk and T cell dysfunction in individuals at risk for type 1 diabetes.
abstract: MicroRNAs (miRNAs) regulate T cell development and function and the disruption of miRNAs in natural regulatory CD4(+) FOXP3(+) T cells (nTreg) leads to autoimmune disease in mice. To investigate miRNA expression in relation to autoimmune disease risk in humans we sequenced them in purified CD4(+) T cell subsets from individuals at high risk of type 1 diabetes (pre-T1D), as well as other healthy individuals. Differences in miRNA expression patterns were observed between specific T cell subsets and, within subsets, between pre-T1D and healthy individuals. Compared to healthy, naive CD4(+) T cells in pre-T1D displayed 32 differentially expressed miRNAs, potentially a template for altered miRNA expression in effector memory T cells in T1D. Naive nTreg in pre-T1D displayed two differentially expressed miRNAs, Let-7c and miR-15a. In contrast, nTreg activated in vivo displayed a large number of differentially expressed miRNAs, revealing a pro-inflammatory and FOXP3-repressive signature. Differential expression of specific miRNAs was also a signpost to altered T cell function. For example, in pre-T1D, increased expression of miR-26a in nTreg activated in vivo or in vitro was associated with decreased expression of its target, the histone methyltransferase EZH2. Chemical inhibition of EZH2 decreased the number of activated naïve nTreg and their expression of nTreg signature genes FOXP3 and TIGIT. Our findings demonstrate that miRNAs differentially expressed in CD4(+) T cell subsets are markers of risk and T cell dysfunction in T1D.
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia; Division of Immunology, Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jingsui Road, Tianhe, Guangzhou, Guangdong, 510623, China.
authors.forename: Yuxia
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Zhi-Ping
authors.initials: ZP
authors.lastname: Feng
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Naselli
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.
authors.forename: Fiona
authors.initials: F
authors.lastname: Bell
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.
authors.forename: James
authors.initials: J
authors.lastname: Wettenhall
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.
authors.forename: Priscilla
authors.initials: P
authors.lastname: Auyeung
authors.affiliation: Murdoch Children's Research Institute, Royal Children's Hospital, 50 Flemington Rd, Parkville, Victoria, 3052, Australia; Department of Paediatrics, University of Melbourne, Victoria, 3010, Australia.
authors.forename: Justine A
authors.initials: JA
authors.lastname: Ellis
authors.affiliation: Murdoch Children's Research Institute, Royal Children's Hospital, 50 Flemington Rd, Parkville, Victoria, 3052, Australia; Department of Paediatrics, University of Melbourne, Victoria, 3010, Australia.
authors.forename: Anne-Louise
authors.initials: AL
authors.lastname: Ponsonby
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Terence P
authors.initials: TP
authors.lastname: Speed
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Mark M W
authors.initials: MM
authors.lastname: Chong
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia. Electronic address: harrison@wehi.edu.au.
authors.forename: Leonard C
authors.initials: LC
authors.lastname: Harrison
mesh_terms: D015415:Biomarkers; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D016000:Cluster Analysis; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics* / Q000276:immunology*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D015723:Gene Library; D020022:Genetic Predisposition to Disease; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D008213:Lymphocyte Activation; D035683:MicroRNAs / Q000235:genetics*; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism
chemical_list: D015415:Biomarkers; D035683:MicroRNAs
keywords: EZH2; FOXP3; TIGIT; Type 1 diabetes; miR-26a; miRNA; nTreg