scholarly journals A RUNX3 enhancer polymorphism associated with ankylosing spondylitis influences recruitment of Interferon Regulatory Factor 5 and factors of the Nucleosome Remodelling Deacetylase Complex in CD8+ T-cells

2019 ◽  
Author(s):  
Matteo Vecellio ◽  
Adrian Cortes ◽  
Sarah Bonham ◽  
Carlo Selmi ◽  
Julian C Knight ◽  
...  
Keyword(s):  
T Cells ◽  
Ankylosing Spondylitis ◽  
Cd8 T Cells ◽  
Binding Protein ◽  
Interferon Regulatory Factor ◽  
Regulatory Factor ◽  
Nurd Complex ◽  
Nucleosome Remodeling ◽  
Nuclear Extracts ◽  
Functional Consequences

ABSTRACTObjectivesTo investigate the functional consequences of the single nucleotide polymorphism rs4648889 in a putative enhancer upstream of the RUNX3 promoter strongly associated with ankylosing spondylitis (AS).MethodsThe effects of rs4648889 on transcription factor (TF) binding were tested by DNA pull-down and quantitative mass spectrometry. The results were validated by electrophoretic mobility gel shift assays (EMSA), Western blot (WB) analysis of the pulled-down eluates, and chromatin immuno-precipitation (ChIP)-qPCR.ResultsSeveral TFs showed differential allelic binding to a 50bp DNA probe spanning rs4648889. Binding was increased to the AS-risk A allele for IKZF3 (aiolos) in nuclear extracts from CD8+ T-cells (3.7-fold, p<0.03) and several components of the NUcleosome Remodeling Deacetylase (NuRD) complex, including Chromodomain-Helicase-DNA-binding protein 4 (3.6-fold, p<0.05) and Retinoblastoma-Binding Protein 4 (4.1-fold, p<0.02). In contrast, binding of interferon regulatory factor (IRF) 5 was increased to the AS-protective G allele. These results were confirmed by EMSA, WB and ChIP-qPCR.ConclusionsThe association of AS with rs4648889 most likely results from its influence on the binding of this enhancer-like region to TFs, including IRF5, IKZF3 and members of the NuRD complex. Further investigation of these factors and RUNX3-related pathways may reveal important new therapeutic possibilities in AS.

scholarly journals POS0362 INVESTIGATING THE ANKYLOSING SPONDYLITIS-ASSOCIATED REGULATORY SNPS AT THE RUNX3 LOCUS WITH A FUNCTIONAL GENOMICS APPROACH

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 411.2-411
Author(s):  
M. Vecellio ◽  
P. B. Wordsworth ◽  
C. J. Cohen
Keyword(s):  
T Cells ◽  
Ankylosing Spondylitis ◽  
Cd8 T Cells ◽  
Risk Allele ◽  
Therapeutic Drug ◽  
Genetic Associations ◽  
Nurd Complex ◽  
Mobility Shift ◽  
The Impact

Background:Of the >100 genetic associations with ankylosing spondylitis (AS), RUNX3 transcription factor (TF) involved in diverse immunological processes, is robustly (10−15) associated.1 The biggest challenge is to understand the mechanism behind this association. We demonstrated the association between AS and the single nucleotide polymorphism (SNP) rs4648889 located in a 2kb regulatory locus upstream of the RUNX3 promoter can be explained by allele-specific effects on TF recruitment that alter gene expression, specifically in CD8+ T-cells.2 We recently dissected the full plethora of TFs affected by rs4648889 AS-associated allele showing the NuRD complex and IRF5 differentially bound and having a crucial role in CD8+ T-cells function3. Nevertheless, other post-GWAS approaches are needed to elucidate the function of RUNX3 AS-associated SNPs (i.e. the lead SNP rs6600247).Objectives:The purpose of this work is to define the functional effect of rs6622047 in CD8+ T-cells and monocytes. In specific, we expect to define the impact of AS-associated allele to TF binding and to evaluate chromosome looping between rs6600247 and the RUNX3 promoter.Methods:The epigenetic landscape of SNP rs6600247 was defined using Roadmap database. In vitro functional studies were performed to characterize the effects of this SNP on TFs binding. Chromosome conformation capture (3C) provided critical functional evidence for looping among AS-associated SNPs and the RUNX3 promoter.Results:(1) In silico data revealed a c-MYC ChIP-seq peak in GM12878 lymphoblastoid cells overlapping rs6600247; (2) Mobility shift assays (EMSAs) and WB-EMSAs showed reduced DNA/protein binding in the presence of the AS-risk allele in CD14+ monocytes. C-MYC binding-site is disrupted and binding abolished in the presence of the AS-risk allele; (3) 3C experiments indicate low interaction frequency between SNP rs6600247 and RUNX3 promoter.Conclusion:The enhancer upstream the RUNX3 gene has a plausible functional role in AS, probably by regulating gene transcription and DNA looping. These observations are critically important in defining dysregulated pathways and potential therapeutic drug targets.References:[1]IGAS et al. Nat Genet. 2013 Jul;45(7):730-8.[2]Vecellio M. et al, Ann Rheum Dis. 2016 Aug;75(8):1534-40.[3]Vecellio et al Arthritis Rheumatol 2020. doi: 10.1002/art.41628.Acknowledgements:We thank Professor Julian Knight for his constructive advices and comments to the present work.Disclosure of Interests:None declared

scholarly journals CD27 Expression Promotes Long-Term Survival of Functional Effector–Memory CD8+Cytotoxic T Lymphocytes in HIV-infected Patients

2004 ◽  
Vol 200 (11) ◽  
pp. 1407-1417 ◽  
Author(s):  
Adrian F. Ochsenbein ◽  
Stanley R. Riddell ◽  
Michele Brown ◽  
Lawrence Corey ◽  
Gabriela M. Baerlocher ◽  
...  
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Cd8 T Cells ◽  
Interleukin 2 ◽  
Tumor Necrosis Factor Receptor ◽  
Cell Receptor ◽  
Effector Memory ◽  
Term Survival ◽  
Functional Consequences

Human immunodeficiency virus (HIV)-specific CD8+ T cells persist in high frequencies in HIV-infected patients despite impaired CD4+ T helper response to the virus, but, unlike other differentiated effector cytotoxic T lymphocytes, most continue to express the tumor necrosis factor receptor family member CD27. Because the ligand for CD27 (CD70) is also overexpressed in HIV-infected hosts, we examined the nature of expression and potential functional consequences of CD27 expression on HIV-specific CD8+ T cells. Analysis of CD27+ and CD27− T cells derived from the same HIV-specific clone revealed that retention of CD27 did not interfere with acquisition of effector functions, and that after T cell receptor stimulation, CD27+ cells that concurrently were triggered via CD27 exhibited more resistance to apoptosis, interleukin 2 production, and proliferation than CD27− T cells. After transfer back into an HIV-infected patient, autologous HIV-specific CD27− T cells rapidly disappeared, but CD27+ T cells derived from the same clone persisted at high frequency. Our findings suggest that the CD27–CD70 interaction in HIV infection may provide CD27+ CD8+ T cells with a survival advantage and compensate for limiting or absent CD4+ T help to maintain the CD8 response.

Chromatin bound by survivin regulates the glycolytic switch in interferon-γ producing CD4+ T cells

2021 ◽  
Author(s):  
Malin Erlandsson ◽  
Karin Andersson ◽  
Nina Oparina ◽  
Venkataragavan Chandrasekaran ◽  
Anastasios Damdimopoulos ◽  
...  
Keyword(s):  
T Cells ◽  
Glucose Utilization ◽  
Interferon Γ ◽  
Interferon Regulatory Factor ◽  
Metabolic Adaptation ◽  
Regulatory Factor ◽  
Cell Functions ◽  
Interferon Regulatory Factor 1 ◽  
Direct Binding ◽  
Nuclear Survivin

Abstract Upon activation, CD4+ T cells adapt metabolically to fulfill their effector function in autoimmunity. Here we show that nuclear survivin is essential for transcriptional regulation of glucose utilization. We found that the glycolytic switch in interferon (IFN) g–producing CD4+ cells is dependent on a complex of survivin with interferon regulatory factor 1 (IRF1), and Smad3 and was reversed by survivin inhibition. Transcriptome analysis of CD4+ cells and sequencing of survivin-bound chromatin identified a hub of metabolism regulating genes whose transcription depended on survivin. Direct binding of survivin to IRF1 and SMAD3 promoted IRF1-mediated transcription, repressed SMAD3 activity, and lowered PFKFB3 production. Inhibiting survivin upregulated PFKFB3, restored glycolysis, and reduced glucose uptake, improving control over IFNg-dependent T-cell functions. Thus, IRF1-survivin-SMAD3 interactions are important for metabolic adaptation of CD4+ cells and provide an attractive strategy to counteract IFNg-dependent inflammation.

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