Journal: Cell Genomics
Article Title: Unraveling an enhancer-silencer regulatory element showing epistatic interaction with a variant that escaped genome-wide association studies
doi: 10.1016/j.xgen.2025.100889
Figure Lengend Snippet: Identification of a cis -regulatory element with a dual enhancer-silencer function (ESpromoter) and its role in inhibiting Jurkat T cell activation (A) Generation of cell lines with a 506-bp deletion of the ESpromoter using two single guide RNAs (gRNA1 and gRNA2) flanking the regulatory region containing the five SNPs, through CRISPR-Cas9 technology. The position of the deletion is indicated relative to the long ATP2B4 (ENST00000367218 and ENST00000367218) and short (ENST00000341360) transcripts of ATP2B4 and the LAX1 gene. Sanger sequencing chromatograms show the genomic sequence of the wild-type (WT) Jurkat clone, and one representative edited clone (Δ Jurkat). (B) RT-qPCR analysis of ATP2B4 long transcript expression (ENST00000357681, ENST00000367218) on WT Jurkat cells and clones deleted for the ESpromoter (Δ1, Δ2, and Δ3) in culture without stimulation (NS, no stimulation [in gray]) or with PMA/ionomycin stimulation for 6 h (S, stimulated [in red]). Clones with a deletion had a decreased ATP2B4 expression under both conditions. Values were generated from three independent experiments performed in triplicate. WT Jurkat NS and S are used as references. All data represent mean values ±SEM. Two-sided Student’s t tests and asterisks indicate significance (∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001). (C) RT-qPCR analysis of LAX1 expression on WT Jurkat cells and on clones deleted for the ESpromoter (Δ1, Δ2, and Δ3) without stimulation (NS, no stimulation [in gray]) or with PMA/ionomycin stimulation for 6 h (S, stimulated [in red]). Clones with a deletion had increased LAX1 expression under both conditions. Values were generated from three independent experiments performed in triplicate. WT Jurkat NS and S are used as references. All data represent mean values ±SEM. Two-sided Student’s t tests and asterisks indicate significance (∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001). (D) Graphs showing the relative luciferase activity under the control of ATP2B4 promoter alone or in combination with the ESpromoter region containing either the major haplotype (maj: TCCGA) or minor haplotype (min: CTTGG) for the five SNPs (rs11240734, rs1541252, rs1541253, rs1541254, and rs1541255) without and with PMA/ionomycin stimulation. Luciferase assays confirmed the enhancer effect of the ESpromoter on the ATP2B4 promoter independently of the haplotype. Values were generated from three independent experiments performed in triplicate. All data represent normalized mean values ±SEM. Two-sided Student’s t tests and asterisks indicate significance (ns, not significant; ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001). (E) Graphs showing the relative luciferase activity under the control of LAX1 promoter alone or in combination with the ESpromoter region containing either the major haplotype (maj) or minor haplotype (min) for the five SNPs (rs11240734, rs1541252, rs1541253, rs1541254, and rs1541255) under PMA/ionomycin stimulation (6 and 24 h). Luciferase assays confirmed the silencer effect of the ESpromoter on the LAX1 promoter independently of the haplotype. Values were generated from three independent experiments performed in triplicate. All data represent normalized mean values ±SEM. Two-sided Student’s t tests and asterisks indicate significance (ns, not significant; ∗∗∗∗ p < 0.0001). (F) T cell activation was assessed based on CD69 staining and flow cytometric gating strategy. Plots showing the results at different time points after PMA/Ionomycin stimulation of WT Jurkat cells, WT clone after CRISPR-Cas9 editing (WTc), and deleted clone for the ESpromoter (Δ3). Representative experiments on 2,000 cells according to forward scatter-horizontal (FSC-H) and anti-CD69 staining with fluorescein isothiocyanate (FITC). The number represents the percentage of cells. The orange window corresponds to CD69-positive cells. The rate of CD69-positive cells increased with stimulation time. (G) Monitoring Jurkat cell activation by anti-CD69 staining through flow cytometry after PMA/ionomycin stimulation. Values represent the average ± SEM of two independent experiments performed in duplicate, indicating the percentage of cells positive for anti-CD69 staining (acquisition of 2,000 cells per clone) for WT Jurkat, and WT clone without genomic edition after CRISPR-Cas9 (WTc). A similar percentage of CD69-positive cells was observed between WT and WTc. (H) Monitoring Jurkat cell activation by anti-CD69 staining through flow cytometry after PMA/ionomycin stimulation. Values represent the average ±SEM of two independent experiments performed in duplicate, indicating the percentage of cells positive for anti-CD69 staining (acquisition of 2,000 cells per clone) for WT clone without genomic edition after CRISPR-Cas9 (WTc) and deleted clones for the ESpromoter (Δ3). A lower number of CD69-positive cells was observed in the Δ3 clone.
Article Snippet: Human: Jurkat cell line: clone E6-1 , ATCC , TIB-152.
Techniques: Activation Assay, CRISPR, Sequencing, Quantitative RT-PCR, Expressing, Clone Assay, Generated, Luciferase, Activity Assay, Control, Staining, Flow Cytometry