An Enhancer Element Harboring Variants Associated with Systemic Lupus Erythematosus Engages the TNFAIP3 Promoter to Influence A20 Expression
Figure 5
The TT>A risk variant exhibits reduced enhancer-promoter interaction frequencies and lower expression of TNFAIP3.
a. 3C-qPCR assays were performed in EBV-transformed B cells homozygous for either risk or non-risk alleles in the TT>A enhancer; crosslinking frequencies between the enhancer and the promoter were normalized to GAPDH control. b, c. Protein expression of A20 and phospho-IκBα in homozygous cell lines were determined using Western blot and were normalized to loading control β-actin. Plots represent the relative expression of densitometric measurements for each cell line. d. Allele-specific 3C sequencing results of EBV cell lines heterozygous for the TT>A alleles. The read counts for each paired allele from 3C samples were normalized to the read counts for each allele from parallel analysis of input genomic DNA not subjected to 3C. Comparisons were made between non-risk and risk alleles for each individual. Statistical differences were calculated using paired t-test.