Fig. 3

DRB1*15:01-associated expression in monocytes. a Spearman correlation between DNA methylation at HLA-DRB1 (exon 2) (450K arrays) and HLA-DRB1 expression quantified by RT-qPCR using primers targeting different segment of the transcript (exon 6 by primer sets 1 and 2, exon 1 by primer set 3, and exon 4-6 by primer set 4). b HLA-DRB1 expression according to DRB1*15:01 haplotype: homozygous (+/+, n = 7, red), heterozygous (+/−, n = 21, orange), and non-carriers (−/−, n = 30, blue) quantified by RT-qPCR (using primer set 1). c HLA-DRB1 expression (n = 4 independent experiments) in PBMCs from DRB1*15:01 non-carriers treated with 5-Aza-2′-deoxycytidine (5-aza-dC). d HLA-DRB1 allele-specific methylation of cg06032474 quantified by MSRE-qPCR from DRB1*15:01 heterozygote (+/−) individuals (n = 20, red and blue colors representing *15:01 and the other allele, respectively). e Relative expression of each HLA-DRB1 allele from DRB1*15:01 heterozygote (+/−) individuals quantified by allele-specific qPCR (n = 26, red and blue colors representing *15:01 and the other allele, respectively). Enhancer (f) and promoter (g) activity of the exon 2 region of DRB1*15:01 using CpG-free promoter-containing (Lucia) and promoter-free (SEAP) reporter gene vectors, respectively. Constructs were partially or fully methylated using HhaI and SssI enzymatic treatment, respectively. Results show relative activity (Lucia or SEAP normalized against Renilla) using five replicates in a representative experiment performed at least 2–3 times. Efficiency of the in vitro methylation is shown in Supplementary Fig. 1f. NA not applicable due to absence of promoter. b–g Data are presented as Tukey boxplots; *p < 0.05 **p < 0.01, ***p < 0.001, using Spearman test (a), ANOVA with Dunn’s (b), or Turkey’s multiple comparison tests (c, f, g), the Mann–Whitney test (pooled alleles A vs. pooled alleles B) (d), and t-test (pooled alleles A vs. pooled alleles B) (e)