Fig. 6: Functional identification of PD-L1 enhancer.

a Interaction of the PD-L1 enhancer and promoter in the Hi-C matrix. b, c Genome Browser view of RNA expression levels, chromatin accessibility, and histone modifications at the PD-L1 gene and enhancer regions in Thp1-macro and Thp1-M.tb cells. NF-κB ChIP-seq peaks (ENCODE, GM15510 cell line) and strengthened ATAC-seq peaks were marked by arrows. d ChIP-qPCR validation of the NF-κB (P65) enrichment on the PD-L1 enhancer and promoter regions. The amount of immunoprecipitated DNA in each sample is represented as signal relative to the total amount of input chromatin (y-axis). Error bars show mean ± SD (standard deviation), n = 3 biologically independent samples. P-values were calculated by two-sided Student’s t-test. e Experimental design of sgRNA-guided enhancer perturbation by the Cas9 protein. f Relative mRNA expression levels of PD-L1 in Thp1-macro cells and the same line after enhancer deletion. Error bars show mean ± SD, n = 3 biologically independent samples. P-values were calculated by two-sided Student’s t-test. g PD-L1 protein levels in Thp1-macro cells and the same cell line after enhancer deletion before and after M.tb infection. Each experiment was replicated three times. h Schematic of enhancer-promoter interaction mediated regulation of PD-L1 expression during M.tb infection.