Supplemental Table S1 | Primer sequences used in this study.;Supplemental Table S2 | List of 1639 TFs from Human Transcription Factors database.;Supplemental Table S3 | Potential STAT2 binding motifs on Region 1 and Region 2.;Supplemental Figures [Figure S1 (Identification of chromatin accessibilities using ATAC-seq profiles.), S2 (Integrative analysis identified STAT2 as a potential upstream for PD-L1.), and S3 (Validation of the interaction between STAT2 and PD-L1.)]

Supplemental Table S1 | Primer sequences used in this study.;Supplemental Table S2 | List of 1639 TFs from Human Transcription Factors database.;Supplemental Table S3 | Potential STAT2 binding motifs on Region 1 and Region 2.;Figure S1 | Identification of chromatin accessibilities using ATAC-seq profiles. (A)For the analysis of chromatin accessibilities, peak calling function was performed.The upset plot and vennpie plot revealed that a considerable fraction of open chromatin regions were around gene promoters. Figure S2 | Integrative analysis identified STAT2 as a potential upstream for PD-L1. (A) Correlation analysis between open chromatin regions and all the database-recorded TFs was performed. The TFs, which were correlated with Region 1 or Region 2, were displayed in the heatmap (r > 0.4, p < 0.05). Compared with other TFs, STAT2 was closely related with both Region 1 (left, r = 0.6, p < 0.05) and Region 2 (right, r = 0.5, p < 0.05). (B) Correlation analysis between PD-L1 expression and expression of the top 5 TFs associated with PD-L1 promoter region 1 or region 2 in Figure S2A. Of these top candidates, STAT2 was the TF with the strongest correlation with PD-L1 expression (r = 0.53, p < 0.05). Figure S3 | Validation of the interaction between STAT2 and PD-L1. (A) The analysis of protein-protein interactions, based on GeneMANIA database, indicated a potential interaction between STAT2 and PD-L1. (B) In cancer cell line HeLa, the overexpression of STAT2 could lead to upregulation of PD-L1 significantly (p < 0.05).

补充表S1 | 本研究所用引物序列；补充表S2 | 人类转录因子数据库（Human Transcription Factors database）收录的1639个转录因子（Transcription Factor, TF）列表；补充表S3 | 1号区域与2号区域上的STAT2潜在结合基序；图S1 | 基于ATAC-seq测序图谱鉴定染色质可及性。(A) 针对染色质可及性分析，本研究执行了峰调用操作。Upset图与维恩饼图显示，大量开放染色质区域位于基因启动子区域附近；图S2 | 整合分析鉴定出STAT2为程序性死亡受体配体1（Programmed Death-Ligand 1，PD-L1）的潜在上游调控因子。(A) 本研究开展了开放染色质区域与数据库收录的全部转录因子（TF）之间的相关性分析。将与1号区域或2号区域存在相关性的TF以热图形式展示（相关系数r>0.4，P<0.05）。相较于其他TF，STAT2与1号区域（左图，r=0.6，P<0.05）及2号区域（右图，r=0.5，P<0.05）均存在显著紧密关联。(B) 针对PD-L1表达与图S2A中与PD-L1启动子1号区域或2号区域相关的前5位TF的表达量开展相关性分析。在上述候选TOP5 TF中，STAT2是与PD-L1表达相关性最强的转录因子（r=0.53，P<0.05）；图S3 | STAT2与PD-L1相互作用的验证。(A) 基于GeneMANIA数据库的蛋白质相互作用分析结果显示，STAT2与PD-L1之间存在潜在相互作用。(B) 在HeLa癌细胞系中，STAT2过表达可显著上调PD-L1的表达（P<0.05）