{"title":"Promoter methylation and increased expression of PD-L1 in patients with active tuberculosis.","authors":"Yen-Han Tseng, Sheng-Wei Pan, Jhong-Ru Huang, Chang-Ching Lee, Jung-Jyh Hung, Po-Kuei Hsu, Nien-Jung Chen, Wei-Juin Su, Yuh-Min Chen, Jia-Yih Feng","doi":"10.15698/mic2024.07.832","DOIUrl":null,"url":null,"abstract":"<p><p>The PD-1/PD-L1 pathway plays a pivotal role in T cell activity and is involved in the pathophysiology of <i>Mycobacterium tuberculosis</i> (MTB) infection. DNA methylation is a mechanism that modulates PD-L1 expression in cancer cells. However, its effect on PD-L1 expression in macrophages after MTB infection remains unknown. We prospectively enrolled patients with active tuberculosis (TB) and non-TB subjects. The expression of PD-L1 and methylation-related genes in peripheral blood mononuclear cells (PBMCs) were investigated and their correlation with disease severity and treatment outcomes were examined. PD-L1 promoter methylation status was evaluated using bisulfite sequencing. Immunohistochemistry (IHC) and immunofluorescence (IF) staining were used to visualize PD-L1- and TET-1-expressing cells in lung tissues from patients with TB and in macrophage cell lines with MTB-related stimulation. In total, 80 patients with active TB and 40 non-TB subjects were enrolled in the analysis. Patients with active TB had significantly higher expression of <i>PD-L1</i>, <i>DNMT3b</i>, <i>TET1</i>, <i>TET2</i>, and lower expression of <i>DNMT1</i>, compared to that in the non-TB subjects. The expression of <i>PD-L1</i> and <i>TET-1</i> was significantly associated with 1-month smear and culture non-conversion. IHC and IF staining demonstrated the co-localization of PD-L1- and TET-1-expressing macrophages in patients with pulmonary TB and in human macrophage cell lines after MTB-related stimulation. DNMT inhibition and <i>TET-1</i> knockdown in human macrophages increased and decreased <i>PD-L1</i> expression, respectively. Overall, <i>PD-L1</i> expression is increased in patients with active TB and is correlated with treatment outcomes. DNA methylation is involved in modulating <i>PD-L1</i> expression in human macrophages.</p>","PeriodicalId":18397,"journal":{"name":"Microbial Cell","volume":null,"pages":null},"PeriodicalIF":4.1000,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11287217/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Microbial Cell","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.15698/mic2024.07.832","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/1/1 0:00:00","PubModel":"eCollection","JCR":"Q2","JCRName":"CELL BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The PD-1/PD-L1 pathway plays a pivotal role in T cell activity and is involved in the pathophysiology of Mycobacterium tuberculosis (MTB) infection. DNA methylation is a mechanism that modulates PD-L1 expression in cancer cells. However, its effect on PD-L1 expression in macrophages after MTB infection remains unknown. We prospectively enrolled patients with active tuberculosis (TB) and non-TB subjects. The expression of PD-L1 and methylation-related genes in peripheral blood mononuclear cells (PBMCs) were investigated and their correlation with disease severity and treatment outcomes were examined. PD-L1 promoter methylation status was evaluated using bisulfite sequencing. Immunohistochemistry (IHC) and immunofluorescence (IF) staining were used to visualize PD-L1- and TET-1-expressing cells in lung tissues from patients with TB and in macrophage cell lines with MTB-related stimulation. In total, 80 patients with active TB and 40 non-TB subjects were enrolled in the analysis. Patients with active TB had significantly higher expression of PD-L1, DNMT3b, TET1, TET2, and lower expression of DNMT1, compared to that in the non-TB subjects. The expression of PD-L1 and TET-1 was significantly associated with 1-month smear and culture non-conversion. IHC and IF staining demonstrated the co-localization of PD-L1- and TET-1-expressing macrophages in patients with pulmonary TB and in human macrophage cell lines after MTB-related stimulation. DNMT inhibition and TET-1 knockdown in human macrophages increased and decreased PD-L1 expression, respectively. Overall, PD-L1 expression is increased in patients with active TB and is correlated with treatment outcomes. DNA methylation is involved in modulating PD-L1 expression in human macrophages.