title: Interferon-sensitive response element (ISRE) is mainly responsible for IFN-alpha-induced upregulation of programmed death-1 (PD-1) in macrophages.
abstract: Programmed death-1 (PD-1), an immunoinhibitory receptor, is upregulated in T cells, B cells, NKT cells, and monocytes upon activation. More specifically, T-cell-associated PD-1 is critically important for maintaining peripheral tolerance through the PD-1-B7-H1 pathway. However, the physiological role of macrophage-associated PD-1 remains unclear. We addressed the molecular mechanism underlying the regulation of PD-1 expression on macrophages in response to IFN-alpha. Based on a luciferase assay using promoter constructs, we found that the promoter region located between -1090 and -1105 nucleotides from the translational start site is essential for PD-1 expression. Electrophoretic mobility-shift assay and site-directed mutagenesis revealed that interferon-sensitive responsive element (ISRE) and STAT1 and STAT2 are primarily responsible for the constitutive expression of PD-1, as well as for the IFN-alpha-mediated upregulation of PD-1. In addition, AG490, a Janus-activated kinase/signal transducer and activator of transcription (JAK/STAT) inhibitor, markedly abolished the responsiveness of bone marrow-derived macrophages (BMM) to IFN-alpha. Our findings support the essential roles of ISRE, STAT1, and STAT2 in the regulation of constitutive and IFN-alpha-mediated PD-1 expression in macrophages.
authors.affiliation: Department of Microbiology, Center for Viral Disease Research, Inje University College of Medicine, Busan 614-735, Republic of Korea.
authors.forename: Hae-Yun
authors.initials: HY
authors.lastname: Cho
authors.forename: Soo-Woon
authors.initials: SW
authors.lastname: Lee
authors.forename: Su-Kil
authors.initials: SK
authors.lastname: Seo
authors.forename: Il-Whan
authors.initials: IW
authors.lastname: Choi
authors.forename: Inhak
authors.initials: I
authors.lastname: Choi
authors.forename: Soo-Woong
authors.initials: SW
authors.lastname: Lee
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism*; D001483:Base Sequence; D001854:Bone Marrow Cells / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation; D006801:Humans; D016898:Interferon-alpha / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D061026:Programmed Cell Death 1 Receptor; D020218:Response Elements; D050794:STAT1 Transcription Factor / Q000378:metabolism; D050795:STAT2 Transcription Factor / Q000378:metabolism; D020032:Tyrphostins / Q000494:pharmacology; D015854:Up-Regulation
chemical_list: D015703:Antigens, CD; D051017:Apoptosis Regulatory Proteins; D004791:Enzyme Inhibitors; D016898:Interferon-alpha; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D050795:STAT2 Transcription Factor; C494084:STAT2 protein, human; C494080:Stat1 protein, mouse; C494085:Stat2 protein, mouse; D020032:Tyrphostins; C095512:alpha-cyano-(3,4-dihydroxy)-N-benzylcinnamide