IFN-beta-induced SOCS-1 negatively regulates CD40 gene expression in macrophages and microglia.
Costimulation between T cells and antigen-presenting cells is required for adaptive immune responses. CD40, a costimulatory molecule, is expressed in macrophages and microglia. The aberrant expression of CD40 is involved in human diseases including multiple sclerosis, rheumatoid arthritis, and Alzheimer's disease. CD40 expression is induced by a variety of stimuli, including IFN-gamma and lipopolysaccharide (LPS). In this study, we describe the molecular basis by which IFN-beta, a cytokine with immunomodulatory properties, regulates CD40 gene expression. IFN-beta induces CD40 expression in macrophages and microglia at the transcriptional level, and GAS elements in the CD40 promoter are required for IFN-beta-induced CD40 promoter activity. The critical role of signal transducers and activators of transcription-1alpha (STAT-1alpha) in this response was confirmed by utilizing primary microglia from STAT-1alpha deficient mice. IFN-beta induces suppressor of cytokine signaling-1 (SOCS-1) gene expression, which inhibits cytokine signaling by inhibiting activation of STAT proteins. The ectopic expression of SOCS-1 abrogates IFN-beta-mediated STAT-1alpha activation and inhibits IFN-beta-induced CD40 expression. IFN-beta-induced recruitment of STAT-1alpha and RNA Pol II and permissive histone modifications on the CD40 promoter are also inhibited by SOCS-1 overexpression. These novel results indicate that IFN-beta-induced SOCS-1 plays an important role in the negative regulation of IFN-beta-induced CD40 gene expression.
Qin
Hongwei
H
Department of Cell Biology, University of Alabama at Birmingham, 1918 University Blvd., MCLM 395, Birmingham, Alabama 35294-0005, USA.
Wilson
Cynthia A
CA
Lee
Sun Jung
SJ
Benveniste
Etty N
EN
D000818:Animals; D019013:CD40 Antigens / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D006801:Humans; D050832:Interferon-Stimulated Gene Factor 3 / Q000235:genetics / Q000378:metabolism; D016899:Interferon-beta / Q000235:genetics / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D017628:Microglia / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D050795:STAT2 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction; D000071222:Suppressor of Cytokine Signaling 1 Protein; D050826:Suppressor of Cytokine Signaling Proteins / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D019013:CD40 Antigens; D002352:Carrier Proteins; D050832:Interferon-Stimulated Gene Factor 3; D016328:NF-kappa B; D012097:Repressor Proteins; D050795:STAT2 Transcription Factor; C491590:Socs1 protein, mouse; C494085:Stat2 protein, mouse; D000071222:Suppressor of Cytokine Signaling 1 Protein; D050826:Suppressor of Cytokine Signaling Proteins; C079868:gamma interferon activation factor; D016899:Interferon-beta; D012319:RNA Polymerase II