title: NF-κB repressing factor downregulates basal expression and mycobacterium tuberculosis induced IP-10 and IL-8 synthesis via interference with NF-κB in monocytes.
abstract: BACKGROUND
  Our previous study showed NF-κB repressing factor (NKRF) downregulates IP-10 and IL-8 synthesis in the peripheral blood mononuclear cells and alveolar macrophages of TB patients with high bacterial loads. However, the mechanism underlying the repressive effect of NKRF is not fully understood.
  
  
  RESULTS
  The levels of IP-10, IL-8 and NKRF were significantly up-regulated in THP-1 cells treated with heated mycobacterium tuberculosis (H. TB). NKRF inhibited NF-κB-mediated IP-10 and IL-8 synthesis and release induced by H. TB. The repressive effect of NKRF is mediated via interference with NF-κB (p65) binding and RNA polymerase II recruitment to promoter sites of IP-10 and IL-8.
  
  
  CONCLUSIONS
  We have elucidated that direct contact with MTb induces IP-10, IL-8 and a concomitant increase in NKRF in THP-1 cells. The up-regulated NKRF serves as an endogenous repressor for IP-10 and IL-8 synthesis to hinder host from robust response to MTb infection.
authors.forename: Kuo-Hsiung
authors.initials: KH
authors.lastname: Huang
authors.forename: Chun-Hua
authors.initials: CH
authors.lastname: Wang
authors.affiliation: Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, 250 Wu-Hsing Street, Taipei 110, Taiwan. chlin@tmu.edu.tw.
authors.forename: Chien-Huang
authors.initials: CH
authors.lastname: Lin
authors.forename: Han-Pin
authors.initials: HP
authors.lastname: Kuo
mesh_terms: D002460:Cell Line; D054357:Chemokine CXCL10 / Q000096:biosynthesis* / Q000235:genetics; D015536:Down-Regulation; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000235:genetics; D009000:Monocytes / Q000378:metabolism* / Q000473:pathology; D009169:Mycobacterium tuberculosis; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism*; D014397:Tuberculosis, Pulmonary / Q000235:genetics / Q000378:metabolism / Q000473:pathology
chemical_list: C114753:CXCL10 protein, human; C508606:CXCL8 protein, human; D054357:Chemokine CXCL10; D016209:Interleukin-8; C111027:NKRF protein, human; C498143:RELA protein, human; D012097:Repressor Proteins; D051996:Transcription Factor RelA; D012319:RNA Polymerase II