title: Intracellular NF-kB-decrease and IKBα increase in human macrophages following CTLA4-Ig treatment.
abstract: OBJECTIVE
  The transcription factor NF-kB is involved in the expression of several genes linked to the immune response, including those of pro-inflammatory cytokines. We investigated cytokine production and NF-kB expression following CTLA4-Ig (abatacept) treatment of cultured human macrophages.
  
  
  METHODS
  Human THP1 cells, differentiated in macrophages, were treated with CTLA4-Ig (100, 500 μg/ml; 3,12,24 hours). Quantitative RT-PCR analysis (qRT-PCR) of mRNA for NF-kB, IKBα and for IL-6, TNF-α, IL-1β, was performed after 3 and 12 hours from treatment. Western blot (WB) analysis for NF-kB and IKBα was performed after 24 hours from treatment.
  
  
  RESULTS
  NF-kB gene expression was significantly downregulated (p<0.05), at 3 and 12 hours from CTLA4-Ig treatment, vs. untreated cells (cnt). IKBα resulted significantly increased vs. cnt (p<0.05), at 12 hours from CTLA4-Ig [500 μg/ml] treatment. After 3 hours, CTLA4-Ig [100 μg/ml] induced a significant decrease of TNF-α and IL-6 (p<0.05), vs. cnt and CTLA4-Ig [500 μg/ml] further reduced TNF-α (p<0.001), vs. cnt. After 12 hours from CTLA4-Ig treatment, a significant downregulation for IL-6 and IL1β expression (p<0.001), vs. cnt, was still evident. Results were confirmed by WB.
  
  
  CONCLUSIONS
  NF-kB pathway seems to be implicated in the CTLA4-Ig modulation of macrophage cytokine expression. NF-kB expression resulted downregulated while its cytoplasmatic inhibitor IKBα was increased.
authors.affiliation: Research Laboratory and Academic Unit of Clinical Rheumatology, Department of Internal Medicine, University of Genova, Genova, Italy. mcutolo@unige.it.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Cutolo
authors.forename: Stefano
authors.initials: S
authors.lastname: Soldano
authors.forename: Paola
authors.initials: P
authors.lastname: Contini
authors.forename: Alberto
authors.initials: A
authors.lastname: Sulli
authors.forename: Bruno
authors.initials: B
authors.lastname: Seriolo
authors.forename: Paola
authors.initials: P
authors.lastname: Montagna
authors.forename: Renata
authors.initials: R
authors.lastname: Brizzolara
mesh_terms: D000069594:Abatacept; D015153:Blotting, Western; D045744:Cell Line, Tumor; D015536:Down-Regulation; D005434:Flow Cytometry; D006801:Humans; D020672:I-kappa B Proteins / Q000235:genetics / Q000378:metabolism*; D018796:Immunoconjugates / Q000494:pharmacology*; D053583:Interleukin-1beta / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008264:Macrophages / Q000187:drug effects* / Q000276:immunology; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D020672:I-kappa B Proteins; C508600:IL6 protein, human; D018796:Immunoconjugates; D053583:Interleukin-1beta; D015850:Interleukin-6; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D000072000:NF-KappaB Inhibitor alpha; D000069594:Abatacept