title: Intravenous immunoglobulin abrogates dendritic cell differentiation induced by interferon-alpha present in serum from patients with systemic lupus erythematosus.
abstract: OBJECTIVE
  Alterations in the function of dendritic cells (DCs) may explain the systemic autoimmune responses that characterize systemic lupus erythematosus (SLE). Even though several reports have documented the beneficial effect of intravenous immunoglobulin (IVIG) in SLE, the underlying mechanisms of action remain poorly understood. Considering the effect of serum factors, including interferon-alpha (IFNalpha), on the activity of DCs, we investigated the effects of IVIG on the differentiation of DCs mediated by serum from SLE patients.
  
  
  METHODS
  DCs were differentiated from peripheral blood monocytes obtained from SLE patients and from healthy blood donors, in the presence of SLE serum. IVIG was used at a concentration of 0.15 mM. A functional assay was performed to assess the inhibitory effect of IVIG on the uptake of nucleosomes by DCs.
  
  
  RESULTS
  IVIG interfered with the differentiation of DCs from SLE patients and healthy donors cultured in the presence of SLE serum. Treatment of DCs with IVIG inhibited the ingestion of nucleosomes by immature DCs, by up to 36%.
  
  
  CONCLUSIONS
  The present findings indicate that IVIG, by down-regulating the IFNalpha-mediated differentiation of DCs and by inhibiting uptake of nucleosomes, may exert an essential immunoregulatory effect in SLE patients at the onset of the immune response, at the DC level. Given the critical role of HLA molecules and the costimulatory signals delivered by CD80 and CD86 in optimal antigen presentation and T cell activation, inhibition of expression of HLA and CD80/CD86 on DCs by IVIG offers a plausible explanation for the efficacy of IVIG in SLE and other immune-mediated inflammatory conditions.
authors.affiliation: INSERM (Unité 430) and Université Pierre et Marie Curie, Institut des Cordeliers, Paris, France.
authors.forename: Jagadeesh
authors.initials: J
authors.lastname: Bayry
authors.forename: Sébastien
authors.initials: S
authors.lastname: Lacroix-Desmazes
authors.forename: Sandrine
authors.initials: S
authors.lastname: Delignat
authors.forename: Luc
authors.initials: L
authors.lastname: Mouthon
authors.forename: Bernard
authors.initials: B
authors.lastname: Weill
authors.forename: Michel D
authors.initials: MD
authors.lastname: Kazatchkine
authors.forename: Srini V
authors.initials: SV
authors.lastname: Kaveri
mesh_terms: D000328:Adult; D002454:Cell Differentiation / Q000276:immunology; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D015536:Down-Regulation / Q000276:immunology; D005260:Female; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000494:pharmacology*; D016898:Interferon-alpha / Q000097:blood*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology* / Q000378:metabolism; D008297:Male; D009000:Monocytes / Q000166:cytology / Q000276:immunology; D009707:Nucleosomes / Q000276:immunology / Q000378:metabolism
chemical_list: D016756:Immunoglobulins, Intravenous; D016898:Interferon-alpha; D009707:Nucleosomes