title: Dysregulation of the granulocyte-macrophage colony-stimulating factor receptor is one of the causes of defective expression of CD80 antigen in systemic lupus erythematosus.
abstract: CD80 and CD86, expressed on the antigen-presenting cells (APCs) provide costimulatory signals for T lymphocytes. Recently, defective expression of CD80 has been reported in systemic lupus erythematosus (SLE) although its mechanism is unclear. Here, expression of the B7 antigens induced by interferon-gamma, interleukin-4 or granulocyte-macrophage stimulating-factor (GM-CSF) along the differentiation process of APCs was investigated. In contrast to CD86, expression of CD80 on the CD14+ cells induced by GM-CSF was reduced in SLE. GM-CSF receptor (GM-CSFR) was down-regulated by GM-CSF or phorbol 12-myristate 13-acetate in both of the normal controls and SLE patients, while this change was more remarkable in the latter. In the presence of 1-(5-isoquinolinsulfonyl)-2-methylpiperazine, an inhibitor of protein kinase C, the PMA-induced down-regulation of GM-CSFR was reversed in the normal controls but not in SLE. These data suggest that dysregulation of the GM-CSFR might be associated with the defective expression of CD80, leading to dysfunction of the APCs in SLE.
authors.affiliation: Third Department of Internal Medicine, Kinki University School of Medicine, Osaka-Sayama, Osaka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Funauchi
authors.forename: B S
authors.initials: BS
authors.lastname: Yoo
authors.forename: Y
authors.initials: Y
authors.lastname: Nozaki
authors.forename: M
authors.initials: M
authors.lastname: Sugiyama
authors.forename: M
authors.initials: M
authors.lastname: Ohno
authors.forename: K
authors.initials: K
authors.lastname: Kinoshita
authors.forename: Akihisa
authors.initials: A
authors.lastname: Kanamaru
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000032:analysis; D018122:B7-1 Antigen / Q000032:analysis*; D051940:B7-2 Antigen; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000032:analysis; D008875:Middle Aged; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / Q000032:analysis / Q000502:physiology*
chemical_list: D015703:Antigens, CD; D018122:B7-1 Antigen; D051940:B7-2 Antigen; C497964:CD86 protein, human; D008562:Membrane Glycoproteins; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor; D015847:Interleukin-4; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor