title: Aberrant expression of regulatory cytokine IL-35 in patients with systemic lupus erythematosus.
abstract: OBJECTIVE
  This study characterizes an IL-35-mediated regulatory role in patients with systemic lupus erythematosus (SLE).
  
  
  METHODS
  Plasma of SLE patients and healthy controls (HCs) was analyzed for the concentrations of IL-35 and soluble gp130 by using ELISA. mRNA expression of IL-35 subunit (p35 and EBI3) and its receptor (gp130 and IL-12Rβ2) in peripheral blood mononuclear cells (PBMCs) was assessed by RT-qPCR. Flow cytometry was performed to evaluate the number of CD4(+)CD25(high)CD127(-)Treg cells and the expression of IL-35 receptor on the CD4+ helper (Th) cells and CD19+ B cells. Plasma collected from SLE patients and HCs was assayed for cytokine and chemokine expression by Luminex multiplex assay.
  
  
  RESULTS
  Plasma IL-35 and soluble gp130 levels positively correlated with each other and were significantly higher in patients with severe SLE compared with HCs. Significantly higher levels of inflammatory cytokines/chemokines CCL2, CXCL8, IL-6, interferon (IFN)-γ, IL-10 and IL-17A were observed in plasma of SLE patients than HCs. mRNA levels of IL-35 and its receptor were significantly positively correlated in PBMCs from SLE patients and their levels were higher in SLE than HCs. The increase significantly correlated with changes in SLE Disease Activity Index (SLEDAI) (all p < 0.05). In addition, the number of Treg cells in severe and moderate SLE patients were both significantly lower than HCs, where the ratio of CD4(+)CD25(-)effector T cell %/CD4(+)CD25(high)CD127(-)Treg % was found to be significantly higher in severe SLE patients. Furthermore, the expression of gp130 on CD4+ Th cells and percentage of Tregs were positively correlated with each other, and both were negatively correlated with SLEDAI.
  
  
  CONCLUSIONS
  Our findings indicate that high level of plasma IL-35 in active SLE patients expressed with low level of IL-35 receptor (gp130) on CD4+ Th cells. These data raise the possibility that the level of IL-35 expression in SLE patients is not sufficient to induce the production of CD4(+)CD25(high)CD127(-)Tregs, and subsequently suppress the release of inflammatory cytokines and chemokines upon inflammation.
authors.affiliation: Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Cai
authors.affiliation: Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China Institute of Chinese Medicine and State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Shatin, NT, Hong Kong.
authors.forename: C K
authors.initials: CK
authors.lastname: Wong
authors.affiliation: Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, NT, Hong Kong.
authors.forename: N W
authors.initials: NW
authors.lastname: Kam
authors.affiliation: Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China.
authors.forename: J
authors.initials: J
authors.lastname: Dong
authors.affiliation: Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China.
authors.forename: D
authors.initials: D
authors.lastname: Jiao
authors.affiliation: Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China.
authors.forename: M
authors.initials: M
authors.lastname: Chu
authors.affiliation: State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa, Macau.
authors.forename: C W K
authors.initials: CW
authors.lastname: Lam
authors.affiliation: Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, NT, Hong Kong lstam@cuhk.edu.hk.
authors.forename: L S
authors.initials: LS
authors.lastname: Tam
mesh_terms: D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D016022:Case-Control Studies; D018925:Chemokines / Q000097:blood; D050822:Cytokine Receptor gp130 / Q000097:blood*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000097:blood; D016753:Interleukin-10 / Q000097:blood; D020381:Interleukin-17 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D007378:Interleukins / Q000097:blood*; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008180:Lupus Erythematosus, Systemic / Q000097:blood*; D008297:Male; D008875:Middle Aged; D050378:T-Lymphocytes, Regulatory / Q000378:metabolism; D055815:Young Adult
chemical_list: D018925:Chemokines; C573415:IFNG protein, human; C508609:IL10 protein, human; C508717:IL17A protein, human; D020381:Interleukin-17; D015850:Interleukin-6; D007378:Interleukins; C532417:interleukin-35, human; D016753:Interleukin-10; D050822:Cytokine Receptor gp130; D007371:Interferon-gamma
keywords: Cytokines; Systemic Lupus Erythematosus Disease Activity Index; interleukin-35; regulatory T cells; systemic lupus erythematosus