The role of interleukin-35-producing regulatory B cells in immune pathogenesis of Kawasaki disease / 中华实用儿科临床杂志

ABSTRACT

Objective To investigate the role of IL-35-producing regulatory B cells(IL-35 + Breg)in immunological pathogenesis of Kawasaki disease (KD).Methods Thirty-two children with KD and 28 age-matched healthy children were allowed to participate in this study.Flow cytometry was performed to evaluate the proportions of IL-35 + Breg as well as requlatory T cells (Treg)and expression levels of associated molecules such as programmed death-ligand 1 (PD-LI),CD169,programmed death 1 (PD-1),CD43,IL-12p35,epstein-Barr virus induced 3 (IL-27 EBI3).IL-12 receptor beta 2 (IL-12 Rβ2),IL-27 receptor alpha (IL-27 Rα),phosphated signal transducer and activator of transcription 1 (pSTAT1) and phosphated signal transducer and activator of transcription 3 (pSTAT3).Transcription levels of the Src homology 2 domain-containing protein tyrosine phosphatase 2 (SHP-2),phosphatase and tensin homolog (PTEN),vav1 guanine nucleotide exchange factor(Vav) in CD19 + B cells were determined by using quantitative real-time PCR.Plasma concentrations of IL-35,tumor necrosis factor α(TNF-α) and IL-12 were measured by adopting enzyme-linked immunosorbent assay.Results (1) The proportions of IL-35 +Breg and its expressions of IL-12p35,IL-27EBI3 and IL-10 in patients with acute KD were lower than those of healthy controls [IL-35 + Breg(5.79 ± 2.60) ％ vs (12.65 ± 5.34) ％;F =19.23,9.70,14.30.7.08;all P ＜ 0.05],but they were significantly increased after intravenous immune globulin (IVIG) treatment [IL-35 + Breg(10.52 ± 4.95) ％;all P ＜ 0.05].(2) The proportions of Treg and its transcriptional levels of IL-12p35 and IL-27 EBI3 were down-regulated during acute KD [Treg(4.12 ± 1.51) ％ vs (8.06 ± 3.32) ％;F =19.70,17.69,38.22;all P ＜ 0.05],but were increased after therapy [Treg(7.39 ± 2.85) ％;P ＜ 0.05].A positive correlation was found between the proportions of Treg and IL-35 + Breg during acute KD (r =0.69,P ＜ 0.05).Meanwhile,plasma concentrations of IL-35 and expression levels of IL-12Rβ2,IL-27Rα,pSTAT1 and pSTAT3 in CD19 + B cells were significantly down-regulated in children with acute KD,but they were increased after treatment(F =8.09,7.54,7.69,5.89,12.59,all P ＜ 0.05).(3) Compared with healthy controls,expressions of PD-L1 and CD169 on CD14 + cells and plasma concentrations of TNF-α and IL-12 were elevated during acute KD (F =24.94,16.53,34.71,19.51;all P ＜ 0.05).Expression levels of PD-1,CD43 and its downstream molecules (SHP-2,PTEN,Vav) in CD19 + B cells were down-regulated during acute KD (F =6.43,5.57,19.52,10.37,11.37;all P ＜ 0.05),and restored remarkably after therapy (all P ＜ 0.05).Conclusion Insufficiency of IL-35 + Breg and its expression of IL-35 may be the important factors contributing to immunological dysfunction in KD.