The Preliminary Mechanism Research Of T Helper Cell 17 And Regulatory T Cells In Kawasaki Disease

Objective: To research the aberrance mechanisms of T helper cell 17 and Regulatory T cells in patients with Kawasaki Disease.Methods:In this study,thirty-two age-matched health children and forty-two children with KD were consented to participate.1.Co-Immunoprecipitationcombined with real-time PCR and Western-Blot was performed to determine IL-17-associating histone methylation,histone acetylation level of IL-17 gene and poly-ubiquitination status of Foxp3 protein in CD4+ T cells.2.The proportions of CD4+IL-17+ cells/ T helper cell 17(Th17)and CD4+CD25highFoxp3+ regulatory T cells(Treg),and expression levels of forkhead box protein P3(Foxp3),IL-10,IL-17,HIF-1αand p STAT3 in CD4+ T cells,were evaluated by flow cytometry.3.Quantitative real-time PCR was used to evaluate levels of IL-17,IL-6Rα,gp130,IL-23 R,IL-23Rβ1,ETV5,SOCS1,SOCS3,TLR4,My D88/TRIF,TNFR1,RIP1,RORγt,p300 m RNA and mi R155 in CD4+ T cells.4.Plasma concentrations of TNF-α,IL-1β,IL-23,IL-21 and IL-6 were measured by enzyme-linked Immunosorbent assay.Results: 1.The rate of Th17,protein level of IL-17 and its associating H3K4me3 were elevated remarkably during aute KD while lower levels of IL-17-associating H3K27 me were found in patients with KD(P<0.05),and a positive correlation existed between the ratio of H3K4me3/H3K27 me and IL-17 m RNA(r=0.69,P<0.05).The patients in KD without coronary artery lesions(KD-CAL-)were lower than the three former items patients with coronary artery lesions(KD-CAL+),while H3K27me3 levels in KD-CAL+ group were lower than that in KD-CAL-group(P<0.05).Moreover,the proportion of Treg and expressions of Foxp3 and IL-10 were found to be lower than the healthy control group(P<0.05),which resulted in a higher ratio of Th17/Treg during acute KD(P<0.05),and all the items mentioned before restored significantly after IVIG treatment(P<0.05).2.Expression levels of p STAT3,ETV5 and mi R155 increased significantly during acute KD,as the negative regulators SOCS1 and SOCS3 of p STAT3 were down-regualted in patients with acute KD.Futhermore,Expressions of p STAT3,ETV5 and mi R155 in KD-CAL+ group were higher than those in KD-CALgroup(P<0.05),as lower levels of SOCS1 and SOCS3 were found in KD-CAL+ group(P<0.05).All the items mentioned before restore to some extent after IVIG therapy(P<0.05).3.Compared with the healthy control group,plasma concentraions of inflammatory cytokines(IL-1β,IL-6,IL-21,IL-23 and TNF-α),surface receptors(TLR4,IL-6Rα/gp130,IL-23R/IL-23Rβ1 and TNFR1)and its downstream adaptors(p STAT3,My D88,TRIF,RIP1)in CD4+T cells were up-regulated during acute KD(P<0.05),and decreased remarkably after IVIG treatment(P<0.05).Simulatneously,all the items aforementioned in KD-CAL-group were found to be lower than those in KD-CAL+ group(P<0.05).4.Acetylation of the histone H3 associated with IL-17 gene and poly-ubiquitination of Foxp3 protein in CD4+T cells increased significantly,as well as more higher expressions of HIF-1α,RORγt and p300 were detected during acute KD(P<0.05),and the five items decreased remarkably after IVIG therapy(P<0.05).Meanwhile,positive correlations between expression of HIF-1α with histone acetylation of IL-17 gene and poly-ubiquitination of Foxp3 protein were observed in patients with acute KD(r=0.65,0.52;P<0.05).Conclusion:Aberrant histone methylation of IL-17-associating H3K4me3 and H3K27me3 may be involved in immune dysfunction of Kawasaki disease and excess activation of HIF-1α signaling may be one of the important factors contributing to the imbalance of Th17/Treg in Kawasaki disease.