The regulatory activity of interleukin-35 to CD4+and CDS+T cells in sepsis patients / 中华急诊医学杂志

ABSTRACT

Objective To investigate plasma interleukin-35(IL-35)expression in sepsis patients,and to assess the regulatory activity of IL-35 on CD4+and CD8+T cells in sepsis patients.Methods A prospective study was conducted.Forty-one sepsis patients and nineteen healthy controls were enrolled in this study.According to the survival outcome on 28 day after admission,sepsis patients were further divided into the survival group(n=30)and death group(n=11).Peripheral blood samples were collected within one hour of visit.Plasma IL-35level was measured by enzyme linked immunosorbent assay(ELISA),while CD3+,CD4+,and CD8+T cell counts were measured by flow cytometry.The correlation between IL-35 expression/T cell counts and sequential organ failure assessment(SOFA)score was also assessed.Peripheral CD4+and CD8+T cells from sepsis patients were purified and stimlated with recombinant human IL-35 for 48 h.mRNA relative levels of T-bet,GATA-3,FoxP3,and RORγt in CD4+T cells and perforin,granzyme B,and FasL in CD8+T cells were measured by real-time PCR.Interferon-γ(IFN-γ,IL-4,IL-10,IL-17,and tumor necrosis factor-α(TNF-α)levels in the cultured supernatants were measured by ELISA.Transcription factor level and cytokine expression was compared prior to and post IL-35 stimulation.Results Plasma IL-35 was significantly elevated in sepsis patients when compared with controls [(76.76±10.33)pg/mL vs(27.53±8.31)pg/mL,P＜0.01],however; it did not correlate with SOFA score(r=O.172,P=0.281).Plasma IL-35 was also notably increased in the death group when compared with the survival group [(83.18±6.48)pg/mL vs(74.40±10.55)pg/mL,P=0.014].Plasma IL-35lvel in the death and survival groups were analyzed by receiver operating characteristic curve with an area under curve of 0.770(P=0.009).There were no remarkable differences of CD3+,CD4+,and CD8+T cell counts between sepsis patients and controls,or between the death and survival groups(all P＞0.05).Moreover,T cell counts were negatively correlated with SOFA score(P＜0.01).IL-35 stimulation resulted in the reduction of mRNA relative level of Th1 transcription factor T-bet and Th17 transcription factor RORγt in CD4+T cells from sepsis patients(P＜0.01),while elevation in regulatory T cell transcription factor FoxP3 mRNA(P＜0.01).However,IL-35 stimulation did not affect Th2 transcription factor GATA-3 mRNA in CD4+T cells(P=0.745).IFN-γ and IL-17 production by CD4+T cells was significantly decreased in response to IL-35 stimulation(P＜0.05),while IL-10 was increased(P＜0.01)and IL-4 was comparable(P=0.536)between CD4+T cells with and without IL-35 stimulation.IL-35 stimulation led to the down-regulation of mRNA relative level of perforin and granzyme B(P＜0.01).However,FasL mRNA was comparable between CD8+T cell with and without IL-35 stimulation(P=0.795).IFN-γ and TNF-α secretion was also reduced in response to IL-35 stimulation(P＜0.05).Conclusion Elevated plasma IL-35 level is an important indicator for poor prognosis of sepsis patients.IL-35 inhibits the activity of CD4+and CD8+T cells in sepsis patients,and might take part in the pathogenesis of sepsis.