Effect of interleukin-21 and dexamethasone on follicular helper T cells in patients with systemic lupus erythematosus / 中华风湿病学杂志

ABSTRACT

Objective To investigate the effect of interleukin(IL)-21 and dexamethasone(Dex)treatment on the percentage of follicular helper T cells(Tfh)in patients with systemic lupus erythematosus (SLE).Methods Peripheral blood mononuclear cells(PBMCs)obtained from 11 SLE patients were cultured in 96 well plates at 106/well with medium as the control,and with rIL-21(200 ng/μl)or rIL-21(200 ng/μl)+Dex(1×10-6 mol/L)for 24 and 72 hours as the study groups.Another 20 samples were collected and incubated with different concentrations of Dex(0,5×10-7 mol/L,1×10-6 mol/L)for 24 hours.After labeling with CD4,PD1 and CXCR5 monoclonal antibodies,the proportions of Tfh cells were assessed by flow cytometry.ELISA was used to detect supernatant antinuclear antibody(ANA)levels.Differences between groups were analyzed by paired t test.Results The percentages of Tfb cells were elevated when incubated with rIL-21 for 24 h and 72 h[24 h(4.3±1.2)％,(5.9±2.4)％;72 h(5.6±4.0)％,(8.0±5.6)％;t=3.48 and 3.05 respectively,P=0.007 and 0.012].Compared with those in the rIL-21 group,the percentages of Tfh cells in the rIL-21+Dex group were decreased(t=4.70 and 2.78,P=0.001 and 0.019).Tfh cells were decreased ina dose-dependent manner when treated with Dex[24 h(4.2±1.3)％;72 h(6.2±4.4)％;t=3.37 and 2.26,P=0.003 and 0.036].There was no difference of supe(rn)atant ANA levels among those groups.Conclusion IL-21 can promote the proliferation of Tfh cells,while Dex inhibits Tfh cell growth and the inhibition effect is dose dependent.Tfh cells may represent a new target for the treatment of SLE.