Expressions of helper T cells and regulatory T cells in peripheral blood of children with dust mite allergic asthma and their clinical significance / 中华实用儿科临床杂志

ABSTRACT

Objective To analyze the expressions of helper T cells (Th) and regulatory T cells (Treg) in peripheral blood of children with dust mite allergic asthma and their clinical significance.Methods Thirty asthmatic children with dust mite positive were included in the study as asthmatic group.Thirty healthy subjects,age and sex matched,were included as healthy control group.Peripheral blood mononuclear cells (PBMC) were isolated by densitygradient centrifugation over Ficoll-Hypaque cushions.The expressions of interferon-γ (IFN-γ),interleukin-4 (IL-4) and Foxp3 in CD4 + T cells with or without dust mite stimulation were assessed by intracellular staining and flow cytometry (FCM).The anti-inducible costimulatory molecule (ICOS),anti-CD2s or anti-cytotoxic T-lymphocyte antigen-4 (CTLA-4) antibodies were added to PBMC and co-cultured for 3 days after dust mite stimulation.The expressions of Thl (CD4 + IFN-γ+ T cells),Th2 (CD4 + IL-4 + T cells) and Treg(CD4 + CD25 + Foxp3 + T cells) were analyzed.The data were analyzed by using statistical software.Results Compared with the healthy control group,in dust mite positive asthma group,the percentage of Thl cells was remarkably increased (P ＜ 0.05),while that of Treg cells was significantly decreased (P ＜ 0.05),and that of Th2 cells were not significantly different (P ＞ 0.05).Compared with nonstimulated PBMC of asthma group,the percentages of Thl and Treg had no significant variation (all P ＞ 0.05),while that of Th2 cells was notably increased (P ＜ 0.01).In the present of anti-ICOS or anti-CD2s antibodies,no significant variation were found about the percentages of Th1 and Treg (all P ＞ 0.05),while expressions of Th2 cells were significantly decreased (all P ＜0.0001).However,in the present of anti-CTLA-4 antibodies,the percentages of Th1,Th2 and Treg had no significant difference (all P ＞ 0.05).Conclusions There is a constructive,allergen independent Th1 activation and Treg deficiency as well as allergen inductivity,ICOS-and CD2s-dependent Th2 activation in the peripheral blood of children with dust mite allergic asthma.