哮喘患儿外周血树突状细胞共刺激分子表达研究

Study of co stimulatory molecules on peripheral blood dendritic cells in asthmatic children

目的 探讨小儿哮喘发作时外周血树突状细胞 (DC)表面协同刺激分子CD4 0、CD80、CD86和HLA DR的表达 ,以及其激发同种异体T淋巴细胞和脐带血幼稚T淋巴细胞 (Na veTcells)的作用 ,为进一步研究小儿哮喘的发病机制及治疗提供新的思路。方法 以Thomas法分离、培养并诱导哮喘患儿和健康儿童外周血DC细胞 ,流式细胞仪 (fluorescentactivatedcellsorter,FACS)检测DC表面协同刺激分子CD4 0、CD80、CD86和HLA DR的表达 ,以及其激发同种异体T淋巴细胞和脐带血幼稚T淋巴细胞的作用。结果 哮喘患儿外周血DC表面CD86和HLA DR的表达较对照组明显升高 (t分别 =3 .3 0 4、9.4 81;P分别 <0 .0 1、0 .0 0 1) ,而CD4 0则显著降低 (t=5 .65 9,P <0 .0 0 1) ;其激发同种异体T淋巴细胞和脐带血幼稚T淋巴细胞的能力较对照组明显增强 (P <0 .0 1～ 0 .0 0 1)。结论 哮喘患儿可通过其DC表面差异表达CD4 0、CD86和HLA DR等协同刺激分子 ,从而使其激发T淋巴细胞的作用增强。所以DC在小儿哮喘发作时起重要作用。

Objective To study the express of the co stimulatory molecules CD40, CD80, CD86, HLA DR and etc on peripheral blood DCs in asthmatic children, and their potentials to stimulate the proliferation of native T cells from cord blood and allogenic T cells from healthy children. It may offer some insight into both the mechanism of the asthma and its therapy.Methods Thomas method is adopted. The adherent precursors of DCs were isolated from peripheral blood of both asthmatic children in acute attack stage and healthy controls in vitro. The expression of the co stimulatory molecules CD40, CD80, CD86, HLA DR and etc on peripheral blood DCs were examined by fluorescent activated cell sorter (FACS), and their potentials to stimulate the proliferation reaction of native T cells from cord blood and T cells from healthy children were observed.Results The results showed that asthmatic children in acute attack stage had remarkably increased expression of the CD86 and HLA DR on peripheral blood DCs ( t =3.304, 9.481 respectively; P <0.01, 0.001 respectively), remarkably decreased expression of the CD40 ( t =5.659, P <0.001) compared with the normal control subjects. At the same time, the asthmatic children in acute attack stage had remarkably increased the ability of DCs inductive allogenic T cells and cord blood T cells proliferation reaction compared with the normal control subjects (All of P <0.01～0.001).Conclusion The expressing levels of co stimulatory molecules CD80 and HLA DR are higher while the CD40 is lower in asthmatic children compared with those in the healthy control group. This result may lead to the sthenic function of DCs in these patients. So DCs plays an important role in children′s asthma.