摘要
为了探讨ITP患儿外周血T细胞蛋白激酶C(PKC)的活性变化及其与T细胞活化和血小板减少程度之间的关系,无菌采集35例ITP患儿及30例正常儿童外周血,采用T细胞分离富集柱法分离纯化T细胞,分别用非同位素标记法检测T细胞PKC的活性变化,用流式细胞仪检测T细胞活化标志FasL蛋白的表达,血细胞计数仪计数血小板的减少程度。结果ITP患儿T细胞PKC的总活性与正常儿童相比明显增强[(0.97±0.21)nmol/ml·min和(0.55±0.13)nmol/ml·min,x±s,P<0.05],T细胞活化标志FasL蛋白表达与正常儿童比较显著升高(CD4+TFasL:32.7%±3.4%和14.7%±4.2%;CD8+TFasL:17.3%±9.7%和11.6%±8.5%,x±s,P<0.05),并且T细胞PKC的活性变化与CD4+TFasL、CD8+TFasL的表达均为显著正相关(r1=0.68,r2=0.53,P<0.05),与血小板计数成显著负相关(r=-0.75,P<0.05)。上述研究结果表明ITP患儿PKC活性增强可能引起T细胞的活化,活性T细胞增多可导致患儿血小板大量损伤,提示PKC信号转导在ITP的免疫病理机制中发挥重要作用。
To observe the changes of protein kinase（PKC） activity of T lymphocytes in peripheral blood of children with idiopathic thrombocytopenia purpura（ITP）and the relation between T cell activation and the intensity of decrease in platelets, peripheral blood was taken under sterile condition from children with ITP （n=35） and healthy children（n=30）, and then T lymphocytes were isolated and purified by the segregation enrichment column of T ceils. The PKC activity of T ceils was detected by non-radioactive assay, and the expression of FasL protein representing the marker for T cell activation was determined by flow cytometry（FCM）. As to the intensity of decrease in platelets, it was counter by hemocytometer. In comparison with the healthy children, the total activity of PKC was significantly enhanced in children with ITP [x±s, （0.97±0.21） nmol/ml·min vs （0.55±0.13） nmol/ml·min, P〈0.05]. Also, the expression of FasL on T cell subpopulation in children with ITP was significantly increased （FasL in CD4^＋T ceils： 32.7%±3.4% vs 14.7%±4.2% FasL on CD8^ ＋T ceils： 17.3%±9.7% vs 11.6%±8.5%, P〈 0.05）. In addition, the changes in PKC activity and the percentages of FasL in CD4^ ＋and CD8^ ＋T ceils were positively correlated （r1=0.68, r2=0.53, P〈0.05）, while the changes in PKC activity and the platelet counts were negatively correlated（r=-0.75, P〈0.05）. It is evident from the results mentioned above that the enhancement of the PKC activity could induce the activation of T lymphocytes in children with ITP, and thereby the activated T lymphocytes could cause damages of platelets in these children, suggesting that the PKC signal transduction may play an important role in immunopathogenesis of idiopathic thrombocytopenia purpura.
出处
《现代免疫学》
CAS
CSCD
北大核心
2005年第6期493-496,共4页
Current Immunology
基金
广东省自然科学社会发展科技计划资助项目(2004024)
