口腔扁平苔藓固有层淋巴细胞中Fas及Fas配体的表达变化

目的 检测Fas及Fas配体(Fas ligand,FasL)在口腔扁平苔藓(oral lichen planus,OLP)固有层淋巴细胞中的蛋白表达,探讨Fas、FasL和活化诱导的细胞死亡(activation-induced cell death,AICD)与OLP发病的关系.方法 采用脱氧核糖核苷酸末端转移酶介导的原位缺口末端标记法检测31例OLP和10例正常口腔黏膜(normal oral mucosa,NOM)中淋巴细胞凋亡情况;分别使用免疫组化法检测组织总淋巴细胞及CD8~+、CD4~+T细胞Fas、FasL的表达.结果 OLP与NOM固有层淋巴细胞凋亡率分别为(1.9±1.8)%、(11.5±9.0)%]差异有统计学意义(P=0.013).OLP淋巴细胞Fas、FasL表达与NOM组相比明显增强阳性表达率分别为52%(16/31)、71%(22/31),P值分别为0.005、0.000].OLP中CD8~+与Fas~+细胞双阳性表达率为10%,与NOM组相比无明显升高(P=0.313),而CD8~+与FasL~+细胞双阳性表达率58%(3/31)]显著升高(P=0.002).CD4~+与Fas~+细胞双阳性表达率为35%(11/31),较NOM组显著升高(P=0.031),其中网纹型的表达明显升高(阳性表达为8/19,P=0.019),但糜烂、萎缩型的表达无显著升高(阳性表达为3/12,P=0.097).CD4~+与FasL~+表达率为16%(5/31),与NOM组相比无明显增强(P=0.182).结论 OLP淋巴细胞凋亡低下;OLP中T细胞亚群Fas、FasL表达不均衡,CD8~+细胞和萎缩、糜烂型OLP中CD4~+细胞可能逃逸AICD,与炎症的持续和进展有关;网纹型OLP中部分CD4~+T细胞可能经历AICD.

Expression of Fas and Fas ligand in infiltrating lymphocytes in patients with oral lichen planus

Objective To examine the expression of Fas and Fas ligand(FasL)in T lymphocytes of oral lichen planus(OLP)and the effects of Fas,FasL and activation-induced cell death(AICD)on OLP.Methods The oral mucosa samples from patients with OLP and nomal oral mucosa were assessed by in situ terminal deoxynucleotidyl transferase(TdT)-mediated deoxvuridine-5'-triphosphate(dUTP)-biotin nick endlabelling(TUNEL)assay for nucleosomal DNA fragmentation of apoptotic cells in infiltrating lymphocytes.Immunohistochemcial technique was used for detection of expression level of Fas and FasL.Immunohistochemcial double labeling was performed to examine the expression of Fas and FasL in CD8~+ T cells and CD4~+ T cells.Results The rate of apoptosis in infiltrating lymphocytes of OLP was(1.9±1.8)%,which was lower than that of normal oral mucosa(P=0.013).The expression of Fas and FasL were increased in lymphocytes of OLP(P=0.005 and 0.000 respectively).The positive rate of double labeled cells of CD8~+ and Fas~+ was not increased in OLP(P=0.313),and of CD8~+ and FasL~+ in OLP was higher than that of normal oral mucosa(P=0.002).The expression of double labeled cells of CD4~+ and Fas~+ in OLP was higher than that of control group(P=0.031).The expression of CD4~+ and Fas~+ T cells in reticular OLP were increased(P=0.019),and of CD4+ and FasL+ did not show remarkable change(P=0.097).Conclusions There was a low frequency of lymphocytic apoptosis.T cells,especial CD8~+ T cells in OLP and CD4~+ T cells in atrophic-erosive OLP appeared to escape from AICD,which may account for the persistense of inflammation.Some CD4~+ T cells in reticular OLP may go through AICD.