口腔扁平苔藓局部浸润淋巴细胞颗粒酶B和穿孔素蛋白表达与上皮细胞凋亡的关系

Correlation between expression of granzyme B and perforin and apoptosis in epithelial cells in oral lichen planus with local lymphocyte infiltration

目的检测口腔扁平苔藓(oral lichen planus,OLP)上皮细胞凋亡状况,观察颗粒酶B、穿孔素在OLP固有层浸润淋巴细胞中的蛋白表达,探讨细胞毒作用对OLP上皮细胞凋亡的影响。方法采用原位缺口末端DNA标记技术,定位检测OLP上皮细胞凋亡情况;分别使用免疫组化法检测颗粒酶B和穿孔素在组织总淋巴细胞以及CD8+细胞中的表达,以健康口腔黏膜组织(NOM)作对照。结果与NOM相比,OLP上皮细胞凋亡显著增加(P=0.037);OLP淋巴细胞中颗粒酶B、穿孔素表达明显增强(P值分别为0.016和0.012),其部分阳性细胞接近上皮基底层。OLP中CD8+/颗粒酶B+细胞双阳性表达和CD8+/穿孔素+细胞双阳性表达较NOM明显升高(P值分别为0.043和0.032)。OLP上皮细胞凋亡与淋巴细胞颗粒酶B和穿孔素表达成正相关(r=0.56,P=0.038;r=0.42,P=0.041)。结论 OLP浸润淋巴细胞包括CD8+T细胞中颗粒酶B、穿孔素表达增强,提示OLP淋巴细胞可能以颗粒酶B、穿孔素作为细胞毒介质攻击口腔上皮细胞引起其凋亡。

Objective To study the expression of granzyme B and perforin and the effect of cytotoxin on apoptosis of epithelial cells in oral lichen planus（OLP）with lymphocyte infiltration by detecting the apoptosis of epithelial cells.Methods Apoptosis of epithelial cells in OLP with lymphocyte infiltration was detected with the terminal deoxymuleotigyl transferase-mediated dUTP-biotin nick end-labeling（TUNEL） technique.Expression of granzyme B and perfoin in lymphocytes and CD8＋ cells was detected with the immunohistochemcial method.Normal oral mucosa（NOM）was used as a control.Results The apoptosis level of epithelial cells and the expression level of granzyme B and perforin were significantly higher in epithelium of OLP than in control（P0.05）.Some positive cells were observed in the basal lamina of epithelium.The double positive expression levels of CD8＋/granzyme B＋ and CD8＋/perfoin＋ were significantly higher in OLP than in control（P0.05）.The apoptosis of epithelial cells in OLP was positively correlated with the expression of granzyme B and perfoin in OLP with lymphocyte infiltration（r=0.56,r=0.42,P0.05）.Conclusion Increased expression of granzyme B and perfoin in OLP with lymphocyte infiltration,including CD8＋ T cells,suggests that lymphocytes in OLP may attack oral epithelial cells as a cytotoxin of granzyme B and perfoin,thus leading to apoptosis of oral epithelial cells.