CD8^+T淋巴细胞、颗粒酶B在人类病毒性心肌炎细胞凋亡中的作用

The role of CD8^+T lymphocytes and granzyme B in cardiomuocyte apoptosis in human viral myocarditis

目的探讨CD8+T淋巴细胞、颗粒酶B与人类病毒性心肌炎(VMC)细胞凋亡的关系。方法筛选中山大学法医鉴定中心2011-2012年尸检案例符合要求的40例人体心脏标本,其中20例为病毒性心肌炎组(VMC组),20例为正常对照组。采用免疫组化法(SP法)分别检测CD8+T淋巴细胞、颗粒酶B在VMC猝死者心肌组织中的表达变化,原位末端标记法(TUNEL)检测心肌细胞凋亡情况,比较两组间的表达差异。结果免疫组化和TUNEL法显示VMC组CD8+T淋巴细胞百分率、颗粒酶B阳性细胞数及细胞凋亡指数(AI)分别为(27.8330±4.5542)%、(2.4100±0.6758)、(12.6475±3.5975)%,明显高于正常对照组的0%、0、(1.8825±0.7781)%,差异均有统计学意义(P<0.05)。Pearson相关性分析表明,VMC组心肌组织中CD8+T淋巴细胞与颗粒酶B蛋白表达呈正相关(r=0.4530,P<0.05),细胞凋亡指数与CD8+T淋巴细胞、颗粒酶B蛋白的表达呈正相关(r=0.4660,r=0.5290,P<0.05)。结论 CD8+T淋巴细胞与颗粒酶B可能是VMC心肌细胞凋亡的重要因素之一,在VMC的发生发展中发挥着重要作用。

Objective To explore the role of CD8＋ T lymphocytes and granzyme B in cardiomuocyte apoptosis in human viral myocarditis （VMC）. Methods 40 cases of suitable heart specimens from autopsy cases in Forensic Center of Sun Yat-sen University in 2011-2012 were collected. 20 cases were the diagnosis of VMC group,20 cases were the control group. The expression of CD8＋ T lymphocytes, granzyme B and apoptosis in myocardial tissues were examined by the methods of immunohistochemistry with streptavidin-perosidase （SP） staining and terminal deoxynucleotidyl transferase （TdT）-mediated dUTP nick end labeling （TUNEL）,and these differences between VMC and control group were analyzed. Results Compared with the control group, CD8＋ T lymphocytes, expression of granzyme B and apoptosis index of VMC group increased remarkably（P〈0.05）. The positive correlation between CD8＋ T lymphocytes and granzyme B was observed （0.4530,P〈0.05）. The change of the apoptosis index was in accordance with those of CD8＋ T lymphocytes and granzyme B （r=0.4660,r=0.5290,P〈0.05）. Conclusion CD8＋ T lymphocytes and granzyme B may be the key factor causing cardiomuocyte apoptosis and play an important role in the genesis and development of human viral myocarditis.