摘要
目的探讨CD8+T淋巴细胞在病毒性心肌炎发病机制中的作用。方法70只4周龄Balb/c健康雄性小鼠随机分为正常对照组(n=15)、病毒感染组(n=55)。正常对照组小鼠腹腔接种不含病毒的Eagle氏液0.15ml,病毒感染组小鼠腹腔接种TCID50为109/ml的CVB3 Nancy株病毒液0.15ml。分别于第7、10、14、21、28天随机取正常对照组小鼠3只,病毒感染组小鼠8只断髓处死。取各组小鼠心肌组织固定、脱水、石蜡包埋,切片后行HE染色、计算心肌病理组织学积分、免疫组化法检测CD8+T淋巴细胞及TUNEL法检测细胞凋亡,光镜下计算CD8+T淋巴细胞数所占浸润细胞数的百分比作为阳性细胞百分率。结果病毒感染组小鼠心肌病理积分、心肌组织中CD8+T淋巴细胞百分率及细胞凋亡率均于第10、14天达高峰(P<0.01);心肌组织中CD8+T淋巴细胞数百分率与心肌病理积分、心肌细胞凋亡率呈显著正相关。结论CD8+T淋巴细胞系小鼠病毒性心肌炎心肌损伤的重要效应细胞,其可能主要通过诱导心肌细胞凋亡而致病。
Objectives To explore the role of CD8^＋T lymphocytes in the pathogenesis of viral myocarditis. Methods Seventy 4-week-old Balb/c male mice were randomly divided into two groups,normal control group （n = 15） and virus infected group （n = 55）. The mice in normal control group were inoculated with 0.15 ml of Eagle＇s solution, while the mice in virus infected group with 0.15 ml（TCID50,10^9/ml） of coxasckievirus B3（CVB3）. Three normal mice and 8 infected mice were sacrificed on Days 7,10,14,21,28 post inoculation （p.i.）. Heart tissues were fixed,dehydrated, embedded in paraffin,sectioned and stained by HE. Histopathologic changes were studied by light microscopy and myocardial histopathologic scores were recorded. The presence of CD8^＋ T lymphocyte in myocardium was determined by immunohistochemistry. Terminal transferase-mediated dUTP-biotin nick end labeling （TUNEL） assay was used to determine apoptosis in cardiomyocyte. The percentage of CD8^＋ T lymphocyte in infiltrating cells was enumerated by counting under light microscopy. Results In the virus infected group, the myocardial histopathologic scores, the apoptosis in cardiomyocytes and the expression of CD8^＋ T lymphocyte peaked on Day 10 and 14 p.i. Significant positive correlation was observed between the expression of CD8^＋ T lymphocytes and both the myocardial histopathologic scores （r = 0.88, P 〈 0.01） and cardiomyocyte apoptosis （r = 0.86, P 〈 0.01）. Conclusions CD8^＋ T lymphocytes might cause apoptosis-induced myocyte injury and play a major role in viral myocarditis.
出处
《临床儿科杂志》
CAS
CSCD
北大核心
2007年第10期811-814,847,共5页
Journal of Clinical Pediatrics
基金
山东省医药卫生科研项目(No.CAIDBAII)
