白细胞介素-17单克隆抗体对病毒性心肌炎小鼠的保护作用及机制

Qian Hong, Liu Lijing

Department of Clinical Medicine, Huaihua Medical College, Huaihua 418000, China.

Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi. 2014 May;30(5):509-12.

OBJECTIVE

To explore the protective effects of interleukin-17 monoclonal antibody (IL-17 mAb) on viral myocarditis (VMC) mice and its possible molecular mechanisms.

METHODS

Ninety BALB/c mice were randomly divided into 4 groups: normal control group (n=15), model group (n=25), isotype control group (n=25) and IL-17 mAb group (n=25). Mice in model, isotype control and IL-17 mAb groups were inoculated with 0.1 mL Eagle's solution containing Coxsackievirus B3 (CVB3) intraperitoneally; and those in normal control group were treated with 0.1 mL Eagle's solution without CVB3. On the day 3 and 5 after inoculation, mice in isotype control and IL-17 mAb groups received intragastric administration of 100 μg non-specific IgG antibody and IL-17 mAb, respectively. On day 7 postinoculation, 5 mice were killed in each group, and the hearts were removed. Virus titer was detected using Reed-Muench method, and CVB3 mRNA copy number was measured by real-time quantitative PCR. All mice were killed on day 14 after weighing body mass (BM). The mortality was compared among groups. Serum was separated and serum cardiac troponin I (cTnI) concentration was detected using ELISA. The heart was removed and weighed to calculate heart index (HM/BM). Histological sections of heart were stained with hematoxylin-eosin and myocardial histopathologic scores were counted under optical microscope. The expression of nuclear factor-κB (NF-κB) p65 was examined by Western blotting. Myocardial interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels were detected by ELISA.

RESULTS

The HM/BM, serum cTnI concentration, NF-κB p65 expression level and myocardial IL-6 and TNF-α contents in model group were higher than those in normal control group (P<0.01). In comparison with model and isotype control groups, mortality, HM/BM, serum cTnI concentration, myocardial histopathologic scores, virus titer, CVB3 mRNA copy number, NF-κB p65 expression level, and myocardial IL-6 and TNF-α contents in IL-17 mAb group were significantly reduced (P<0.05 or 0.01). There was no difference in the above indicators between isotype control group and model group(P>0.05).

CONCLUSION

IL-17 mAb can improve myocardial injury in VMC mice, and the mechanisms are associated with the inhibition of viral replication and NF-κB activation.

目的

探讨白细胞介素-17单克隆抗体（IL-17 mAb）对病毒性心肌炎（VMC）小鼠的保护作用及其可能的分子机制。

方法

将90只BALB/c小鼠随机分为4组：正常对照组（n = 15）、模型组（n = 25）、同型对照抗体组（n = 25）和IL-17 mAb组（n = 25）。模型组、同型对照抗体组和IL-17 mAb组小鼠腹腔注射0.1 mL含柯萨奇病毒B3（CVB3）的伊格尔氏液；正常对照组小鼠注射0.1 mL不含CVB3的伊格尔氏液。接种后第3天和第5天，同型对照抗体组和IL-17 mAb组小鼠分别灌胃100 μg非特异性IgG抗体和IL-17 mAb。接种后第7天，每组处死5只小鼠，取出心脏。采用里德-孟奇法检测病毒滴度，实时定量PCR法检测CVB3 mRNA拷贝数。称量体重后，于接种后第14天处死所有小鼠。比较各组小鼠的死亡率。分离血清，采用酶联免疫吸附测定法（ELISA）检测血清心肌肌钙蛋白I（cTnI）浓度。取出心脏称重，计算心脏指数（心脏重量/体重）。心脏组织切片进行苏木精-伊红染色，在光学显微镜下计数心肌组织病理学评分。采用蛋白质印迹法检测核因子-κB（NF-κB）p65的表达。采用ELISA检测心肌白细胞介素-6（IL-6）和肿瘤坏死因子-α（TNF-α）水平。

结果

模型组的心脏指数、血清cTnI浓度、NF-κB p65表达水平以及心肌IL-6和TNF-α含量均高于正常对照组（P < 0.01）。与模型组和同型对照抗体组相比，IL-17 mAb组的死亡率、心脏指数、血清cTnI浓度、心肌组织病理学评分、病毒滴度、CVB3 mRNA拷贝数、NF-κB p65表达水平以及心肌IL-6和TNF-α含量均显著降低（P < 0.05或0.01）。同型对照抗体组与模型组上述指标比较，差异无统计学意义（P > 0.05）。