豚鼠和BALB/c小鼠对SEC2超抗原作用敏感性的比较

Comparison of the Superantigen Sensitivity on Staphylococcal Enterotoxins C2 in Guinea Pigs and BALB/c Mice

比较分析豚鼠和BALB/c小鼠对金黄色葡萄球菌肠毒素C2(Staphylococcus enterotoxin C2,SEC2)超抗原作用的敏感性差异,确定更适合用于SEC2超抗原作用研究的模式动物。体外试验,以梯度浓度SEC2刺激豚鼠和BALB/c小鼠的外周血单个核细胞(Peripheral blood mononuclear cell,PBMC)和脾淋巴细胞,MTS染色法检测其增殖;体内实验,SEC2腹腔注射豚鼠和BALB/c小鼠,每隔3 d检测豚鼠和小鼠的体重、体温变化情况;每隔7 d采血,ELISA法检测血清中IL-4、IFN-γ、IL-2和TNF-α分泌水平。不同浓度的SEC2均能刺激小鼠的PBMC和脾淋巴细胞显著增殖(P<0.05),而对豚鼠的PBMC和脾淋巴细胞无效。腹腔注射后,SEC2组和对照组豚鼠和小鼠的体温均无显著性变化(P>0.05);豚鼠SEC2组体重在给药后期显著低于对照组(P<0.05),小鼠的SEC2组体重在给药后第3-30天均显著低于对照组(P<0.05),此后恢复到正常水平(P>0.05);给药后各时间点,小鼠的SEC2组血清中细胞因子IL-4、IFN-γ、IL-2和TNF-α的分泌水平均显著高于对照组(P<0.05),而豚鼠的SEC2组血清中细胞因子分泌水平与对照组无显著性差异(P>0.05)。与豚鼠相比,BALB/c小鼠对SEC2超抗原活性的敏感程度更高,且表现出很好的剂量和时间效应,适合作为模式动物用于SEC2的超抗原活性研究。

This work is to analyze and compare the superantigen sensitivity on staphylococcal enterotoxins C2（SEC2）in guinea pigs and BALB/c mice, and determine the model animal for the researches of superantigen sensitivity on SEC2. In vitro, peripheral blood mononuclear cell（PBMC）and splenocytes from guinea pigs and BALB/c mice were respectively stimulated with SEC2 at gradient concentration, and the cell proliferation was tested by MTS assay;In vivo, the changes of temperature and weight of guinea pigs and mice were measured at interval of 3 d after the intraperitoneal injection of SEC2. Meanwhile, the serums were collected at interval of 7 d to detect the levels of IL-4, IFN-γ, IL-2 and TNF-αby ELISA. SEC2 of different concentrations significantly stimulated the proliferation of PBMC and splenocytes from BALB/c mouse（P〈0.05）, but not so from guinea pigs（P〉0.05）. After intraperitoneal injection of SEC2, there was no significant difference in body temperature of both guinea pigs and mice（P〉0.05）compared to the control. In the later phase of the experiment, the body weights of guinea pigs in SEC2 group were significantly lower than those in control group（P〈0.05）. And the body weights of mice in SEC2 group were also significantly lower than those in control group during day 3 to 30, but recovered to normal level at the end of the experiment（P〉0.05）. The cytokines IL-4, IFN-γ, IL-2 and TNF-αin serum of mice of SEC2 group were significantly elevated compared with in control group（P〈0.05）. However, there was no significant difference in guinea pigs administrated with SEC2 and physiological saline（P〉0.05）. In conclusion, comparing with guinea pigs, BALB/c mice are more sensitive to the stimulation of SEC2 with promising dose-dependent and time-dependent manner. Therefore, BALB/c mouse is a suitable model animal for the researches of superantigen activity.