hsBAFF对小鼠脾脏B淋巴细胞增殖与免疫应答及胞内Ca2+水平的影响

目的：探讨大肠杆菌表达的人源可溶性B淋巴细胞激活因子hsBAFF对小鼠脾脏B淋巴细胞免疫反应及其对胞内游离Ca^2＋信号变化的影响。方法：选择20只健康ICR小鼠,雌雄各半,随机分成两组（n=10）：①对照组;②hsBAFF实验组。实验组小鼠腹腔注射含hsBAFF（0．1mg／kgbw）的PBS溶液,对照组注射同等剂量的PBS溶液．连续8d。用MTT法检测小鼠脾脏B淋巴细胞的增殖及其对LPS刺激的免疫反应,并用激光共聚焦显微镜分析脾脏B淋巴细胞胞内钙离子水平（[Ca^2＋]i）变化。结果：hsBAFF注射小鼠的脾脏B淋巴细胞增殖和对LPS刺激的免疫反应均明显高于对照组（P〈0．05）;hsBAFF注射组[Ca^2＋]i荧光强度维持在相对稳定的高水平上波动,平均荧光强度显著高于对照组（P〈0．01）,且荧光强度变化率小于对照组。结论：大肠杆菌表达的hsBAFF能促进B淋巴细胞的增殖和免疫应答,从而增强机体免疫功能。hsBAFF激活小鼠脾脏B淋巴细胞可能与[Ca^2＋]i升高有关。

Effects of splenic B lymphocyte proliferation and response and intracellular Ca2+ of hsBAFF in mice

Aim:To investigate effects of hsBAFF synthesized in Escherichia coli on spleen B lymphocyte immune response and its intracellular free Ca2 ([Ca2 ]i) signaling in mice.Methods:Twenty ICR mice,half males-half females,were chosen and randomly divided into a normal control group(n=10) and a hsBAFF treatment group(n=10).The mice in hsBAFF treatment group were given abdominal cavity injection of hsBAFF solution which was diluted with phosphate buffered saline(PBS) at dosage of 0.1 mg/kg body weight once each day for over eight days.The mice in control group were received abdominal injection of PBS at the same dose and frequency.Spleen B lymphocyte proliferation and its immune response to LPS stimulation in mice were evaluated using an MTT assay,and change of spleen B lymphocyte[Ca2 ]i was assayed under a laser scanning confocal microscope.Results:B lymphocyte proliferation and its immune response to LPS stimulation were significantly higher in hsBAFF-treated mice than in control mice(P<0.05).The B lymphocyte [Ca2 ]i fluorescence intensity in hsBAFF-treated mice maintained at a relatively high level fluctuation,and its average intensity was significantly higher to that of control mice(P<0.01),but change rate of the intensity was lower compared to that of control group.Conclusion:hsBAFF synthesized in Escherichia coli can enhance immune function in the body by increasing B lymphocyte proliferation and its immune response.hsBAFF-activated B lymphocyte function may be associated with increasing B lymphocytes[Ca2 ]i.