日本血吸虫可溶性虫卵抗原对B细胞的活化作用及其机制的初步研究

A study of B cells activation mechanisms induced by Schistosoma japonicum soluble egg antigens

目的:观察日本血吸虫可溶性虫卵抗原(SEA)是否能够诱导小鼠B细胞活化及其机制。方法:SEA和脂多糖(LPS)分别体外刺激小鼠脾脏CD19+B细胞,72 h后用流式细胞术分别检测B细胞表面CD80、CD86及CD40的表达和B细胞细胞周期的改变;用荧光染料CFSE分裂法检测B细胞增殖;用ELISA法检测培养上清中白介素(IL-)10、IL-6、γ干扰素(IFN-γ)和转化生长因子β(TGF-β)的水平。同时利用ERK、JNK、p38MAPK和NF-κB信号转导抑制剂检测B细胞分泌细胞因子水平的变化。结果:SEA与LPS组可以活化小鼠脾脏CD19+B细胞,使其表面高表达CD80、CD86和CD40;同时诱导S/G2期的B细胞比例显著增加,SEA可以诱导B细胞增殖。SEA与LPS能刺激脾脏CD19+B细胞分泌高水平的IL-10、IL-6。分别阻断NF-κB、ERK、JNK和p38MAPK信号转导通路后可以抑制B细胞IL-10和IL-6的分泌。结论:SEA可以上调小鼠脾脏B细胞表面共刺激分子表达、促进其增殖。同时,SEA可以通过NF-κB、ERK、JNK和p38MAPK信号转导通路刺激小鼠B细胞分泌细胞因子。

Objective：To observe the effect of the solube egg antigen （SEA） on B cell function and the related signal transduction. Methods：In vitro, mouse spleen CD19＋ B cells were stimulated by SEA or LPS for 72 hours. Then the expression of CD80, CD86 and CD40 and cell cycle were analyzed by flow cytometry, and the dilution of CFSE was assayed by flow cytometry. At the same time, the IL-10, IL-6, IFN-γ and TGF-β level in cultured supernatants were detected by ELISA. PD98059 （ERK inhibitor）, SP600125 （JNK inhibitor）, SB203580 （p38MAPK inhibitor） and PDTC （NF-κB inhibitor） were used to study the signal pathways for the induced secretion of IL-10, IL-6 in B cells. Results：The expression of CD80, CD86 and CD40 was up-regulated in B cells stimulated by SEA or LPS. And the ratio of B cells entered S/G2-phase was increased after stimulated by SEA or LPS. SEA or LPS promote B cell proliferation. The IL-10 and IL-6 secretion increased in mouse spleen B cells culture supernatants stimulated by SEA or LPS （P 〈 0.01）. Furthermore, PD98059, SP600125, SB203580 and PDTC inhibited the cytokine secretion in B cells stimulated by SEA or LPS. Conclusion：SEA could up-regulate and promote co-stimulatory molecules expression on B cells and the B cells proliferation. At the same time, SEA could induce the IL-10 and IL-6 secretion of B cells through NF-κB, ERK, JNK and p38MAPK signal transduction pathway.