CD25分子胞外段基因免疫应答中B淋巴细胞的变化及意义

The change of B lymphocytes in DNA vaccine encoding CD25 extracellular domain induced immune response

目的用鼠CD25分子胞外段基因疫苗免疫Balb/c小鼠,观察其诱导的体液免疫应答中B淋巴细胞的变化并探讨其意义。方法用pcDNA3.1-CD25胞外段真核表达质粒分别在第0天、第10天和第20天肌肉注射免疫同系Balb/c小鼠,酶联免疫法(ELISA)检测抗CD25胞外段的抗体水平及亚型,FACS检测脾细胞中B淋巴细胞的比例变化及细胞因子IL-4、IL-10和IFN-γ的表达变化。结果与对照组相比,CD25胞外段基因免疫组小鼠血清抗CD25抗体在免疫后逐渐升高,第30天达最高峰;抗CD25抗体主要以IgG1为主;免疫小鼠脾细胞中B细胞的比例变化不显著(P>0.05),但高分泌IL-4和IL-10(P<0.05),而低分泌IFN-γ(P<0.05)。结论 CD25胞外段蛋白基因免疫中B细胞功能变化显著,这为后续深入研究体液免疫应答在T细胞疫苗中的作用提供了前期实验基础。

Objective To evaluate the change of B lymphocytes in humoral immune response induced by DNA vaccine encoding mouse CD25 extracellular domain（CD25e）.Methods Balb/c female mice were inoculated by intramuscular injection of pcDNA3.1-CD25e on day 0,day 10 and day 20,respectively.The titers of antibody to CD25e,as well as the class and subclass of antibody,were assayed with indirect enzyme-linked immunosorbent assay（ELISA）.The percentage of B cells in splenocytes and IL-4,IL-10 and IFN-γ production of B cells were analyzed by FACS.Results Compared with that in control group,the titer of antibody specific to CD25e steadily increased and reached the peak on day 30.The antibody specific to CD25e mainly comprised IgG1.The percentage of B cells in splenocytes did not change significantly（P0.05）.IL-4 and IL-10 production of B cells in splenocytes from pcDNA3.1-CD25e immunized mice was higher than that in control group（P0.05）.By contrast,IFN-γ production of B cells decreased significantly（P0.05）.Conclusion CD25e DNA vaccine effectively induces the change in B cell function and provides foundation for further research on the role of humoral immune response in T cell vaccine.