中文摘要：

目的 探讨多房棘球绦虫重组BCG—EmⅡ／3疫苗免疫和多房棘球绦虫（Em）原头节攻击后小鼠脾CD4^＋和CD8^＋T淋巴细胞亚群的变化。方法 Balb／c小鼠随机分为疫苗皮下注射组、鼻腔接种组、空载体对照组、卡介苗（BCG）对照组和磷酸缓冲液（PBS）对照组。疫苗免疫8周时用Em原头节进行攻击，感染后18周杀鼠取脾，分离脾细胞，流式细胞仪检测脾CD4^＋和CD8^＋T淋巴细胞亚群的百分比。结果 疫苗皮下注射组和鼻腔接种组的脾CD4^＋T细胞亚群比值分别为0．345±0．018、0．314±0．014，与PBS对照组（0．216±0．027）比较明显增高（q值分别为3．93、3．76，P〈0．01）；CD8^＋T细胞亚群比值分别为0．091±0．005、0．083±0．007，与PBS对照组（0．085±0．018）比较无明显变化（q值分别为0．92、0．89，P〉0．05）；CD4^＋／CD8^＋亚群比值分别为3．81±0．30、3．80±0．44，与PBS对照组（2．75±1．08）比较明显增高（q值分别为3.25、3．06，P〈0．01）。皮下注射组的CD4^＋和CD8^＋T细胞亚群数目显著高于鼻腔内接种组（q值分别为3．52、2．63，P〈0．01或〈0．05）。结论 CD4^＋T细胞亚群在多房棘球绦虫重组BCG-EmⅡ／3疫苗诱导的小鼠抗Em原头节攻击感染的保护性免疫机制中起关键作用。

英文摘要：

Objective To investigate changes of subsets of splenocytes in mice immunized with recombinant BCG-EmⅡ/3 vaccine against Echinococcus multilocularis （Em） and challenged with Em protoscoleces. Methods Balb/c mice were subcutaneously and intranasally vaccinated respectively and challenged with Em protoscoleces 8 weeks later. On the 18^th week of infection, the mice were sacrificed, splenocytes were separated to measure subsets of CD4^＋ and CD8^＋T cells by FACsort, Blank vector, BCG and PBS served as control. Results In the groups of immunization, CD4^＋ subset and ratio of CD4^＋/CD8^＋ subset increased obviously, but CD8^＋ subset increased slightly. The number of CD4^＋ and CD8^＋ subset in the subcutaneous group were higher than that in the intranasal group. Conclusion CD4^＋ subset may play an important role in the protection against Em protoscoleces chanllenge in mice induced by rBCG-EmⅡ/3 vaccine.