日本血吸虫副肌球蛋白全基因核酸疫苗在小鼠诱生的保护性免疫力

目的： 研究日本血吸虫大陆株副肌球蛋白全基因核酸疫苗免疫Ｃ５７ ＢＬ／６ 及ＢＡＬＢ／ｃ 小鼠诱生的保护性免疫力。方法： 将构建的日本血吸虫大陆株副肌球蛋白全基因核酸疫苗 （ｐＣＭＶ－ＳｊＣ９７） 经后腿胫前肌免疫Ｃ５７ＢＬ／６及ＢＡＬＢ／ｃ小鼠， 共免疫３ 次， 每次间隔３ ｗ ｋ。末次免疫后３ ｗ ｋ 以血吸虫尾蚴攻击感染， ６ ｗｋ 后计数成虫负荷及肝、脾、肠组织虫卵数。设不含ＳｊＣ９７ 编码基因的空载体质粒免疫组为对照组。结果： ｐＣＭＶ－ＳｊＣ９７ 免疫Ｃ５７ ＢＬ／６ 小鼠主要诱生ＩｇＧ２ａ 和ＩｇＧ２ｂ 亚类， 而免疫ＢＡＬＢ／ｃ小鼠除诱生ＩｇＧ２ａ 和ＩｇＧ２ｂ 亚类外， 还诱生ＩｇＧ１。ｐＣＭＶ－ＳｊＣ９７ 免疫Ｃ５７ＢＬ／６ 小鼠诱生较明显的减虫率 （３５．５％ ～４１．１％ ） 和减卵率 （肝、脾及肠组织减卵率分别为４４．５％ ～５９．６％ 、５６．７％ ～８２．４％ 及５７．９％ ）， 而对ＢＡＬＢ／ｃ小鼠未诱生保护性。结论： ｐＣＭＶ－ＳｊＣ９７ 核酸疫苗能对Ｃ５７ＢＬ／６ 小鼠诱生较明显保护性免疫力， 而对ＢＡＬＢ／ｃ 小鼠未诱生免疫保护力

INDUCTION OF PROTECTIVE IMMUNITY IN MICE AGAINST SCHISTOSOMA JAPONICUM BY NUCLEIC ACID VACCINE ENCODING THE FULL-LENGTH PARAMYOSIN*

AIM: To investigate the immune efficacy of nucleic acid vaccination in mice against full\|length paramyosin of Chinese Schistosoma japonicum. METHODS: C\-\{57\}BL/6 and BALB/c mice were vaccinated intramuscularly with the nucleic acid vaccine (pCMV\|SjC97) encoding the full\|length gene of paramyosin of Chinese S.japonicum. Each group was immunized three times at weeks 0, 3 and 6. Mice vaccinated with pCMV blank vector served as negative control. Mice were challenged three weeks after final DNA boosting by percutaneous infection with cercariae. Six weeks after infection the mice were perfused, worm burden and eggs in the livers, spleens and intestines were counted. Sera from vaccinated mice were collected from the tail vein at weeks 0, 3, 6 and 9, respectively. RESULTS: C\-\{57\}BL/6 mice vaccinated with pCMV\|SjC97 produced predominantly IgG2a and IgG2b; whereas in BALB/c mice, IgG1, IgG2a and IgG2b antibodies. Immunization with the pCMV\|SjC97 in C\-\{57\}BL/6 mice could confer significant worm reduction rate (35\^5%-41\^4%,P<0\^05) and egg reduction rate (liver:44\^5%-59\^6%, P<0\^05; spleen:56\^7%-82\^4%, P<0\^05; intestines:57\^9%, P<0\^05), but not in BALB/c mice. CONCLUSION: The nucleic acid vaccine, pCMV\|SjC97, could induce protective immunity in C\-\{57\}BL/6 mice significantly.