日本血吸虫DNA疫苗pCDSj32在小鼠皮肤组织内的表达及其保护性免疫效果观察

INTRADERMAL IMMUNIZATIOM WITH DNA VACCINE pCD SjWTHZ32 FOR SCHISTOSOMIASIS JAPONICA AND ITS EFFICACY OF PROTECTIVE IMMUNITY

目的用皮内基因免疫注射的方法定位显示重组质粒ｐＣＤＳｊ３２在皮肤细胞的表达及其诱发小鼠抗日本血吸虫尾蚴攻击感染的保护性免疫效果。方法用生理盐水做媒体，将大量制备的质粒ｐＣＤＳｊ３２溶至１００μｇ／１００μ１，于小鼠尾根部远端１～２ｃｍ处进行皮内注射，４ｗｋ后取注射部位皮肤，石蜡包埋、切片，用间接免疫荧光法和免疫组化技术观察ｐＣＤＳｊ３２在皮肤细胞的表达。对照组和１００μｇ／１００μ１ｐＣＤＳｊ３２单剂量免疫组小鼠各１０只，于免疫后４ｗｋ，分别用４０条日本血吸虫尾蚴攻击感染，计数成虫数和每克肝组织虫卵数。结果ｐＣＤＳｊ３２皮内免疫注射后，可在朗罕细胞、表皮的角质形成细胞、真皮的成纤维细胞和毛囊基底细胞的胞浆内表达，表达产物具有免疫原性。与对照组相比，１００μｇ／１００μ１ｐＣＤＳｊ３２单剂量免疫后４ｗｋ，可产生较好的保护效果，减成虫率达３８．３０％，肝脏组织减虫卵率为５６．０１％。结论首次用皮内基因免疫的方法证明日本血吸虫ＤＮＡ疫苗ｐＣＤＳｊ３２可在皮肤多种细胞内表达，并可诱导小鼠产生较强的抗血吸虫感染的保护力。该免疫方法是继肌肉免疫注射之后又一种颇为有效的基因免疫途径，它将为抗血吸虫感染免疫提供一种模拟生理?

Aim To demonstrate intradermal expression and to observe the protective immunity after inoculation with recombinant DNA vaccine pCD Sj 32 for Schistosomiasis japonica in mice,the method of intradermal gene immunization was used. Methods Largescale preparation of pCDSj32 was dissolved to 100 g/100 l using normal saline as solvent,then intradermal injection was performed 12cm from the root end of the tail in mice.4wk post inoculation,the skins were cut,paraffinned and sectioned.The expressed results were observed using IFA and immunohistochemistry.10 mice were vaccinated with single dosage of 100 g pCD Sj 32 plasmid.The immunized group and the control were challenged with 40 cercariae simultaneously 4wk after injection of pCD Sj 32.The adult worms as well as the eggs from the liver tissues of mice were counted. Results The recombinant 32kDa protein was expressed in the plasma of keratinocytes,Langerhan's cells,fibroblasts, and hairfollicles under the epidermis or in the dermis.The expressed product possesses antigenicity.Mice immunized intradermally with a single dosage of 100g pCD Sj32 the adult worm burdens and EPG in the livers reduced 38.30% and 56.01%respectively when challenged with 40 cercariae after the vaccination. Conclusion The results confirmed that DNA vaccine pCDSj32 for Schistosomiasis japonica was expressed in some kinds of cells under the epidermis or in the dermis with the method of intradrmal gene immunization.Protective immunity against the infection of Schistosoma japonicum could be induced by the expressed product.The similar report has not been seen by now. Intradermal gene immunization is another way following the intramuscular gene injection,and it would be expected to provide an efficient route for gene immunization that mimics a physiologic response to the infection of Schistosoma.