弓形虫表面抗原P30 DNA疫苗免疫小鼠诱导体液免疫应答及保护性的初步观察

目的观察弓形虫表面抗原P30 DNA疫苗免疫BALB/c小鼠诱导其体内产生的体液免疫应答及抗虫感染的免疫保护作用. 方法重组质粒pBK-P30用生理盐水稀释后,肌注免疫BALB/c小鼠.分别于免疫后5周和10周,ELISA测定IgG抗体滴度;取免疫鼠的血液、肺、心脏、肝脏、脾、肾脏及肌肉PCR扩增P30基因;免疫鼠腹腔注射弓形虫速殖子攻击感染.结果两次检测,均可测到特异性IgG抗体,且抗体的滴度随免疫时间的延长而增高;免疫后5周,免疫鼠的上述组织均可扩增出P30基因条带,但免疫后10周仅血液扩增出特异P30基因条带;弓形虫速殖子腹腔攻击感染,免疫组鼠的平均存活时间较对照组鼠延长,但统计学差异不显著(P＞0.05). 结论弓形虫表面抗原P30 DNA疫苗能诱导BALB/c小鼠产生特异性体液免疫应答及部分抗虫免疫保护作用.

STUDY ON THE HUMORAL AND PROTECTIVE IMMUNE RESPONSES INDUCED BY P30 DNA VACCINE OF TOXOPLASMA GONDII IN MICE

Objective To observe the humoral and protective immune responses induced by the P30 DNA vaccine of Toxoplasma gondii in mice. Methods Large scale preparation of the recombinant plasmid pBK-P30 was dissolved with normal saline and injected into BALB/c mice via muscles. After 5 and 10 weeks immunization, The IgG antibodies in serum from vaccined mice were detected by ELISA. The P30 gene from the blood, lung, heart, liver, spleen, kidney and muscle of immunized mice was detected by means of PCR. The vaccinated mice were challenged by RH tachyzoite of T. gondii through intraperitonea injection. Results Two times detected result showed that specific IgG antibody in serum from vaccinated mice could be detected and the titer of IgG gradually rose with time prolong. After 5 weeks immunization, the P30 gene had been amplified specially from different organs and tissues of immunized BALB/c mice by PCR technique, but the P30 gene fragment was only amplified specially from blood after 10 weeks immunization. The average survival time of vaccinated mice was longer than that of control groups after mice were challenged with RH tachyzoites, but there were not remarkable difference(P>0.05). Conclusion The P30 DNA vaccine of T. gondii could elicit humoral and partial immune responses against the infection of T. gondii.