血吸虫生殖产卵相关基因pcDNA3/Sj SDISP DNA在小鼠体内的组织分布及整合的观察

Observations on the tissue distribution and potential intergration to the host genome in mice inoculated with DNA vaccine (recombinant plasmid pcDNA3/SjSDISP) associated with fecundity of Schisosoma japonicum

目的探讨日本血吸虫生殖产卵相关基因DNA在小鼠体内组织分布以及整合到宿主基因组上的可能性。方法将生殖产卵相关基因重组质粒pcDNA3/Sj SDISP经肌注免疫小鼠后,在注射后12h、1w、3w和6w取小鼠各组织,抽提其基因组DNA进行PCR扩增,然后纯化基因组DNA进行PCR扩增,结果经琼脂糖凝胶电泳分析。结果注射后12h,在血液、心、肝、脾、肺、肾及注射部位肌肉中可检测到pcDNA3/Sj SDISP,至第1w,仍可在部分小鼠中检测到,至第3w不再检出。未发现生殖产卵相关基因pcDNA3/Sj SDISP整合入小鼠基因组中。结论肌注pcDNA3/Sj SDISP后,可在组织中广泛分布,但并未持续存在体内。未发现与宿主细胞基因组整合的直接证据。

To investigate the tissue distribution of the fecundity associated genes and the possibility of integration of these genes to the host genome in mice immunized with DNA vaccine pcDNA3/SjSDISP, this recombinant plasmid was injected to mice by intra muscular route and various tissues were removed from the immunized mice at 12 hours, 1, 3 and 6 weeks after immunization. The total tissue I）NAs were extracted and amplified by PCR. Then, the genomie DNA of host cells was purified from the non-integrated free-plasmid for PCR amplification and the results were identified by agarose gel electrophoresis, It was found that the plasmid DNA pcDNA3/SjSDISP could be detected in blood, heart, liver, spleen and the injected muscle loci 12 hours after immunization. It could be detected in some mice one week later but disappeared completely 3 weeks post-inoculation. In addition,there was no sign of integration of the recombinant plasmid into mouse genome. It is evident that the recombinant plasmid pcDNA3/SiSIDISP distributes in a broad range of tissues after intramuscular injection, but it exists only for a limited period of time in vivo. There is no direct evidence of danger that the recombinant plasmid can integrate to the host genome.