Screening the Schistosoma mansoni transcriptome for genes differentially expressed in the schistosomulum stage in search for vaccine candidates
Screening the Schistosoma mansoni transcriptome for genes differentially expressed in the schistosomulum stage in search for vaccine candidates
复制标题
DOI：
10.1007/s00436-010-2045-1
复制
发表时间：
2011-01-01
影响因子：
2
通讯作者：
de Cerqueira Leite, Luciana Cezar
中科院分区：
文献类型：
--
作者：
Farias, Leonardo P.;Tararam, Cibele A.;de Cerqueira Leite, Luciana Cezar
血吸虫病影响全世界2亿多人；另有6亿人面临感染风险。在减毒尾蚴疫苗模型中，血吸虫期被认为是保护性免疫的目标。为了鉴定血吸虫期与尾蚴相关的上调基因，我们通过观察两个阶段EST文库中读取的相对频率，探索了曼氏血吸虫的转录组。对血吸虫中400个可能上调的基因进行了基因本体分类分析，重点分析了那些与其他生物蛋白不相似的编码预测蛋白，假设它们可能是对宿主生存重要的寄生虫特异性蛋白。用实时逆转录聚合酶链反应（RT-PCR）验证了9个选定基因中的5个（56%）在血吸虫体中相对于尾蚴的上调。我们通过DNA疫苗免疫和寄生虫攻击测试了它们在小鼠中的保护潜力。其中一种可减少16-17%的虫负荷，表明其具有保护作用。我们的研究结果表明，使用阶段相关ESTs频率作为差异表达的指示，结合DNA疫苗筛选，在鉴定有待进一步研究的潜在候选疫苗的新蛋白方面具有价值和注意事项。
Schistosomiasis affects more than 200 million people worldwide; another 600 million are at risk of infection. The schistosomulum stage is believed to be the target of protective immunity in the attenuated cercaria vaccine model. In an attempt to identify genes up-regulated in the schistosomulum stage in relation to cercaria, we explored the Schistosoma mansoni transcriptome by looking at the relative frequency of reads in EST libraries from both stages. The 400 genes potentially up-regulated in schistosomula were analyzed as to their Gene Ontology categorization, and we have focused on those encoding-predicted proteins with no similarity to proteins of other organisms, assuming they could be parasite-specific proteins important for survival in the host. Up-regulation in schistosomulum relative to cercaria was validated with real-time reverse transcription polymerase chain reaction (RT-PCR) for five out of nine selected genes (56%). We tested their protective potential in mice through immunization with DNA vaccines followed by a parasite challenge. Worm burden reductions of 16-17% were observed for one of them, indicating its protective potential. Our results demonstrate the value and caveats of using stage-associated frequency of ESTs as an indication of differential expression coupled to DNA vaccine screening in the identification of novel proteins to be further investigated as potential vaccine candidates.