Genome-wide screening of the novel malaria transmission-blocking vaccine candidates

对新型疟疾传播阻断候选疫苗进行全基因组筛选

基本信息

批准号：
16390125
负责人：
TSUBOI Takafumi
金额：
$ 9.6万
依托单位：
Ehime University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16390125/
关键词：
malaria vaccine genome-wide recombinant protein synthesis transmission-blocking International scientist exchange Thailand

项目摘要

Malaria remains one of the leading causes of both morbidity and mortality of humans residing in the tropical countries. The evidence of increasing resistance of the Plasmodium falciparum parasite to chemotherapeutic agents, such as chloroquine, highlights the critical need for an effective vaccine. However, the effective malaria vaccine has never been achieved to date. Since the genomic sequence of P.falciparum together with stage-specific proteome data was completed in October 2002, we have now free access to the genome data to search for novel vaccine candidates. However, one of the bottlenecks for the vaccine development is the high AT content in exons of P.falciparum, which will considerably inhibit the recombinant protein expression using conventional methods. Our strategy is to express recombinant proteins for the characterization of each protein based on the genome sequences of P.falciparum without using synthetic gene. Transmission-blocking vaccines (TBVs) prevent the transmiss … More ion of malaria by inducing antibodies against antigens specifically expressed on the sexual stage parasites. Since well-characterized TBV candidates are only four (Pfs25, Pfs28, Pfs48/45, and Pfs230), it would be necessary to prepare novel TBV candidates as many as possible for a successful TBV development. In order to identify the novel TBV candidates, we searched a combined dataset from genome and transcriptome databases and we selected 192 genes, which are expected to be expressed only in gametocyte stage of P.falciparum. These genes were cloned into plasmids and templates were prepared for transcription through PCR-based procedures, followed by high throughput recombinant protein synthesis by wheat germ cell-free system. Using this approach, we succeeded in obtaining 120 recombinant proteins. After the screening of these recombinant proteins to identify novel TBV candidates with anti-gametocyte monoclonal antibodies, we have identified a novel antigen expressed on the surface of gametocyte stage. Less

疟疾仍然是热带国家人类发病和死亡的主要原因之一。恶性疟原虫对氯喹等化疗药物的耐药性不断增强，这凸显了对有效疫苗的迫切需要。自从 2002 年 10 月完成了恶性疟原虫的基因组序列以及特定阶段的蛋白质组数据以来，迄今为止尚未实现有效的疟疾疫苗，我们现在可以免费获取。然而，疫苗开发的瓶颈之一是恶性疟原虫外显子中的高AT含量，这将显着抑制使用常规方法的重组蛋白表达。基于恶性疟原虫基因组序列的蛋白质来表征每种蛋白质，而不使用合成基因，通过诱导针对特定表达的抗原的抗体来防止疟疾的传播。由于特征明确的 TBV 候选者只有四种（Pfs25、Pfs28、Pfs48/45 和 Pfs230），因此有必要准备尽可能多的新 TBV 候选者，以便成功开发 TBV。为了确定新的 TBV 候选者，我们从基因组和转录组数据库中搜索了组合数据集，并选择了 192 个基因，这些基因预计仅在配子体阶段表达将这些基因克隆到质粒中，并通过基于 PCR 的程序制备转录模板，然后通过小麦胚芽无细胞系统进行高通量重组蛋白合成，之后我们成功获得了 120 种重组蛋白。通过筛选这些重组蛋白，用抗配子体单克隆抗体鉴定新的 TBV 候选物，我们鉴定出了在配子体阶段表面表达的新抗原。