2007 Fiscal Year Final Research Report Summary
Comprehensive screening and identification of the novel malaria transmission-blocking vaccine candidate antigens
Project/Area Number |
18390129
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Parasitology (including Sanitary zoology)
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Research Institution | Ehime University |
Principal Investigator |
TSUBOI Takafumi Ehime University, Cell-free Science and Technology Research Center, Professor (00188616)
|
Co-Investigator(Kenkyū-buntansha) |
TAKEO Satoru Ehime University, Cell-free Science and Technology Research Center, Senior Assistant Professor (40302666)
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Project Period (FY) |
2006 – 2007
|
Keywords | malaria / vaccine / infectious diseases / biotechnology / genome / International scientist exchange / Thailand |
Research Abstract |
Malaria transmission-blocking vaccines (TBVs) prevent the transmission of malaria by inducing antibodies against antigens specifically expressed on the sexual stage parasites. Since well-characterized TBV candidates are only four, it would be necessary to identify novel TBV candidates for a successful TBV development. In order to identify the novel TBV candidates, we searched a combined dataset from genome and transcriptome databases and selected 192 genes, which are expected to be expressed only in gametocyte stage of P. falciparum. These genes were cloned into plasmids and 170 of the template cDNA clones 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 148 recombinant proteins. After the screening of these recombinant proteins to identify novel TBV candidates with malaria patient sera harboring parasite transmission-blocking antibodies, we have identified 27 novel antigens. After subclone these candidate genes into pEU plasmid for the large-scale expression using the wheat germ cell-free system, we have expressed and affinity purified 22 targets. In order to obtain antisera, we immunized these proteins into mice. After the confirmation of the immunoreactivity of these antisera against parasites, we examined the transmission-blocking efficacy of the sera. Finally we identified the two novel parasite antigens, which induced transmission-blocking antibodies in mice. Accordingly, this approach will be useful for the novel transmission-blocking vaccine candidate discovery.
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Research Products
(8 results)