Selection and identification of malaria vaccine target molecule using bioinformatics and DNA vaccination.

Abstract

Following a genome-wide search for a blood stage malaria DNA-based vaccine using web-based bioinformatic tools, 29 genes from the annotated Plasmodium yoelii genome sequence (www.PlasmoDB.org and www.tigr.org) were identified as encoding GPI-anchored proteins. Target genes were those with orthologues in P. falciparum, containing an N-terminal signal sequence containing hydrophobic amino acid stretch and signal P criteria, a transmembrane-like domain and GPI anchor motif. Focusing on the blood stage, we extracted mRNA from pRBCs, PCR-amplified 22 out of the 29 selected genes, and eventually cloned nine of these into a DNA vaccine plasmid, pVAX 200-DEST. Biojector-mediated delivery of the nine DNA vaccines was conducted using ShimaJET to C57BL/6 mice at a dose of 4 μg/mouse three times at an interval of 3 weeks. Two weeks after the second booster, immunized mice were challenged with P. y. yoelii 17XL-parasitized RBCs and the level of parasitaemia, protection and survival was assessed. Immunization with one gene (PY03470) resulted in 2-4 days of delayed onset and level of parasitaemia and was associated with increased survival compared to non-immunized mice. Antibody production was, however, low following DNA vaccination, as determined by immunofluorescence assay. Recombinant protein from this gene, GPI8p transamidase-related protein (rPyTAM) in PBS or emulsified with GERBU adjuvant was also used to immunize another set of C57BL/6 mice with 10-20 μg/mouse three times at 3-week interval. Higher antibody response was obtained as determined by ELISA with similar protective effects as observed after DNA vaccination.

• Authors: M N Shuaibu, M Kikuchi, M S Cherif, G K Helegbe, T Yanagi, K Hirayama
• Journal: Vaccine (Vaccine) Vol. 28 Issue 42 Pg. 6868-75 (Oct 04 2010) ISSN: 1873-2518 [Electronic] Netherlands
• PMID: 20709002 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2010 Elsevier Ltd. All rights reserved.

Chemical References

• Antibodies, Protozoan
• Antigens, Protozoan
• Glycosylphosphatidylinositols
• Malaria Vaccines
• Recombinant Proteins
• Vaccines, DNA

Topics

• Animals
• Antibodies, Protozoan (blood)
• Antigens, Protozoan (genetics, immunology)
• Cloning, Molecular
• Computational Biology
• Female
• Genes, Protozoan
• Glycosylphosphatidylinositols (genetics)
• Immunization, Secondary
• Malaria (immunology, prevention & control)
• Malaria Vaccines (genetics, immunology)
• Mice
• Mice, Inbred C57BL
• Plasmids
• Plasmodium yoelii (genetics)
• Recombinant Proteins (genetics, immunology)
• Vaccines, DNA (genetics, immunology)