title: A new malaria antigen produces partial protection against Plasmodium yoelii challenge.
abstract: Of all the parasitic diseases, malaria is the number one killer. Despite tremendous efforts in disease control and research, nearly a million people, primarily children, still die from the disease each year, partly due to drug resistance and the lack of an effective vaccine. Many parasite antigens have been identified and evaluated for vaccine development; however, none has been approved for human use. Antigenic variation, complex life cycle, and inadequate understanding of the mechanisms of parasite-host interaction and of host immune response all contribute to the lack of an effective vaccine for malaria control. In a recent search of genome-wide polymorphism in Plasmodium falciparum, several molecules were found to be recognized by sera from patients infected with the P. falciparum parasite. Here, we have expressed a 350-amino acid N terminus from one of the homologous candidate antigen genes from the rodent malaria parasite Plasmodium yoelii (Py01157, a putative dentin phosphorin) in bacteria and evaluated the immune response and protection generated after immunization with the recombinant protein. We showed that the recombinant protein was recognized by sera from both mice and humans infected with malaria parasites. Partial protection was observed after challenge with non-lethal P. yoelii 17XNL but not with the lethal P. yoelii 17XL parasite. Further tests using a full-length protein or the conserved C terminus may provide additional information on whether this protein has the potential for being a malaria vaccine.
authors.affiliation: State Key Laboratory of Stress Cell Biology, Xiamen University, 422 Siming South Road, Xiamen, Fujian 361005, People's Republic of China.
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yanwei
authors.initials: Y
authors.lastname: Qi
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.forename: Shengfa
authors.initials: S
authors.lastname: Liu
authors.forename: Lingxian
authors.initials: L
authors.lastname: Hong
authors.forename: Tianlong
authors.initials: T
authors.lastname: Lin
authors.forename: Carole
authors.initials: C
authors.lastname: Long
authors.forename: Xin-Zhuan
authors.initials: XZ
authors.lastname: Su
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology*; D015153:Blotting, Western; D003001:Cloning, Molecular; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007114:Immunization; D008288:Malaria / Q000276:immunology / Q000469:parasitology / Q000517:prevention & control*; D017780:Malaria Vaccines / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010967:Plasmodium yoelii / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D017422:Sequence Analysis, DNA
chemical_list: D000953:Antigens, Protozoan; D017780:Malaria Vaccines; D015800:Protozoan Proteins; D011994:Recombinant Proteins