title: Molecular and immunological characterization of Babesia gibsoni and Babesia microti heat shock protein-70.
abstract: Serological immunoscreening was used to identify a gene encoding heat shock protein-70 from Babesia gibsoni (BgHSP-70) that showed high homology with HSP-70s from other apicomplexan parasites. This gene corresponded to a full-length cDNA containing an open reading frame of 1968 bp predicted to result in a 70-kDa mature protein consisting of 656 amino acids. Analysis of the expression levels of BgHSP-70 indicated elevated transcription from cultured parasites incubated at 40 degrees C for 1 h, but not at 30 degrees C. Interestingly, antiserum raised against recombinant BgHSP-70 protein reacted specifically not only with a 70-kDa protein of B. gibsoni but also with a corresponding native protein of B. microti (BmHSP-70), indicating the high degree of conservation of this protein. The BmHSP-70 gene was then isolated and characterized and the immunoprotective properties of recombinant BgHSP-70 (rBgHSP-70) and rBmHSP-70 were compared in vitro and in vivo. Both proteins had potent mitogenic effects on murine and canine mononuclear cells as evidenced by high proliferative responses and IFN-gamma production after stimulation. Immunization regimes in BALB/c and C57BL/6 mice using rBgHSP-70 and rBmHSP-70 elicited high antibody levels, with concurrent significant reductions in peripheral parasitaemias. Taken together, these results emphasize the potential of HSP-70s as a molecular adjuvant vaccine.
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, Japan.
authors.forename: M Alaa
authors.initials: MA
authors.lastname: Terkawi
authors.forename: G
authors.initials: G
authors.lastname: Aboge
authors.forename: H
authors.initials: H
authors.lastname: Jia
authors.forename: Y-K
authors.initials: YK
authors.lastname: Goo
authors.forename: H
authors.initials: H
authors.lastname: Ooka
authors.forename: J
authors.initials: J
authors.lastname: Yamagishi
authors.forename: Y
authors.initials: Y
authors.lastname: Nishikawa
authors.forename: N
authors.initials: N
authors.lastname: Yokoyama
authors.forename: I
authors.initials: I
authors.lastname: Igarashi
authors.forename: S-I
authors.initials: SI
authors.lastname: Kawazu
authors.forename: K
authors.initials: K
authors.lastname: Fujisaki
authors.forename: X
authors.initials: X
authors.lastname: Xuan
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan; D001403:Babesia / Q000235:genetics* / Q000276:immunology*; D041001:Babesia microti / Q000235:genetics / Q000276:immunology; D049109:Cell Proliferation; D002478:Cells, Cultured; D016054:DNA, Protozoan / Q000235:genetics; D004285:Dogs; D020869:Gene Expression Profiling; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology*; D006358:Hot Temperature; D007371:Interferon-gamma / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008970:Molecular Weight; D016366:Open Reading Frames; D018512:Parasitemia / Q000517:prevention & control; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology*; D016052:Protozoan Vaccines / Q000276:immunology; D014614:Vaccines, Synthetic / Q000276:immunology
chemical_list: D000913:Antibodies, Protozoan; D016054:DNA, Protozoan; D018840:HSP70 Heat-Shock Proteins; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; D014614:Vaccines, Synthetic; D007371:Interferon-gamma