title: Molecular characterization of a new Babesia bovis thrombospondin-related anonymous protein (BbTRAP2).
abstract: A gene encoding a Babesia bovis protein that shares significant degree of similarity to other apicomplexan thrombospondin-related anonymous proteins (TRAPs) was found in the genomic database and designated as BbTRAP2. Recombinant protein containing a conserved region of BbTRAP2 was produced in E. coli. A high antigenicity of recombinant BbTRAP2 (rBbTRAP2) was observed with field B. bovis-infected bovine sera collected from geographically different regions of the world. Moreover, antiserum against rBbTRAP2 specifically reacted with the authentic protein by Western blot analysis and an indirect fluorescent antibody test. Three bands corresponding to 104-, 76-, and 44-kDa proteins were identified in the parasite lysates and two bands of 76- and 44-kDa proteins were detected in the supernatant of cultivated parasites, indicating that BbTRAP2 was proteolytically processed and shed into the culture. Apical and surface localizations of BbTRAP2 were observed in the intracellular and extracellular parasites, respectively, by confocal laser microscopic examination. Moreover, native BbTRAP2 was precipitated by bovine erythrocytes, suggesting its role in the attachment to erythrocytes. Furthermore, the specific antibody to rBbTRAP2 inhibited the growth of B. bovis in a concentration-dependent manner. Consistently, pre-incubation of the free merozoites with the antibody to rBbTRAP2 resulted in an inhibition of the parasite invasion into host erythrocytes. Interestingly, the antibody to rBbTRAP2 was the most inhibitive for the parasite's growth as compared to those of a set of antisera produced against different recombinant proteins, including merozoite surface antigen 2c (BbMSA-2c), rhoptry-associated protein 1 C-terminal (BbRAP-1CT), and spherical body protein 1 (BbSBP-1). These results suggest that BbTRAP2 might be a potential candidate for development of a subunit vaccine against B. bovis infection.
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
authors.forename: Mohamad Alaa
authors.initials: MA
authors.lastname: Terkawi
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
authors.forename: Jadsada
authors.initials: J
authors.lastname: Ratthanophart
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan ; Department of Animal Medicine and Infectious Diseases, Faculty of Veterinary Medicine, Sadat City University, Minoufiya, Egypt.
authors.forename: Akram
authors.initials: A
authors.lastname: Salama
authors.affiliation: Department of Parasitology, Faculty of Veterinary Medicine, Sadat City University, Minoufiya, Egypt.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: AbouLaila
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
authors.forename: Masahito
authors.initials: M
authors.lastname: Asada
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Ueno
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
authors.forename: Hend
authors.initials: H
authors.lastname: Alhasan
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
authors.forename: Azirwan
authors.initials: A
authors.lastname: Guswanto
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
authors.forename: Tatsunori
authors.initials: T
authors.lastname: Masatani
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
authors.forename: Naoaki
authors.initials: N
authors.lastname: Yokoyama
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Nishikawa
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
authors.forename: Xuenan
authors.initials: X
authors.lastname: Xuan
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Igarashi
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000494:pharmacology; D016793:Babesia bovis / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D002417:Cattle; D015800:Protozoan Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D016052:Protozoan Vaccines / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism
chemical_list: D000913:Antibodies, Protozoan; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; D011994:Recombinant Proteins; C069428:thrombospondin-related adhesive protein, protozoan