Characterization of the Babesia gibsoni 12-kDa protein as a potential antigen for the serodiagnosis.
A novel gene, BgP12, encoding a 12-kDa protein was identified from Babesia gibsoni. The full-length cDNA of BgP12 contains an open reading frame of 378 bp, corresponding to 126 amino acid (aa) residues consisting of a putative 26 aa signal peptide and a 100 aa mature protein. The recombinant BgP12 (rBgP12) lacking the N-terminal signal peptide was expressed in Escherichia coli as a soluble glutathione S-transferase (GST) fusion protein (rBgP12) that produced an anti-rBgP12 serum in mice after immunization. Using this anti-rBgP12 serum, a native 12-kDa protein in B. gibsoni was recognized by Western blot analysis. Immunofluorescent antibody tests (IFAT) revealed that BgP12 was mainly seen during the ring stage of B. gibsoni trophozoite. An indirect enzyme-linked immunosorbent assay (ELISA) using the rBgP12 detected specific antibodies in the sequential sera of a dog experimentally infected with B. gibsoni beginning 10 days post-infection to 442 days post-infection, even when the dog became chronically infected and showed a low level of parasitemia. Moreover, the antigen did not show cross-reaction with antibodies to the closely related apicomplexan parasites, indicating that the rBgP12 might be an immunodominant antigen for B. gibsoni infection that could be used as a diagnostic antigen for B. gibsoni infection with high specificity and sensitivity.
Goo
Youn-Kyoung
YK
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan. s01152@st.obihiro.ac.jp
Jia
Honglin
H
Aboge
G Oluga
GO
Terkawi
M Alaa
MA
Lee
Eung-goo
EG
Yamagishi
Junya
J
Nishikawa
Yoshifumi
Y
Jang
Hyung-Kwan
HK
Sunaga
Fujiko
F
Namikawa
Kazuhiko
K
Fujisaki
Kozo
K
Xuan
Xuenan
X
D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D001403:Babesia / Q000145:classification / Q000254:growth & development / Q000276:immunology*; D001404:Babesiosis / Q000175:diagnosis / Q000276:immunology / Q000469:parasitology / Q000662:veterinary*; D001483:Base Sequence; D003001:Cloning, Molecular; D004283:Dog Diseases / Q000175:diagnosis* / Q000276:immunology / Q000469:parasitology; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D008969:Molecular Sequence Data; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D017422:Sequence Analysis, DNA; D012698:Serologic Tests
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D015800:Protozoan Proteins; D011994:Recombinant Proteins