Babesia microti: molecular and antigenic characterizations of a novel 94-kDa protein (BmP94).
A novel gene, BmP94, encoding 94-kDa protein of Babesia microti was identified by immunoscreening of the cDNA expression library. The full-length of BmP94 was expressed in Escherichia coli (rBmP94), which resulted in insoluble form with low yield, and the truncated hydrophilic C-terminus region of the gene was expressed as a soluble protein (rBmP94/CT) with improved productivity. Antiserum raised against rBmP94/CT recognized the 94-kDa native protein in the parasite extract by Western blot analysis. Next, an ELISA using rBmP94/CT was evaluated for diagnostic use, and it demonstrated high sensitivity and specificity when tested with the sera from mice experimentally infected with B. microti and closely related parasites. Moreover, the immunoprotective property of rBmP94/CT as a subunit vaccine was evaluated in BALB/c mice against a B. microti challenge, but no significant protection was observed. Our data suggest that the immunodominant antigen BmP94 could be a promising candidate for diagnostic use for human babesiosis.
Ooka
Hideo
H
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
Terkawi
Mohamad Alaa
MA
Goo
Youn-Kyoung
YK
Luo
Yuzi
Y
Li
Yan
Y
Yamagishi
Junya
J
Nishikawa
Yoshifumi
Y
Igarashi
Ikuo
I
Xuan
Xuenan
X
D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology*; D041001:Babesia microti / Q000235:genetics / Q000276:immunology*; D001404:Babesiosis / Q000175:diagnosis* / Q000517:prevention & control; D015153:Blotting, Western; D004195:Disease Models, Animal; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007106:Immune Sera / Q000276:immunology; D016056:Immunodominant Epitopes / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008813:Mice, Inbred ICR; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D016052:Protozoan Vaccines / Q000235:genetics / Q000276:immunology; D012680:Sensitivity and Specificity; D014611:Vaccination; D022223:Vaccines, Subunit / Q000235:genetics / Q000276:immunology
D000953:Antigens, Protozoan; D007106:Immune Sera; D016056:Immunodominant Epitopes; D016052:Protozoan Vaccines; D022223:Vaccines, Subunit