We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
A novel <italic>Babesia orientalis</italic> 135-kilodalton spherical body protein like: identification of its secretion into cytoplasm of infected erythrocytes.
- Authors
Guo, Jiaying; Hu, Jinfang; Sun, Yali; Yu, Long; He, Junwei; He, Pei; Nie, Zheng; Li, Muxiao; Zhan, Xueyan; Zhao, Yangnan; Luo, Xiaoying; Liu, Junlong; He, Lan; Zhao, Junlong
- Abstract
Background: The spherical body is a distinct organelle only existing in <italic>Babesia</italic> and <italic>Theileria</italic>. Spherical body proteins (SBPs) are secreted from spherical bodies and incorporated into the cytoplasm of infected erythrocytes during invasion and post-invasion stages. Four different SBP homologues (SBP1, SBP2, SBP3 and SBP4) have been identified in <italic>Babesia bovis</italic> and <italic>Babesia bigemina</italic>. So far, there has been no report available about the identification of SBPs in <italic>Babesia orientalis</italic>. Methods: The SBP3-like in <italic>B. orientalis</italic> (BoSBP3-like) was cloned, sequenced, characterized and compared to the SBP3 sequences of <italic>B. bovis</italic> and <italic>B. bigemina</italic> by bioinformatics analyses. The BoSBP3-like gene was truncated into three fragments: BoSBP3-like-1 (915 bp), BoSBP3-like-2 (1311 bp) and BoSBP3-like-3 (1011 bp), which were amplified and cloned into the expression vector pET-28a and expressed as three truncated recombinant (His-fusion) proteins. The immunogenicity, native forms and localization of BoSBP3-like were identified by western blot and indirect immunofluorescence assay (IFA). Results: The BoSBP3-like gene was intronless with an open reading frame (ORF) of 3237 bp, encoded a 1079 amino acid polypeptide with a predicted size of 135 kDa, and contained a cysteine-rich region, three dispersing FAINT domains and a signal peptide (1–16 aa) at the N-terminus. The amino acid sequence of BoSBP3-like was 61.6 and 35.0% identical to that of <italic>B. bovis</italic> and <italic>B. bigemina</italic>, respectively. BoSBP3-like was identified as 135 kDa in the parasite lysate by rabbit antiserum against the truncated recombinant BoSBP3-like-1 (rBoSBP3-like-1). Three specific bands corresponding to rBoSBP3-like-1 (1–305 aa, 43 kDa), rBoSBP3-like-2 (306–742 aa, 58 kDa) and rBoSBP3-like-3 (743–1079 aa, 52 kDa) were detected by reaction with serum from <italic>B. orientalis-</italic>infected buffalo. The BoSBP3-like was not only localized in the spherical body of <italic>B. orientalis</italic> but also in the cytoplasm of infected erythrocytes of buffalo as puncta-like protein specks at both single and paired parasite development stages. Conclusions: Through secretion into the cytoplasm of infected erythrocytes, BoSBP3-like may play a significant role in adaptation, interaction, and modification related to the host environment to benefit the growth and survival of <italic>Babesia</italic>. BoSBP3-like could react with the serum from <italic>B. orientalis</italic>-infected buffalo, but not healthy buffalo, implicating that BoSBP3-like is highly antigenic and may serve as a candidate diagnostic antigen for the detection of <italic>B. orientalis</italic>.
- Subjects
BABESIA; CYTOPLASM; ERYTHROCYTES; SECRETION; PROTEINS; BIOINFORMATICS
- Publication
Parasites & Vectors, 2018, Vol 11, p1
- ISSN
1756-3305
- Publication type
Article
- DOI
10.1186/s13071-018-2795-7