Identification of the antigenic region of Neospora caninum dense granule protein 7 using ELISA. Issue 6 (December 2018)

• Record Type: Journal Article
• Authors: Abdelbaky, Hanan H.; Fereig, Ragab M.; Nishikawa, Yoshifumi
• Is Part Of: Parasitology international. Volume 67:Issue 6(2018:Dec.)
• Page Start: 675
• Page End: 678
• Publication Date: 2018-12
• Subjects: Neospora caninum -- Antigenicity -- Dense granule protein 7 -- Dog -- Cattle; Parasitology -- Periodicals; Parasites -- Periodicals; Parasitic Diseases -- Periodicals; Parasitology -- Periodicals; Parasitologie -- Périodiques; 571.99905
• DOI: 10.1016/j.parint.2018.06.012
• Languages: English
• ISSNs: 1383-5769

Abstract

Abstract: Dense granule protein 7 (NcGRA7) is a potent diagnostic antigen of Neospora caninum. Some studies have reported on the difficult expression, low yield, and variable degree of solubility of recombinant NcGRA7. We aimed to unravel the possible causes for these issues and tested NcGRA7 antigenicity in enzyme linked immunosorbent assays (ELISAs). The NcGRA7 coding sequence (217 amino acids) was split into five amino acid regions: NcGRA7m (27–217), NcGRA7m3 (27–160), NcGRA7m4 (27–135), NcGRA7m5 (161–190), and NcGRA7m6 (188–217). Three fragments, NcGRA7m, NcGRA7m3 and NcGRA7m4, exhibited high antigenic properties when tested against experimentally-infected mice and dog sera by ELISA. High levels of IgG2 antibodies against NcGRA7m3 were observed in field dog sera. In experimentally and naturally-infected cattle, the N. caninum -specific sera only reacted with NcGRA7m, indicating that this antigenic region differs among the three animal species. This study presents valuable information about the antigenic properties and topology of NcGRA7, and highlights its suitability for diagnostic purposes. Graphical abstract: Highlights: The NcGRA7 coding sequence was split into five fragments for protein expression. Antisera from mice, dogs and cattle to Neospora caninum were tested against NcGRA7 fragments. The whole sequence without the signal peptide encodes the highly antigenic region. The C-terminal protein fragments were not antigenic. NcGRA7 protein fragment antigenicity varied according to the animal species tested.