Immunoproteomic analysis of proteins from unsporulated Oocysts of Eimeria tenella in MALDI TOF/TOF tandem mass spectrometry

Authors: Li, Charles; LIU, LIHENG - Jiangxi Agricultural University; ZHENCHAO, ZHANG - Henan Institute Of Science And Technology; SHUAI, WANG - Henan Institute Of Science And Technology

Submitted to: Parasite
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/6/2017
Publication Date: 12/1/2017
Citation: Li, C.Z., Liu, L., Zhenchao, Z., Shuai, W. 2017. Immunoproteomic analysis of proteins from unsporulated Oocysts of Eimeria tenella in MALDI TOF/TOF tandem mass spectrometry. Parasite. 24:48.

Interpretive Summary: Poultry food industry is facing the challenges from the increasing cost due to control of infectious diseases, among which one of top enteric diseases is coccidiosis. Coccidiosis is caused by several kinds of intestinal parasites called Eimeria spp, which result in gut damage, weight loss, the production underperformance, and impacts animal welfare with estimated economic loss of 2 billion annually in USA poultry industry. Among the Eimeria parasites, Eimeria tenella species is the most virulent. Although Eimeria is currently controlled by the prophylactic medication as an in-feed supplement, increasing pressure from government regulation and appearance of the drug resistant parasites will force the poultry industry to consider alternative strategies to control this disease. Before effective alternative solution to drugs is sought, the parasite components of immune importance and disease-causing mechanism needs to be elucidated. In collaboration with agricultural scientists in China, the ARS scientists joined the efforts in analyzing the protein components of parasite Eimeria tenella which cross-react with antiserum specific for this parasite and were detected with advanced analytic instruments. Dozens of individual proteins from the parasite oocytes were identified with separation via gel electrophoresis, mass spectrometry platform and comparison with a protein database. These valuable data will help scientists further understand the parasite biology, vaccine targets and infection mechanisms in disease-causing and immune evasion, and lead them to develop effective vaccines to contain parasite infections.

Technical Abstract: Immunoproteomic approaches were conducted to identify antigenic proteins from the total proteins of unsporulated oocysts of Eimeria tenella (E. tenella). Approximately 101 protein spots were recognized by chicken sera infected experimentally with E. tenella. Fourty-six spots of unsporulated oocysts were excised from preparative gels and identified by matrix-assisted laser desorption ionization time-of-flight MS (MALDI-TOF-MS) and MALDI-TOF-TOF-MS. For unsporulated oocysts, fourteen known proteins of Eimeria tenella and 17 homologous proteins to other apicomplexan or protozoan parasites were identified using 'Mascot' server. These proteins included: lactate dehydrogenase, enolase, actin depolymerizing factor (ADF), immunoglobulin heavy chain binding protein, pyruvate kinase (PK), tubulin beta chain (Beta-tubulin) and hypothetical protein of E. tenella, heat shock protein of Eimeria acervulina, several hypothetical proteins of Paramecium tetraurelia, 6-phosphofructokinase and an hypothetical protein of Plasmodium vivax, PfmpC and an hypothetical protein of Plasmodium falciparum 3D7 and polyadenylate-binding protein 2 and several hypothetical proteins of Tetrahymena thermophila SB210. The remaining proteins were searched against the E. tenella protein sequence database using 'Mascot in-house' (version 2.1) search engine in automated mode, and 12 unknown proteins were identified. The amino acid sequence of the unknown proteins were searched using BLAST against non-redundant sequence databases (NCBI), and 9 homologous proteins in unsporulated oocyst were found homologous to proteins of other apicomplexan parasites. These findings provided some evidence for understanding parasitic biology, pathopoiesis, immunologenicity and immune evasion mechanisms of E. tenella. Keywords: E. tenella; unsporulated oocysts; immunoproteome