Vaccination with Eimeria tenella Elongation Factor-1alpha Recombinant Protein Induces protective Immunity against E. tenella and E. maxima infections

Authors: LIN, RUI QING - South China Agricultural University; Lillehoj, Hyun; LEE, SEUNG - Kangwon National University; OH, SUNGTAEK - Konkuk University; Panebra, Alfredo; LILLEHOJ, ERICK - University Of Maryland

Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/2/2017
Publication Date: 6/7/2017
Publication URL: http://handle.nal.usda.gov/10113/5706603
Citation: Lin, R.Q., Lillehoj, H.S., Lee, S.K., Oh, .S, Panebra, A., Lillehoj, E.P. 2017. Vaccination with Eimeria tenella Elongation Factor-1a Recombinant Protein Induces Protective Immunity against E. tenella and E. maxima Infections. Veterinary Parasitology. 243:79-84.

Interpretive Summary: Coccidiosis is caused by several distinct Eimeria species that primarily infect the intestine of poultry with significant negative consequences on gut function. Coccidiosis costs US industry more than $3.2 billion economic loss and there is no effective treatment method other than live vaccines and drugs. Therefore ability to control the coccidiosis effectively will have a significant impact in poultry industry and reduce the use of antibiotics in poultry production. In this paper, ARS scientists and scientists in China collaborated in a research that led to the identification of a new vaccine antigen of Eimeria parasites that strongly promoted host protective immune response against avian coccidiosis. In order to test the effectiveness of this vaccine, the authors cloned the new gene called chicken EF1alpha and produced a large amount of recombinant protein to test in chickens. When young birds were immunized with this protein right after hatch, they showed a strong protective immunity against coccidiosis challenge infection and produced high levels of antibodies against this protein. Furthermore, vaccination of young birds with this vaccine induced a significant protection against live parasite challenge infection and protected the vaccinated birds against coccidiosis-induced body weight loss. These results show that Eimeria EF-1alpha protein may represent a potential vaccine antigen that can protect against ill effects of avian coccidiosis in the field.

Technical Abstract: Avian coccidiosis is caused by multiple species of the apicomplexan protozoan, Eimeria, and is one of the most economically devastating enteric diseases for the poultry industry worldwide. Host immunity to Eimeria infection, however, is relatively species-specific. The ability to immunize chickens against different species of Eimeria using a single vaccine will have a major beneficial impact on commercial poultry production. In this paper, we describe the molecular cloning, purification, and vaccination efficacy of a novel Eimeria vaccine candidate, elongation factor-1a (EF-1a). One day-old broiler chickens were given two subcutaneous immunizations one week apart with E. coli-expressed E. tenella recombinant (r)EF-1a protein and evaluated for protection against challenge infection with E. tenella or E. maxima. rEF-1a-vaccinated chickens exhibited increased body weight gains, decreased fecal oocyst output, and greater serum anti-EF-1a antibody levels following challenge infection with either E. tenella or E. maxima compared with unimmunized controls. Vaccination with EF-1a may represent a new approach to inducing cross-protective immunity against avian coccidiosis in the field. Key words: Chicken; Eimeria; EF-1a; coccidiosis, immune protection