title: Embryo vaccination against Eimeria tenella and E. acervulina infections using recombinant proteins and cytokine adjuvants.
abstract: Avian coccidiosis is an intestinal disease caused by protozoa of the genus Eimeria. To investigate the potential of recombinant protein vaccines to control coccidiosis, we cloned 2 Eimeria sp. genes (EtMIC2 and 3-1E), expressed and purified their encoded proteins, and determined the efficacy of in ovo immunization to protect against Eimeria infections. Immunogen-specific serum antibody titers, parasite fecal shedding, and body weight gains were measured as parameters of disease. When administered alone, the recombinant EtMIC2 gene product induced significantly higher antibody responses, lower oocyst fecal shedding, and increased weight gains compared with nonvaccinated controls following infection with E. tenella. Combined embryo immunization with the EtMIC2 protein plus chicken cytokine or chemokine genes demonstrated that all 3 parameters of vaccination were improved compared with those of EtMIC2 alone. In particular, covaccination with EtMIC2 plus interleukin (IL)-8, IL-16, transforming growth factor-beta4, or lymphotactin significantly decreased oocyst shedding and improved weight gains beyond those achieved by EtMIC2 alone. Finally, individual vaccination with either EtMIC2 or 3-1E stimulated protection against infection by the heterologous parasite E. acervulina. Taken together, these results indicate that in ovo vaccination with the EtMIC2 protein plus cytokine/chemokine genes may be an effective method to control coccidiosis.
authors.affiliation: Animal Parasitic Diseases Laboratory, Animal and Natural Resources Institute, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland 20705, USA. hlilleho@anri.barc.usda.gov
authors.forename: Hyun S
authors.initials: HS
authors.lastname: Lillehoj
authors.forename: Xicheng
authors.initials: X
authors.lastname: Ding
authors.forename: Rami A
authors.initials: RA
authors.lastname: Dalloul
authors.forename: Takanori
authors.initials: T
authors.lastname: Sato
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yasuda
authors.forename: Erik P
authors.initials: EP
authors.lastname: Lillehoj
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D002642:Chick Embryo / Q000276:immunology*; D002645:Chickens / Q000469:parasitology*; D003048:Coccidiosis / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D016207:Cytokines / Q000235:genetics / Q000276:immunology; D004539:Eimeria / Q000276:immunology*; D016786:Eimeria tenella / Q000276:immunology; D007117:Immunization, Secondary / Q000662:veterinary; D010063:Ovum / Q000276:immunology; D011201:Poultry Diseases / Q000276:immunology / Q000517:prevention & control*; D016052:Protozoan Vaccines / Q000008:administration & dosage*; D013047:Specific Pathogen-Free Organisms; D014611:Vaccination / Q000379:methods / Q000662:veterinary; D019444:Vaccines, DNA / Q000008:administration & dosage; D014614:Vaccines, Synthetic / Q000008:administration & dosage
chemical_list: D000913:Antibodies, Protozoan; D016207:Cytokines; D016052:Protozoan Vaccines; D019444:Vaccines, DNA; D014614:Vaccines, Synthetic