title: Identification and characterization of a cDNA clone-encoding antigen of Eimeria acervulina.
abstract: Eimeria spp. are the causative agents of coccidiosis, a major disease affecting the poultry industry. So far, only a few antigen genes of E. acervulina have been reported. In this study, a clone, named as cSZ-JN2, was identified from a cDNA expression library prepared from E. acervulina sporozoite stage with the ability to stimulate the chicken immune response. The sequence analysis showed that the open reading fragment (ORF) of cSZ-JN2 was 153 bp in size and encoded a predicted protein of 50 amino acids of Mr 5·3 kDa. BLASTN search revealed that cSZ-JN2 had no significant homology with the known genes of E. acervulina or any other organism (GenBank). The recombinant cSZ-JN2 antigen expressed in E. coli was recognized strongly by serum from chickens experimentally infected with E. acervulina. Immunofluorescence analysis using antibody against recombinant cSZ-JN2 indicated that this protein was expressed in sporozoite and merozoite developmental stages. Animal challenge experiments demonstrated that the recombinant protein of cSZ-JN2 and DNA vaccine carrying cSZ-JN2 could significantly increase the average body weight gains, decrease the mean lesion scores and the oocyst outputs of the immunized chickens and presented anti-coccidial indices of more than 165. All the above results suggested that the cSZ-JN2 was a novel E. acervulina antigen and could be an effective candidate for the development of a new vaccine against E. acervulina infection.
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, PR China.
authors.forename: Huili
authors.initials: H
authors.lastname: Zhu
authors.forename: Lixin
authors.initials: L
authors.lastname: Xu
authors.forename: Ruofeng
authors.initials: R
authors.lastname: Yan
authors.forename: Xiaokai
authors.initials: X
authors.lastname: Song
authors.forename: Fang
authors.initials: F
authors.lastname: Tang
authors.forename: Song
authors.initials: S
authors.lastname: Wang
authors.forename: Xiangrui
authors.initials: X
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D002645:Chickens; D003048:Coccidiosis / Q000517:prevention & control / Q000662:veterinary*; D016207:Cytokines / Q000097:blood; D018076:DNA, Complementary / Q000235:genetics*; D004539:Eimeria / Q000235:genetics* / Q000276:immunology*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D015723:Gene Library; D007074:Immunoglobulin G / Q000097:blood; D008969:Molecular Sequence Data; D011201:Poultry Diseases / Q000469:parasitology* / Q000517:prevention & control; D011994:Recombinant Proteins; D019444:Vaccines, DNA / Q000276:immunology
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D016207:Cytokines; D018076:DNA, Complementary; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D019444:Vaccines, DNA