Efficacy of DNA vaccines carrying Eimeria acervulina lactate dehydrogenase antigen gene against coccidiosis.
The efficacies of DNA vaccines encoding either Eimeria acervulina lactate dehydrogenase (LDH) antigen or a combination of LDH antigen and chicken IL-2 or IFN-gamma were evaluated against chicken coccidiosis. Three vaccine plasmids pVAX-LDH, pVAX-LDH-IFN-gamma and pVAX-LDH-IL-2 were constructed using the eukaryotic expression vector pVAX1. Expressions of proteins encoded by plasmids DNA in vivo were detected by reverse transcription-polymerase chain reaction (RT-PCR) and western blot assay. Average body weight gain, oocyst output, survival rate and lesion scores were measured to evaluate the protective effects of vaccination on challenge infection. The results showed that DNA vaccines could obviously alleviate body weight loss, duodenal lesions, oocyst output and enhance oocyst decrease ratio. Anti-coccidial indexes (ACIs) of pVAX-LDH-IFN-gamma and pVAX-LDH-IL-2 groups were higher than that of other groups. Flow cytometric analysis of T lymphocytes in spleen and cecal tonsil demonstrated that DNA vaccines had significantly increased percentages of CD3(+) T cells compared with pVAX1 alone or TE buffer. The results provided the first proof that DNA vaccine carrying E. acervulina LDH antigen gene induced protective immunity against homologous infection and its effect could be enhanced by co-expression of chicken IL-2 or IFN-gamma.
Song
Hongyan
H
College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China.
Yan
Ruofeng
R
Xu
Lixin
L
Song
Xiaokai
X
Shah
Muhammad Ali A
MA
Zhu
Huili
H
Li
Xiangrui
X
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002645:Chickens / Q000469:parasitology*; D003048:Coccidiosis / Q000517:prevention & control / Q000662:veterinary*; D016054:DNA, Protozoan / Q000737:chemistry; D004539:Eimeria / Q000201:enzymology* / Q000235:genetics / Q000276:immunology; D007111:Immunity, Cellular; D007770:L-Lactate Dehydrogenase / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D008221:Lymphoid Tissue / Q000166:cytology / Q000276:immunology; D010957:Plasmids / Q000235:genetics; D011201:Poultry Diseases / Q000469:parasitology / Q000517:prevention & control*; D016052:Protozoan Vaccines / Q000276:immunology / Q000592:standards*; D011897:Random Allocation; D013154:Spleen / Q000166:cytology / Q000276:immunology; D019444:Vaccines, DNA / Q000276:immunology / Q000592:standards
D016054:DNA, Protozoan; D016052:Protozoan Vaccines; D019444:Vaccines, DNA; D007770:L-Lactate Dehydrogenase