Protection of Japanese flounder (Paralichthys olivaceus) against Vibrio anguillarum with a DNA vaccine containing the mutated zinc-metalloprotease gene.
Vibrio anguillarum is one of the causative agents of vibriosis, a systemic disease of fish characterized by acute hemorrhagic septicemia. The extracellular zinc metalloprotease (EmpA) is a putative virulence factor involved in pathogenicity of V. anguillarum. Here we described the results of immunization against V. anguillarum with the plasmid expressing the mutated EmpA (m-EmpA7), which had no protelytic activity or cytotoxicity. In vitro protein expression of m-empA7 gene was determined by fluorescent microscopy and Western-blot after transfection of Chinese hamster ovary (CHO) and human embryonic kidney (HEK293T) cell lines. All three groups of fish immunized with a single intramuscular (i.m.) injection of different doses of the m-EmpA7 DNA vaccine showed significant serum antibody levels after vaccination, compared with the fish injected with the control eukaryotic expression vector pEGFP-N1 and PBS. In addition, fish receiving the DNA vaccine developed a protective response to a live V. anguillarum challenge 4 weeks post-inoculation, as demonstrated by increased survival of vaccinated fish over the control and by decreased histological alterations in vaccinated fish. Furthermore, humoral immune responses and protective effects were significantly increased at higher vaccine doses using a single intramuscularly injection route.
Department of Marine Biology, College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China.
Hui
H
Yang
Jixiang
J
Chen
Guanpin
G
Yang
Xiao-Hua
XH
Zhang
Rui
R
Liu
Xiaoping
X
Xue
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology*; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D005393:Fish Diseases / Q000276:immunology / Q000517:prevention & control*; D005432:Flounder / Q000276:immunology*; D006801:Humans; D045726:Metalloproteases / Q000235:genetics / Q000276:immunology*; D009132:Muscles / Q000276:immunology; D010957:Plasmids; D019444:Vaccines, DNA / Q000276:immunology*; D014733:Vibrio / Q000276:immunology; D014735:Vibrio Infections / Q000276:immunology / Q000517:prevention & control*
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D019444:Vaccines, DNA; C500552:EmpA protein, Vibrio anguillarum; D045726:Metalloproteases