Immunoprotective analysis of VhhP2, a Vibrio harveyi vaccine candidate.
VhhP2 is an outer membrane protein identified in a pathogenic Vibrio harveyi strain, T4, isolated from diseased fish. When used as a subunit vaccine, purified recombinant VhhP2 affords high level of protection upon Japanese flounder against V. harveyi challenge. Vaccination with VhhP2 induced the expression of a number of immune-related genes, especially those encoding immunoglobulin M (IgM) and major histocompatibility complex (MHC) IIalpha. A VhhP2 surface display system, in the form of the fish commensal strain PF3 harboring the vhhP2-expressing plasmid pJVP, was constructed. PF3/pJVP is able to produce and present recombinant VhhP2 on cell surface. Vaccination of fish with live PF3/pJVP via intraperitoneal injection elicited strong immunoprotection. Vaccination of fish orally with live PF3/pJVP embedded in alginate microspheres also induced effective immunoprotection. In addition, a VhhP2-based surface display system was created, in which VhhP2 serves as a carrier for the surface delivery of a heterologous Edwardsiella tarda immunogen, Et18, that is fused in-frame to VhhP2. DH5alpha/pJVP18, which expresses and surface-displays the VhhP2-Et18 chimera, proved to be an effective vaccine that can protect fish against infections by V. harveyi and E. tarda to the extents comparable to those produced by vaccination with purified recombinant VhhP2 and Et18, respectively. These data suggest that VhhP2 may be applied as a vaccine and a vaccine carrier against infections by V. harveyi and other pathogens such as E. tarda.
Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, PR China.
Kun
K
Sun
Wei-Wei
WW
Zhang
Jin-Hui
JH
Hou
Li
L
Sun
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D001428:Bacterial Vaccines / Q000235:genetics / Q000276:immunology*; D005393:Fish Diseases / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D005432:Flounder / Q000276:immunology*; D010957:Plasmids / Q000235:genetics; D021122:Protein Subunits / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics; D014733:Vibrio / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D014735:Vibrio Infections / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control*
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D021122:Protein Subunits; D011994:Recombinant Proteins