Characterization of OmpK, GAPDH and their fusion OmpK-GAPDH derived from Vibrio harveyi outer membrane proteins: their immunoprotective ability against vibriosis in large yellow croaker (Pseudosciaena crocea).
OBJECTIVE
To investigate the immunoprotection of three recombinant proteins derived from the Vibrio harveyi outer membrane proteins (OMPs) OmpK, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and their fusion OmpK-GAPDH as vaccine candidates from vibriosis of large yellow croaker (Pseudosciaena crocea).


METHODS
The ompK gene, of which the leader sequence was omitted, was fused with the gapdh gene. Three recombinant proteins r-OmpK, r-GAPDH and r-OmpK-GAPDH were expressed and purified. Western blots were carried out to detect the specificity of the antibodies raised against the recombinant proteins; Fish were immunized with recombinant proteins and challenged by native V. harveyi. The immunoresponse to the recombinant proteins were determined by ELISA and phagocytic activity assay.


CONCLUSIONS
The fusion protein r-OmpK-GAPDH can afford greater protection against the wild V. harveyi than r-OmpK or r-GAPDH alone or their mixture in humoral and cellular immunity, indicating that OmpK and GAPDH could produce a synergistic immunoprotection against vibriosis of large yellow croaker (Pseudosciaena crocea) when fused into OmpK-GAPDH with a linker.


CONCLUSIONS
It has been realized that a multi-component OMP antigen can induce a higher frequency of immune effectors than a single OMP. The results presented here bring forth a good suggestion for the subunit vaccine design based on the OMPs of gram-negative pathogens.
Zhang
C
C
College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, China.
Yu
L
L
Qian
R
R
D000818:Animals; D000917:Antibody Formation; D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D003001:Cloning, Molecular; D005393:Fish Diseases / Q000276:immunology / Q000517:prevention & control*; D005818:Genetic Engineering; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D007106:Immune Sera / Q000276:immunology / Q000494:pharmacology*; D007111:Immunity, Cellular; D008264:Macrophages / Q000502:physiology; D010473:Perciformes / Q000276:immunology / Q000382:microbiology; D010587:Phagocytosis; D016133:Polymerase Chain Reaction / Q000379:methods; D011487:Protein Conformation; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000494:pharmacology; D017422:Sequence Analysis, DNA; D014611:Vaccination; D014733:Vibrio / Q000378:metabolism*; D014735:Vibrio Infections / Q000276:immunology / Q000517:prevention & control* / Q000662:veterinary*
D001426:Bacterial Proteins; D007106:Immune Sera; D011993:Recombinant Fusion Proteins; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases