A protective immune response is generated in rainbow trout by an OmpH-like surface antigen (P18) of Flavobacterium psychrophilum.
Investigations of the surface characteristics of Flavobacterium psychrophilum, an important pathogen of fish, assisted us in identifying a surface protein termed P18. In the current study, we developed a simple and efficient procedure for the purification of this protein by a two-step method. First, P18 was selectively released from flavobacteria by a heat-HEPES treatment of the cells and then subjected to anion-exchange high-performance liquid chromatography. De novo sequencing was used to generate a fragmented peptide spectrum from purified P18. Comparison of two obtained peptide sequences with a partial genome sequence of F. psychrophilum (INRA, Jouy-en-Josas, France) identified one gene encoding a 166-amino-acid OmpH-like protein that mostly likely undergoes N-terminal cleavage of the 23-residue signal peptide. The susceptibility of the OmpH-like protein to proteinase K treatment and the bacteriostatic/bactericidal activities of anti-OmpH-like protein antibodies indicated that this protein is actually exposed on the surface of F. psychrophilum. Vaccination trials showed that the OmpH-like protein can induce a high titer of anti-OmpH-like protein antibodies which are protective. Taken together, these results suggest that this surface protein produced by F. psychrophilum could be used in future vaccine development as a promising candidate antigen.
Dumetz
Fabien
F
Laboratoire de Microbiologie et de Biochimie Appliquées, Ecole Nationale d'Ingénieurs des Travaux Agricoles de Bordeaux, France.
Duchaud
Eric
E
LaPatra
Scott E
SE
Le Marrec
Claire
C
Claverol
Stéphane
S
Urdaci
Maria-C
MC
Le Hénaff
Michel
M
D000595:Amino Acid Sequence; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology; D005393:Fish Diseases / Q000276:immunology / Q000517:prevention & control*; D045826:Flavobacteriaceae Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary; D005417:Flavobacterium / Q000276:immunology*; D008969:Molecular Sequence Data; D017686:Oncorhynchus mykiss / Q000276:immunology*; D017422:Sequence Analysis, DNA; D014611:Vaccination / Q000662:veterinary*
D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; C067128:ompH protein, bacteria