Identification of a ribosomal L10-like protein from Flavobacterium psychrophilum as a recombinant vaccine candidate for rainbow trout fry syndrome.
The psychrophilic bacterium Flavobacterium psychrophilum is a rapidly emerging, virulent pathogen of a variety of commercially important finfish species, including salmonids. No vaccines against F. psychrophilum are currently available, partly due to its recalcitrant growth in vitro. Consequently, we explored the possibility of constructing recombinant vaccines in Escherichia coli as a prophylactic biotechnological strategy to counter F. psychrophilum infections. An immunoreactive clone from a F. psychrophilum expression library was found to express a approximately 16 kDa protein antigen. A proteomics approach was taken to identify the ORF encoding the approximately 16 kDa protein. Tryptic fragments of the approximately 16 kDa protein were analyzed by MALDI-TOF mass spectrometry and compared to theoretical (in silico) tryptic fragments of translated ORFs predicted within the cloned DNA. The target protein was identified as a 166 amino acid protein (named 7-166) with homology to rplJ which encodes bacterial ribosomal protein L10. Whenhighly expressed in E. coli as an N-terminal fusion protein, this chimera reacted with convalescent rainbow trout serum. When adjuvanted and administered intraperitoneally to immature rainbow trout a high level of protection (82% RPS) was afforded against virulent F. psychrophilum challenge; thus establishing F. psychrophilumrplJ homologue 7-166 as a promising vaccine candidate for RTFS.
Crump
Elizabeth M
EM
Department of Biochemistry and Microbiology, University of Victoria, Victoria, B.C., Canada.
Burian
Ján
J
Allen
Philippe D
PD
Gale
Stephen
S
Kay
William W
WW
D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D001428:Bacterial Vaccines / Q000235:genetics / Q000276:immunology*; D015153:Blotting, Western; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D005393:Fish Diseases / Q000276:immunology* / Q000382:microbiology; D045826:Flavobacteriaceae Infections / Q000276:immunology / Q000382:microbiology; D005417:Flavobacterium / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D015723:Gene Library; D017686:Oncorhynchus mykiss / Q000276:immunology* / Q000382:microbiology; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D000080882:Ribosomal Protein L10; D012269:Ribosomal Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D011994:Recombinant Proteins; D012269:Ribosomal Proteins