Multi-immunogenic outer membrane vesicles derived from an MsbB-deficient Salmonella enterica serovar typhimurium mutant.
To develop low endotoxic and multi-immunogenic outer membrane vesicles (OMVs), a deletion mutant of the msbB gene in Salmonella enterica serovar Typhimurium (S. Typhimurium) was used as a source of low endotoxic OMV, and an expression vector of the canine parvovirus (CPV) VP2 epitope fused to the bacterial OmpA protein was constructed and transformed into the Salmonella deltaAmsbB mutant. In a lethality test, BALB/c mice injected intraperitoneally with the Salmonella deltaAmsbB mutant survived for 7 days, whereas mice injected intraperitoneally with the wild type survived for 3 days. Moreover, all mice inoculated orally with the deltaAmsbB mutant survived for 30 days, but 80% of mice inoculated orally with the wild type survived. The OmpA::CPV VP2 epitope fusion protein was expressed successfully and associated with the outer membrane and OMV fractions from the mutant S. Typhimurium transformed with the fusion protein-expressing vector. In immunogenicity tests, sera obtained from the mice immunized with either the Salmonella msbB mutant or its OMVs containing the OmpA::CPV VP2 epitope showed bactericidal activities against wild-type S. Typhimurium and contained specific antibodies to the CPV VP2 epitope. In the hemagglutination inhibition (HI) assay as a measurement of CPV-neutralizing activity in the immune sera, there was an 8-fold increase of HI titer in the OMV-immunized group compared with the control. These results suggested that the CPV-neutralizing antibody response was raised by immunization with OMV containing the OmpA::CPV VP2 epitope, as well as the protective immune response against S. Typhimurium in BALB/c mice.
Lee
Sang-Rae
SR
The National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Ochang, Cheongwon, Chungbuk 363-883, Korea.
Kim
Sang-Hyun
SH
Jeong
Kang-Jin
KJ
Kim
Keun-Su
KS
Kim
Young-Hyun
YH
Kim
Sung-Jin
SJ
Kim
Ekyune
E
Kim
Jung-Woo
JW
Chang
Kyu-Tae
KT
D000217:Acyltransferases / Q000235:genetics* / Q000276:immunology; D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D000914:Antibodies, Viral / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000276:immunology*; D001426:Bacterial Proteins / Q000235:genetics* / Q000276:immunology; D002460:Cell Line; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation; D017993:Parvovirus, Canine / Q000235:genetics / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D012480:Salmonella Infections / Q000276:immunology* / Q000382:microbiology / Q000821:virology; D012486:Salmonella typhimurium / Q000235:genetics* / Q000276:immunology; D022161:Transport Vesicles / Q000235:genetics / Q000276:immunology*
D000907:Antibodies, Bacterial; D000914:Antibodies, Viral; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins; C078167:OMPA outer membrane proteins; D000217:Acyltransferases