The differential protein expression profiles and immunogenicity of tachyzoites and bradyzoites of in vitro cultured Neospora caninum.
We report a study on the variations in the protein expression profiles of tachyzoites and bradyzoites of Neospora caninum. The in vitro stage conversion of N. caninum-infected Vero cells was induced by continuous treatment of infected cultures with 70 muM sodium nitroprusside (SNP) for up to 9 days. The stage conversion indicated by the expression of the bradyzoite-specific antigen BAG1 was analyzed by immunofluoresence assay. Morphological changes between tachyzoites and bradyzoites and localization of nuclei were demonstrated by transmission electron microscopy. Notably, we showed the differential protein expression profiles of tachyzoites and bradyzoites of N. caninum upon treatment with SNP. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis indicated different protein patterns between tachyzoites and bradyzoites. Furthermore, Western blotting using rabbit polyclonal antibodies directed against tachyzoites revealed several reactive bands, one of which represented a tachyzoite-specific antigen of approximately 40 kDa remarkably expressed in the tachyzoite stage, but was absent from bradyzoites. Moreover, rabbit polyclonal serum raised against bradyzoites recognized a significant increased expression of an antigen with a MW of approximately 25 kDa in bradyzoites by Western blotting, suggesting that this protein is specifically expressed at the bradyzoite stage. Taken together, our data showed that differential protein expression profiling is a useful tool for discriminating between the two stages during tachyzoite-bradyzoite interconversion in N. caninum infections.
Kang
Seung-Won
SW
Department of Bacteria and Parasitology, National Veterinary Research and Quarantine Service (NVRQS), 480 Anyang 6 dong, Anyang City 420-480, South Korea. kangsw@mail.nvrqs.go.kr
Lee
Eun-Hang
EH
Jean
Young-Hwa
YH
Choe
Se-Eun
SE
Van Quyen
Dong
D
Lee
Myeong-Sok
MS
D000818:Animals; D015153:Blotting, Western; D002522:Chlorocebus aethiops; D004591:Electrophoresis, Polyacrylamide Gel; D005455:Fluorescent Antibody Technique; D005656:Fungal Proteins / Q000032:analysis* / Q000737:chemistry / Q000276:immunology*; D046529:Microscopy, Electron, Transmission; D008970:Molecular Weight; D018688:Neospora / Q000737:chemistry* / Q000254:growth & development* / Q000276:immunology / Q000648:ultrastructure; D009599:Nitroprusside / Q000378:metabolism; D020543:Proteome / Q000032:analysis* / Q000276:immunology*; D014709:Vero Cells
D005656:Fungal Proteins; D020543:Proteome; D009599:Nitroprusside