Detection Of Differential Proteins In ST Cells Infected With Porcine Parvovirus Virus Using ITRAQ

Objective:In this study, we used the isobaric Tags for Relative and Absolute Quantitation (iTRAQ) combined with molecular biology methods to screen and obtain key proteins which might be associated with the infection of PPV. The present work may supply some basic data for pathogenic mechanisms of PPV in sows, as well new ideas for studying viral diseases associated with animal reproductive failure.Materials and Methods:In this study, firstly, levels of VP2 gene and its protein of PPV were detected at 12 h,24 h,36 h,48 h and 60 h of post infection using PCR and indirect immunofluorescence (ICC) in ST cells, respectively. Total proteins were extracted from infected or uninfected cells with PPV at this point time with optimal virus VP2 expression. Proteome profile was obtained using iTRAQ combined with LC-ESI-MS/MS analytical technique. Further, the differential proteins were collected by using bioinformatics analysis based on their biological processes, their cellular structural components and molecular functions, and networks between proteins were also established. In addition, several differential proteins were validated using real-time PCR and Western Blot (WB), including five up-regulated and and four down-regulated proteins.Results:Levels of PPV VP2 showed a higher expression after cells were infected with PPV for 60 h. In these samples, total 27,608 peptides with 5002 proteins were obtained; 218 proteins of these proteins were differentially expressed after infection (difference was defined as with a change fold more than 1.2 times), including 130 of them are down-regulated, and 88 proteins were up-regulated. These differential preotein are mainly related to cell cycle, cell growth, metabolism, cell skeleton, endocrine and intracellular transcription and translation. Data from validation of the selected proteins showed similar trends as those from the iTRAQ assay.In conclusion, in the present study, protein profiles, the differentially expressed proteins as networks between them were obtained after PPV infection in ST cells, but the roles of these proteins in PPV infection require further investigation.