Graduate Student Expo 2011
Wei Yu Chen, PhD candidate
Not all the PRRSV are created equal
Advisor: F. Zuckermann
The molecular mechanisms used by PRRSV to modulate hosts’ IFNa/b responses have not been detailed, especially in the porcine alveolar macrophage. Recently, several studies shown that the overexpressed PRRSV nsp1 is able to inhibit the activity of TFs such as CREB/ p300, NFkB, IRF3 and SP1, which are responsible for IFNa/b gene transcription, suggesting the possible mechanism used by PRRSV to down-regulate the IFNa/b production. However, these studies were performed on the non-natural PRRSV permissive cell by using an overexpression approach and did not discuss the variation among PRRSV strains. The high variation of PRRSV genome makes it become important while studying the PRRSV-host interaction. In this study, several PRRSV strains were subjected into the analysis and the results shows that the modulation of host IFNa/b responses by PRRSV is strain-dependent. Our data show that the conventional wild type strains are able to induce the IFNa production in AM cell line while the unconventional strains inhibit the IFNa production. Consistently, the real-time PCR shows the greater transcription activity of IFNa/b in unconventional-infected cell than in conventional-infected cell. The transcription factor activity assay suggested this bipolar IFNa/b responses might resulted from the different capacity in modulating the phosphorylation of the transcription factor, NFkB and IRF3.