Hu, SishunHosey, Kristen L.Derbigny, Wilbert A.2016-06-172016-06-172015-03-23Hu, S., Hosey, K. L., & Derbigny, W. A. (2015). Analyses of the Pathways Involved in Early- and Late-Phase Induction of IFN-Beta during C. muridarum Infection of Oviduct Epithelial Cells. PLoS ONE, 10(3), e0119235. http://doi.org/10.1371/journal.pone.0119235https://hdl.handle.net/1805/10023We previously reported that the IFN-β secreted by Chlamydia muridarum-infected murine oviduct epithelial cells (OE cells) was mostly dependent on the TLR3 signaling pathway. To further characterize the mechanisms of IFN-β synthesis during Chlamydia infection of OE cells in vitro, we utilized specific inhibitory drugs to clarify the roles of IRF3 and NF-κB on both early- and late-phase C. muridarum infections. Our results showed that the pathways involved in the early-phase of IFN-β production were distinct from that in the late-phase of IFN-β production. Disruption of IRF3 activation using an inhibitor of TBK-1 at early-phase Chlamydia infection had a significant impact on the overall synthesis of IFN-β; however, disruption of IRF3 activation at late times during infection had no effect. Interestingly, inhibition of NF-κB early during Chlamydia infection also had a negative effect on IFN-β production; however, its impact was not significant. Our data show that the transcription factor IRF7 was induced late during Chlamydia infection, which is indicative of a positive feedback mechanism of IFN-β synthesis late during infection. In contrast, IRF7 appears to play little or no role in the early synthesis of IFN-β during Chlamydia infection. Finally, we demonstrate that antibiotics that target chlamydial DNA replication are much more effective at reducing IFN-β synthesis during infection versus antibiotics that target chlamydial transcription. These results provide evidence that early- and late-phase IFN-β production have distinct signaling pathways in Chlamydia-infected OE cells, and suggest that Chlamydia DNA replication might provide a link to the currently unknown chlamydial PAMP for TLR3.en-USPublisher PolicyChlamydia muridarumEpithelial CellsInterferon Regulatory Factor-3Interferon-betaArticle