Lentiviral Knockdown of Transcription Factor STAT1 in to Assess Its Role in the Restriction of Tick-borne Flaviviruses.

Cellular infection with tick-borne flaviviruses (TBFVs) results in activation of the interferon (IFN) signaling pathway and subsequent upregulation of numerous genes termed IFN stimulated genes (ISGs) ( Schoggins , 2011 ). Many ISGs function to prevent virus pathogenesis by acting in a broad or specific manner through protein-protein interactions (Duggal and Emerman, 2012). The potency of the IFN signaling response determines the outcome of TBFV infection (Best, 2017; Carletti , 2017 ). Interestingly, data from our lab show that TBFV replication is significantly restricted in cells of the reservoir species thereby suggesting a potent antiviral response ( Izuogu , 2017 ). We assessed the relative contribution of IFN signaling to resistance in by knocking down a major transcription factor in the IFN response pathway. Signal transducer and activator of transcription 1 (STAT1) was specifically targeted in cells by shRNA technology. We further tested the impact of gene knockdown on the ability of cells to respond to IFN and restrict virus replication; the results indicate that when STAT1 expression is altered, cells have a decreased response to IFN stimulation and are significantly more susceptible to TBFV replication.