Fig. 5.

Expression of type III IFN (IFN-λ1) is induced in DAOY cells following TBEV infection. DAOY cells were treated with IFN-β (10 ng ml⁻¹) and, where indicated, infected with TBEV after 12 h (m.o.i. 5), or only infected with TBEV, or mock-treated. Three independent biological replicates were included for each of the combinations (untreated mock cells; IFN-β-treated mock cells; untreated cells infected with TBEV; IFN-β-pre-treated cells infected with TBEV). Total cellular RNA was isolated at 24 h p.i. and further processed for transcriptome analysis. (a) Relative quantification of type I, II and III IFN mRNA levels in DAOY cells. The ΔΔ-ct method, using HPRT as a housekeeping gene, was employed for relative fold-change calculation; the mean of three biological replicates with standard deviation is shown. Significant differences to the control (mock-infected cells) were calculated by Student’s t-test (**P<0.01). (b) -Δ ct values of type I, II and III IFNs normalized to the HPRT gene; the mean of three biological replicates with standard deviation is shown. The dotted line represents the sensitivity of the qPCR. Significant differences were calculated by Student’s t-test (***P<0.001, ****P<0.0001). (c) Schematic overview of the IFN-λ (IFNL1) signalling network (as identified by IPA software). Identified up-regulated (red) transcripts in TBEV-infected DAOY cells are displayed.