Hantaan Virus Infection Induces CXCL10 Expression through TLR3, RIG-I, and MDA-5 Pathways Correlated with the Disease Severity
Figure 4
NF-κB1 and IRF7 upregulate CXCL10 expression. (a) Schematic diagram of full-length, truncated, and mutated CXCL10 promoter constructs. (b) Various truncated CXCL10 promoter constructs were transfected into 293T cell lines, and the relative luciferase activities to the pGL3-basic vector were detected. The data showed that the NF-B and ISRE sites in −267/+97 construct were of importance in regulation of the transcription of CXCL10 gene. (c) Influences of mutated NF-κB sites on activity of the CXCL10 promoter indicated that NF-B1 site may play a more important role. (d) Real-time PCR was used to prove that only IRF7 upregulated substantially at 48 h post-HTNV infection on HUVEC model. (e) When transfected into HUVECs for 24 h with siRNA (upper panel), specific to p65 or IRF7, respectively, and then infected the cells with HTNV (MOI = 1) for another 48 h, the expressions of CXCL10 reduced (lower panel). All the experiments were repeated in triplicate. mRNA data were generated from three independent experiments with three independent HUVECs donors. Data were means ± SE. *, CXCL10 promoter versus pGL3-basic vector transfected cell; HTNV infected or poly (I:C) treated versus medium treated cells; and siRNA specific to p65 or IRF7, versus siNC treated cells.
