TLR7 and TNFA are miR-17 and miR-19a targets. (A) Luciferase assays were performed with reporter vectors containing native and mutated TLR7 (first and third rows) and TNFA (second and fourth rows) 3′UTRs after transient transfection into NIH-3T3 cells stably expressing miR-17 (top 2 rows) or miR-19a (bottom 2 rows). Shown on the left are schematic representations of the TLR7 and TNFA 3′UTR sequences containing potential miR-17 and miR-19a binding sites. Positions of the mutations are marked as *’s and the corresponding constructs are called TLR7-μ and TNF-μ. Luciferase activity is presented relative to that obtained with transfection of the control vector. (B) Splenic stromal cells were transfected with pGFP-C-lenti-miR-17 (left panels) or pGFP-C-lenti-miR-19a (right panels) viruses. Endogenous TLR7 and TNFA levels, measured by real-time PCR after 48 hours and normalized to HPRT, were significantly downregulated compared with cells transfected with the scrambled control. The average and SD of 3 separate experiments are shown. **P < .01; ***P < .001. RLU, relative luciferase units; Scr, scrambled control.