Figure 1. US28 constitutively induces promoter activation and secretion of VEGF via HIF-1.

NIH-3T3 cells stably expressing US28 A. or U251 cells with inducible expression of US28 B. were assayed for binding of radiolabeled ¹²⁵I-CCL5 (200 pM) and displacement with unlabeled US28 ligand CX3CL1 (100 nM). C. 48 hour secretion of VEGF-A in the supernatant of synchronized mock and US28-expressing NIH-3T3 or U251 cells. D. VEGF-A secretion after 24/48 hour incubation with or without HIF-1 dimerization inhibitor acriflavine (1 μM) treatment. Significant differences between conditions are depicted by asterisks (*** = P < 0.001, **** = P < 0.0001). E. HEK293T cells transfected with US28 and VEGF promoter reporter gene were treated with HIF-1 dimerization inhibitor acriflavine (1 μM), VEGF promoter activity was measured after 24 hours.