Characterization of miRNA vectors in the MPRO cell line. MPRO cells were transiently transfected with pGL3-luciferase reporter vector and plasmids encoding specific miRNA sequences targeting the luciferase enzyme (Luc) or a control sequence (Con) either using a CMV promoter (A) or the MRP8 promoter (B). Results from luciferase assays are reported as relative light units (RLUs). The miRNA targeting Luc efficiently reduced luciferase expression/activity compared with a control sequence. (C) MPRO cells were transfected with CMV-miR-Luc or CMV-miR-CD18 and selected using blasticidin. Shown is an example of blasticidin-resistant miR-CD18 (shaded) and miR-Luc (open) clones subjected to FACs analysis for CD18 (left panel) and PSGL-1 (right panel) expression. The histograms for isotype controls are indicated.