In
vitro screening of a second library of exclusively
DC-specific promoters. Promoter constructs are screened for GFP expression
relative to the hCMV-IE1 promoter (positive control). The observed
RPU of all 16 second library promoters in the target DC2.4 cells and
all four off-target cells (C2C12, NIH-3T3, CaCO-2, HUVEC). Promoters
display activities ranging ∼20–61% in the target DC2.4
cells and <5% in all off-target cells. Values represent the mean
± standard deviation across three independent transfections,
each performed in triplicate. (B) Schematic illustration of the architecture
of the top three and bottom three second library promoters ranked
RPU in the target DC2.4 cells, showing the differential representation
of TFREs across both promoter categories.