Figure 4.

ScFv-directed PA mediates selective protein translocation into XCR1-positive cells. Relative cell viability from the translocated A-chain of diphtheria toxin (DTA) into (A) XCR1⁺ and (B) XCR1^– CHO cells. Cells were incubated (72 h) with 10-fold serial dilutions of LF_N-DTA in the presence of 20 nM PA, scFv-mPAC, or scFv-mPAC[F427A]. Relative viability (% viable cells) was determined by measuring luminescence from a Cell Titer-Glo assay; the viability was normalized to untreated cells. Data represent the mean of three replicate wells ± the standard deviation (s.d.). Data are representative of two independent experiments.