Figure 3

Channel blockers increase titers of Lv-Kv1.4 and Lv-TREK, but not those of Lv-GFP and Lv-HERG. (A) Ba²⁺ had no effect on the titer of Lv-GFP. After 293T cells were transfected with Lv-GFP and helper plasmids, they were incubated in the presence or absence of 0.3 mM BaCl₂ for 48 h. The titers in the unconcentrated aliquots were determined by measuring the number of GFP-positive cell clusters after the transduction to 293T cells (n = 5). (B) Increase in Lv-Kv1.4 titer. The addition of 4-AP (0.5 mM) significantly increased the titer of Lv-Kv1.4. Because the lentiviral vectors prepared in the presence or absence of blocker were prepared concurrently, the data were analyzed with a paired t test (n = 5, p < 0.05). (C) Increase in Lv-TREK titer. Similarly, the transfected 293T cells were incubated in the presence or absence of 1 mM BaCl₂, and the titers were measured (p < 0.05, n = 5). (D) No increase in Lv-HERG titer. In contrast, the addition of E-4031 did not increase the titer of Lv-HERG (n = 8).