Stimulation of 32D infectants with mSLF on X9/D3 stromal cells.
32D infectants were cocultured with mSLF-expressing X9/D3 stromal cells. KitWT, KitYF719, KitYF728, and 32D uninfected cells were incubated with X9/D3 cells for 18 hours, followed by a 6 hours3H-thymidine pulse. Cells were then harvested and incorporated counts were determined by scintillation counting. Fold stimulation represents stimulation of cells on X9/D3 cells compared with stimulation observed on SLF-negative parental Sl/Sl4cells according to the formula in “Materials and methods.” Incorporation levels for fibroblasts alone were typically 9000 to 10 000 cpm, whereas cocultures resulted in 12 000 to 19 000 cpm depending on the cell type. Error bars represent the standard error determined from triplicate measurements.
