Stimulation of 32D infectants with plate-bound anti–c-Kit antibodies.
The 96-well plates were coated with 10 μg/mL mouse-antirat antibodies for 2 hours at 4°C, followed by coating with various concentrations of anti–c-Kit antibodies (ACK-2). KitWT (filled), KitYF719 (hatched), KitYF728 (empty), and 32D uninfected cells (stippled) were then added to coated plates for 18 hours, followed by a 6 hours3H-thymidine pulse. Cells were then harvested and incorporated counts were determined by scintillation counting. Stimulation of 32D cells with both ACK-2 and secondary antibodies was measured as fold stimulation over counts obtained from stimulation with secondary antibodies alone. Incorporation stimulated by ACK-2 varied from 2000 to 7000 cpm, depending on the cell type. Incorporation by the infectants in the absence of ACK-2 was always less than 1000 cpm. Similar results were obtained if fold stimulation was measured over counts obtained from ACK-2 alone. Error bars represent the standard error determined from triplicate measurements.
