Effect of Hematopoietic Growth Factors on c-kitReceptor Dimerization
| Cell Line . | Growth Factor . | FITC Mean Fluorescence Intensity . | Cy3 Mean Fluorescence Intensity . | Acceptor/ Donor Ratio . |
|---|---|---|---|---|
| UT-7/Epo | 0 | 86 | 42 | 0.49 |
| SCF | 37 | 59 | 1.59 | |
| Epo | 80 | 47 | 0.59 | |
| GM-CSF | 85 | 41 | 0.48 | |
| UT-7/Tpo | 0 | 46 | 156 | 3.39 |
| SCF | 36 | 175 | 4.86 | |
| Tpo | 54 | 170 | 3.15 | |
| GM-CSF | 46 | 155 | 3.37 |
| Cell Line . | Growth Factor . | FITC Mean Fluorescence Intensity . | Cy3 Mean Fluorescence Intensity . | Acceptor/ Donor Ratio . |
|---|---|---|---|---|
| UT-7/Epo | 0 | 86 | 42 | 0.49 |
| SCF | 37 | 59 | 1.59 | |
| Epo | 80 | 47 | 0.59 | |
| GM-CSF | 85 | 41 | 0.48 | |
| UT-7/Tpo | 0 | 46 | 156 | 3.39 |
| SCF | 36 | 175 | 4.86 | |
| Tpo | 54 | 170 | 3.15 | |
| GM-CSF | 46 | 155 | 3.37 |
UT-7/Epo cells or UT-7/Tpo cells were labeled with 104D2-FITC and 104D2-Cy3, then incubated with no added growth factor, SCF (100 ng/mL), GM-CSF (2.5 ng/mL), IL-3 (2.5 ng/mL), Epo (4 U/mL), or Tpo (50 ng/mL) for 1 hour at 37°C, fixed, and analyzed as described in Table 2. The results of 1 of 5 similar experiments with UT-7/Epo cells, and 1 of 3 similar experiments with UT-7/Tpo cells, are shown. Analysis of variance with a post hoc student's t-test was used to determine the significance of the differences in the acceptor/donor ratio in the absence or presence of growth factors in the 5 experiments with UT-7/Epo cells. The acceptor/donor ratio for the UT-7/Epo cells incubated with either SCF or with Epo was different from the acceptor/donor ratio of the cells incubated with no added growth factor (P < .01, SCF v no added growth factor;P < .01, Epo v no added growth factor).