CLL cell proliferation is enhanced when cocultured with autologous Plexin-B1+ BM stromal cells
| Day . | CLL cells alone . | + Autologous stromal cells* . | + Autologous stromal cells + sCD100† . |
|---|---|---|---|
| 1 | 0.4 (± 0.1) | 1.6 (± 0.1) | 0.6 (± 1.4) |
| 3 | 0.5 (± 0.2) | 4.5 (± 1.3) | 0.5 (± 0.5) |
| 4 | 0.3 (± 0.2) | 4.6 (± 1.3) | 0.2 (± 0.1) |
| Day . | CLL cells alone . | + Autologous stromal cells* . | + Autologous stromal cells + sCD100† . |
|---|---|---|---|
| 1 | 0.4 (± 0.1) | 1.6 (± 0.1) | 0.6 (± 1.4) |
| 3 | 0.5 (± 0.2) | 4.5 (± 1.3) | 0.5 (± 0.5) |
| 4 | 0.3 (± 0.2) | 4.6 (± 1.3) | 0.2 (± 0.1) |
Leukemic cells significantly enhanced their proliferative activity when cocultured with autologous Plexin-B1+ BM stromal cells in comparison with CLL cells alone (*P < .01). The effect on proliferation was significantly abolished by soluble CD100 (stromal cells + sCD100; †P < .05). Proliferation activity was measured by the evaluation of DNA content after PI staining. The numbers express the percentage of CLL cells in S, G2, M phases of the cell cycle and represent the mean values ± standard deviations obtained in 2 independent experiments.