CLL cell viability is sustained when exposed to Plexin-B1 transfectants (MLP/Plex-B1)
| Day . | CLL cells alone . | + MLP . | + MLP/Plex-B1* . | + MLP/Plex-B1 + sCD100 . | + CD40L . | + MLP + CD40L . | + MLP/Plex-B1 + CD40L . |
|---|---|---|---|---|---|---|---|
| 1 | 66 (± 7.1) | 58 (± 8.8) | 65 (± 9.5) | 63 (± 3.4) | 55 (± 10) | 58 (± 8.3) | 69 (± 7) |
| 2 | 52 (± 6.4) | 56 (± 7.1) | 70 (± 4.5) | 57† (± 6) | 52 (± 8.4) | 59 (± 4.8) | 72 (± 4.1) |
| 3 | 48 (± 3.9) | 52 (± 4.2) | 67 (± 3.2) | 40† (± 4.5) | 53 (± 2.7) | 54 (± 3.3) | 75 (± 2.5) |
| 4 | 38 (± 6.4) | 53 (± 7.2) | 73 (± 4.5) | 41† (± 4.3) | 53 (± 7.4) | 54 (± 5.2) | 75 (± 3.9) |
| Day . | CLL cells alone . | + MLP . | + MLP/Plex-B1* . | + MLP/Plex-B1 + sCD100 . | + CD40L . | + MLP + CD40L . | + MLP/Plex-B1 + CD40L . |
|---|---|---|---|---|---|---|---|
| 1 | 66 (± 7.1) | 58 (± 8.8) | 65 (± 9.5) | 63 (± 3.4) | 55 (± 10) | 58 (± 8.3) | 69 (± 7) |
| 2 | 52 (± 6.4) | 56 (± 7.1) | 70 (± 4.5) | 57† (± 6) | 52 (± 8.4) | 59 (± 4.8) | 72 (± 4.1) |
| 3 | 48 (± 3.9) | 52 (± 4.2) | 67 (± 3.2) | 40† (± 4.5) | 53 (± 2.7) | 54 (± 3.3) | 75 (± 2.5) |
| 4 | 38 (± 6.4) | 53 (± 7.2) | 73 (± 4.5) | 41† (± 4.3) | 53 (± 7.4) | 54 (± 5.2) | 75 (± 3.9) |
Leukemic cells significantly sustained their viability when exposed to Plexin-B1 transfectants (MLP/Plex-B1) in comparison with MLP wild type (*P < .05). The effect on viability was significantly abolished by soluble CD100 (MLP/Plex-B1 or stromal cells + sCD100; †P < .05). The coculture experiments were performed also in the presence of soluble CD40L (MLP or MLP/Plex-B1 + CD40L). Viability was assessed by cytofluorograph analysis of Annexin V staining. The numbers express the percentage of viable CLL cells and represent the mean values ± standard deviations obtained in 12 independent experiments.