CD19+CD5+ cell viability and proliferation are sustained by CD100/Plexin-B1 interaction
| . | CD19+CD5+ cells alone . | + MLP . | + MLP/Plex-B1* . | + CD40L . | + MLP + CD40L . | + MLP/Plex-B1 + CD40L . |
|---|---|---|---|---|---|---|
| Viability | ||||||
| Day 2 | 8 (± 10.8) | 38 (± 4.1) | 62 (± 3.9) | 32 (± 12.3) | 44 (± 7.1) | 68 (± 2.5) |
| Day 3 | 5 (± 9.4) | 34 (± 4.9) | 69 (± 3.2) | 18 (± 6.9) | 37 (± 8.4) | 72 (± 3.7) |
| Day 4 | 5 (± 7.6) | 32 (± 8.2) | 67 (± 4.5) | 20 (± 5.6) | 36 (± 7.3) | 71 (± 3.0) |
| Proliferation | ||||||
| Day 2 | 1.6 (± 0.3) | 2.8 (± 1.0) | 6.0 (± 1.8) | 3.2 (± 0.8) | 3.5 (± 1.1) | 6.4 (± 1.5) |
| Day 3 | 1.3 (± 0.4) | 3.2 (± 0.9) | 9.7 (± 1.4) | 1.6 (± 0.4) | 3.7 (± 1.4) | 7.0 (± 1.7) |
| Day 4 | 1.1 (± 0.2) | 3.3 (± 1.0) | 9.5 (± 1.6) | 1.7 (± 0.2) | 3.7 (± 1.2) | 7.2 (± 1.0) |
| . | CD19+CD5+ cells alone . | + MLP . | + MLP/Plex-B1* . | + CD40L . | + MLP + CD40L . | + MLP/Plex-B1 + CD40L . |
|---|---|---|---|---|---|---|
| Viability | ||||||
| Day 2 | 8 (± 10.8) | 38 (± 4.1) | 62 (± 3.9) | 32 (± 12.3) | 44 (± 7.1) | 68 (± 2.5) |
| Day 3 | 5 (± 9.4) | 34 (± 4.9) | 69 (± 3.2) | 18 (± 6.9) | 37 (± 8.4) | 72 (± 3.7) |
| Day 4 | 5 (± 7.6) | 32 (± 8.2) | 67 (± 4.5) | 20 (± 5.6) | 36 (± 7.3) | 71 (± 3.0) |
| Proliferation | ||||||
| Day 2 | 1.6 (± 0.3) | 2.8 (± 1.0) | 6.0 (± 1.8) | 3.2 (± 0.8) | 3.5 (± 1.1) | 6.4 (± 1.5) |
| Day 3 | 1.3 (± 0.4) | 3.2 (± 0.9) | 9.7 (± 1.4) | 1.6 (± 0.4) | 3.7 (± 1.4) | 7.0 (± 1.7) |
| Day 4 | 1.1 (± 0.2) | 3.3 (± 1.0) | 9.5 (± 1.6) | 1.7 (± 0.2) | 3.7 (± 1.2) | 7.2 (± 1.0) |
CD19+CD5+ B cells significantly sustained their viability and increased their proliferation when exposed to Plexin-B1 transfectants (MLP/Plex-B1) in comparison with MLP wild type (*P < .01). 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 and proliferation activity was measured by the evaluation of DNA content after PI staining. The numbers express the percentage of CD19+CD5+cells in S, G2, M phases of the cell cycle and represent the mean values ± standard deviations obtained in 5 independent experiments.