Addition of an anti–SDF-1 antibody or SDF-1 antagonist to previously activated LTCs of normal bone marrow cells prevents the return of the primitive CFCs in the adherent layer to a quiescent state 4 to 5 days later
| Addition . | Killed by 3H-thymidine (%) . | ||
|---|---|---|---|
| Primitive BFU-Es . | CFU-GMs . | ||
| Primitive . | Mature . | ||
| None | 0 ± 4 | 4 ± 5 | 43 ± 2 |
| Anti–SDF-1 antibody | 36 ± 3 | 44 ± 4 | 38 ± 3 |
| Control antibody | 0 ± 8 | 12 ± 6 | 44 ± 2 |
| SDF-1 (G2) | 49 ± 3 | 51 ± 5 | 38 ± 1 |
| Addition . | Killed by 3H-thymidine (%) . | ||
|---|---|---|---|
| Primitive BFU-Es . | CFU-GMs . | ||
| Primitive . | Mature . | ||
| None | 0 ± 4 | 4 ± 5 | 43 ± 2 |
| Anti–SDF-1 antibody | 36 ± 3 | 44 ± 4 | 38 ± 3 |
| Control antibody | 0 ± 8 | 12 ± 6 | 44 ± 2 |
| SDF-1 (G2) | 49 ± 3 | 51 ± 5 | 38 ± 1 |
Anti-SDF-1 (and control antibody) were added at 30 μg/mL, and SDF-1(G2) was added at 10 μg/mL. Results shown are the mean ± SEM of data from 4 independent experiments. Both the anti–SDF-1 antibody and SDF-1(G2) had a significant effect compared with no addition (P < .001) or control antibody (P < .01) on the cycling of the primitive BFU-Es and primitive CFU-GMs, but not on the mature CFU-GMs (P > .05). The total colony counts in the control groups (no3H-thymidine) ranged from 14 to 134.