Trafficking of granulocytes, CFU-GMs, and HSCs in marrow of parabiotic mice at baseline and after cytokine or AMD3100 mobilization
Mobilization regimen*†and wk of parabiosis . | No. pairs . | Mean % partner granulocytes‡± SD . | Mean % partner CFU-GMs‡± SD . | Mean % partner HSCs‡§± SD . |
|---|---|---|---|---|
| None | ||||
| 3 | 3 | 2.3 ± 0.6 | 2.4 ± 0.4 | 1.0 ± 0.8 |
| 6 | 3 | 2.9 ± 0.1 | 3.5 ± 1.4 | 1.4 ± 0.4 |
| G + S | ||||
| 1 mobilization cycle | ||||
| 3 | 3 | 5.9 ± 3.9 | 6.1 ± 4.4 | 2.9 ± 1.1 |
| 6 | 4 | 10.9 ± 6.2 | 9.8 ± 5.4 | 10.1 ± 6.2∥ |
| 3 mobilization cycles | ||||
| 5 | 3 | 16.4 ± 4.1 | 17.6 ± 4.7 | 18.1 ± 10.6∥ |
| 6 | 3 | 18.7 ± 9.1 | 20.7 ± 9.7 | 13.4 ± 9.9∥ |
| AMD3100 | ||||
| 1 mobilization cycle | ||||
| 6 | 3 | 5.6 ± 2.8 | 5.7 ± 2.3 | 5.5 ± 2.3∥ |
Mobilization regimen*†and wk of parabiosis . | No. pairs . | Mean % partner granulocytes‡± SD . | Mean % partner CFU-GMs‡± SD . | Mean % partner HSCs‡§± SD . |
|---|---|---|---|---|
| None | ||||
| 3 | 3 | 2.3 ± 0.6 | 2.4 ± 0.4 | 1.0 ± 0.8 |
| 6 | 3 | 2.9 ± 0.1 | 3.5 ± 1.4 | 1.4 ± 0.4 |
| G + S | ||||
| 1 mobilization cycle | ||||
| 3 | 3 | 5.9 ± 3.9 | 6.1 ± 4.4 | 2.9 ± 1.1 |
| 6 | 4 | 10.9 ± 6.2 | 9.8 ± 5.4 | 10.1 ± 6.2∥ |
| 3 mobilization cycles | ||||
| 5 | 3 | 16.4 ± 4.1 | 17.6 ± 4.7 | 18.1 ± 10.6∥ |
| 6 | 3 | 18.7 ± 9.1 | 20.7 ± 9.7 | 13.4 ± 9.9∥ |
| AMD3100 | ||||
| 1 mobilization cycle | ||||
| 6 | 3 | 5.6 ± 2.8 | 5.7 ± 2.3 | 5.5 ± 2.3∥ |
Mice received G-CSF (G; 200 μg/kg) and SCF (25 μg/kg; G + S) subcutaneously on days 17 to 20 (1 cycle mobilization), or on days 17 to 20, days 24 to 27, and days 31 to 34 (3 cycles of mobilization) of parabiosis. Phenotypes of HSCs in marrow were assessed by secondary transplantation 1 day or 1 week after cytokine administration (ie, after 5 or 6 weeks of parabiosis, respectively)
Mice received AMD3100 (5 mg/kg) subcutaneously on day 21 of parabiosis. Phenotypes of HSCs in marrow were assessed at 6 weeks of parabiosis
To calculate the percentage of granulocytes, CFU-GMs, and HSCs that were exchanged, data from the parabiotic pairs (PeP3b and ROSA26) were averaged
The percentages of blood and marrow granulocytes as well as marrow CFU-GMs of ROSA26 versus PeP3b phenotype were averaged in each secondary recipient to determine the percentage of HSCs of partner phenotype. The percentages of blood and marrow lymphocytes of ROSA26 versus PeP3b phenotype were also determined; HSC engraftment defined by lymphoid chimerism was always equivalent to HSC engraftment defined by granulocytic chimerism. As an example, the percentage of marrow HSCs of partner origin was 5.5% ± 2.3% (granulocytic chimerism) or 6.4% ± 3.8% (lymphoid chimerism) 3 weeks after AMD3100 injection (ie, after 6 weeks of parabiosis)
P ≤ .05 compared with control (no mobilization) mice