Table 2.
All HSC activity from the Flk2-Sca-1+Lineage-c-kit+ population is contained within the CD48- subset of cells
| Donor | Cell dose | No. mice that engrafted/no. mice total | No. mice with long-term multilineage reconstitution/no. mice total | Frequency of cells that long-term multilineage reconstituted |
|---|---|---|---|---|
| Young | ||||
| FSLK48– | 10 | 5/5 | 5/5 | CNBC |
| FSLK48+ | 10 | 0/6 | 0/6 | NA |
| Old | ||||
| FSLK48– | 15 | 8/8 | 6/8 | 1 in 11.0 |
| FSLK48+ | 15 | 0/8 | 0/8 | NA |
| Reconstituted | ||||
| FSLK48– | 15 | 5/5 | 2/5 | 1 in 29.9 |
| FSLK48+ | 15 | 0/7 | 0/7 | NA |
| Mobilized | ||||
| FSLK48– | 15 | 3/4 | 2/4 | 1 in 22.1 |
| FSLK48+ | 15 | 0/8 | 0/8 | NA |
The indicated number of donor-type (CD45.2+) FLK2–Sca-1+Lineage–c-kit+ cells from young adult bone marrow, old adult bone marrow, reconstituted bone marrow, and day-7 cyclophosphanide/G-CSF–mobilized splenocytes were transplanted intravenously into lethally irradiated recipients (CD45.1+) along with recipient-type 200 000 whole bone marrow cells. Recipients were considered engrafted by donor cells if any CD45.2+ cells were detected in their peripheral blood (above background: > 0.3 of myeloid cells or > 0.1-0.15 of lymphoid cells). Mice were considered long-term multilineage reconstituted if donor-type myeloid, B, and T cells were present for at least 16 weeks after reconstitution. The frequency of cells that gave long-term multilineage reconstitution (HSCs) was calculated based on limitdilution Poisson statistics.21 NA indicates not applicable because no HSC activity was detected; CNBC, could not be calculated because all mice were LTMR.