Table 5.

CD150⁺CD48^-Sca-1⁺Lineage^-c-kit⁺ cells from old, reconstituted, and cyclophosphamide/G-CSF-mobilized mice are highly enriched for long-term self-renewing, multipotent HSCs

Donor/experiment	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
1	8/8	7/8	1 in 2.0
Old
1	4/7	3/7	1 in 5.9
2	6/12	5/12	1 in 6.1
3	5/9	3/9	1 in 7.9
4	4/9	3/9	1 in 7.9
Reconstituted
1	3/6	3/6	1 in 4.8
2	12/13	10/13	1 in 2.6
3	7/9	3/9	1 in 7.9
Mobilized
1	5/8	5/8	1 in 3.6

Three (CD45.1⁺) CD50⁺CD48^–Sca-1⁺lin^–c-kit⁺ cells from old, reconstituted, or day-7 cyclophosphamide/G-CSF–mobilized splenocytes were transplanted intravenously into lethally irradiated recipients (CD45.2⁺) along with 300 000 CD150^– recipient-type cells or 200 000 whole bone marrow cells for radioprotection. There was no apparent difference in the frequency of donor cells that long-term multilineage reconstituted based on the nature of cells used for radioprotection. Recipients were considered long-term multilineage reconstituted if donor-type myeloid, B, and T cells were present for at least 16 weeks after transplantation.