Percentage of donor-derived chimerism in transplanted mice.

Percentage of donor-derived chimerism in mice transplanted with Sca-1⁺lin⁻ cells, Sca-1⁺lin⁻ AM⁺ or AM⁻cells (panel A), or Sca-1⁺lin⁻ cells fractionated with the use of CD49d and CD49e simultaneously (panel B). Lethally irradiated C57BL/6 mice were transplanted with 1 × 10³ total Sca-1⁺lin⁻ cells (hatched bar), Sca-1⁺lin⁻AM⁺ (black bars), or Sca-1⁺lin⁻AM⁻ (gray bars), all of B6.Gpi-1^a origin, along with 3 × 10⁴ C57BL/6 competitor cells. Chimerism was monitored monthly by hemoglobin analysis of peripheral blood cells. Horizontal black lines represent mean engraftment in mice transplanted with “antibody control” cells (Sca-1⁺lin⁻cells treated with the AM antibody but not sorted for the AM phenotype). Data are expressed in panel A as the mean ± SEM of 3 to 12 mice per group from 1 to 5 separate experiments (analyzed at 6 months posttransplantation), and in panel B as the mean ± SEM of 3 to 5 mice per group in 1 experiment. Trends in engraftment similar to that seen in panel A were obtained in experiments in which B6.BoyJ donor cells were used along with 1 × 10⁵ C57BL/6 competitor cells. *The presence of statistical significance between the AM⁺ and AM⁻ fraction of Sca-1⁺lin⁻ cells; P < .05. **The presence of statistical significance between Sca-1⁺lin⁻ CD49e⁺CD49d^dim cells and each of the other 3 phenotypes at 8 months posttransplantation.