Expression of AMs on engrafting and nonengrafting phenotypes of Sca-1⁺lin⁻ cells.

Sca-1⁺lin⁻ cells were subfractionated by cell sorting into AM⁺/AM^bright or AM⁻/AM^dim groups with the use of CD11a (■), CD43 (♦), CD49d (●), CD49e (○), and CD62L (▪) to give engrafting or nonengrafting phenotypes, designated E and NE, respectively. CD44 was omitted in the primary sort since this marker was not useful in defining engrafting phenotypes (Figure 2). These resulting 10 groups of cells were phenotyped for their expression of other AMs not used in the primary sort (listed at the top of each scatter plot), and the percentage of each engrafting (E) and nonengrafting (NE) phenotype positive for expression of other AMs was calculated after subtracting nonspecific background fluorescence. Each individual data point represents the percentage of positive expression; horizontal bars are mean expression. For example, the open circles in Panel A represent the expression of CD11a on CD49e⁺ cells (E) and CD49e⁻ cells (NE). In panel B, open squares represent expression of CD43 on CD11a⁻ cells (E) and CD11a⁺ cells (NE), also shown in panel G. Since 100% of Sca-1⁺lin⁻ cells express CD44 and CD49d (Table 1), only the proportion of engrafting and nonengrafting phenotypes positive for CD44^bright and CD49d^bright expression was calculated. The histogram in panel G illustrates the high level of expression of CD43 (x-axis) on Sca-1[⁺lin⁻ CD11a⁻ cells (open histogram) relative to CD11a⁺ cells (filled histogram), while panel H shows the high level of expression of CD43 on Sca-1⁺lin⁻ CD49e⁺ cells (open histogram) relative to CD49e⁻ cells (filled histogram). Data are from 1 of 2 experiments with similar results.