Lymphoid differentiation potential of in vitro-generated CD45RA^hiCD7⁺ HPCs. (A) Generation of CD45RA^hiCD7⁺ HPCs from CD45RA^intCD7^- and CD45RA^hiLin^- HPCs: based on sorting gates set on CD34⁺CD7^-CD19^- cells, CD45RA^intCD10^- (ie, CD45RA^intCD7^-) and CD45RA^hiCD10^- (ie, CD45RA^hiLin^-) cells were sorted and cultured onto MS5 cells with FL for 4 to 6 days. Cells were gated based on high CD34 expression and analyzed by FACS for CD45RA and CD7. Percentages of labeled cells are indicated; data are from 1 of 3 experiments. (B) Analysis of NK cell and BL differentiation potentials of in vitro-generated CD45RA^hiCD7⁺ HPCs: CD45RA^intCD7^- HPC-derived CD45RA^hiCD7⁺ cells were sorted on culture day 6 and seeded in limiting-dilution under the NK or B conditions. Upper panels show NK cell and BL progenitor frequencies; lower panels display mean percentages and SD of CD56⁺ and CD19⁺ cells in the corresponding replicate cell-containing wells. Data are from 1 experiment of 2. (C) TL potential of CD45RA^intCD7^- HPC-derived CD45RA^hiCD7⁺ cells: sorted CD45RA^hiCD7⁺ cells were cocultured for 3 weeks with OP9-DL1 cells, as indicated in the legend of Figure 4B, before FACS analysis. Percentages of labeled cells are indicated; data are from 1 of 2 experiments.