Sustained Notch1 signaling does not prevent CD4 ISP thymocytes from adopting an αβ T-cell fate, but enhances cellular expansion. (A) Flow cytometry analysis of CD3 versus TCRαβ or TCRγδ expression on electronically gated GFP+ cells generated from ICN1-transduced (ICN1) or mock-transduced (GFP) CD4 ISP thymic precursors after 12 days in FTOC. (B) TCRαβ+/TCRγδ+ cell ratios recovered from mock-transduced (open bars) and ICN1-transduced (filled bars) CD4 ISP thymic precursors (296 ± 177 and 16 ± 7.6, respectively). Values are the mean ± SD of absolute cell number ratios observed at 5 different time points along FTOC. (C) Absolute numbers of GFP+-gated total cells derived from ICN1- (▪) or mock-transduced (○) CD4 ISP thymocytes in FTOCs at the indicated time points. Absolute numbers were normalized to 2 × 103 GFP+ transduced cells/lobe. (D) Percentages of CD4 ISP, DP, TCRγδ+, and TCRαβ+ SP cells derived from ICN1- (ICN1) or mock-transduced (GFP) CD4 ISP progenitors at the indicated time points in FTOCs. Results are representative of 3 independent experiments.
