Figure 1.
PL08 substantially stimulates the expansion of human hematopoietic stem cells (HSCs) in vitro. (A) A total of 2×105 human umbilical cord blood nucleated cells (hUCBNCs) were isolated and co-cultured with PL08 cells, PL08 cells that were previously treated with Mito (PL08+M), or PL01 cells in StemSpan medium supplemented with hSCF, hTPO, PTN, and hFLT3L (STPF). In culture, hUCBNCs were separated from stromal cells using Transwell membranes. In another control group (Liquid), 2×105 hUCBNCs were isolated and cultured without any stromal cells in StemSpan medium supplemented with STPF. Cultured hUCBNC were counted and analyzed every three days (n=4). (B) Representative FACS plots show the percentages of Lin-CD34+CD38− cells in PL08, PL08+M, PL01, and liquid culture conditions. (C) Summary of absolute numbers of Lin-CD34+CD38− cells cultured in PL08, PL08+M, PL01, or liquid conditions at day 12 from four independent experiments (n=4). Data represent mean+s.e.m. *P≤0.05 versus bar 3 for bar 1; **P≤0.01 versus bar 2 and bar 4 (for bar 1). (D) The colony numbers of CFU assays obtained from cultured cells as described in (A). Data represent mean+s.e.m. (n=4). *P≤0.05 versus bar 2, bar 3 and bar 4 (for bar 1). *P≤0.05 for bar 11 versus bar 12. BFU-E: erythroid colonies; GM: granulocyte-monocyte colonies; GEMM: granulocyte, erythrocyte, monocyte and megakaryocyte colonies.