Figure 5. Sorting schemes for normal and leukemic hematopoietic cell populations.

(a) Fluorescence activated cell sorting (FACS) can be used to enrich hematopoietic stem and progenitor cell (HSPC) populations from human umbilical cord blood (UBC) or bone marrow (BM) samples. Hematopoietic stem cells (HSC), multipotent progenitors (MPP), lymphoid-primed multi-potent progenitors (L-MPP), common myeloid progenitors (CMP), granulocyte/macrophage progenitors (GMP) and megakaryocyte/erythroid progenitors (MEP) can be isolated from enriched total CD34⁺ cells based on differential expression of CD38, CD123, CD45RA, and CD90. HSC, MPP and LMPP reside within the CD34⁺/CD38^lo/- fraction, whereas CMP, GMP, and MEP are found within the CD34⁺/CD38⁺ fraction. One representative cord blood sample with subpopulation gating is depicted. (b) Flow cytometry gating strategy of a representative primary patient leukemia sample shows that most human leukemia blasts can be discriminated from normal hematopoietic cells based on their lower surface expression of CD45. Gating on CD45^low cells and additional staining of T-cells with CD3 allows for reliable enrichment of human leukemia blasts. Both sorting strategies concomitantly deplete donor T-cells, minimizing the risk of xenogeneic graft versus host disease (Xeno-GvHD).