CD133 is a positive marker for a distinct class of primitive human cord blood-derived CD34-negative hematopoietic stem cells

Abstract

The identification of human CD34-negative (CD34−) hematopoietic stem cells (HSCs) provides a new concept for the hierarchy in the human HSC compartment. Previous studies demonstrated that CD34− severe combined immunodeficiency (SCID)-repopulating cells (SRCs) are a distinct class of primitive HSCs in comparison to the well-characterized CD34+CD38− SRCs. However, the purification level of rare CD34− SRCs in 18 lineage marker-negative (Lin−) CD34− cells (1/1000) is still very low compared with that of CD34+CD38− SRCs (1/40). As in the mouse, it will be necessary to identify useful positive markers for a high degree of purification of rare human CD34− SRCs. Using 18Lin−CD34− cells, we analyzed the expression of candidate positive markers by flow cytometric analysis. We finally identified CD133 as a reliable positive marker of human CB-derived CD34− SRCs and succeeded in highly purifying primitive human CD34− HSCs. The limiting dilution analysis demonstrated that the incidence of CD34− SRCs in 18Lin−CD34−CD133+ cells was 1/142, which is the highest level of purification of these unique CD34− HSCs to date. Furthermore, CD133 expression clearly segregated the SRC activities of 18Lin−CD34− cells, as well as 18Lin−CD34+ cells, in their positive fractions, indicating its functional significance as a common cell surface maker to isolate effectively both CD34+ and CD34− SRCs.

Multi-color immune-phenotyping of CD34 subsets reveals unexpected differences between various stem cell sources

“…Their median age was 10 years (range 0. [8][9][10][11][12][13][14][15][16][17][18]. Conditioning regimens were myeloablative (n = 11) and reduced intensity (n = 10).…”

“…6,15 CD133/Prominin-1 was included only recently into a panel of markers to define different CD34 subsets. 16 Based on these studies, Görgens et al 17 suggested a revision of the most recent model of human hematopoiesis, the composite model (Figure 1), originally proposed by the Jacobsen group. 14,18 According to this, multi-potent progenitors (MPP) represent early CD34 developmental stages enriched within the CD45RA − CD133 + CD38 low CD10 − cell fraction most of which dividing asymmetrically.…”

A Novel High-Throughput Screening Platform Reveals an Optimized Cytokine Formulation for Human Hematopoietic Progenitor Cell Expansion

“…Although CD34 has been traditionally used to mark the HSPC compartment, substantial evidence indicates that expression of CD133 correlates better with long-term repopulation ability than CD34 [18,21], an observation supported by the fact that CB has higher proportions of CD133 + cells than mPB and BM [19,49]. The discrimination of a more defined population using the markers Lin -CD38 -CD34 + CD45RA -CD90 + CD49f + [23], which closely correlates with long-term repopulation ability, can only be achieved by multifactorial flow cytometry.…”

OKT3 prevents xenogeneic GVHD and allows reliable xenograft initiation from unfractionated human hematopoietic tissues

“…Although the existence of rare, poorly engrafting CD34 in xenotransplant studies could be omitting some critical cells that are included in clinical stem cell transplants in humans. 13,14 In this study, we set out to prevent GVHD from ruining precious primary leukemia samples. We found that anti T-cell antibodies were effective therapies in xenografts, with OKT3 and UCHT1 showing superior results to ATG due to off-target effects of ATG at the dose used.…”