In vivo dynamics of human cord blood-derived CD34− SCID-repopulating cells using intra-bone marrow injection

Abstract

The identification of human CD34-negative (CD34 À ) hematopoietic stem cells (HSCs) provides a new concept for the hierarchy in the human HSC compartment. This study investigated the long-term repopulating capacity and redistribution kinetics of human cord blood-derived CD34 À severe combined immunodeficiency (SCID)-repopulating cells (SRCs) and compared them with those of CD34 þ CD38 þ and CD34 þ CD38 À SRCs using the intra-bone marrow injection (IBMI) to clarify the characteristics of CD34 À SRCs. On the basis of the limiting dilution analyses data, estimated numbers of CD34 þ CD38 þ , CD34 þ CD38 À , and CD34 À SRCs were transplanted to NOD/SCID mice by IBMI. The human cell repopulation at the site of injection and the other bones were serially investigated. Interestingly, CD34 þ CD38 þ , CD34 þ CD38 À , and CD34 À SRCs began to migrate to other bones 2 and 5 weeks after the transplantation, respectively. Accordingly, the initiation of migration seemed to differ between the CD34 þ and CD34 À SRCs. In addition, CD34 þ CD38 þ SRCs only sustained a shortterm repopulation. However, both CD34 þ CD38 À and CD34 À SRCs had longer-term repopulation capacity. Taken together, these findings showed that CD34 À SRCs show different in vivo kinetics, thus suggesting that the identified CD34 À SRCs are a distinct class of primitive HSCs in comparison to the CD34 þ CD38 þ and CD34 þ CD38 À SRCs.

Optimization of Intrabone Delivery of Hematopoietic Progenitor Cells in a Swine Model Using Cell Radiolabeling with [89]zirconium

“…Xenotransplantation of human UCB HPCs into mice utilizing direct IB-injection achieves superior long-term engraftment and the ability for secondary SCID mouse repopulation (22)(23)(24). These preclinical small-animal models cannot predict engraftment kinetics in humans undergoing IB-HCT.…”

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

“…21, 22, 23 Moreover, our in vivo kinetic analysis clearly demonstrated that only one or two CD34 − SRCs had potent human hematopoietic cell reconstitution potentials, which was almost equivalent to that of 5–10 CD34 + CD38 − SRCs. 24, 25 Using this highly efficient SRC assay, we demonstrated that the surface immunophenotype of CD34 − SRCs is Lin − CD34 − c-kit − flt3 − . 23, 26 However, the frequency of CD34 − SRCs in these 13Lin − CD34 − cells is approximately 1/25 000, which is still very low in comparison to the frequency (1/40) of CD34 + CD38 − SRCs in 13Lin − CD34 − cells.…”

Mouse Dental Pulp Stem Cells Support Human Umbilical Cord Blood-Derived Hematopoietic Stem/Progenitor Cells in Vitro

“…As reported previously, CB-derived CD34 − SRCs could produce CD34 + SRCs in vitro (7,(11)(12)(13)41). In order to investigate whether DPSCs and BM-MSCs have the potential to support human hematopoietic stem/progenitor cells (HSPCs) in vitro, 2,000 human CB-derived 18Lin − CD34 + or 18Lin − CD34 − cells (shown in factor (G-CSF)] for 1 week.…”

“…Then, the SRC activities of human CB-derived 18Lin − CD34 + and 18Lin − CD34 − cells cocultured with mouse BM-MSCs or DPSCs were evaluated using NOG mice as reported previously (7,(11)(12)(13)41). Human CBderived 18Lin − CD34 + or 18Lin − CD34 − cells cocultured with mouse BM-MSCs, DPSCs, or without feeder cells were transplanted into NOG mice by the IBMI method.…”