Ex Vivo Culture of Human Cord Blood Hematopoietic Stem/Progenitor Cells Adversely Influences Their Distribution to Other Bone Marrow Compartments After Intra-Bone Marrow Transplantation

Abstract

Intra-bone marrow injection is a novel strategy for hematopoietic stem cell transplantation. Here, we investigated whether ex vivo culture of cord blood hematopoietic stem/ progenitor cells influences their reconstitution in bone marrow after intra-bone marrow transplantation. Freshly isolated AC133؉ cells or cells derived from AC133 ؉ cells cultured with cytokines (stem cell factor, flt-3 ligand, and thrombopoietin) for 5 days were injected into the bone marrow of the left tibia in irradiated NOD/SCID mice. In the bone marrow of the injected left tibia, the engraftment levels of human CD45 ؉ cells at 6 weeks after transplantation did not differ considerably between transplantation of noncultured and cytokine-cultured cells. However, the migration and distribution of transplanted cells to the bone marrow of other, noninjected bones were extremely reduced for cytokine-treated cells compared with noncultured cells. Similar findings were observed for engraftment of CD34 ؉ cells. Administration of granulocyte colony-stimulating factor to mice after transplantation induced the migration of cytokine-cultured cells to the bone marrow of previously aspirated bone but not to other intact bones. These data suggest that ex vivo manipulation of hematopoietic progenitor/stem cells significantly affects their migration properties to other bone marrow compartments after intra-bone marrow transplantation. Our data raise a caution for future clinical applications of the intra-bone marrow transplantation method using ex vivo-manipulated hematopoietic stem cells. STEM CELLS 2008;26:543-549 Disclosure of potential conflicts of interest is found at the end of this article.

Engraftment defect of cytokine‐cultured adult human mobilized CD34+ cells is related to reduced adhesion to bone marrow niche elements

“…We found that levels of engraftment were consistently higher in the injected bone, for both fresh and cytokine‐cultured hCD34 + cells (Fig E). Lower engraftment in non‐injected bones has also been observed for CB CD34 + cells (Yamamura et al , ), but here the inability to colonize non‐injected bones appears to accentuate the engraftment defect of MPB cells cultured in cytokines (Fig E).…”

“…These data indicate that the observed engraftment defect of cultured hCD34 + cells is related, at least partly, to reduced anchorage within appropriate BM niches. Of note, Yamamura et al () observed, using AC133 + CB cells, that 5‐d culture in cytokines did not impair engraftment in injected tibiae, but that cultured cells had a reduced ability to colonize non‐injected bones, in comparison with fresh cells. In the case of MPB CD34 + cells, ex vivo culture appears to impair both lodgment in injected sites, as well as homing to non‐injected bones, thus accentuating the reduced engraftment potential of these cells.…”

Engraftment Efficiency after Intra–Bone Marrow versus Intravenous Transplantation of Bone Marrow Cells in a Canine Nonmyeloablative Dog Leukocyte Antigen-Identical Transplantation Model

“…and IBM-II HSCT. Several comparative studies that used different conditioning regimens as well as different species indicated that IBM HSCT facilitate the early engraftment [24][25][26]. In addition, higher levels of donor chimerism were observed in comparison with i.v.…”

Co-culture of hematopoietic stem cells with mesenchymal stem cells increases VCAM-1-dependent migration of primitive hematopoietic stem cells

“…The effect of MSC co-culturing on HSC adhesion molecule expression was assessed, as cytokines increased the expression of several HSC adhesion molecules, including the counterreceptors for VCAM-1 and fibronectin [3,4]. Co-culturing HSC with MSC did not significantly modify cytokine-induced changes in HSC CD49d (VLA-4 a-chain), CD49e (VLA-5 achain), CD44 and CD54 expression ( Fig.…”

“…HSC cytokine expansion has failed to improve transplantation success rates; this finding has been correlated with a loss of ''stemness'' that takes place after HSC division [1]. However, evidence of reduced cytokinestimulated HSC repopulating ability prior to cell division [2] and high engrafting levels in directly injected cytokineexpanded HSC into the bones points to a homing defect rather than just a differentiation event [3].…”