Post-chemotherapy and cytokine pretreated marrow stromal cell layers suppress hematopoiesis from normal donor CD34+ cells

Abstract

Summary:Marrow stromal layers were used to investigate the potential role of negative regulators produced by the marrow microenvironment as one potential cause of hematopoietic suppression after chemotherapy and cytokines. Stromal layers were established from marrow of normal or prechemotherapy donors and breast cancer patients after hematological recovery from one cycle of 5-fluorouracil, leucovorin, doxorubicin, and cyclophosphamide and GM-CSF or PIXY321 (GM-CSF/IL-3 fusion protein). Normal donor CD34 + cells were placed in contact with stromal layers, and the number of colony-forming units for granulocytes and macrophages (CFU-GM) was determined. There were 25-79% fewer CFU-GM in post-chemotherapy stromal layer cocultures than in no chemotherapy cocultures. With neutralizing antibody to TNF-␣ the number of CFU-GM in no chemotherapy and post-chemotherapy stromal cocultures was, respectively, 96 ؎ 7% (n = 5) and 142 ؎ 8% (n = 5) of the number with no antibody treatment. PIXY321 and GM-CSF pretreated stromal layers also suppressed production of CFU-GM. Anti-TNF-␣ promoted an increase in CFU-GM numbers from GM-CSF, but not PIXY321, pretreated stromal cocultures. The results demonstrate that post-chemotherapy marrow stromal layers were deficient in supporting in vitro hematopoiesis and suggest that negative regulators induced by chemotherapy and cytokines may be one cause for this defect.

Adventage of mesenchymal stem cells (MSC) expansion directly from purified bone marrow CD105+ and CD271+ cells.

“…Presence of N-cadherin positive cells in CD271 and RossetteSep fractions is intriguing in the light of recent reports showing that spindle-shaped, N-cadherin + osteoblasts (SNO) form niches supporting hematopoietic cells development [40]. Preservation or even enrichment of SNO precursor cells before subsequent transplantation could be of great importance for reconstitution of hematopoietic niches after myeloablative therapies which negatively affect bone marrow microenvironment [41][42][43].…”

Optical Imaging of PKH‐Labeled Hematopoietic Cells in Recipient Bone Marrow In Vivo

“…Previous studies have demonstrated that stromal cell lines support HSC survival in long-term cultures, emphasizing a collaborative mode of interaction between donor cells and the recipient BM microenvironment [27][28][29]. However, numerous studies have pointed out that the expressions of cytokines and cell-surface ligands of both HSCs and stromal cells were altered by the interaction itself and varied in different experimental conditions [29][30][31].…”

“…Cellular homing to the host BM is mediated by a variety of molecular interactions and is influenced by the phenotype of Askenasy,Farkas 510 the transplanted cells and their stage in the cell cycle [11-16, 19, 42-45]. Then, the cells interact with the BM stromal microenvironment and the extracellular matrix in a complex manner, as suggested by the large number of ligands and receptors shown to affect seeding and engraftment [11,16,[21][22][23][24][25][26][27][28][29]. Despite the identification of several important molecular mechanisms of homing and seeding, much remains unknown about these early events of engraftment.…”

“…Transplanted cells are presumed to lodge in a hematopoietic niche composed of various stromal elements [20] that provides ligands for adhesion and signals that control the quiescence, self-renewal, proliferation, and differentiation of the hematopoietic progenitors and stem cells [21][22][23][24][25][26]. Considering that our limited understanding of BM physiology imposes severe limitations on simulation of the conditions in vitro, the self-imposed critique of studies performed in culture is well taken [21,[27][28][29]. In fact, the interaction of hematopoietic cells with the BM stroma induces reciprocal changes in the expression of ligands and cytokines, which are markedly affected by culture conditions [29][30][31].…”

Effect of mesenchymal stem cell transplantation on the engraftment of human hematopoietic stem cells and leukemic cells in mice model

“…So it might be desirable to repair or replace a damaged bone marrow stromal compartment possibly by transplanting donor stromal cells [4][5][6][7]. Given the fact that donor-derived stromal cells do not engraft following conventional HSCT due to the limited number of stromal cells present in a typical allograft even having a competitive advantage over the damaged recipient's stroma, donor stromal cell engraftment could be achieved by transplanting a large number of MSCs that had been expanded in culture [8].…”