Preferential expansion of human umbilical cord blood-derived CD34-positive cells on major histocompatibility complex-matched amnion-derived mesenchymal stem cells.

Background: We previously found in a murine hematopoietic system that hematopoietic stem cells show high differentiation and proliferation capacity on bone marrow-derived mesenchymal stem cells/stromal cells (microenvironment) with "self" major histocompatibility complex (MHC).

Design And Methods: We examined whether amnion-derived adherent cells have the characteristics of mesenchymal stem cells, and whether these adherent cells can support the proliferation of umbilical cord blood-derived lineage-negative and CD34-positive cells (Lin(-)CD34(+) cells) obtained from the same fetus to a greater extent than those derived from other fetuses.

Results: Culture-expanded amnion-derived adherent cells expressed mesenchymal stem cell markers and HLA-ABC molecules and could differentiate into osteoblasts, adipocytes and chondrocyte-like cells, indicating that the cells have the characteristics of mesenchymal stem cells.

Contribution of neural cell adhesion molecule (NCAM) to hemopoietic system in monkeys.

Neural cell adhesion molecules (CD56) are important adhesion molecules that are mainly expressed on neural cells and natural killer cells. Although freshly isolated cynomolgus monkey bone marrow cells (BMCs) contained only a few CD56-positive cells, almost all the BM adherent cells (obtained after a 2- to 3-week culture of the BMCs) were stained positively with anti-CD56 monoclonal antibody (mAb). The BM adherent cells showed uniformly fibroblastic morphology and were negative for hematolymphoid markers (CD4, CD8, CD11b, CD14, CD34, and CD45).

Analyses of very early hemopoietic regeneration after bone marrow transplantation: comparison of intravenous and intrabone marrow routes.

In bone marrow transplantation (BMT), bone marrow cells (BMCs) have traditionally been injected intravenously. However, remarkable advantages of BMT via the intra-bone-marrow (IBM) route (IBM-BMT) over the intravenous route (IV-BMT) have been recently documented by several laboratories. To clarify the mechanisms underlying these advantages, we analyzed the kinetics of hemopoietic regeneration after IBM-BMT or IV-BMT in normal strains of mice.

Simultaneous injection of bone marrow cells and stromal cells into bone marrow accelerates hematopoiesis in vivo.

We have previously demonstrated that stromal cells can support the proliferation and differentiation of hematopoietic cells in vitro and in vivo and that a major histocompatibility complex restriction exists between hematopoietic stem cells and stromal cells. We have also found that intra-bone marrow (IBM) injection of allogeneic bone marrow cells (BMCs) leads to more rapid reconstitution of hematopoietic cells than intravenous injection. In the present study, we examine the effect of simultaneous injection of stromal cells and BMCs into the same bone marrow on the recovery of donor hematopoietic cells and demonstrate that simultaneous IBM injection of BMCs plus stromal cells is more effective in reconstituting recipients with donor hematopoietic cells than intravenous injection of BMCs plus stromal cells or IBM injection of BMCs alone.

Induction of tolerance in quadruple chimeric mice.

Human cord blood (CB) contains hematopoietic stem cells and progenitors. Because the major limitation to a widespread use of CB for transplantation lies in its limited volume, it is necessary to combine the CB from several donors. In this study, we show that lethally irradiated mice can be reconstituted with the injection of a mixture of T cell-depleted bone marrow cells (BMCs; total, 3 x 10(6)) obtained from three fully allogeneic mouse strains in two different mouse combinations.