| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2005: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 2004: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Research Abstract |
Intra-bone marrow-xenotransplantation was studied. As a source of hematopoietic stem cells, human cord blood and bone marrow was used.
As a recipient, NOD-SCID β2-null mice aged 5-8 weeks was used. CD34 positive cells (20000-100,000 cord blood cells or 100,000-1,000,000 bone marrow cells) were transplanted in tibiae of recipient mice after 300cGy of irradiation. Same number of cells were transplanted intravenously as controls. Mice were killed after 8 weeks from the transplantation, then cells from bone marrow, peripheral blood and spleen were stained with anti-human CD45,CD19,CD11,CD3, and Glycophorin A antibodies. Cells were analyzed with FACS Calibur. Both intravenous and intra-bone marrow transplantation of cord blood showed high efficiency of engraftment, and no significant differences were observed. In the transplantation of bone marrow cells, only a few engraftments of human cells were observed both intra-bone marrow and intravenous transplantation. Next we tested treatment of CD34 positive bone marrow cells with human protease before transplantation. Surprisingly, up to 80% of human cell engraftment were observed in the intra-bone marrow transplanted mice, and only a few engraftments were observed in the intravenously transplanted mice. So far, it is unclear why pretreatment of bone marrow cells with protease is effective in intra-bone marrow xenotransplantation. Proteases are known as regulator of granulopoiesis. They might play important roles not only in granulopoiesis but also modulating molecules that contribute homing of stem cells.
We are investigating the molecular change on bone marrow stem cells after treatment of proteases.
We also investigated impaired granulopoiesis in childhood neutropenia.
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