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The 2004 Annual Meeting (January 14-20, 2004) of OASYS_NEW |
Not yet assigned to a slot - 12:20 AM
New Method of Stem and Early Progenitor Cells Transplantation in Limb Allografts
Introduction: This study was designed to investigate the effect of the intraosseous allotransplantation of the donor specific stem and early progenitor cells on the level of donor specific chimerism and survival rate of the rat hind limb allograft transplants.
Methods: Eighteen rat hind limb allograft transplantations were performed across major histocompatibility barriers between Lewis-Brown-Norway (LBN, RT1n+l, F1) and Lewis (LEW, RT11) rats in 3 groups, six animals each. No intraosseous stem and progenitor cell transplantation was performed in isograft and allograft rejection controls (groups 1 and 2). In-group 3, 0.8-1.2x106 bone marrow stem and progenitor cells were injected intraosseously into the recipient’s opposite tibia just before limb allograft transplantation.
Bone marrow stem and progenitor cells separation was performed by targeting stem and progenitor cells with mouse anti-rat FITC - conjugated CD90 mAb (Clone - OX-7; BD, San Jose, CA) and tagging with goat anti FITC magnetic-beads conjugated, followed by isolation on the MidiMACS LS+ columns. Separated and purified (efficacy >95% confirmed by flow cytometry) stem and early progenitor cells were injected intramedullary into the bone marrow cavity of the recipient’s contralateral limb.
Results: Transplants from isograft group survived indefinitely. Allograft controls rejected transplants uniformly on day 7 after limb transplantation. The injection of separated and purified CD90+ stem and progenitor cells of the donor origin extended survival of the transplanted limb up to 15 days in group 3. Lymphoid chimerism level was also higher in-group 3 (3.4%) when compared with group 2 (0.6%).
Conclusions: In this preliminary study introduced a novel method for transplantation of the stem and early progenitor cells of the donor origin into the recipient’s bone marrow cavity. This technique of intraosseus injection of donor stem cells resulted in the extension of allograft survival. Further studies combining immunomodulatory therapies and stem cells transfer are in progress.