The Effect Of Cotransplantation Of Ex Vivo Expanded Human Cord Blood Hematopoietic Cells In Combination With Cultured Barrow-derived Mesenchymal Stem Cells In Vutro To Early Hematopoietic Reconstitution In NOD/SCID Mice

Objective: To explore the effect of cotransplantation of ex vivo expanded cord blood nuclear cells in combination with adult bone marrow-derived mesenchymal stem cells (MSC) to early hematopoietic reconstitution in sublethally irradiated NOD/SCID mice, in order to resolve the insufficiency numbers of hematopoietic stem/progenitor cells (HSPC), which do not satisfy the transplantation need of high weigh patients, as well as the early engraftment prolong after cord blood transplantation(CBT), and then to extent clinical application of CBT.Methods: After cryopreserved CB was thawed, according to 2.0× 10~4 CBCD34~+ cells (1.05×10~7 NC) being injected per mouse as the lowest dose, its 1/4 or 1/6 was ex vivo expanded in serum-free, stromal-free culture medium in combination with SCF, FL, TPO, and IL-3 for 7 days differently. Mononuclear cells (MNC) were separated from adult bone marrow by Ficoll-Hypaque gradient centrifugation. Mesenchymal stem cells (MSC) were enriched from MNC with density gradient ceintrifugation and cell adherent method. MSCs were ex vivo cultured continuously and passaged to the third progeny. Sublethally irradiated (400cGy, 200cGy /min) NOD/SCID mice were transplanted intraverously with non-cultured and cultured CB NC in presence or absence of MSC, or with non-expanded CB NC in presence of MSC, or with CB NC only, human CD45~+ CD34~+, CD33~+, CD71~+, and CD19~+ cells of bone marrow, spleen, and peripheral blood...