Improved Hematopoiesis in Anemic Sl / SP ’ Mice by Splenectomy and Therapeutic Transplantation of a Hematopoietic Microenvironment

The ability of a clonal hematopoiesis-supportive bonemarrow stromal cell line GBlneor to engraft and alter the microenvironment-induced anemia of SI/Sl ’ mice was studied. Prior to stromal cell transplantation. SI/SId mice received 1 Gy total body irradiation (TBI) and 1 3 Gy to the right hind limb. Two months after intravenous (IV) injection of 5 x 1 GBlneor cells. 54.4% ± 1 7.0% donor origin (G41 8’) colony-forming cells were recovered from the right hind limb of SI/SId mice. Long-term bone marrow cultures (LTBMCs) established from GBlneor transplanted mice produced 1 89.5 CFU-GEMM-forming progenitors/flask over 1 0 weeks compared with 52.7 ± 6.2 CFU-GEMM forming progenitors /flask from irradiated nontransplanted SI/Sld mice. A partial correction of macrocytic anemia was detected 2 months after GBlneor transplantation in splenectomized. irradiated SI/SId mice (HgB 7.2 ± 0.4 g/dL; MCV 68.3 ± 7.0 fI) compared to splenectomized, irradiated, nontransplanted SI/SId mice (HgB 5.5 ± 1 .1 g/dL; MCV 76 ± 8.5 fL) or control SI/SId mice (HgB 5.4 ± 0.5 g/dL; MCV 82.4 ± 1 .3 fI). Mean RBC volume distribution