Bone marrow transplantation strategies.

(A) For total bone marrow transplantations, 5×10⁶ T cell-depleted total bone marrow cells from donor mice were injected i.v. into lethally irradiated (2×550 cGy) mice, as indicated. Semi-lethally irradiated (450 cGy) mice were injected with FACS-sorted 4×10⁵ CD11b⁺ myeloid cells, 4×10⁵ CD19b⁺ B cells or 4×10⁴ common myeloid progenitors (CMP) cells. 4×10⁵ CD11b⁺ myeloid cells were also transferred into non-irradiated mice. After 3 weeks mice were sacrificed, engraftment of transplanted bone marrow was evaluated by FACS and pancreata were analyzed by histology for the presence of bone marrow-derived cells at the tumor site. (B) Schematic illustration of syngeneic TRAMP-C1 tumor experiments. 5×10⁵ TRAMP-C1 cells were injected into the flank of either C57BL/6 previously reconstituted with bone marrow of beta-actin-GFP transgenic mice or bone marrow of double-transgenic CD11b-Cre;Z/EG mice, and tumors were allowed to grow for 3 to 4 weeks. FACS analysis was used to assess bone marrow reconstitution or Cre recombinase-mediated GFP expression, respectively. Histological sections from TRAMP-C1 tumors were analyzed by immunofluorescence for the presence of GFP⁺ cells. (C–E) Flow cytometry-based strategy for cell sorting. (C) Within a scatter gate excluding lymphocytes, CD11b^high/GFP^high cells were isolated by FACS. (D) CD19⁺ was used as marker for the isolation of B lymphocytes. (E) CMP cells were sorted as lin⁻/Sca-1⁻/IL7Rα⁻/cKit⁺ as described in Methods.