Figure 6.

(A) Bid−/− bone marrow displays normal numbers of progenitor cells. FACS-staining profiles of progenitor populations from littermate Bid+/+ or Bid−/− bone marrow (14–16 mo of age). The lineage (Lin) cocktail consists of: CD3, CD4, CD8, B220, CD19, Ter119, Mac-1, Gr-1. Lin⁻, c-kit⁺, Sca-1⁻ cells were collected by flow sorting, and stained for CD34 and FcγII/III to delineate subpopulations of progenitor cells. HSCs were defined as Lin⁻, c-kit^high, Sca-1^high. Myeloid-erythroid progenitors were defined as Lin⁻ c-kit^highCD34⁻ FcγII/III^lo, GMPs were defined as Lin⁻ c-kit^highCD34⁺FcγII/III^high, and CMPs were defined as Lin⁻ c-kit^highCD34⁺FcγII/III^lo. (B) Transferred Bid−/− leukemic bone marrow demonstrates an expansion of GMP. FACS-staining profiles of progenitor populations of bone marrow from a secondary transplant of leukemic Bid−/− bone marrow reveals increased lin^neg, Sca1^pos, c-kit^pos cells consistent with expansion of GMP cells. Immunophenotype of bone marrow (C) and spleen (D) cells from a representative, primary leukemic Bid-deficient mouse. Flow cytometric analysis revealed an expansion of myeloid precursor cells and mature monocytes. There is a corresponding relative depletion of T cells (CD3+, CD4+, CD8+) and B cells (B220+). Plasma cells (CD138+B220−) and macrophages (F4/80+) were not expanded. Samples were gated on live cells based on forward and side scatter profiles.