F36VFGFR1 can expand stHSCs. (A-B) Average percentages of GFP+ red cells, platelets, granulocytes (polys), monocytes (monos), B cells, and T cells in 10 mice that were given transplants of 8 × 106 F36VFGFR1-transduced cells obtained from cultures initiated with 2.5 × 106 transduced marrow cells, and expanded 11 × 106-fold over 28 days in AP20187. (A) Results from 5 mice that were given cotransplants of 1 × 105 fresh bone marrow cells. (B) Results from 5 mice that were given transplants of F36VFGFR1-expanded cells alone. Error bars depict standard deviations. (C) Three-arm LAM-PCR of sorted granulocytes (G), monocytes (M), erythroid cells (E), B cells (B), and T cells (T) from the marrow (BM) and spleens (Sp) of 2 mice (numbers 6028 and 6030) from panel B. Sequencing of LAM-PCR products from mouse 6030 revealed a provirus insertion in chromosome 2 at position 118236195. DNAs from the indicated cell isolates were subjected to 38 cycles of amplification using an LTR primer and a host genomic primer. (D) Individual (symbols) and average (line) red cell, white cell, and platelet counts of mice depicted in panel B, 3 months after transplantation (ex vivo; circles) and a normal control mouse (CTL; triangles). A second identical experiment showed lower levels of donor-origin cells for only 65 days after transplantation. The repopulating ability of F36VFGFR1-transduced cells fell dramatically when cultured for longer than 28 days (data not shown).
