R. Namikawa et al., Administration of Flk2/Flt3 ligand induces expansion of human high-proliferative potential colony-forming cells in the SCID-hu mouse, EXP HEMATOL, 27(6), 1999, pp. 1029-1037
The effects of Flk2/Flt3 ligand (FL) administration on human hematopoiesis
were investigated using SCID-hu mice transplanted with human fetal bone fra
gments. Treatment with recombinant human FL induced significant increases i
n the frequencies of the high-proliferative potential colony-forming cells
and low-proliferative potential colony-forming cells in steady-state human
bone marrow. FL also promoted the expansion of high-proliferative potential
colony-forming cells and low-proliferative potential colony-forming cells
in the human bone marrow during the recovery phase after irradiation, which
was evident in increases in the frequencies as well as in the absolute num
bers of colony-forming cells, Furthermore, higher percentages of CD33(+)CD1
5(-) cells were found in the marrows treated with FL as compared to that of
controls, indicating that FL hastened the recovery of at least some aspect
of myelopoiesis after irradiation. These results indicate that FL induces
the expansion of primitive hematopoietic progenitor cells in vivo and, ther
efore, may be useful in treating patients to promote an early hematopoietic
recovery after cytoablative therapies. (C) 1999 International Society for
Experimental Hematology, Published by Elsevier Science Inc.