In vivo stem cell function of interleukin-3-induced blast cells
J Tsunoda, S Okada, J Suda, K Nagayoshi, H Nakauchi, K Hatake, Y Miura and T Suda
Department of Medicine, Jichi Medical School, Tochigi-ken, Japan.
The treatment of mice with high doses of 5-fluorouracil (5-FU) results in
an enrichment of primitive hematopoietic progenitors. Using this procedure,
we obtained a new class of murine hematopoietic colonies that had very high
secondary plating efficiencies in vitro and could differentiate into not
only myeloid cells but also into lymphoid lineage cells. The phenotypes of
interleukin-3 (IL-3) induced blast colony cells were Thy-1-positive and
lineage-marker-negative. We examined whether these blast colony cells
contained primitive hematopoietic stem cells in vivo and could reconstitute
hematopoietic tissues in lethally irradiated mice. Blast colony cells could
generate macroscopic visible spleen colonies on days 8 and 12, and 5 x
10(3) blast cells were sufficient to protect them from lethally
irradiation. It was shown that 6 or 8 weeks after transplantation of 5 x
10(3) blast cells, donor male cells were detected in the spleen and thymus
of the female recipients but not in the bone marrow by Southern blot
analysis using Y-encoded DNA probe. After 10 weeks, bone marrow cells were
partially repopulated from donor cells. In a congenic mouse system,
donor-derived cells (Ly5.2) were detected in the thymus and spleen 6 weeks
after transplantation. Fluorescence-activated cell sorter analyses showed
that B cells and macrophages developed from donor cells in the spleen. In
the thymus, donor-derived cells were found in CD4, CD8 double-positive,
single-positive, and double-negative populations. Reconstitution of bone
marrow was delayed and myeloid and lymphoid cells were detected 10 weeks
after transplantation. These results indicate that IL-3-induced blast cells
contain the primitive hematopoietic stem cells capable of reconstituting
hematopoietic organs in lethally irradiated mice.
Volume 78,
Issue 2,
pp. 318-322,
07/15/1991
Copyright © 1991 by The American Society of Hematology
