Purified murine hematopoietic stem cells function longer on nonirradiated
W41/Wv than on +/+ irradiated stroma
F Vecchini, KD Patrene and SS Boggs
Department of Radiation Oncology, University of Pittsburgh School of
Medicine, PA 15261.
Mouse bone marrow (BM) was separated into low-density, lineage- negative,
wheat germ agglutinin-positive (WGA+), Rhodamine-123 bright (Rhbright) or
dim (Rhdim) cells to obtain populations that were highly enriched for
committed progenitors (Rhbright cells) or for more primitive stem cells
(Rhdim). When 2,500 Rhbright or Rhdim cells were seeded onto 6-week-old
irradiated (20 Gy) long-term BM cultures (LTBMC), the nonadherent cell
production from Rhbright cells was transient and ended after 5 weeks.
Production from Rhdim cells did not begin until week 3, peaked at week 5,
and ended at week 8, when the irradiated stroma seemed to fail. Termination
of cell production from Rhdim cells did not occur in nonirradiated LTBMC
from W41/Wv mice. During peak nonadherent cell production, 25% to 30% of
the cells in the nonirradiated LTBMC from W41/Wv mice had donor cell
markers. Two approaches were tested to try to enhance the proportion or
number of donor cells. Addition of Origen-HGF at the time of seeding Rhdim
cells caused a nonspecific increase in both host and donor cell production,
but a specific increase in production of donor cells was obtained by
seeding the cultures at 2 weeks rather than 6 weeks. Limiting dilution of
Rhdim cells gave the same frequency of wells producing cells on both
irradiated +/+ and nonirradiated W41/Wv or W/Wv cultures.
Volume 81,
Issue 6,
pp. 1489-1496,
03/15/1993
Copyright © 1993 by The American Society of Hematology
