T- and B-lymphocyte differentiation potentials of spleen colony-forming
cells
F Lepault, S Ezine and MC Gagnerault
CNRS URA 1461, Hopital Necker, Paris, France.
Cells that generate splenic colonies within 8 days (day-8 colony- forming
units-spleen [CFU-s]) are generally thought to differentiate only into
erythroid/myeloid cells. The T and B lymphocyte differentiation potentials
of day-8 CFU-s were evaluated and compared with those of day-12 and
5-fluorouracil (5-FU) CFU-s. This was achieved by analyzing, after
intravenous and intrathymic injection, the lymphocyte progeny of cells
contained within individual splenic colonies collected at day 8 and day 12
post-bone marrow cell transfer into irradiated congenic recipients. A large
majority of day-8 spleen colonies generated T cells when transferred
intrathymically. After intravenous (IV) injection of day-8 colonies,
donor-type thymocytes emerged in 33% of the animals reconstituted with only
1 day-8 colony, but in 83% of those inoculated with a pool of 5 colonies.
All post-5-FU and 75% of day-12 colonies gave rise to thymocytes after IV
injection. B cells were generated by a high proportion of day-8 colonies,
and by all day-12 and post 5-FU colonies. These results demonstrate that
progenitors of T and B lymphocytes are generated within spleen colonies
produced by at least some day-8 CFU-s and virtually all day-12 CFU-s.
Whether these progenitors are CFU-s themselves or committed precursors
remains an open question.
Volume 81,
Issue 4,
pp. 950-955,
02/15/1993
Copyright © 1993 by The American Society of Hematology
