Myeloproliferative syndrome induced by MPSV in DBA/2 mice: presence of a
mixed-colonies promoting activity (MPA) in the spleen
MC Le Bousse-Kerdiles, F Smadja-Joffe, B Klein, C Jasmin, M Comisso and W Ostertag
The myeloproliferative syndrome induced by the myeloproliferative sarcoma
virus (MPSV) in DBA/2 mice stimulates the proliferation of pluripotent
hemopoietic stem cells (HSC) and of progenitors committed toward
granulomacrophagic and erythroid cell lines. This stimulation may result
from a direct effect of the MPSV on HSC or from an indirect effect via
locally secreted factors. Normal isogenic bone marrow cells were incubated
in the mixed colony-forming unit system in semisolid medium supplemented
with conditioned media obtained after incubating neoplastic spleen cells
for 3 days at 37 degrees C. These spleen conditioned media contain an
activity that is physically separable from MPSV by ultracentrifugation and
which, in the presence of a very low quantity of erythropoietin, can induce
in vitro the proliferation and differentiation of pluripotent HSC, detected
by this Mix-CFU technique. We termed this activity mixed-colonies promoting
activity (MPA). These results suggest that the hyperplasia of the
nonlymphoid hematopoietic system in the neoplastic spleen results from an
indirect effect of the MPSV on pluripotent HSC via locally secreted
factors.
Volume 61,
Issue 3,
pp. 520-524,
03/01/1983
Copyright © 1983 by The American Society of Hematology
