The effects of purified recombinant murine interleukin-3 and/or purified
natural murine CSF-1 in vivo on the proliferation of murine high- and
low-proliferative potential colony-forming cells: demonstration of in vivo
synergism
DE Williams, G Hangoc, S Cooper, HS Boswell, RK Shadduck, S Gillis, A Waheed, D Urdal and HE Broxmeyer
Purified natural murine L cell (macrophage) colony-stimulating factor
(nCSF-1) and purified recombinant murine interleukin-3 (rIL-3) were
administered to normal or lactoferrin-pretreated mice 20 to 24 hours before
sacrifice. rIL-3 and nCSF-1 administered separately increased the
percentage of macrophage high-proliferative potential colony- forming cells
(HPP-CFC) and low-proliferative potential colony-forming cells (LPP-CFC) in
active cell cycle. Endotoxin was not detected in the samples of nCSF-1 or
rIL-3 with the Limulus lysate test, and the in vitro and in vivo
hematopoietic stimulatory effects of both molecules were abolished or
markedly reduced by 30 minutes' treatment at 100 degrees C, which
demonstrates that the effects noted in vivo were not due to endotoxin.
Combinations of low concentrations of rIL-3 and nCSF- 1, which by
themselves were inactive, increased the percentage of HPP- CFC and LPP-CFC
in active cell cycle in a synergistic fashion. No significant change in the
number of HPP-CFC or LPP-CFC per femur or femoral nucleated cellularity was
observed. Thus, rIL-3 and nCSF-1 can synergize to effect the proliferation
of the same cell populations in vivo.
Volume 70,
Issue 2,
pp. 401-403,
08/01/1987
Copyright © 1987 by The American Society of Hematology
