Limiting-dilution analysis of the effects of colony-stimulating factors,
phytohemagglutinin, and hydrocortisone on hematopoietic progenitor cell
growth
Y Takaue, CL Reading, AJ Roome, KA Dicke, S Tindle, M Chandran and B Devaraj
Department of Pediatrics, University of Texas M.D. Anderson Hospital and
Tumor Institute, Houston 77025.
The effects of colony-stimulating factors (CSFs), phytohemagglutinin (PHA),
and hydrocortisone on the growth of human bone marrow hematopoietic
progenitor cells (granulocyte-macrophage; GM) were analyzed in a
limiting-dilution assay (LDA). Both low-density bone marrow cells separated
by discontinuous Percoll gradients and a T cell- depleted and
progenitor-enriched cell fraction obtained by the combination of
counterflow elutriation centrifugation and Percoll gradients were examined
in LDA. GCT (monocytoid cell line-conditioned medium containing GM-CSF),
human placenta-conditioned medium, bladder carcinoma cell line
5637-conditioned medium (containing GM- and G-CSF), and recombinant CSF
(G-CSF) directly induced proliferation of progenitors with single-hit
kinetics. In some instances, however, PHA- stimulated
lymphocyte-conditioned medium (containing G- and GM-CSF) showed deviation
from single-hit kinetics, which demonstrated the presence of factor(s)
suppressive to progenitor growth. In a T cell- depleted,
progenitor-enriched fraction, PHA alone was found to suppress progenitor
growth at a level as low as 100 ng/mL. The addition of hydrocortisone
(10(-6) mol/L) increased the progenitor frequency but suppressed progenitor
growth at 10(-4) mol/L. LDA appears to be a valuable method for exploring
mechanisms of factors regulating hematopoietic cell growth.
Volume 70,
Issue 5,
pp. 1611-1618,
11/01/1987
Copyright © 1987 by The American Society of Hematology
