The Proliferative State of Granulocytic Progenitor Cells in Human Blood and Marrow

Abstract

A double layer agar technique was used to investigate the proliferative state of granulocytic progenitor cells (Colony Forming Units in Culture; CFUc) in human peripheral blood and bone marrow. The sensitivity of the progenitor cells to the S‐phase specific agent, hydroxyurea, was used as an index of the proportion of cells engaged in DNA synthesis. In the presence of low concentrations of colony stimulating factor (CSF) the CFUc were found to be virtually insensitive to the drug. However, when cultured in the presence of increasing concentrations of CSF the proportion of CFUc apparently killed by hydroxyurea increased to a maximum of 23% for those cells in the blood and 39% for those in the marrow. The results indicate that CFUc which are slowly proliferating are sensitive to low concentrations of CSF. In contrast, those CFUc which are proliferating more rapidly require high concentrations of CSF before they will form colonies in culture. A model has been devised which suggests that as CFUc mature, their cell cycle time shortens and their sensitivity to CSF decreases.

Characterization of erythroid and granulocyte monocyte progenitors in human cord blood

“…The result may be explained in the light of velocity sedimentation profiles and data on DNA synthetic fraction of haemopoietic progenitors. The progenitors in adult blood are homogeneous, small and of low suicidal fraction representing a population of very early cells in the stem cell hierarchy migrating from the bone marrow (21). By contrast cord blood progenitors constitute a more heterogeneous population with respect to the cell volume distribution profile of higher suicidal fraction.…”

Production of Colony-Stimulating Activity by Circulating Leukocytes from Patients with Chronic Myeloid Leukemia at Various Phases of the Disease

“…Standen et al [10] demonstrated that for both human BM and PB MNC as overlayers, colony yield increased linearly with increasing concentrations of feeder cells until a plateau was reached with feeder cell doses of 1 x 109 leukocytes per plate. Therefore, this system provides a sensitive assay for PBL CSA.…”