Regulated proliferation of primitive hematopoietic progenitor cells in long-term human marrow cultures

Journal Article · Tue Oct 01 04:00:00 EDT 1985 · Blood; (United States)

OSTI ID:6429176

Cashman, J; Eaves, A C; Eaves, C J

We have examined the cycling status of various classes of erythroid and granulopoietic progenitor populations maintained for many weeks in standard normal long-term human marrow cultures. These were initiated with a single inoculum of marrow aspirate and were routinely fed by weekly removal of half of the nonadherent cells and replacement of half of the growth medium. Progenitors of large erythroid colonies (more than eight erythroblast clusters) present in the nonadherent fraction and progenitors of small granulocyte/macrophage colonies (fewer than 500 cells) present in both the nonadherent and adherent fractions were found to be actively cycling at all times examined (28% to 63% kill following a 20-minute exposure to 20 microCi/mL of high specific activity /sup 3/H-thymidine). In contrast, progenitors of large granulocyte/macrophage colonies (more than 500 cells) and progenitors of large erythroid colonies (more than eight erythroblast clusters), present in the adherent layer, consistently alternated between a quiescent state at the time of each weekly medium change and a proliferating state two to three days later (0% to 13% kill and 21% to 49% kill, respectively). Additional experiments revealed that the activation of primitive progenitors in the adherent layer was not dependent on the addition of fresh glutamine or hydrocortisone, nor on the physical manipulations involved in changing the growth medium. These studies provide the first direct evidence that normal long-term human marrow cultures support the continued turnover of a variety of early hematopoietic progenitor cell types. Further, they indicate that the proliferative activity of the most primitive of these progenitors is regulated by stage-specific cell-cell interactions that are subject to manipulation.

• Research Organization: Univ. of British Columbia, Vancouver, Canada
• OSTI ID: 6429176
• Journal Information: Blood; (United States), Journal Name: Blood; (United States) Vol. 4; ISSN BLOOA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
AZINES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY
BODY FLUIDS
BONE MARROW CELLS
CELL CYCLE
CELL DIVISION
CELL PROLIFERATION
CONNECTIVE TISSUE CELLS
HEMATOPOIETIC SYSTEM
HETEROCYCLIC COMPOUNDS
LABELLED COMPOUNDS
LEUKOCYTES
MACROPHAGES
MATERIALS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHAGOCYTES
PYRIMIDINES
RIBOSIDES
SOMATIC CELLS
THYMIDINE
TRITIUM COMPOUNDS