Quantitation of the quiescent fraction of long-term culture-initiating cells in normal human blood and marrow and the kinetics of their growth factor-stimulated entry into S-phase in vitro

L. Ponchio, E. Conneally, C. Eaves

Research output: Contribution to journalArticle

66 Citations (Scopus)

Abstract

A method for quantitating the proportion of cycling long-term culture- initiating cells (LTC-IC) in heterogeneous populations of human hematopoietic cells is described. This procedure involves incubating the cells of interest for 16 to 24 hours in a serum-free medium containing 100 ng/mL Steel factor (SF), 20 ng/mL interleukin-3 (IL-3), and 20 ng/mL granulocyte-colony- stimulating factor (G-CSF), with or without 20 μCi/mL of high specific activity 3H-thymidine (3H-Tdr) before plating the recovered cells in standard LTC-IC assays. The details of this procedure are based in part on the finding that the number of LTC-IC (regardless of their cycling status) remains constant for at least 24 hours under these culture conditions, as long as 3H-Tdr is not present. In addition, we have determined that a 16- hour period of exposure to the 3H-Tdr is sufficient to maximize the discrimination of cycling LTC-IC but not long enough to allow a detectable redistribution of LTC-IC between noncycling and cycling compartments. Finally, any isotope reutilization that may occur is not sufficient to affect the LTC-IC 3H-Tdr suicide values measured. Application of this methodology to normally circulating LTC-IC showed these to be a primarily quiescent population. However, within 72 hours of incubation in a serum-free medium containing SF, IL-3, and G-CSF, most had entered S-phase, although there was no net change in their numbers. This suggests that, under certain conditions in vitro, self-renewal divisions of LTC-IC can occur and, at least initially, balance any losses of these cells due to their differentiation or death. In contrast, many of the LTC-IC in freshly aspirated samples of normal marrow were found to be proliferating, although those that were initially quiescent could also he recruited into S-phase within 72 hours in vitro when incubated under the same conditions used to stimulate circulating LTC-IC. This modified 3H-Tdr suicide procedure should facilitate further investigation of the mechanisms regulating the turnover of the most primitive compartments of human hematopoietic cells and how these may be altered in disease states or exploited for a variety of therapeutic applications.

Original languageEnglish
Pages (from-to)3314-3321
Number of pages8
JournalBlood
Volume86
Issue number9
Publication statusPublished - 1995

Fingerprint

S Phase
Cell culture
Intercellular Signaling Peptides and Proteins
Blood
Cell Culture Techniques
Bone Marrow
Kinetics
Stem Cell Factor
Interleukin-3
Serum-Free Culture Media
Granulocyte Colony-Stimulating Factor
Suicide
In Vitro Techniques
Plating
Isotopes
Thymidine
Population
Assays
Cells

ASJC Scopus subject areas

  • Hematology

Cite this

Quantitation of the quiescent fraction of long-term culture-initiating cells in normal human blood and marrow and the kinetics of their growth factor-stimulated entry into S-phase in vitro. / Ponchio, L.; Conneally, E.; Eaves, C.

In: Blood, Vol. 86, No. 9, 1995, p. 3314-3321.

Research output: Contribution to journalArticle

@article{34fa221b4c6141aeb54e49823cd4a53d,
title = "Quantitation of the quiescent fraction of long-term culture-initiating cells in normal human blood and marrow and the kinetics of their growth factor-stimulated entry into S-phase in vitro",
abstract = "A method for quantitating the proportion of cycling long-term culture- initiating cells (LTC-IC) in heterogeneous populations of human hematopoietic cells is described. This procedure involves incubating the cells of interest for 16 to 24 hours in a serum-free medium containing 100 ng/mL Steel factor (SF), 20 ng/mL interleukin-3 (IL-3), and 20 ng/mL granulocyte-colony- stimulating factor (G-CSF), with or without 20 μCi/mL of high specific activity 3H-thymidine (3H-Tdr) before plating the recovered cells in standard LTC-IC assays. The details of this procedure are based in part on the finding that the number of LTC-IC (regardless of their cycling status) remains constant for at least 24 hours under these culture conditions, as long as 3H-Tdr is not present. In addition, we have determined that a 16- hour period of exposure to the 3H-Tdr is sufficient to maximize the discrimination of cycling LTC-IC but not long enough to allow a detectable redistribution of LTC-IC between noncycling and cycling compartments. Finally, any isotope reutilization that may occur is not sufficient to affect the LTC-IC 3H-Tdr suicide values measured. Application of this methodology to normally circulating LTC-IC showed these to be a primarily quiescent population. However, within 72 hours of incubation in a serum-free medium containing SF, IL-3, and G-CSF, most had entered S-phase, although there was no net change in their numbers. This suggests that, under certain conditions in vitro, self-renewal divisions of LTC-IC can occur and, at least initially, balance any losses of these cells due to their differentiation or death. In contrast, many of the LTC-IC in freshly aspirated samples of normal marrow were found to be proliferating, although those that were initially quiescent could also he recruited into S-phase within 72 hours in vitro when incubated under the same conditions used to stimulate circulating LTC-IC. This modified 3H-Tdr suicide procedure should facilitate further investigation of the mechanisms regulating the turnover of the most primitive compartments of human hematopoietic cells and how these may be altered in disease states or exploited for a variety of therapeutic applications.",
author = "L. Ponchio and E. Conneally and C. Eaves",
year = "1995",
language = "English",
volume = "86",
pages = "3314--3321",
journal = "Blood",
issn = "0006-4971",
publisher = "American Society of Hematology",
number = "9",

}

TY - JOUR

T1 - Quantitation of the quiescent fraction of long-term culture-initiating cells in normal human blood and marrow and the kinetics of their growth factor-stimulated entry into S-phase in vitro

AU - Ponchio, L.

AU - Conneally, E.

AU - Eaves, C.

PY - 1995

Y1 - 1995

N2 - A method for quantitating the proportion of cycling long-term culture- initiating cells (LTC-IC) in heterogeneous populations of human hematopoietic cells is described. This procedure involves incubating the cells of interest for 16 to 24 hours in a serum-free medium containing 100 ng/mL Steel factor (SF), 20 ng/mL interleukin-3 (IL-3), and 20 ng/mL granulocyte-colony- stimulating factor (G-CSF), with or without 20 μCi/mL of high specific activity 3H-thymidine (3H-Tdr) before plating the recovered cells in standard LTC-IC assays. The details of this procedure are based in part on the finding that the number of LTC-IC (regardless of their cycling status) remains constant for at least 24 hours under these culture conditions, as long as 3H-Tdr is not present. In addition, we have determined that a 16- hour period of exposure to the 3H-Tdr is sufficient to maximize the discrimination of cycling LTC-IC but not long enough to allow a detectable redistribution of LTC-IC between noncycling and cycling compartments. Finally, any isotope reutilization that may occur is not sufficient to affect the LTC-IC 3H-Tdr suicide values measured. Application of this methodology to normally circulating LTC-IC showed these to be a primarily quiescent population. However, within 72 hours of incubation in a serum-free medium containing SF, IL-3, and G-CSF, most had entered S-phase, although there was no net change in their numbers. This suggests that, under certain conditions in vitro, self-renewal divisions of LTC-IC can occur and, at least initially, balance any losses of these cells due to their differentiation or death. In contrast, many of the LTC-IC in freshly aspirated samples of normal marrow were found to be proliferating, although those that were initially quiescent could also he recruited into S-phase within 72 hours in vitro when incubated under the same conditions used to stimulate circulating LTC-IC. This modified 3H-Tdr suicide procedure should facilitate further investigation of the mechanisms regulating the turnover of the most primitive compartments of human hematopoietic cells and how these may be altered in disease states or exploited for a variety of therapeutic applications.

AB - A method for quantitating the proportion of cycling long-term culture- initiating cells (LTC-IC) in heterogeneous populations of human hematopoietic cells is described. This procedure involves incubating the cells of interest for 16 to 24 hours in a serum-free medium containing 100 ng/mL Steel factor (SF), 20 ng/mL interleukin-3 (IL-3), and 20 ng/mL granulocyte-colony- stimulating factor (G-CSF), with or without 20 μCi/mL of high specific activity 3H-thymidine (3H-Tdr) before plating the recovered cells in standard LTC-IC assays. The details of this procedure are based in part on the finding that the number of LTC-IC (regardless of their cycling status) remains constant for at least 24 hours under these culture conditions, as long as 3H-Tdr is not present. In addition, we have determined that a 16- hour period of exposure to the 3H-Tdr is sufficient to maximize the discrimination of cycling LTC-IC but not long enough to allow a detectable redistribution of LTC-IC between noncycling and cycling compartments. Finally, any isotope reutilization that may occur is not sufficient to affect the LTC-IC 3H-Tdr suicide values measured. Application of this methodology to normally circulating LTC-IC showed these to be a primarily quiescent population. However, within 72 hours of incubation in a serum-free medium containing SF, IL-3, and G-CSF, most had entered S-phase, although there was no net change in their numbers. This suggests that, under certain conditions in vitro, self-renewal divisions of LTC-IC can occur and, at least initially, balance any losses of these cells due to their differentiation or death. In contrast, many of the LTC-IC in freshly aspirated samples of normal marrow were found to be proliferating, although those that were initially quiescent could also he recruited into S-phase within 72 hours in vitro when incubated under the same conditions used to stimulate circulating LTC-IC. This modified 3H-Tdr suicide procedure should facilitate further investigation of the mechanisms regulating the turnover of the most primitive compartments of human hematopoietic cells and how these may be altered in disease states or exploited for a variety of therapeutic applications.

UR - http://www.scopus.com/inward/record.url?scp=0028803338&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028803338&partnerID=8YFLogxK

M3 - Article

VL - 86

SP - 3314

EP - 3321

JO - Blood

JF - Blood

SN - 0006-4971

IS - 9

ER -