Studies on the hyperthermic sensitivity of the murine hematopoietic stem cell compartment. II. Heat effect on donor stem cells with long-term repopulating ability.
Variations in hyperthermic sensitivity among different hematopoietic progenitor and stem cell populations of the bone marrow have been previously described for clonogenic subsets responsible for short-term hematopoiesis. However, less is known of the heat sensitivity of more primitive stem cells capable of long-term repopulation in irradiated recipients. In the present study, control and heat-treated (60 minutes at 43 degrees C) donor bone marrow cells from congenic B6-Gpi-1a mice were transplanted at different cell doses (10(4), 10(5), 10(6), and 10(7) nucleated cells) in pre-irradiated (6 Gy) B6-Gpi-1b mice. The development and levels of donor marrow engraftment were determined from blood Gpi phenotyping, and the bone marrow dose required for equivalent long-term engraftment at 20 weeks provided an estimate of the surviving fraction corresponding to primitive stem cells of long-term repopulating ability (LTRA). Comparison with previous bone marrow cell survival values demonstrates that LTRA cells are less sensitive to hyperthermic treatment than other hematopoietic subsets, confirming a relationship between the heat sensitivity and the hierarchical structure of the hematopoietic stem cell compartment.
Wierenga
P K
PK
Department of Radiobiology, University of Groningen, The Netherlands.
Konings
A W
AW
Down
J D
JD
D000818:Animals; D016465:Bone Marrow Purging / Q000379:methods*; D016026:Bone Marrow Transplantation / Q000502:physiology*; D002470:Cell Survival; D002999:Clone Cells / Q000502:physiology; D005260:Female; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D006358:Hot Temperature; D051379:Mice; D008810:Mice, Inbred C57BL; D011828:Radiation Chimera; D018183:Transplantation Chimera