Loss of long-term repopulating ability in long-term bone marrow culture.
We have studied the maintenance of stem cells with long-term multilineage repopulating ability from murine bone marrow, cultured on a pre-established bone marrow-derived stromal cell layer, both in a qualitative and quantitative way. Female bone marrow cells were cultured for a period of 1-4 weeks and compared with uncultured cells for their ability to establish and maintain a level of 50% chimerism in a sex-mismatched bone marrow transplantation model. Chimerism was determined in nucleated cells using fluorescence in situ hybridization with a murine Y-chromosome-specific probe. We observed a rapid decline in the ability of cultured marrow cells to repopulate the blood, bone marrow, spleen, and thymus of sublethally irradiated male recipients. After 4 weeks of culture only 5% of the long-term repopulating ability of the inoculated bone marrow cells remained. The remaining long-term repopulating cells, however, had similar qualities to establish and maintain long-term engraftment compared to fresh bone marrow, as judged from their ability to give stable chimerism over a period of 6 months. These observations are relevant for the therapeutic applications of long-term bone marrow cultures in purging protocols prior to autologous bone marrow transplantation of acute and chronic myeloid leukemic patients, and for the use of long-term marrow cultures when introducing foreign genetic material in hematopoietic stem cells.
van der Sluijs
J P
JP
Institute of Hematology, Erasmus University, Rotterdam, The Netherlands.
van den Bos
C
C
Baert
M R
MR
van Beurden
C A
CA
Ploemacher
R E
RE
D000818:Animals; D001854:Bone Marrow Cells; D016026:Bone Marrow Transplantation / Q000473:pathology*; D002478:Cells, Cultured; D002678:Chimera; D005260:Female; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D013997:Time Factors