Purified canine CD34+Lin- marrow cells transduced with retroviral vectors give rise to long-term multi-lineage hematopoiesis.
Human CD34+ cells have been shown to retain long-term hematopoietic engrafting potential in preclinical and clinical studies. However, recent studies of human and murine CD34- stem cells suggest that these are functionally important early progenitors. Using autologous transplantation, we investigated whether canine CD34 and CD34- marrow cells could be transduced and give rise to long-term hematopoiesis. CD34+Lin- and CD34-Lin- cell populations purified by fluorescence-activated cell sorting were separately cocultivated with retroviral vectors LN (CD34+Lin-) and LNY (CD34-Lin-), which carry the neomycin (neo) gene. After myeloablative total body irradiation (920 cGy), 3 dogs received transplants of both CD34+Lin- cells and CD34-Lin- cells and 2 dogs received only CD34-Lin- cells. Untransduced autologous marrow cells were given to ensure hematopoietic recovery. Using CFU-C assays, transduction efficiencies of CD34+Lin- cells ranged from 6% to 18% with no CFU-C formation from CD34-Lin- cells. PCR-based detection of the neo gene from WBCs was used to detect transduced cells weekly after transplantation. Additional PCR studies in 3 dogs given both CD34+Lin- and CD34-Lin- cells were performed on monocytes, granulocytes, and T cells (2 dogs, one at 7.5 months and the other at 9 months) and granulocytes (1 dog at 12 months). LN was detected up to 12 months posttransplantation in WBCs and mono-myeloid and lymphoid populations from 3 dogs receiving transplants of transduced CD34+Lin- cells. LNY was not detected at any time after transplantation in 5 dogs that received transduced CD34-Lin- cells. Whereas canine CD34+Lin- marrow cells contributed to long-term multilineage hematopoiesis, progeny of CD34-Lin- progenitor cells were not detected after transplantation in these experiments.
Bruno
B
B
Clinical Research Division, Fred Hutchinson Cancer Research Center, University of Washington Medical School, Seattle, USA.
Goerner
M A
MA
Nash
R A
RA
Storb
R
R
Kiem
H P
HP
McSweeney
P A
PA
D000818:Animals; D018952:Antigens, CD34 / Q000502:physiology*; D001854:Bone Marrow Cells / Q000276:immunology / Q000378:metabolism; D018929:Cell Culture Techniques; D019070:Cell Lineage; D004285:Dogs; D005822:Genetic Vectors; D006085:Graft Survival / Q000276:immunology; D006410:Hematopoiesis / Q000276:immunology; D023421:Models, Animal; D012190:Retroviridae / Q000235:genetics; D033581:Stem Cell Transplantation / Q000379:methods*; D014161:Transduction, Genetic; D014182:Transplantation, Autologous / Q000379:methods
D018952:Antigens, CD34