Patterns of organ-specific engraftment by stem cell subsets and committed progenitors.
The kinetics of blood and organ engraftment following transplants of defined populations of hematopoietic stem/progenitor cells were investigated utilizing cell populations defined by surface antigen and rhodamine-123 staining. While long-term repopulating stem cells, short-term multipotent progenitors and committed progenitors all reconstituted peripheral blood red cells and splenic cellularity, only the population of cells that includes highly enriched long-term repopulating stem cells (Thy-1.1lowLinnegSca-1+Rh123low) reconstituted marrow cellularity. In addition, peripheral blood platelet and nucleated cell count increased only after transplant of the long-term repopulating population. These results argue that the major cell population that functions to reconstitute hematopoiesis after bone marrow transplantation is a primitive, marrow-homing stem cell. Transplantation of highly enriched multipotent progenitors that lack long-term reconstituting potential had no impact on hematopoietic recovery, apart from a transient increase in circulating erythrocytes. These results suggest that the primary cell population that functions to reconstitute hematopoiesis in a transplant setting is the long-term repopulating stem cell. This observation is discussed in the context of the normal hematopoietic process.
Nibley
W E
WE
Department of Medicine, University of Utah, Salt Lake City, USA.
Pohlmann
S J
SJ
Spangrude
G J
GJ
D000818:Animals; D000943:Antigens, Differentiation / Q000032:analysis; D001792:Blood Platelets; D001854:Bone Marrow Cells; D004912:Erythrocytes; D006410:Hematopoiesis / Q000502:physiology*; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000737:chemistry / Q000166:cytology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009928:Organ Specificity; D013154:Spleen / Q000166:cytology
D000943:Antigens, Differentiation