Sequential analysis of hematopoietic reconstitution achieved by transplantation of hematopoietic stem cells.
We confirmed that murine hematopoietic stem cells express the c-kit molecule but not lymphohematopoietic lineage markers. These lineage marker-negative c-kit-positive (Lin- c-kit+) cells were further divided according to the uptake of rhodamine-123 (Rh-123). Approximately 1,000 Lin- c-kit+ rhodamine-123dull cells, which contained 4.0 +/- 1.3 and 12.5 +/- 1.9 day 8 and day 12 spleen colony-forming units (CFU-S), respectively, rescued the 100% of lethally irradiated mice. One third of these cells formed colonies in the presence of interleukin-3 plus erythropoietin. The time course of the hematopoietic reconstitution of this primitive hematopoietic stem cell fraction was investigated by using Ly-5 congenic mice. Although myeloid cells and B lymphocytes were detected in the peripheral blood 2 to 3 weeks after transplantation, T lymphocytes were not detected until 4 weeks after transplantation. It is generally assumed that myeloid cells and B lymphocytes grow in the bone marrow and that T lymphocytes must pass through the thymus. For the first 2 to 3 weeks after transplantation, donor-type T lymphocytes were not dominant in the thymus, and most donor type cells were CD4/CD8 double-negative or double-positive (including CD4low and CD8low). Four weeks after transplantation, donor-type T lymphocytes were dominant and the ratio of CD4/CD8 cells had recovered to the normal pattern. However, significant numbers of T lymphocytes were detected in the peripheral blood at this stage. Sequential analysis of hematopoietic reconstitution from primitive stem cells demonstrates that myeloid and B-lymphoid lineages occurred earlier than that of the T-lymphoid lineages.
Okada
S
S
Department of Medicine, Jichi Medical School, Tochigi-ken, Japan.
Nagayoshi
K
K
Nakauchi
H
H
Nishikawa
S
S
Miura
Y
Y
Suda
T
T
D000818:Animals; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D003114:Colony-Forming Units Assay; D006410:Hematopoiesis; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000737:chemistry; D017493:Leukocyte Common Antigens / Q000032:analysis; D051379:Mice; D008810:Mice, Inbred C57BL; D011518:Proto-Oncogene Proteins / Q000032:analysis; D019009:Proto-Oncogene Proteins c-kit; D020112:Rhodamine 123; D012235:Rhodamines
D015704:CD4 Antigens; D016827:CD8 Antigens; D011518:Proto-Oncogene Proteins; D012235:Rhodamines; D020112:Rhodamine 123; D019009:Proto-Oncogene Proteins c-kit; D017493:Leukocyte Common Antigens