Pluripotent hemopoietic stem cells are c-kit<low.
Pluripotent hemopoietic stem cells (P-HSCs) were thought to be c-kit+, but recent reports indicate that they are c-kit(low). In the present report, we provide evidence using Ly5 congenic mice that P-HSCs are c-kit(<low). Lineage-negative (Lin-)/CD71- cells among bone marrow cells (BMCs) from C57BL/6 Ly5.1 mice were separated into major histocompatibility complex class I(high) (class I(high))/c-kit(low) and class I(high)/ c-kit(<low) populations. Each population (500 cells) was transplanted into lethally (9.0 Gy) irradiated C57BL/6 Ly5.2 congenic mice along with Ly5.2 (2 x 10(5)) compromised cells. Donor-derived Ly5.1+ cells were detected 6 months after transplantation in primary recipients reconstituted with either class I(high)/c-kit(low) or class I(high)/c-kit(<low) cells. BMCs (1 x 10(6)) from the primary recipients were further transplanted into secondary recipients (Ly5.2 mice) to assess their long term repopulating activity. Six months after bone marrow transplantation, Ly5.1+ cells in all lineages were detected only in secondary recipients that had been given BMCs from the primary recipients reconstituted with class I(high)/c-kit(<low) cells but not in cells that were class I(high)/c-kit(low). When the BMCs (1 x 10(6)) of these secondary recipients were further transplanted into tertiary recipients, all tertiary recipients that had been given BMCs from the secondary recipients originally reconstituted with Lin-/CD71-/class I(high)/c-kit(low) cells died within 10 days whereas all six tertiary recipients originally reconstituted with Lin-/CD71-/class I(high)/c-kit(<low) cells showed donor (Ly5.1+)-derived cells in their peripheral blood. In the single tertiary recipient that was killed, donor-derived T cells, B cells, macrophages, and granulocytes also were detected in several major hematolymphoid organs. The remaining five mice continue to survive more than 6 months after the tertiary bone marrow transplantation.
Doi
H
H
First Department of Pathology, Kansai Medical University, Moriguchi City, Osaka, Japan.
Inaba
M
M
Yamamoto
Y
Y
Taketani
S
S
Mori
S I
SI
Sugihara
A
A
Ogata
H
H
Toki
J
J
Hisha
H
H
Inaba
K
K
Sogo
S
S
Adachi
M
M
Matsuda
T
T
Good
R A
RA
Ikehara
S
S
D000818:Animals; D001854:Bone Marrow Cells; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D016133:Polymerase Chain Reaction; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D013154:Spleen / Q000166:cytology; D013950:Thymus Gland / Q000166:cytology
D019009:Proto-Oncogene Proteins c-kit