Involvement of CSF-1 in generating a stroma-independent hematopoietic stem cell line.
The hematopoietic stem cell line, Myl-D7, is maintained by a self-renewing stem cell population that spontaneously generates myeloid, lymphoid, and erythroid progeny. MS-5 stromal cells are necessary for the growth of Myl-D7 cells. One component of the Myl-D7 cells proliferation activity released by MS-5 stromal cells was enriched by Q sepharose fractionation and shown to be colony stimulating factor-1 (CSF-1) by Western blotting, BAC1.2F5 cell bioassay and inhibition of Myl-D7 proliferation by CSF-1 antibody. The requirement of Myl-D7 cells for CSF-1 was also demonstrated independently by selecting for rare, stroma-independent Myl-D7 mutant clones able to grow without stroma and additional factors. Eighty-nine stroma-independent mutant clones were obtained and belonged to two classes. The majority of mutants did not secrete any growth promoting activity. The second, rarer class of mutants releases a factor that stimulates proliferation/survival for up to several months and approximately half of the secretors express high levels of CSF-1 mRNA. Wild type Myl-D7 grown with supernatants from the secretor cells retained the stem cell phenotype. These data suggest that CSF-1 may act as a key factor in stroma-regulated hematopoiesis and cell-cell interaction.
Heberlein
Christoph
C
CellTec GmbH, Frohmestrasse, Hamburg, Germany.
Friel
Jutta
J
Itoh
Katsuhiko
K
Medlock
Eugene
E
Li
Luke
L
Nakayama
Naoki
N
Stocking
Carol
C
Geldmacher
Maren
M
Ostertag
Wolfram
W
D000818:Animals; D002458:Cell Fractionation; D002460:Cell Line; D049109:Cell Proliferation; D002999:Clone Cells / Q000378:metabolism*; D017077:Culture Media, Conditioned / Q000737:chemistry / Q000378:metabolism*; D006133:Growth Substances / Q000378:metabolism / Q000502:physiology; D006412:Hematopoietic Stem Cells; D016173:Macrophage Colony-Stimulating Factor / Q000502:physiology*; D051379:Mice; D017154:Stromal Cells
D017077:Culture Media, Conditioned; D006133:Growth Substances; D016173:Macrophage Colony-Stimulating Factor