title: Transforming growth factor beta directly regulates primitive murine hematopoietic cell proliferation.
abstract: We previously reported that transforming growth factor beta (TGF-beta) selectively inhibits colony-stimulating factor-driven hematopoietic progenitor cell growth. We report here that TGF-beta 1 can act directly on hematopoietic progenitors to inhibit the growth of the most primitive progenitors measurable in vitro. Highly enriched populations of hematopoietic progenitor cells were obtained by isolating lineage negative (Lin-), Thy-1-positive (Thy-1+) fresh bone marrow cells, or by isolating cells from interleukin-3 (IL-3) supplemented bone marrow cultures expressing Thy-1 antigen with the fluorescent activated cell sorter. TGF-beta 1 inhibited IL-3-induced Thy-1 expression on Thy-1-negative (Thy-1-) bone marrow cells in a dose-dependent manner with an ED50 of 5 to 10 pmol/L. In addition, TGF-beta 1 inhibited the formation of multipotent and mixed colonies by isolated Thy-1+ cells, while single lineage granulocyte and macrophage colonies were not affected. The growth of Thy-1+ Lin- cells incubated as single cells in Terasaki plates in medium supplemented with IL-3 were inhibited by TGF-beta, demonstrating a direct inhibitory effect. Hematopoietic stem cells, which have a high proliferative potential (HPP) when responding to combinations of growth factors in vitro, have been detected in the bone marrow of normal mice and mice surviving a single injection of 5-fluorouracil. TGF-beta 1 inhibited the growth of all subpopulations of HPP colony forming cells (CFC) in a dose-dependent manner with an ED50 of 5 to 10 pmol/L. Thus, TGF-beta directly inhibits the growth of the most immature hematopoietic cells measurable in vitro.
authors.affiliation: Laboratory of Molecular Immunoregulation, Program Resources, Inc, National Cancer Institute, Frederick, MD 21701.
authors.forename: J R
authors.initials: JR
authors.lastname: Keller
authors.forename: I K
authors.initials: IK
authors.lastname: Mcniece
authors.forename: K T
authors.initials: KT
authors.lastname: Sill
authors.forename: L R
authors.initials: LR
authors.lastname: Ellingsworth
authors.forename: P J
authors.initials: PJ
authors.lastname: Quesenberry
authors.forename: G K
authors.initials: GK
authors.lastname: Sing
authors.forename: F W
authors.initials: FW
authors.lastname: Ruscetti
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000378:metabolism; D001854:Bone Marrow Cells; D002455:Cell Division / Q000187:drug effects; D003115:Colony-Stimulating Factors / Q000494:pharmacology; D005434:Flow Cytometry; D006133:Growth Substances / Q000494:pharmacology; D006410:Hematopoiesis / Q000187:drug effects; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects*; D007377:Interleukin-3 / Q000494:pharmacology; D016173:Macrophage Colony-Stimulating Factor; D051379:Mice; D018800:Thy-1 Antigens; D015291:Transforming Growth Factors / Q000494:pharmacology*
chemical_list: D000954:Antigens, Surface; D003115:Colony-Stimulating Factors; D006133:Growth Substances; D007377:Interleukin-3; D018800:Thy-1 Antigens; D015291:Transforming Growth Factors; D016173:Macrophage Colony-Stimulating Factor