Unique pathway of IL-3-driven hemopoietic differentiation.
The results of this study support a proposed sequence of IL-3-induced hemopoietic cell proliferation and differentiation. Specifically, IL-3 uniquely induces the transient expression of Thy-1 Ag on Thy-1- bone marrow cells during a 2-wk culture period. Thy-1 Ag is expressed on immature myeloid cells that are undergoing lineage restrictions to granulocytes, macrophages, and mast cells. Flow microfluorimetry-separated Thy-1+ cells require the addition of IL-3 or granulocyte/macrophage-CSF to the culture medium for continued growth and, as these cells divide and undergo terminal differentiation they gradually lose Thy-1 Ag expression. The loss of Thy-1 expression is not strictly correlated with cellular proliferation since the expression of Thy-1 decreases on proliferating cells. Last, IL-3 does not maintain the Thy-1- stem cell population that can give rise to Thy-1+ cells in vitro. The relevance of this scheme of differentiation to normal hemopoiesis and to differentiation-arrested IL-3-dependent leukemic cell populations is discussed.
Keller
J R
JR
Biological Carcinogenesis Development Program, NCI-Frederick Cancer Research Facility, MD 21701.
Ihle
J N
JN
D000818:Animals; D000954:Antigens, Surface / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002469:Cell Separation; D000939:Epitopes / Q000276:immunology / Q000378:metabolism; D005434:Flow Cytometry; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D006412:Hematopoietic Stem Cells / Q000201:enzymology / Q000276:immunology* / Q000502:physiology; D007377:Interleukin-3 / Q000502:physiology*; D007700:Kinetics; D051379:Mice; D008807:Mice, Inbred BALB C; D010641:Phenotype; D018800:Thy-1 Antigens
D000954:Antigens, Surface; D000939:Epitopes; D007377:Interleukin-3; D018800:Thy-1 Antigens; D005954:Glucosephosphate Dehydrogenase