The Effects of TGFβ on Haemopoietic Cells

Abstract

Transforming growth factor β (TGFβ) suppresses the growth of differentiation inducible, murine IL-3-dependent multipotential cell lines but has no growth inhibitory effect upon an IL-3-independent (leukaemic) cell line arising from one of them, nor on IL-3-dependent cell lines that are unable to undergo differentiation. TGFβ inhibits in vitro colony formation by normal multipotential haemopoietic progenitor cells. Bipotential progenitors recruited by GM-CSF are, however, more resistant to the inhibitory effects of TGFβ, whereas progenitors recruited by the lineage restricted factor, M-CSF, are sensitive to the inhibitory effects. These data indicate that responsiveness to TGFβ is differentiation linked and studies with the cell lines suggest that response (or lack of response) is not determined solely by levels of expression of TGFβ receptors. Furthermore, the effects of TGFβ2 on haemopoietic progenitors are very similar to those induced by TGFβ.

Key Words:

• TGFβ haemopoiesis
• stem cells