Regulation of T cell receptor γ gene expression by cytokines in murine hematopoietic cells

Murine IL-3-dependent myeloid cell lines express transcripts from non-rearranged TCRγ genes and this expression is dependent upon IL-3. To investigate this observation in general terms we examined various IL-3 dependent cell lines for TCRγ gene expression. We also examined various cytokines to test their potential to induce TCRγ gene expression. All IL-3 dependent cell lines expressed TCRγ transcripts. The IL-3 induced expression was sensitive to protein synthesis inhibitors. This demonstrated that the TCRγ genes belong to the early growth factor response class. IL-3, IL-4, GM-CSF and Erytropoietin (EPO), but not G-CSF, induced TCR gene expression. 32D cells transfected with the IL-2β chain receptor became responsive to IL-2 as a growth factor and induced TCRγ gamma gene expression. The induction of TCRγ gene expression by the cytokines was not correlated to their growth promoting activity. This indicated different signaling pathways.