Differential regulation of tumour necrosis factor-α mRNA degradation in macrophages by interleukin-4 and interferon-γ
Article first published online: 30 OCT 2003
Volume 87, Issue 4, pages 551–558, April 1996
How to Cite
SUK, K. and ERICKSON, K. L. (1996), Differential regulation of tumour necrosis factor-α mRNA degradation in macrophages by interleukin-4 and interferon-γ. Immunology, 87: 551–558. doi: 10.1046/j.1365-2567.1996.500561.x
- Issue published online: 30 OCT 2003
- Article first published online: 30 OCT 2003
Interferon-γ (IFN-γ) and interleukin-4 (IL-4) have been reported previously to mediate similar as well as antagonistic effects on murine macrophage functions. One effect common to both is the enhancement of tumour necrosis factor-α (TNF-α) secretion in macrophages. To assess further the effects of these two lymphokines on macrophage TNF-α production, we investigated the role of these lymphokines in the induction and stability of TNF-α messages along with interleukin-1 (IL-1) as a comparison. IFN-γ and IL-4 increased lipopolysaccharide (LPS)-induced TNF-α, IL-1 steady-state message levels. In contrast to IL-1 messages, whose degradation was not significantly affected by either lymphokine, the stability of TNF-α messages differed after IFN-γ and IL-4 treatment. Although IL-4 treatment increased the TNF-α transcription rate, an increase in the degradation rate of TNF-α mRNA in the IL-4-treated cells resulted in a lower level of steady-state mRNA than in the IFN-γ-treated cells. Additionally, a 18 000 MW cytoplasmic factor was found to have specific binding activity to the AU-rich sequences of the TNF-α message in peritoneal macrophages. Although the binding activity of this factor was not affected by either IFN-γ or IL-4, the binding of the factor to AU-rich sequences appeared to be important in the rapid degradation of TNF-α messages. Thus IFN-γ and IL-4 may differentially affect the post-transcriptional control of TNF-α gene expression. And this lymphokine-mediated post-transcriptional control of the TNF-α gene does not appear to involve the alteration of binding activity of the 18 000 MW AU-rich sequence binding factor.