| First Author | Naora H | Year | 1994 |
| Journal | Blood | Volume | 83 |
| Issue | 12 | Pages | 3620-8 |
| PubMed ID | 8204886 | Mgi Jnum | J:18693 |
| Mgi Id | MGI:66934 | Doi | 10.1182/blood.v83.12.3620.3620 |
| Citation | Naora H, et al. (1994) Mechanisms regulating the mRNA levels of interleukin-5 and two other coordinately expressed lymphokines in the murine T lymphoma EL4.23. Blood 83(12):3620-8 |
| abstractText | The mechanisms that regulate the mRNA levels of interleukin-5 (IL-5) were compared with those regulating the mRNA levels of two other coordinately expressed lymphokines in the murine T lymphoma EL4.23. Our results indicate that IL-5 mRNA levels are independently regulated from those of IL-2 and granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNAs. The induction of IL-5 mRNA by phorbol 12-myristate 13-acetate (PMA) stimulation was found to be cyclosporin A-resistant, in contrast to the induction of IL-2 and GM-CSF mRNAs. Although the three lymphokine mRNAs were not detected in unstimulated cells by Northern blot analysis, the GM-CSF gene was found by nuclear run-off analysis to be constitutively transcribed. However, the IL-2 and IL-5 genes were transcriptionally inactive in the absence of PMA stimulation. The induction of IL-5 mRNA by PMA stimulation primarily involved increased transcriptional activity. In contrast, GM-CSF mRNA induction predominantly involved enhanced mRNA stability. Both transcriptional and mRNA stabilization mechanisms appeared to regulate IL-2 mRNA induction. The activation of IL-2 and IL-5 gene transcription was dependent on de novo protein synthesis. Cellular treatment with cycloheximide enhanced IL-2 gene transcription once activation was initiated, implicating the involvement of a labile repressor(s). Furthermore, IL-5 mRNA was more stable than IL-2 and GM-CSF mRNAs. These latter two species were stabilized by cycloheximide, suggesting that a labile mechanism may regulate their degradation. |
