Interferon-γ upregulates interleukin-8 gene expression in human monocytic cells by a posttranscriptional mechanism

M. C. Bosco, G. L. Gusella, I. Espinoza-Delgado, D. L. Longo, L. Varesio

Research output: Contribution to journalArticle

Abstract

Interleukin-8 (IL-8) is a neutrophil chemotactic and activating cytokine that is produced in response to several stimuli. Because monocytic cells are important producers of IL-8, we investigated whether interferon-γ (IFN-γ), a potent inducer of activation and differentiation of mononuclear phagocytes, affected IL-8 expression in this cell lineage. We found a low constitutive level of IL-8 mRNA expression that was upregulated by IFN-γ in a dose- and time-dependent manner and via a protein-synthesis-dependent process in the human monocytic cell line U937. IL-8 protein secretion was also stimulated by IFN-γ. Nuclear run-on experiments showed that the IL-8 gene was transcriptionally active in control cells and that IFN-γ did not enhance the transcriptional activity. The increase in IL-8 mRNA by IFN-γ was concomitant with the stabilization of the mRNA and, therefore, controlled primarily at a posttranscriptional level. These results represent the first evidence that IFN-γ upregulates IL-8 gene expression in cells of the monocytic lineage, and show the involvement of posttranscriptional mechanisms in the induction of IL-8 mRNA.

Original languageEnglish
Pages (from-to)537-542
Number of pages6
JournalBlood
Volume83
Issue number2
Publication statusPublished - Jan 15 1994

ASJC Scopus subject areas

  • Hematology

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