Interleukin-5 mRNA stability in human T cells is regulated differently than interleukin-2, interleukin-3, interleukin-4, granulocyte/macrophage colony-stimulating factor, and interferon-gamma

Am J Respir Cell Mol Biol. 1998 May;18(5):631-42. doi: 10.1165/ajrcmb.18.5.3046.

Abstract

Interleukin-5 (IL-5) transcriptional activation and mRNA stability were investigated in a human TH0 T-cell clone (SP-B21) and in nonclonal CD4 TH2 cells, differentiated in vitro from peripheral blood T cells. Cells were stimulated with alpha-CD3 monoclonal antibody (mAb) with and without alpha-CD28 mAb. Comparison to other cytokine genes revealed aspects of mRNA regulation unique to IL-5. The half-life (t1/2) of IL-5 mRNA, determined by addition of actinomycin D (ActinoD) or cyclosporin A (CSA) was longer (by >= 2 h) than that of IL-2, IL-3, IL-4, interferon-gamma, or granulocyte/macrophage colony-stimulating factor. With the exception of IL-5, t1/2 values were significantly shorter with CSA as the transcriptional inhibitor than with ActinoD. The t1/2 value of IL-5 mRNA, but not the other cytokine transcripts, determined with either ActinoD or CSA, was longer than predicted from the kinetics of steady-state mRNA decline. Co-stimulation of both cell types with alpha-CD28 mAb increased the stability of cytokine transcripts weakly, and IL-5 remained the most stable transcript. Thus, the degradation pathway that targets IL-5 is distinct from the other cytokine transcripts measured and involves proteins whose transcription is blocked by ActinoD and CSA. From examination of the levels of transcription initiation (nuclear run-on assay) and steady-state mRNA attained in cultures stimulated in the presence of the protein synthesis inhibitor, cycloheximide, only IL-5 transcription initiation had an absolute dependency on new protein synthesis.

MeSH terms

  • Antibodies, Monoclonal / pharmacology
  • CD28 Antigens / immunology
  • CD3 Complex / immunology
  • CD4-Positive T-Lymphocytes / chemistry
  • CD4-Positive T-Lymphocytes / cytology
  • CD4-Positive T-Lymphocytes / physiology*
  • Cells, Cultured
  • Cyclosporine / pharmacology
  • Dactinomycin / pharmacology
  • Gene Expression Regulation / drug effects
  • Gene Expression Regulation / immunology*
  • Granulocyte-Macrophage Colony-Stimulating Factor / genetics*
  • Humans
  • Immunosuppressive Agents / pharmacology
  • Interferon-gamma / genetics*
  • Interleukin-2 / genetics
  • Interleukin-3 / genetics
  • Interleukin-4 / genetics
  • Interleukin-5 / biosynthesis
  • Interleukin-5 / genetics
  • Interleukins / genetics*
  • Kinetics
  • Nucleic Acid Synthesis Inhibitors / pharmacology
  • RNA, Messenger / metabolism
  • Transcription, Genetic / immunology

Substances

  • Antibodies, Monoclonal
  • CD28 Antigens
  • CD3 Complex
  • Immunosuppressive Agents
  • Interleukin-2
  • Interleukin-3
  • Interleukin-5
  • Interleukins
  • Nucleic Acid Synthesis Inhibitors
  • RNA, Messenger
  • Dactinomycin
  • Interleukin-4
  • Interferon-gamma
  • Granulocyte-Macrophage Colony-Stimulating Factor
  • Cyclosporine