INHIBITION OF NITRIC-OXIDE SYNTHESIS BY INTERLEUKIN-4 MAY INVOLVE INHIBITING THE ACTIVATION OF PROTEIN KINASE-C-EPSILON

SANDS W., BULUT V., SEVERN A., XU D., LIEW F.

EUROPEAN JOURNAL OF IMMUNOLOGY, vol.24, no.10, pp.2345-2350, 1994 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 24 Issue: 10
  • Publication Date: 1994
  • Doi Number: 10.1002/eji.1830241013
  • Journal Name: EUROPEAN JOURNAL OF IMMUNOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.2345-2350
  • Keywords: INTERLEUKIN-4, NITRIC OXIDE, PROTEIN KINASE C, INTERFERON-GAMMA, MACROPHAGE, NECROSIS-FACTOR-ALPHA, LEISHMANIA-MAJOR AMASTIGOTES, DEPENDENT KILLING MECHANISM, MURINE MACROPHAGES, IFN-GAMMA, T-CELLS, SIGNAL TRANSDUCTION, MOUSE MACROPHAGES, INTERFERON-GAMMA, INDUCTION
  • Gazi University Affiliated: No

Abstract

The murine macrophage cell line, J774,when activated with interferon-gamma (IFN-gamma), expressed high level of inducible nitric oxide synthase (iNOS) and bound significantly more [H-3]-phorbol-dibutyrate (PBu(2)) compared to non-activated cells. The increased PBu(2) binding to the particulate fraction of the cells is a measure of activation and translocation of protein kinase C (PKC). Both the expression of iNOS and the enhanced PBu(2) binding in the activated J774 cells were significantly inhibited by the pretreatment of the cells with murine recombinant interleukin-4 (IL-4). Stimulation of J774 cells by IFN-gamma and lipopolysaccharide results in the translocation predominantly of the epsilon isoform of PKC (PKC-epsilon), and this is inhibited by IL-4. The inhibition of PKC activation was also evident by measuring the PKC activity in the cytosolic fraction of the IL-4-treated cells. Activated 5774 cells pretreated with IL-4 or a PKC-specific inhibitor (RO31-8220) failed to express mRNA of iNOS analyzed by PCR. These results, therefore, suggest that the inhibition of nitric oxide synthesis in activated murine macrophages by IL-4 is at the transcriptional level and may involve the inhibition of the activation of PKC-epsilon.