Aim: To describe functional and molecular characteristics of interferon-γ (IFN-γ) activation in neonatal mononuclear phagocytes (monocytes and macrophages). Methods and Results: Exposure of cord and adult macrophages to IFN-γ gave quantitatively different results in Candida killing, as well as in release of superoxide anion (O2-). Ar concentrations of 100 U ml-1 IFN-γ, maximal increase in these functions with adult macrophages was achieved, whereas no enhancement of killing and O2- release by cord macrophages could be detected. Expression of IFN-γ receptors was comparable on cord and adult cells and specific binding of [125I]IFN-γ to cord monocytes and macrophages was even higher compared with adult cells. By flow cytometry, elements of IFN-γ receptor-mediated signaling in cord and adult monocytes and macrophages were studied. Monoclonal antibodies against the native form of the signal transducer and activator of transcription-1 (STAT-1) revealed comparable expression of this protein in cord and adult macrophages. However, STAT-1 phosphorylation in response to IFN-γ was significantly decreased in neonatal monocytes (p < 0.05) and macrophages (p < 0.01) compared with adult cells. Conclusion: These data suggest deficient cytokine receptor signaling in neonatal mononuclear phagocytes exposed to IFN-γ.
|Number of pages||3|
|Journal||Acta Paediatrica, International Journal of Paediatrics, Supplement|
|Publication status||Published - Nov 27 2002|
- Cord blood
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health