Interleukin-10 in combination with interferon-gamma and tumor necrosis factor-alpha enhances in vitro production of nitric oxide by murine resident paritoneal macrophage

Abstract

Resident peritoneal macrophages obtained from CBA/J mice were cultured in the presence of recombinant interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), and interleukin-10 (IL-10). IFN-gamma-stimulated nitric oxide (NO) formation, IL-10 substantially enhanced the production of NO generated by IFN-gamma + TNF-alpha, irrespective of the timing and dosing of any of the three cytokines. Increased levels of iNOS mRNA after the triple combination of IFN-gamma + TNF-alpha + IL-10 versus IFN-gamma + TNF-alpha suggest that the NO-enhancing effect is mediated, at the least partially, at the transcriptional level. Collectively, the present data support the view that IL-10 is not a general macrophage deactivating factor or a suppressor of gene expression.