IFN-gamma production of adult rat astrocytes triggered by TNF-alpha.

IFN-gamma plays an important role in modulating inflammatory responses within the CNS. The cell type responsible for IFN-gamma production within the CNS is less well defined. We examined the production and regulation of IFN-gamma by adult rat astrocytes. IFN-gamma was hardly detectable in cultured astrocytes, while addition of TNF-alpha dose-dependently induced IFN-gamma production by astrocytes. No IFN-gamma production by astrocytes could be induced by LPS, IL-10 or TGF-beta 1. TNF-alpha-induced IFN-gamma production by astrocytes was inhibited by treatment of astrocytes with TGF-beta 1, but not IL-10. TNF-alpha induced IFN-gamma production by astrocytes was confirmed by using immunocytochemical staining. The data suggest that astrocyte-derived IFN-gamma induced by TNF-alpha may participate in local immune reactions of the brain in an autocrine and paracrine fashion.