Human brain astrocytes mediate TRAIL-mediated apoptosis after treatment with IFN-gamma

TNF-related apoptosis inducing ligand (TRAIL) expressions were studied in primary human brain astrocytes in response to pro-inflammatory cytokines. When astrocytes were treated with IL-1beta, TNF-alpha or IFN-gamma, TRAIL was induced in cultured fetal astrocytes. In particular, IFN-gamma induced the highest levels of TRAIL in cultured astrocytes. When astrocytes were pre-treated with IFN-gamma, they induced apoptosis in TRAIL-sensitive Peer cells. Our results suggest that IFN-gamma modulates the expression of TRAIL in astrocytes, which may enhance cytotoxic sensitivity of infiltrating immune cells or brain cells other than astrocytes during inflammation of brain.