DIFFERENTIAL REGULATION OF C3 GENE-EXPRESSION IN HUMAN ASTROGLIOMA CELLS BY INTERFERON-GAMMA AND INTERLEUKIN-1-BETA

In this report, we examined interferon-gamma (IFN-gamma) and interleuk in-1 beta IL-1 beta)-mediated regulation of the expression of C3, the third component of complement, in a human astroglioma cell line. Inter leukin-1 beta induced C3 protein expression ten-fold more rapidly than IFN-gamma. De novo protein synthesis was required for IFN-gamma to st imulate C3 expression, while cycloheximide and IL-1 beta treatment of cells markedly increased C3 expression. Actinomycin D, inhibited C3 ge ne induction by IFN-gamma and IL-1 beta suggesting that these cytokine s act, in part, at the transcriptional level to enhance C3 expression. Understanding cytokine-mediated regulation of complement gene express ion in the astrocyte is important in defining the role of these molecu les in CNS inflammation and autoimmune diseases.