Synergistic induction of CXCL10 protein in astrocytes treated with virus and cytokines. Supernatants from cells treated with either virus or cytokine or both virus and cytokines were collected at A) 12hrs for A172 cells and B) 24hrs for primary human astrocytes and analyzed for CXCL10 protein levels by ELISA. Both A172 and primary human astrocytes showed a significant increase in CXCL10 protein levels in the cells treated with virus in conjunction with the cytokines, then either treatment alone. Treatment of A172 cells with neutralizing gp120 antibodies abrogated the synergistic effect. The data represents the mean ± SD from three independent experiments. Statistical significance from independent experiments was calculated (***, p < 0.001, **, p < 0.01).