FIG. 8.

Effect of a ceramide inhibitor on TNF-α release by L. donovani-infected macrophages. Macrophages were cultured in a 96-well plate (10⁶ cells/ml) with or without LPS (1 μg/ml) and treated with FB-1, followed by infection with L. donovani promastigotes as described in the Fig. 1 legend. The mouse TNF-α (mTNF-α) level in the cell culture supernatant was measured by sandwich ELISA (see Materials and Methods). Results are expressed as means ± SD of data from replicate experiments. **, P < 0.003 (restoration of mTNF-α release with respect to infected control macrophages); ***, P < 0.001 (restoration of mTNF-α release with respect to LPS-stimulated infected macrophages).