FIGURE 2.

Effect of L. donovani infection on MAPK activity and caspase cascade. A–C and F, macrophages were infected with L. donovani for the indicated time periods followed by either H₂O₂ treatment for 1 h or not. Cells were washed and expression of various MAPKs (A), pro- and cleaved forms of caspase-9 and -7 (B), pro- and cleaved forms of caspase-3 (C), and cleaved PARP (F) were evaluated by immunoblotting with respective antibodies. D, infected cells were treated with H₂O₂ for 1 h and total cellular extracts (10 μg of protein per sample) were used to determine caspase-3 activity using Ac-DEVD-pNA as substrate. E, infected cells were treated with Z-LEHD-fmk (50 μm) for 1 h followed by H₂O₂ treatment for 1 h. Expression of pro- and cleaved forms of caspases-3 and -7 were determined by Western blotting. Results are representative of three individual experiments, and the error bars represent mean ± S.D. (n = 3). ns, not significant. *, p < 0.05; **, p < 0.01; ***, p < 0.001 by Student's t test.