Fig. 4.

Efficient activation of PKCδ^−/− macrophages. Bacterial growth (A) and secretion of nitrite (B), cytokines (C–E), and chemokine (F) into the culture supernatant by WT and PKCδ^−/− BMDMs 12 h p.i. with live LM, LLO-deficient LM mutant strain (ΔLLO), or heat-killed LM (HKLM). Macrophages were either activated overnight with IFN-γ or not stimulated. Data shown are means ± SEM of triplicate samples. LM results are representative of three independent experiments, and ΔLLO and HKLM results are from one experiment (*, P < 0.05; **, P < 0.01; ***, P < 0.001).