Figure 6.

Cell free supernatants from B. anthracis secreting ALO lyse human monocyte derived macrophages significantly more than the ALO knockout strain, UT231, in a dose dependent manner. Percent viability of hMDMs from three different donors measured by trypan blue after the addition of filter sterilized B. anthracis supernatants in presence of heat-inactivated 10% FBS. The 3 h time point is shown, as little lysis was observed at earlier time points. Results are representative of results from three different experiments. (Dose, p < 0.001, strain, p < 0.001, dose by strain interaction, p = 0.044, as calculated by 2-way ANOVA. Tukey test showing significant differences between UT231/7702, UT231/UT231(pUTE544), 7702/UT231(pUTE544), p < 0.001)