Figure 3.

BA spore–induced signaling and gene expression in macrophages depend on MyD88, but not other signaling adaptors for microbial sensors. (A–D) Macrophages from the indicated mice were exposed to BA spores at moi of 3. Relative mRNA amounts for spore-induced genes at the indicated time points after exposure were determined by qPCR and presented in color-coded arbitrary units (A). Whole-cell lysates (B and C), and cytoplasmic and nuclear extracts (D) were prepared at the indicated time points after exposure, and analyzed by immunoblotting. (E and F) WT and MyD88-KO mice were infected with BA (10⁷ and 2.5 × 10⁶ cfu per host; E and F, respectively) by footpad injection of spores. Host survival (n = 6–7 mice per group) was monitored for 10 d (E). Bacterial burdens in popliteal lymph nodes were determined 3 d after infection (F). Data are from one experiment (A and B) or representative of two experiments with similar results (C–F). **, P < 0.01; Log-rank test (E) and Student’s t test (F).