Live F. tularensis suppresses an ongoing inflammatory immune response induced by F. novicida. Primary BMDMs derived from C57BL/6 mice were infected with F. tularensis (Ft) LVS, F. novicida (Fn), UV-killed F. tularensis LVS (UV Ft LVS), UV-killed F. novicida (UV Fn), or a combination of these organisms at 100 m.o.i. (n = 3–5 biological replicates). The cell supernatants were collected at 24 h post-infection and analyzed for levels of TNF-α and IL-6. The data are representative of four independent experiments conducted with identical results. The data were analyzed by one-way ANOVA with Tukey-Kramer post-test, and a p value of 0.05 or less was considered significant.