<i>L</i>. <i>pneumophila legS2</i> mutant replicates in human MDMs and wild-type mice and their derived macrophages.

<p>A) BMDMs were infected with wild-type <i>L</i>. <i>pneumophila</i>, JR32, or <i>ΔlegS2</i> for 1, 24, 48 and 72h. The colony forming units (CFUs) were scored at the indicated time points. B) hMDMs were infected with wild-type <i>L</i>. <i>pneumophila</i>, JR32, or <i>ΔlegS2</i> for 1, 24, 48 and 72h. Data are shown as mean + SD of n = 3. Asterisks indicate significant differences, and a two tailed t-test was used to calculate the <i>P</i> value (*<i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001). (C and D) Four female C57BL/6 mice per group received 1x10⁶ of JR32 or <i>legs2</i> bacteria intratracheally. Lungs were homogenized and plated for CFUs, counting at (C) 4 or (D) 48 h post infection. (C and D) Data are shown as mean + SD of four mice. Asterisks indicate significant differences (***<i>P</i><0.001); a two tailed t-test was used to calculate the <i>P</i>-value.