Fig. 2

MEKi modulates in vivo macrophage polarization. Alveolar macrophages were obtained from BAL a and lungs b from C57BL/6J mice 4 days after infection with 5 × 10⁶ CFU P. aeruginosa that received carrier or MEKi treatments delivered by i.p. injection on days 2 and 3 after infection. a Alveolar macrophages from BAL were isolated and used for measurement of M2 gene expression. The levels of Ccl17, Retnla, Arg1, and Tgfb1 were measured relative to Hprt control and data were normalized to carrier-treated animals; n = 10/group. Error bars show the mean ± SEM, analyses used parametric unpaired t-test. b Single cell suspensions of cells obtained after lung digestion were used for staining and flow cytometry analyses. Alveolar macrophages were identified as CD45⁺/Ly6G⁻/CD11c⁺/SigF⁺ cells and the ΔMFI of carrier (n = 6) and MEKi (n = 5) treated mice from one representative experiment of two are shown. Error bars show the mean ± SEM, analyses used parametric unpaired t-test. * p < 0.05, ** p < 0.01