PAR2 cleavage is required for Poly(I:C)-dependent monocyte/macrophage recruitment to the lungs. (A) Schematic overview of PAR2 mutation PAR2^G37I and PAR2^R38 and their cleavage resistance to different proteases. (B) Cell count in BAL in unchallenged and Poly(I:C) treated of F2rl1^G37I, F2rl1^R38E and WT mice. (C) Flow cytometry gating strategy to identify different cell populations in whole lung cell suspensions, pregated on viable, single CD45⁺ cells. (D) Flow cytometry analysis of whole lung cell suspensions from F2rl1^R38E and WT mice after Poly(I:C) treatment. Mean ± SD; the 2-way ANOVA with the Sidak multiple comparison test (panel A) or the unpaired Student t test (panel C). ∗P < .05; ∗∗P < .01; ∗∗∗P < .001; ∗∗∗∗P < .0001. SSC, side scatter; MHCII, major histocompatibility complex class II; NK cells, natural killer cells.