Figure 1. Expression of Mmp28 in myeloid cells.

(A) Expression of Mmp28 in BM cells at time of harvest and during differentiation to macrophages in the presence of M-CSF relative to expression at Day 7 (set to one). Mmp28 expression decreased during culture, with a slight increase at Day 7. Overall, expression remained significant at all times (n=3/genotype/time-point). RQ (Fold increase). (B) Expression of Mmp28 by monocyte populations in naive (gray bars) or infected (black bars) mice reveals selective expression of Mmp28 by Ly6c^high monocytes, with reduced expression after infection (n=3 mice/genotype). (C) Expression of Mmp28 in macrophage subpopulations isolated from the alveolar space reveals greater expression of Mmp28 by recruited macrophages (CD11b^int, CD11b^high) compared with resident cells (CD11b^low; n=3 mice/genotype). (D) Expression of Mmp28 in stimulated BMDM (relative to Day 7, untreated BMDM). LPS, IL-4/13, Poly(I:C), and C. pneumoniae all increased Mmp28 gene expression, with the exception of IFN-γ, which did not alter Mmp28 expression significantly (n=3–6/genotype/condition).