CXC chemokine expression in situ. (A) IL-17RA^KO mice fail to up-regulate CXC chemokines in response to Pg infection. Serum samples from WT and IL-17RA^KO mice in Figure 1 were analyzed for Groα and LIX by ELISA. Standard deviations are shown. *Statistically significant differences between Pg-infected compared with Sham-infected mouse strains as assessed by unpaired t test (LIX, P < .001; Groα, P < .05). n.s. indicate not significant. (B) CXCR2^KO mice are susceptible to Pg-induced bone loss. CXCR2^KO or WT mice (BALB/c background) were infected with Pg or sham (n = 4-6), and ABC/CEJ distances on the left maxillary jaw were evaluated as in Figure 1. Net bone loss with standard deviations is shown. (C) Representative images of maxillary jaws in Pg-infected WT or CXCR2^KO mice, taken as in Figure 1D. (D) Source of CXC chemokines in Pg infection. Sections from Pg-infected WT mice (adjacent sections as in Figure 4B) were stained with antisera that recognizes Groα, LIX, and MIP2. Blue arrows indicate representative monocyte/macrophages; black arrows indicate representative fibroblasts. Image obtained with a 200×/0.45 objective lens. n.s. indicates not significant.