Figure 4.

(A) Wild type and IRF4-deficient mice underwent unilateral IR after having received an i.v. injection of control liposomes or clodronate that depletes macrophages and DCs. Clodronate treatment prevented renal inflammation seen in untreated IRF4-deficient mice and evidenced by intrarenal expression of pro-inflammatory mediators. Data are expressed as mean of the ratio vs. the respective 18s rRNA level ± SEM. *p < 0.05 vs. wild type. (B) Sections of kidneys of WT and Irf4^−/− mice were stained for F4/80, 5 weeks after unilateral IRI. Number of infiltrating macrophages was assessed as stained area per HPF (n = 8–10 animals per group; each dot represents the average of at least three high-power fields per animal). (B,C) BMDMs from WT and Irf4^−/− mice were cultured and stimulated with IL-4 and IL-13 as M2 differentiating agents, or LPS + IFN-γ for M1 differentiation. Flow cytometric analysis was performed for M2 (Arg1⁺) and M1 (iNOS⁺) CD11b⁺ and F4/80⁺ cells. (D,E) Mice were injected with LPS. Mice were euthanized after 12 h to obtain plasma samples for determination of the indicated cytokines. (F,G) Flow cytometry of spleen T-cell populations was performed from WT and Irf4^−/− mice under normal conditions and 12 h after injection of LPS. Intracellular staining for IFN-γ or IL-5, respectively, was used to differentiate Th1 and Th2 type T-cell responses. *p < 0.05, ***p < 0.001; **p < 0.01.