Figure 4.

IL-1–induced IL-8 production in IRAK4-null dermal fibroblasts reconstituted with IRAK4 variants. A, reconstitution of IL-1–induced IL-8 cytokine production. Human IRAK4-null dermal fibroblasts (P15 from Fig. 1A) were infected with the indicated MOIs of WT, R12C/R391H/T458I, and D329A IRAK4 adenovirus for 72 h and stimulated for 4 h with 10 ng/ml IL-1β. B, Western blotting of IRAK4 and tubulin from A. C, IL-8 levels measured in A normalized to IRAK4 expression levels determined in B and expressed as a percentage of WT activity. Data reflect the mean from four independent experiments. Error bars, S.D.