Figure 6

Joint homogenates were prepared from both Wt and IL-18 gene-knockout mice injected with zymosan to induce zymosan-induced arthritis (ZIA). All tissue homogenates were initially measured for total protein content to normalize cytokine expression to total protein content for comparison between cytokines. Cytokines measured included IL-1β IL-6, IL-17, TNF-α MCP-1/CCL2, MIP-1α/CCL3, MIP-3α/CCL20, RANTES/CCL5, and VEGF. Although all cytokines measured were detectable in all the tissue homogenates, significant decreases of IL-17 (a), VEGF (b), and MIP-3α/CCL20 (c) were found in the IL-18 gene-knockout homogenates compared with Wt mice. Conversely, MCP-1/CCL2 (d) was significantly increased in the same homogenates from IL-18 gene-knockout compared with Wt mice (n = number of joints examined)