IL-18 blockade with a monoclonal anti–IL-18R antibody protects from splenic changes induced by repeated TLR9 stimulation in IL-18BP^−/−mice. Male IL-18BP^−/− mice received CpG injections on days 0, 2, and 4 and were either treated with an isotype control (n = 11) or a monoclonal anti–IL-18R (n = 12) antibody. All mice were killed on day 7. (A) Spleen weights, normalized to body weight, from isotype and anti–IL-18R–treated IL-18BP^−/− mice are shown. Data were pooled from 2 independent experiments. The number of (Bi) total and CD45⁺ cells, (Bii) total T cells, CD4⁺ T cells, CD8⁺ T cells, and B cells, and (Biii) conventional DCs (cDCs), plasmacytoid DCs (pDCs), monocytes/macrophages (mono/macro), and neutrophils (neutro) in the spleen are reported for isotype (n = 6) and anti–IL-18R antibody–treated (n = 6) IL-18BP^−/− mice. Data are from 1 experiment and are representative of 2 experiments. The Mann-Whitney U test was used to compare isotype control and anti–IL-18R antibody–treated mice at 1 time point.