Figure 2.

Co-treatment of IL-27 with a tolerizing dose of LPS inhibits induction of endotoxin tolerance in human monocytes and macrophages. THP-1 cells (A), PMA–THP-1 cells (B), primary human monocytes (C), and primary human macrophages (D) were stimulated with LPS (10 ng/ml), IL-27 (100 ng/ml), or LPS + IL-27 simultaneously for 24 h (1°). Cells were washed and challenged with LPS (100 ng/ml) for 4 h (2°). TNF-α production was measured in cell-free supernatants by ELISA. The -fold change of TNF-α production was calculated relative to untolerized (1° med/2° LPS) cells. Graphs present mean ± S.E. of at least six independent experiments or at least six different blood donors.