Figure 1

Immune adaptation in response to multiple LPS challenges. (A-C) Cytokine production in response to repeated systemic challenges with LPS. Levels of protein expression of inflammatory cytokines in serum (A), spleen (B), and brain (C) in saline or LPS- injected mice. LPS challenges were given on three consecutive days, with 24 h between each injection. Cytokine levels were measured 3 h after each LPS injection and compared to cytokine levels in naïve mice. (D) Changes in burrowing behaviour and body weight upon multiple LPS challenges. Error bars represent SEM from five animals per time point (P < 0.05 (*), P < 0.01 (**), P < 0.001 (***) versus naïve control). This experiment was repeated three times with similar results.