Figure 4.

TLR3 co‐stimulation of microglia does not lead to overshooting responses. (a–k) WT microglial cells were stimulated for 24 hr with TLR2 or TLR3 agonists alone or in combination. Cell culture supernatants were collected and cytokine production was measured by multiplex assay (IL‐12p70, IL‐23, IL‐27, IL‐22, IFN‐γ, IL‐4, and IL‐5) or ELISA (TNF, IL‐6, IFN‐β, and IL‐1β). Significant statistical differences relative to TLR2 are represented by *; to TLR3 by #. (l) WT and IFNAR−/− microglial cells were stimulated for 24 hr with the TLR2 or TLR3 agonists alone or in combination. Cell culture supernatants were collected and IL‐27 production was measured by multiplex. (m) WT microglial cells were stimulated for 24 hr with the TLR2 agonist, IFN‐β or IL‐27 alone or in combination. Cell culture supernatants were collected and IL‐10 production was measured by ELISA. Significant statistical differences relative to TLR2 are represented by *; to TLR2 + IFN‐β by #; to TLR2 + IL‐27 by $. The detection limit for each cytokine is represented as a dotted line in each graph. Represented are the mean ± SD for triplicate wells per condition set after mixed cultures generated from independent mice. Statistical differences were assessed by student's t test or one‐way ANOVA. Significant statistical differences are represented by one symbol, p < .05; two, p < .01; three, p < .001; and four, p < .0001. bdl, below detection level