Figure 11. Relationship between TLR2 and signaling pathways regulating IL-12 family member expression in microglia.

Intact Gram-positive bacteria trigger TLR9 activation via CpG DNA, which stimulates IL-12 family member production. In the absence of TLR2, TLR9 activation remains unchecked, resulting in exaggerated cytokine release. Both PI3K and MAPK pathways influence IL-12 expression in response to intact bacteria.