Eicosanoids in the Innate Immune Response: TLR and Non-TLR Routes

Figure 6

Diagram of AA metabolism in DC stimulated with zymosan particles. The mannan and $\beta$-glucan components of zymosan are recognized by at least DC-SIGN, TLR2, and dectin-1. This gives rise to a series of signaling events implicating activation of Syk and Src families of tyrosine kinases. Both routes converge to activate phospholipase C$\gamma$ and through the generation of diacylglycerol activate protein kinase C and mitogen-activated protein kinase (MAPK) cascades. Phosphorylation by MAPK and ${\text{Ca}}^{2+}$-driven translocation of ${\text{cPLA}}_2$ explain AA release from cell phospholipids. Activation of I$\kappa$B kinases via MyD88 is a major factor explaining COX-2 induction. The CARD9/MALT1/BCL10/TRAF6 complex is involved in the activation of I$\kappa$B kinases. DAG, diacylglycerol; IP3, inositol 1,4,5-trisphosphate; PLC$\gamma$, phospholipase C$\gamma$; P-Y, phosphotyrosine.