Fig. 4.

The signaling pathways for CLRs. Dectin-1, Dectin-2/Dectin3 and Mincle/Dectin-3 are activated by their ligands and then activate Syk. Afterward, Syk initiates caspase activation and recruits CARD9/BCL10/MALT1 complex to induce the expression of canonical NF-κB dependent proinflammatory molecules. Moreover, Dectin-1-Syk kinase signaling (i) initiates ROS production, which can mediate NLRP3 inflammasome formation and maturation of IL-1β and IL-18; (ii) promotes noncanonical caspase-8 inflammasome and then actives IL-1β production; (iii) initiates NFAT activation; (iv) mediates Ras-GRF1/H-Ras/CARD9 complex formation to induce ERK activation. In addition, Dectin-1 and DC-SIGN activate Ras, then induce Raf-1 mediated non-canonical NF-κB activation and subsequently promote proinflammatory molecule expression