Figure 4.
cGAS is important for DNA-induced inflammasome. (a) Pathways that can be activated by dsDNA to activate the inflammasome. To the left is the published AIM2-dependent pathway. To the right is the proposed pathway mediated by cGAMP. (b) Relative cGAS as determined by qPCR of JAWSII cells containing empty vector (sh-ev) or shRNA targeting cGAS (sh-cGAS). (c) IFN-β or (d) IL-1β levels of supernatants from JAWSII DCs primed with LPS then transfected with dAdT, transfection reagent alone (TFXN), or not treated (NT). (e and f) IL-1β (e) or IFN-β (f) levels of supernatants from BMDM primed with LPS then transfected with the indicated PAMP or DAMP, or not transfected (NT). n = 3 independent experiments, mean ± SEM. ***, P < 0.001; ****, P < 0.0001. (g) Confocal microscopy of LPS-primed JAWSII cells expressing AIM2-Flag transfected with 10 µg/ml dAdT and 130 pmol fluorescein-labeled 2′3′-cGAMP for 4 h. During the final hour, FLICA-660 was added to detect caspase-1. Bars, 5 μm. Cells were imaged on a Zeiss 700 confocal microscope. Pseudocolors: blue, AIM2-Flag; green, fluorescein-labeled 2′3′-cGAMP; red, dAdT-rhodamine; and magenta, caspase-1.