Extended Data Fig. 2: Super-resolution imaging of STING in CCVs.

a, Large-field-of-view STED image showing the colocalization of pSTING and CCVs. HeLa cGAS/STING double KO cells were transfected with mCherry-clathrin and Flag-STING. One day later they were stimulated with 1 µM diABZI for 2.5 h and then fixed and stained for pSTING. Two representative events highlighted in the boxes were magnified (see Fig. 1d). Scale bar, 2 μm. The image depicts n = 1 cell out of 62 cells imaged over the course of 2 independent experiments, including 25 cells showing clear colocalization and 3 exhibiting clathrin ring structures. b,c, CLEM of HeLa STING KO cells stably reconstituted with GFP-hSTING stimulated for 2.5 h with 1 µM diABZI (b) or left untreated (c). For the stimulated cell (b), some regions with accumulation of high GFP–STING intensity (yellow boxes) were re-imaged by electron microscopy (EM) in higher resolution at relevant Z-heights. Zoom-in and higher-resolution electron microscopy slices from box 3 is shown in Fig. 1e. LM – light microscopy (Airyscan). White arrows indicate CCVs. Scale bars in (b), 2 µm (un-zoomed top images) and 0.5 µm (zoom-in box images). Scale bars in (c), 1 µm. n = 1 out of 3 stimulated cells (b) and n = 1 out of 2 non-stimulated cells imaged from one sample per condition prepared for CLEM.