Fig. 2: Detection of ASC specks in fixed tissue from donated livers.

Representative images of ASC specks, indicating the presence of activated inflammasomes, detected by immunofluorescence in THP-1 cells (a) or liver tissue (b–d). a THP-1 cells were in vitro primed with LPS for 4 hours and then incubated in the presence or absence of nigericin for an additional 1 hour. Following stimulation, the cells were fixed, centrifuged, and embedded in a specialized processing gel. The gel block was then processed, including fixation in PaxGene medium and paraffin embedding. The white-lined square in the upper right corner represents a magnification of the image. White arrowheads indicate the presence of ASC specks represented as a green dot. The bar-graph depicts the quantification of ASC specks per nucleus in three independent images. ***p ≤ 0.001. b Two different patterns of ASC speck staining can be found in fixed liver tissues. In the upper picture, green dots, indicated by white arrowheads, are detected, while in the lower picture, a reticular structure surrounding the nucleus is shown. A magnification of each image is shown on the right side. Two representative images are shown. c Liver biopsy samples were double counter-stained with anti-ASC antibody (green) and anti-CD68 antibody (red) (Invitrogen; #14-0688-82). White arrowheads indicate the presence of ASC specks. d Liver biopsy samples were double counter-stained with anti-ASC (green) and anti-active IL-1β (red) (Invitrogen; #PA5-105048). Green arrowheads signal single staining for ASC specks, red arrowheads indicate the presence of single staining for active IL-1β, while yellow arrowheads show co-staining for both markers. Two representative images are shown.