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Free keywords:
NLRP3 INFLAMMASOME ACTIVATION; RECRUITMENT DOMAIN PROTEIN; NF-KAPPA-B;
SUPERRESOLUTION MICROSCOPY; HUMAN MONOCYTES; PYRIN DOMAIN; ADAPTER ASC;
CELL-DEATH; BINDING; REDISTRIBUTIONScience & Technology - Other Topics;
Abstract:
The NLRP3 inflammasome is a central component of the innate immune system. Its activation leads to for-mation of the ASC speck, a supramolecular assembly of the inflammasome adaptor protein ASC. Different models, based on ASC overexpression, have been proposed for the structure of the ASC speck. Using dual-color 3D super-resolution imaging (dSTORM and DNA-PAINT), we visualized the ASC speck structure following NLRP3 inflammasome activation using endogenous ASC expression. A complete structure was only obtainable by labeling with both anti-ASC antibodies and nanobodies. The complex varies in diameter between similar to 800 and 1000 nm, and is composed of a dense core with emerging filaments. Dual-color confocal fluorescence microscopy indicated that the ASC speck does not colocalize with the microtubule-organizing center at late time points after Nigericin stimulation. From super-resolution images of whole cells, the ASC specks were sorted into a pseudo-time sequence indicating that they become denser but not larger during formation.
