Fig. 3

Validation of RNA processing bodies (PB)/stress granules (SG) as a target of the SSc autoimmune response. a HeLa cell lysates were immunoprecipitated using patient sera, resolved by SDS-PAGE, and probed with antibodies targeting known PB and SG proteins; HeLa whole cell lysate was used as a control. b Immunofluorescence was performed in U2OS cells treated with sodium (meta)arsenite to induce the formation of SG. Cells were then fixed with 4 % paraformaldehyde and permeabilized with 5 % normal horse serum and 0.1 % digitonin in Tris-buffered saline. Staining was performed with anti-eIF3b (SG marker), anti-SK1-Hedls (PB marker), and patient sera. Representative images depicting co-localization between patient sera and SG/PB markers are shown, with sites of co-localization circled in red. RNAP RNA polymerase, CENP centromere protein TOPI topoisomerase I