Fig. 4

Cellular distribution of IL-23 in synovial membrane of RA patients. Double immunofluorescence analysis in RA synovium was performed using specific antibodies against IL-23p19 (green), CD68 or vimentin (red). DAPI- (blue) stained nuclei. p19 double staining with CD68+ macrophages showing that ELN does not form a microarchitectural niche for IL-23-producing cells (a and b). IL-23 expression by vimentin-positive stromal cells (c). Magnification × 25. DAPI 4′,6-diamidino-2-phenylindole, IL interleukin, RA rheumatoid arthritis. ELN: ectopic lymphoid neogenesis