Figure 1From: Rheumatoid arthritis synovium contains plasmacytoid dendritic cellsNuclear RelB-CD123+ plasmacytoid dendritic cells (pDCs) are located in close association with cells expressing tumor necrosis factor (TNF)-α in lymphoid aggregates of rheumatoid arthritis (RA) synovial tissue. Sections of frozen normal human synovial tissue (a, b, e) or synovial tissue from a patient with untreated active RA (c, f, g) or formalin-fixed sections from a patient with active RA (d, h, i) were stained with anti-CD11c (brown, a, c), anti-CD123 (brown, b, d), or anti-TNF-α (brown, g) using an immunoperoxidase technique. For double staining, sections were stained with Ulex (red) and anti-CD123 (brown, e, f, g) or with RelB (purple) and CD123 (brown, h, i) using a double, immunoperoxidase–immunoalkaline phosphatase technique. All sections were counterstained with hematoxylin (blue) except h and i, in which the nucleus of CD123+ cells appears as a hole. The thick arrow in d identifies a blood vessel. Thin arrows denote representative CD123+ perivascular DCs (d), representative double-stained vessels (e), a CD123+ cell within a blood vessel (f), and nuclei stained by RelB (h). Data are representative of at least three separate RA donors in individual experiments. Scale bars represent 20 μm.Back to article page