Figure 1

Synovial cytokine expression at an early disease-preceding time point. Representative micrographs illustrating immunohistochemical staining of cryocut synovial tissue for expressions of high-mobility group chromosomal box protein 1 (HMGB1) (a), interleukin-1-beta (IL-1β) (b), and tumor necrosis factor (TNF) (c) three days after immunization. A thin, non-proliferative synovia is evident at this disease-preceding time point. TNF- and IL-1β-expressing cells are located in superficial parts of the synovial lining layer. HMGB1 expression was restricted to cell nuclei at this early time point. (d) A representative section is stained with irrelevant control antibody. Original magnification ×125.