Figure 5

CD123⁺ and CD11c⁺ synovial fluid (SF) dendritic cells (DCs) are efficient antigen-presenting cells (APCs) and induce secretion of tumor necrosis factor α. Freshly sorted CD123⁺CD11c^- or CD11c⁺CD123^- DCs from either normal peripheral blood (PB) (a–d) or rheumatoid arthritis (RA) SF (e–h) were incubated with 10⁵ purified normal allogeneic T cells. T-cell proliferation was measured by [³H]thymidine incorporation of triplicate wells after 60 hours (a, e). Unstimulated T-cell proliferation was routinely <500 cpm. Data represent means ± standard error of the mean of triplicate wells and are from three individual PB and SF donors. The concentrations of IFNγ, IL-10, and tumor necrosis factor (TNF)-α were measured in supernatants of allogeneic mixed lymphocyte reactions stimulated by sorted PB (b–d) or SF DCs (f–h). Data are means of duplicate samples and are from two separate SF donors.