CD1c+ myeloid dendritic cells are abundantly present in joints of rheumatoid arthritis patients and express increased levels of antigen-presenting and costimulatory molecules. (A) Representative fluorescence-activated cell sorting (FACS) dot plot of CD1c-expressing myeloid dendritic cells (mDCs) and CD19+ cells in the peripheral blood (PB) and synovial fluid (SF) of a rheumatoid arthritis (RA) patient. (B) mDC numbers are increased in SF versus PB of RA patients (n = 10), and SF mDCs express higher CD1c levels. Percentages (%) of the total mononuclear cell (MNC) population and mean fluorescent intensity (MFI) of CD1c expression are given. (C) mDCs derived from SF (n = 5) express enhanced levels of antigen-presenting (human leukocyte antigen class II (HLA-II)) and costimulatory molecules (CD80, CD86 and CD40) as compared with PB-derived mDCs (n = 3). Representative histograms of isotype control (open) and HLA-II, CD80, CD86 and CD40 (filled) expression and mean are shown (MFI corrected for isotype fluorescence). Statistically significant differences of *P <0.05 and **P <0.01.
Moret et al. Arthritis Research & Therapy 2013 15:R155 doi:10.1186/ar4338