Potential cross-talk between DCs and Tregs.

A) Influx of FoxP3+ cells (red nuclear stain) in mouse synovial tissue at day 28 (2). Morphological picture of synovial tissue (1) were marked area indicates site of FoxP3 staining (2), and negative control (3). Scale bar  = 100 μm B). Intensity of MHCII expression on splenic pDCs (measured by gMFI). C) Expression of co-stimulatory molecule PD-L1 on splenic and nodal pDCs (tinted gray  =  FMO, black  =  PD-L1 expression on pDC). D) Frequency of pDCs in arthritic synovial tissue and intensity of CD11c expression on pDCs E) Immunofluorescent staining (2) of rheumatic synovial tissue (1) in vicinity of germinal center formation shows co-localization and potential cross-talk between DCs (CD11c+, red) and Tregs (FoxP3+, green). V  =  vessel, Scale bar  = 100 μm. Data are presented as mean ± SEM and statistical significance was assessed using unpaired t-test. *P<.05.