Figure 2: Dexamethasone (DXM) preconditioning improves the effect of 4-hour lipopolysaccharide-(LPS-) stimulated dendritic cells (DCs) in modulating active CIA. (a) Isolated CD11c+ DCs were stimulated with LPS for 4 hours (4hLPS/CII/DCs) and loaded for 24 hours with bovine type II collagen (CII) or left unloaded (4hLPS/DCs). LPS-untreated DCs loaded with CII (0hLPS/CII/DCs) or unloaded (0hLPS/DCs), or treated for 24 hours with LPS (24hLPS/DCs) were used as controls. The expression of major histocompatibility complex (MHC) class II and costimulatory molecules (CD86 and CD40) was analyzed by flow cytometry. Values are expressed as percentage of increase in mean fluorescence intensity (MFI) related to 0hLPS/DCs. Data from a representative experiment of three experiments performed are shown. ** and ***. (b) Cytokine production by differentially stimulated DCs was assessed by ELISA. Bars represent the mean of three experiments performed in duplicate. ** and ***. (c) Mice with active CIA received 2.0 mg/kg DXM from days 29 to day 34 after CIA induction (DXM group). Then, mice were inoculated intraperitoneally at day 35 with DCs as follows: 4-hour LPS-stimulated DCs (DXM/4hLPS/DCs) and 4-hour LPS-stimulated DCs loaded with CII (DXM/4hLPS/CII/DCs). The 4hLPS/CII/DCs group received 4-hour LPS-stimulated DCs loaded with CII, but without DXM preconditioning. The CIA control group corresponds to mice that did not receive any treatment. The two-tailed ANOVA test and Bonferroni’s post-test were applied when comparing Joint Score and Swollen Joints Severity Score curves from day 44 to day 70. Data from a representative experiment of three experiments performed with 8–10 mice per group are shown. * in DXM/4hLPS/CII/DCs versus CIA group.