FIGURE 7.

The protective effect of IFN-α in AIA requires the presence of pDC both in the sensitization and arthritis phase. AIA was induced in female mice with IFN-α treatment as described in Materials and Methods, with or without pDC-depletion by daily injections of the 120G8 Ab day 0–8 (sensitization phase) or day 20–27 (arthritis phase). (A) The level of arthritis is expressed as severity score (mean ± SEM, n ≥ 6). Comparison between groups was made by Mann–Whitney U test. *p < 0.05, **p < 0.01. (B) Quantitative densitometry analysis of western blots performed for IDO1 expression at days 4 and 28 in total splenocytes of mice subjected to AIA with IFN-α treatment with or without depletion of pDC in the sensitization or arthritis phase, as in (A). Data are presented as IDO1/β tubulin ratio and are representative of three experiments.