Figure 2.

The expression of IRF8, a representative target of TRIM21 ubiquitination, was also decreased in BD monocytes. (a) IRF8 protein levels in monocytes from 18 BD patients and five healthy control subjects, as determined by western blot. Cell lysates were from the same sample used in the analysis depicted in Fig. 1a and b. Primary monocytes (c) and THP-1 cells (d) were transfected with scrambled RNA or TRIM21 siRNA (10 nM) for 24 h. Expression of TRIM21 and IRF8 was detected by immunoblotting. TRIM21 and IRF8 expression was quantitated by densitometry following normalization to GAPDH expression as indicated in the accompanying graph. Data are represented as the mean ± SD. (e) Monocytes isolated from healthy controls or BD patients were stimulated with LPS (1 µg/ml) for 24 h. Supernatants were collected, and secretion of IL-12/23p40 was measured by ELISA. (f) Primary monocytes from healthy controls were transfected with scrambled RNA or TRIM21 siRNA (10 nM) for 24 h, and the transfected cells were stimulated with LPS (1 µg/ml) for 24 h, and the secretion of IL-12/23p40 was measured by ELISA. Data are represented as the mean ± SD. *P < 0.05. **P < 0.01. ***P < 0.001. The cropped blots are displayed and full-length blots are shown in the Supplementary Information.