Supplementary Figure 6: IRF8 targets and represses Irf4 in activated B cells.

(a) ChIP-seq tracks for IRF4 (red) and IRF8 (blue) at Irf4 gene. IRF8 targeted region in Irf4 gene is highlighted with box. The DNaseI-seq track is from ENCODE (GSM1014190).
(b) Expression of Irf4 gene was analyzed by Q-PCR at indicated time points in Irf8+/+ and Irf8–/– FO B cells stimulated with 0.4 μg/ml LPS. Pou2f1 transcripts were used for normalization. The relative expression of indicated gene in Irf4–/– cells is in relation to its expression in wild-type cells at 24 h. Data is from two independent experiments (mean±SEM, *P < 0.001).
(c) Proposed gene regulatory network with two double negative feedback loops that orchestrates activated B cell responses. Schematic is generated using BioTapestry. Arrowheads represent gene activation inputs and barred lines signify repression; dashed lines indicate that a gene regulatory relationship could be indirect; thin red line represents a low level IRF4 gene output whereas thick red line represents a higher level IRF4 gene output.