Figure 3: C/EBPβ controls inflammatory cytokine release in DCs.

(a) RT–qPCR arrays were performed with RNA extracted from splenic DCs isolated from tumour-naive Wt (B6) and CD11c.Cre × C/EBPβ^flox/flox (C/EBPβ^−/−) animals or from Wt and C/EBPβ^−/− lymphoma cell recipients 10 and 13 days after tumour challenge (n>10 mice per group; n=3–5 independent experiments). Altered gene expression levels are depicted as x-fold expression normalized to DCs from untreated Wt mice set arbitrarily at 1 (solid horizontal line). Bars represent means±s.e.m.; a Mann–Whitney test was used; *P<0.05. (b) RT–qPCR arrays were performed with RNA extracted from splenic DCs isolated from tumour-naive Wt (B6) and Wt lymphoma cell recipients 10–13 days after tumour challenge (n=10 mice per group; n=2 independent experiments). Altered gene expression levels for genes involved in growth control and adhesion were depicted as x-fold expression normalized to DCs from untreated Wt mice. (c) Single gene-focused RT–qPCR for IGF-1 expression in DCs from naive versus lymphoma B-cell-challenged Wt or C/EBPβ^−/− mice is presented as for the arrays (DCs from two to three animals were pooled per genotype). In b,c, bars represent means±s.e.m.; a Student’s t-test was applied. *P<0.05; ***P<0.001. (d) Surface expression of cytokine receptors on Eμ-Myc lymphoma B cells (B220⁺; n=3–5 independent clones per marker; isotype control, shaded curve). One representative histogram for each cytokine receptor is shown. (e) Spleen sections of naive (n=2) and tumour-challenged mice (days 9–11; n=4) stained for CD11c⁺ DCs, C/EBPβ⁺ and DAPI. A representative section of each group and an enlarged inlet of the boxed area are shown on the right. (f) Spleen sections as in e stained for CD11c⁺, pSTAT3⁺ and DAPI. A representative section of each group is shown. Scale bars, 100 μm.