Figure 6: Id1 is upregulated via a TGFβ-dependent mechanism and downregulates key genes involved in DC maturation.

(a) Id1 mRNA relative expression levels in day 6 Lin⁻ cells differentiated in the presence of 100 ng μl⁻¹ of murine recombinant proteins (VEGF, IL-6, BMP-7, -9 and -10, and TGFβ compared with Lin⁻ cells differentiated in control media, as determined by qPCR analysis (means±s.e.m., n=6, analysis of variance (ANOVA), ^****P<0.0001, ^**P<0.01, *P<0.05). (b) Id1 mRNA expression levels in day 6 Lin⁻ cells differentiated in the presence of B16F10 CM (abbreviation introduced in Fig 2) alone, with anti-TGFβ and anti-IgG compared with control media, as determined by qPCR analysis (means±s.e.m., n=6, ANOVA, ^***P<0.001, ^**P<0.01). (c) Irf8 mRNA relative expression levels of day 6 WT Lin⁻ cells differentiated in the presence of 100 ng μl⁻¹ of TGFβ, B16F10 CM alone, with anti-TGFβ and anti-IgG compared with control media, as determined by qPCR analysis (means±s.e.m., n=6, ANOVA, ****P<0.0001, ***P<0.001). (d) Irf8 mRNA relative expression levels of day 6 Id1^−/− Lin⁻ cells differentiated in the presence of 100 ng μl⁻¹ of TGFβ, B16F10 CM alone, with anti-TGFβ and anti-IgG compared with control media, as determined by qPCR analysis (means±s.e.m., n=6, ANOVA; NS, not significant). Four independent experiments were performed.