Figure 2. CSF-1R expression on mouse and human TECs.

(A) Left panel: mouse TECs express CSF-1R mRNA. CSF-1R transcript expression, normalized to GAPDH expression, determined by real-time PCR in primary cultured TECs derived from WT B6 mice and in cells of the proximal TEC line, C1. TECs from Csf1R^–/– mice and a T cell line (DO11.10) served as negative controls, and WT BM macrophages and cells of the RAW 264 macrophage cell line served as positive controls. Right panel: CSF-1 upregulates TEC CSF-1R transcript expression. C1 cells were incubated with CSF-1 (100 ng/ml) for 24 hours and 48 hours. Results are representative of 3 separate experiments. Means ± SEM are shown. Bottom left panel: Primary TECs express CSF-1R protein. Primary WT BM macrophages and primary Csf1R^–/– TECs served as positive and negative controls, respectively (n = 2–3 per group). Original magnification, ×40. Bottom right panel: CSF-1R protein detected in lysates of cultured primary WT TECs. Western blot of CSF-1R immunoprecipitates. WT BM macrophages (at less than one-third the amount of TEC protein) served as a positive control. (B) Left panel: CSF-1R transcript expression in cultured cells of the human proximal TEC line, HK2, determined by real-time PCR. The Jurkat T cell line, the human leukemic monocytic leukemia (U937), the human erythromyeloblastoid leukemia cell line (K562), and the human leukemic cell line (HL60), all stimulated with TPA, served as positive controls. Results are representative of 3 separate experiments. Data represent means ± SEM. Right panel: Human TECs (HK2 line) express CSF-1R protein detected by Western blotting. TPA-stimulated U937 cells and Jurkat T cells served as positive and negative controls, respectively.