Figure 1. C/EBP-δ regulates tumor-induced expansion of MDSCs.

Gr-1 and CD11b double positive cells were isolated by FACS sorting from spleens of C57Bl/6 mice with or without subcutaneous (s.c.) implantation of 3LL tumors. Total RNA was isolated and subjected to semi-quantitative RT-PCR (Panel A) and qPCR (Panel B) for C/EBP-δ expression. n = 3 mice per group, **p < 0.01. Gr-1CD11b double positive cells were analyzed by flow cytometry in spleens from age and sex matched C/EBP-δ null mice and littermate WT mice (Panel C) n = 5 mice per group. 5 × 10⁵ 3LL tumor cells were s.c. implanted into age and sex matched C/EBP-δ null mice and littermate WT mice for approximately 3 weeks. Single cell suspensions were made from spleens of mice with similar size tumors and analyzed by flow cytometry for Gr-1 and CD11b double positive cells (Panel D). The levels of Gr-1+CD11b+ cells in spleens (Panel E) and blood (Panel F) of tumor-bearing mice were plotted. n = 7 mice per group, **p < 0.01. Each experiment was repeated twice. Representative flow images are shown.