Figure 5. miR-155 targets socs1 within MDSCs.

(A) miR-155 expression was measured by the real-time quantitative RT-PCR in splenic Gr1⁺CD11b⁺ cells from WT naïve mice, LLC1 tumor-bearing WT mice, and (B) miR-155^−/− tumor bearing mice (n=3). (C) Socs1 gene expression was measured by the real-time quantitative RT-PCR in splenic WT or miR-155^−/− Gr1⁺CD11b⁺ cells from naïve mice and LLC1 tumor-bearing mice (n=5). (D) To identify the function of SOCS1 within Gr1⁺CD11b⁺ MDSC, miR-155^−/− MDSCs were transfected with siRNAs against SOCS1 or control oligos, and WT MDSCs were also transfected with control oligos by AMAXA. MDSCs 48 h after transfection were added at different ratios to OT-I splenocytes stimulated with OVA-I peptides for 3d, and ³[H] thymidine uptake was measured. Data are given as means ± SEM. Data are representative of 2 independent experiments. *, p<0.05; **, p<0.01.