Fig. 1

Pvt1 is highly expressed in tumor-expanded G-MDSCs. A total of 2 × 10^{^6} Lewis lung carcinoma cells (LLCs) were introduced via s.c. injection into C57BL/6 mice. After 4 weeks, bone marrow cells, splenocytes and a single-cell suspension derived from tumor tissues were collected, and G-MDSCs were later sorted. Splenocytes from wild-type (WT) C57BL/6 mice were collected, and G-MDSCs were isolated. Hierarchical clustering analysis of lncRNAs and protein-coding RNAs that were differentially expressed (fold change > 2) in G-MDSCs sorted from tumor tissue of Lewis tumor-bearing mice and spleens of WT C57BL/6 mice. a Clustering tree for lncRNAs; the expression values are represented in shades of red and green, indicating expression above and below normal values, respectively. b The purity of sorted G-MDSCs was determined via flow cytometry by assessing the expression of two surface markers: Ly6G and CD11b. c The expression level of Pvt1 in total RNA isolated from G-MDSCs from the bone marrow, spleen and tumor tissues of Lewis-bearing mice was measured by qRT-PCR. Fresh G-MDSCs isolated from bone marrow (BM) from WT C57BL/6 mice served as the control. Bone marrow cells (1 × 10^{^6}) from WT C57BL/6 mice were plated in 24-well plates in 1 mL of RPMI 1640 medium containing 10% FBS, 20 ng/mL IL-6 and 20 ng/mL GM-CSF. The cells were then collected, and G-MDSCs were sorted 3 days later. d G-MDSCs cocultured with CFSE-labeled CD4⁺ T cells at a ratio of 1:1 in the presence of anti-CD3 mAb and anti-CD28 mAb for 72 h. The proliferation of CD4⁺ T cells was detected by flow cytometry at 488 nm excitation light. e Arg1 activity in G-MDSCs induced from BM cells was measured. f ROS production in G-MDSCs was analyzed via flow cytometry. g The expression level of Pvt1 in G-MDSCs was detected using qRT-PCR. ***p < 0.001, and **p < 0.01; ns: no significance