Low-density miRNA microarray of induced mouse myeloid-derived suppressor cell

Myeloid-derived suppressor cells (MDSCs) are one of the main cell populations that negatively regulate immune responses. However, the mechanism underlying the differentiation and expansion of MDSCs remains unclear. Employing a low-density miRNA microarray and a TaqMan probe-based qRT-PCR assay, we investigated the miRNAs expression profiles of MDSC. Compared to freshly isolated BM cells, BM-MDSCs had a significantly altered miRNA profile. There were 45 miRNAs that were upregulated and 17 miRNAs that were downregulated more than 2-fold. Among these miRNAs, miR-155 and miR-21 have the highest upregulation after cytokine induction. BM cells were planted into dishes using RPMI1640 medium supplemented with 2 mM L-glutamine, 10mM HEPES, 20µM 2-mercaptoethanol, 150 U/ml streptomycin, 200 U/ml penicillin, 10% FBS and stimulated with combinations of GM-CSF (40ng/ml), and IL-6 (40ng/ml). Cells were cultured at 37°C in 5% CO2-humidified atmosphere for 4 days.Total RNA were isolated, low-density miRNA microarray was performed