Expression data from spleen-derived and tumor-induced CD11b+ MDSC

CD11b+ myeloid-derived suppressor cells (MDSCs) have been shown to become activated at the tumor site and acquired a more suppressive phenotype compared to the splenic counterpart. This activated status promotes cancer progression by creating an immune suppressive niche around the tumor, by providing nourishment to the neoplastic cells, and by promoting metastases. To start understanding the differences between splenic and tumor infiltrating CD11b, genome-wide transcriptome analysis was performed. We used gene expression analysis to identify those factors, secreted by tumor-infiltrating MDSC, which could drive emathopoiesis. Moreover, we compare gene expression profile of tumor-induced MDSC, obtained from either the spleen or the tumor infiltrate of tumor-bearing mice. CD11b+ cells were immunomagnetically enriched from various murine tissues and experimental conditions. cRNA samples were prepared according to Expression Analysis: Technical Manual. 701021 Rev. 5. Santa Clara, CA, Affymetrix; 2004, and hybridized to the Affymetrix GeneChip MOE430 2.0 array which contains more than 45,000 probe sets, representing more than 34,000 genes. CD11b+ cells obtained from the spleen of healthy BALB/c mice were used as reference sample for tumor induced CD11b+ MDSC, enriched from either the spleen or the tumor infiltrate of tumor-bearing mice.