Project name: Mus musculus

Description: Tumor growth is associated with a profound alteration of myelopoiesis, leading to recruitment of immunosuppressive cells known as myeloid-derived suppressor cells (MDSCs). Analyzing the cytokines affecting myelo-monocytic differentiation produced by various experimental tumors, we found that GM-CSF, G-CSF, and IL-6 allowed a rapid generation of MDSCs from precursors present in mouse and human bone marrow (BM). BM-MDSCs induced by GM-CSF+IL-6 possessed the highest tolerogenic activity, as revealed by the ability to impair the priming of IFN- -producing CD8+ T cells upon in vivo adoptive transfer. Moreover, adoptive transfer of syngeneic, GM-CSF+IL-6-conditioned MDSCs to diabetic mice transplanted with allogeneic pancreatic islets resulted in long term acceptance of the allograft and correction of the diabetic status. Cytokines inducing MDSCs acted on a common molecular pathway. Immunoregulatory activity of both tumor-induced and BM-derived MDSCs was entirely dependent on C/EBP transcription factor, a key component of the emergency myelopoiesis triggered by stress and inflammation. Adoptive transfer of tumor antigen-specific CD8+ T lymphocytes resulted in therapy of established tumors only in mice lacking C/EBP in myeloid compartment. These data unveil another link between inflammation and cancer and identify a novel molecular target to control tumor-induced immune suppression.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 and the tumor infiltrate of tumor bearing mice, and in vitro bone marrow-derived MDSC.Overall design: CD11b+ cells were immunomagnetically enriched from various murine tissue and experimental conditions, and cRNA samples were prepared accordingly 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 and C57BL/6 mice were used as reference sample for tumor induced CD11b+ MDSC, enriched from either the spleen and the tumor infiltrate of tumor-bearing mice. Moreover CD11b+ cells enriched from fresh bone marrow were used as reference sample for in vitro bone marrow-differentiated MDSC, obtained with either GM-CSF+IL-6 and GM-CSF+G-CSF 4 days cytokine cocktail treatment.

Data type: Transcriptome or Gene expression

Sample scope: Multiisolate

Relevance: ModelOrganism

Release date: 2010-06-03

Last updated: 2010-05-20