Project description:It is suggested that decidual polymorphonuclear myeloid-derived suppressor cell (PMN-MDSCs) are a group of activated suppressive neutrophils. Decidual microenvironment can facilitate circulating neutrophils with phenotypes and functions of PMN-MDSCs. The mechanism of PMN-MDSCs differentiation induced by decidual microenvironment has not been fully understood. Here we performed whole genome expression profile of 3 decidual PMN-MDSCs and autologous neutrophils from normal early pregnancy. Total RNA were extracted. The arrays were scanned by the Agilent Scanner G2505C. There were differences of gene expression pattern between decidual PMN-MDSCs and autologous neutrophils in early normal pregnancy.
Project description:We found that PMN-MDSCs level is elevated in the advanced ICCs tissues and is positively associated with the METTL1 and m7G tRNA modification levels. We further showed that impaired m7G tRNA modification impedes the PMN-MDSCs infiltration and inhibits ICC progression. Mechanistically, METTL1-mediated m7G tRNA modification selectively regulates the translation of human CXCL8 and mouse Cxcl5 transcripts, which facilitates the migration of PMN-MDSCs via binding to their cognate receptor CXCR2. Co-blockade of METTL1 and CXCR2 significantly enhances the efficacy of anti-PD-1 treatment in ICC. Taken together, our study reveals the cellular and molecular basis of crosstalk between ICC cells and MDSCs in shaping TIME and affecting ICIs efficacy, which enables reasonable design of new combined therapy targeting dysregulated mRNA translation and suppressive TIME.
Project description:Polymorphonuclear myeloid-derived suppressor cell (PMN-MDSC), also named pathologically activated neutrophil, is a critical component of tumor microenvironment (TME), playing crucial roles in tumor progression and therapy resistance. CD300ld is specifically expressed in normal neutrophils and is upregulated in PMN-MDSCs upon tumor bearing. CD300ld knockout (KO) inhibits the development of multiple tumor types in a PMN-MDSC-dependent manner. Here, we compared the transcriptome of PMN-MDSCs from WT mice and CD300ld KO mice.
Project description:Myeloid-derived suppressor cells (MDSCs) are myeloid precursors which exert potent immunosuppressive properties in cancer. Despite the extensive knowledge on mechanisms implicated in mobilization, recruitment and function of MDSCs, still their therapeutic targeting remains an unmet need in cancer immunotherapy suggesting that unappreciated mechanisms of MDSC-mediated suppression exist. Herein, we demonstrate an important role of NLRP3 inflammasome in the functional properties of MDSCs in tumor-bearing hosts. Specifically, Nlrp3-deficient mice exhibited reduced tumor growth compared to wild-type animals and induction of robust anti-tumor immunity, accompanied by re-wiring of the MDSC compartment. Interestingly, both monocytic (M-MDSCs) and granulocytic (G-MDSCs) subsets from Nlrp3-/- mice displayed impaired suppressive activity and demonstrated significant transcriptomic alterations supporting the loss-of-function and associated with metabolic re-programming. Finally, therapeutic targeting of NLRP3 inhibited tumor development and re-programmed the MDSC compartment. These findings propose that targeting NLRP3 in MDSCs could overcome tumor-induced tolerance and may provide new checkpoints of cancer immunotherapy.
Project 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. 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.
Project description:Analysis of MDSC subsets from naive blood and RMA-S blood and RMA-S tumor, respectively. Tumor-infiltrating MO-MDSCs changed their expression pattern compared to blood and exhibited high levels of chemokines Total RNA obtained from PMN-MDSCs and MO-MDSCs from naive blood or from blood and tumor of RMA-S bearing mice
Project description:Myeloid-derived suppressor cells (MDSCs) are increased by tumor-derived factors and suppress anti-tumor immunity. MDSCs obtained at a late time point after tumor injection had stronger suppressive activity than MDSCs obtained at an early time point, as measured by T cell proliferation assays. To find factors in MDSCs that change during tumor growth, we analyzed gene expression profiles from MDSCs at different time points after tumor injection. We found that immune response-related genes were down-regulated, but pro-tumor function-related genes were up-regulated in both Mo-MDSCs and PMN-MDSCs at the late time point. Among differentially expressed genes, FK506 binding protein 51 (FKBP51), which is a member of the immunophilin protein family and plays a role in immunoregulation, was increased in the Mo- and PMN-MDSCs isolated from the late time points. Experiments using siRNA and a chemical inhibitor of FKBP51 revealed that FKBP51 contributes to the regulation of the suppressive function of MDSCs by increasing iNOS, ARG1, and ROS levels and enhancing NF-kappaB activity. Collectively, our data suggest that FKBP51 is a novel molecule that can be targeted to regulate the immunosuppressive function of MDSCs. To identify the factors that licensed MDSCs to be more suppressive as tumors grow, we analyzed gene expression profiles in the two subsets of MDSCs at different time points (3wks, 6wks) during tumor progression. CD11b+Ly-6C(high)Ly-6G(low) Mo-MDSCs and CD11b+Ly-6C(low)Ly-6G(high) PMN-MDSCs were sorted from pooled spleens of naïve mice and Her-2/CT26 tumor-bearing mice. Total RNA was purified and gene expression was analyzed by the Affymetrix GeneChip® Mouse Gene 1.0 ST Array.
Project description:The BRAF inhibitor dabrafenib has been reported to activate the integrated stress response (ISR) kinase GCN2, and the therapeutic effect has been partially attributed to GCN2 activation. Since ISR signaling is a key component of myeloid-derived suppressor cell (MDSC) development and function, we measured the effect of dabrafenib on MDSC differentiation and suppressive activity. Our data showed that dabrafenib attenuated MDSC ability to suppress T cell activity, which was associated with a GCN2-dependent block of the transition from monocytic progenitor to polymorphonuclear (PMN)-MDSCs and proliferative arrest resulting in PMN-MDSC loss. Transcriptional profiling revealed that dabrafenib-driven GCN2 activation altered metabolic features in MDSCs enhancing oxidative respiration, and attenuated transcriptional programs required for PMN development. Thus, ourdata reveals transcriptional networks that govern MDSC developmental programs, and the impact of GCN2 stress signaling on the innate immune landscape in tumors, providing novel insight into potentially beneficial off target effects of dabrafenib.
Project 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.