Project description:Myeloid derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells with differentiation program partially blocked in pathological conditions such as cancer. Through inhibition of T cells especially cytotoxic T lymphocytes (CTLs), MDSCs play important tumor-promoting roles and maintain a state of immunological anergy and tolerance We used microarrays to profile gene expression of Gr-MDSC and identified differentially altered genes under different drug treatment.
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: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.
Project description:Differentially expressed genes of CD11b+Gr-1+ immature myeloid cells (IMCs) in the bone marrow and colonic tumor setting of histidine decarboxylase (HDC)-KO mice were examined by microarray (Affymetrix Mouse 430.2 array). Myeloid differentiation-related candidate genes were sought to be isolated and functionally studied. Total RNA of HDC-expressing CD11b+Gr-1+ IMCs of bone marrow were extracted from HDC-EGFP and HDC-EGFP/HDC-KO mice (3 mice in each group). CD11b+Gr-1+ myeloid-derived suppressor cells (MDSCs) of colon tumor were sorted from 10-12 colon tumors of WT and HDC-KO mice (5 mice in each group), and pooled to extract total RNA for microarray studies. Two technical replicates for each of the four groups. Four sets of comparisons were performed to screen for upregulated or downregulated genes in the HDC-KO CD11b+Gr-1+ IMCs or MDSCs (experiment group) compared to the WT group: (1) HDC-expressing CD11b+Gr-1+ IMCs of bone marrow of HDC KO mice compared to bone marrow IMCs of WT mice; (2) CD11b+Gr-1+ MDSCs in tumors of HDC-KO mice compared to WT mice; (3) CD11b+Gr-1+ MDSCs of WT colon tumors compared to IMCs in the WT bone marrow; and (4) CD11b+Gr-1+ MDSCs of colon tumors of HDC-KO mice compared to IMCs in the bone marrow of HDC-KO mice.
Project description:We sorted the MDSCs from the bone marrows of B16-F10 tumor-bearing mice and the naive mice. In addition, we cultured MDSCs in vitro to determine the effect of DOX (5µM).
Project description:Myeloid derived suppressor cells (MDSCs) markedly expand and participate in the suppression of immune responses in inflammation and tumor microenvironment. It was confirmed that MDSCs could be generated in vitro from bone marrow cells (BMCs) after 4 days GM-CSF only or GM-CSF plus IL-6 treatment. To identify the regulation of MDSCs in tumor microenvironment, we analyzed the gene expression from tumor cell ID8 supernant-induced MDSCs compared to BMCs.
Project description:Myeloid-derived suppressor cells (MDSCs) as a population of myeloid cells enriched in cancer patients with immunosuppressive function. Further studies have determined that MDSCs are comprised of two groups: polymorphonuclear-MDSCs (G-MDSCs) and monocytic-MDSCs (M-MDSCs). We used a microbeads kit (Miltenyi) to isolate G-MDSCs and M-MDSCs with markers Ly6c2-Ly6g+CD11b+ and Ly6c2+Ly6g-CD11b+, respectively. And then using bulk RNA-seq to anlysis the enrichment gene expression in G-or M-MDSC which from wild type, APCmin mutant adenoma and immune deffiency mice.
Project description:Myeloid-derived suppressor cells (MDSCs) represent a group of immature myeloid cells composed of myeloid progenitor cells and immature myeloid cells that can negatively regulate immune responses by inhibiting T cell function. Our lab and other groups have shown that injection of a lethal or sublethal dose of LPS into mice can result in the expansion of MDSCs in the bone marrow, spleen and blood. Until now, the molecular mechanisms responsible for this expansion were poorly studied. Specifically, the role of the individual microRNAs (miRNAs) involved remained largely unknown. We performed microarray analysis to compare the miRNA expression profiles of Gr-1+CD11b+ cells sorted from the bone marrow of LPS-injected and PBS-injected mice. We identified let-7e, which was highly upregulated in the LPS-treated group, as a potent regulator of LPS-induced MDSC expansion. Furthermore, let-7e overexpression in bone marrow chimeric mice leads to a noticeable increase in the population of Gr-1+CD11b+ cells, which results from reduced cellular apoptosis. Further studies showed that let-7e can directly target caspase-3 to inhibit cell apoptosis, and upregulation of let-7e in LPS-stimulated MDSCs could be due to the relieved repression of let-7e transcription exerted by downregulated GATA2. Our findings suggest that LPS expands MDSCs by inhibiting apoptosis through the regulation of the GATA2/let-7e axis.