Project description:Administration of G-CSF mobilizes a unique population of CD11b+Ly6C+CD34+mature monocytes that can inhibit GVHD in murine models of BMT via an iNOS-dependent mechanism. The transcriptional profiles of flow sorted lineage-CD11b+CD34+ cells from G-CSF treated mice were compared with conventional splenic Ly6C+ and Ly6C- monocytes, progenitor cells and cultured myeloid-derived suppressor cells. Further comparisons were made with lineage-CD11b+CD34+ cells from G-CSF treated mice that had been grown in culture or that were derived from iNOS ko mice. We used microarrays to detail the global programme of gene expression underlying diffrenetiation of each of these cell types Lin-CD11b+CD34+ populations were isolated directly from the spleens of G-CSF-treated C57BL/6 mice or iNOS ko mice. In untreated C57BL/6 mice, Lin-CD11b+CD115+Ly6C+ and Lin-CD11b+CD115+Ly6C- monocytes were isolated from the spleen and Lin-CD117+CD115+CD135-Ly6C+CD11b- common monocyte progenitors were isolated from the bone marrow. Myeloid-derived suppressor cells (Ly6C+CD11b+ cells derived from G-CSF, GM-CSF and IL-13 cultured C57BL/6 bone marrow) were also isolated and compared with the above populations. Lin-CD11b+CD34+ spleen cells derived from G-CSF-treated C57BL/6 mice were cultured for 3 days in Flt3 ligand and SCF and then compared to the original input population.
Project description:Interferon Regulatory Factor-8, an Integral Determinant of Myeloid-Derived Suppressor Cell Subset Development. Myeloid-derived suppressor cells (MDSC) are a major barrier to anticancer responses. Although much is known about how MDSC promote tumor progression, little is known about how they develop. We hypothesized that MDSC develop as a consequence of tumor-induced downregulation of interferon regulatory factor-8 (IRF-8), a key myeloid developmental transcription factor. We showed that: 1) IRF8-deficiency in mice generated myeloid populations highly homologous to tumor-induced MDSC; 2) IRF-8 overexpression in mice reduced MDSC accumulation and retarded tumor growth; 3) MDSC-inducing factors, G-CSF or GM-CSF, facilitated IRF-8 downregulation via STAT3- or STAT5-dependent pathways, respectively; and 4) IRF-8 levels in MDSC-like subsets of breast cancer patients were depressed compared to healthy donors. Altogether, our data implicate IRF-8 as a novel MDSC-dependent transcription factor.
Project description:The methylation profiles of bisulfite-modified DNA of human CD14+ monocytes were compared with derived immature dendritic cells (GM-CSF/IL-4 ), myeloid-derived suppressor cells (GM-CSF/IL-4/PGE-2), EP2 antagonized myeloid-derived suppressor cells (GM-CSF/IL-4/PGE-2/ PF 04418948 5 µM), EP4 antagonized myeloid-derived suppressor cells (GM-CSF/IL-4/PGE-2/ L-161,982 5 µM) and EP2 + EP4 antagonized myeloid-derived suppressor cells (GM-CSF/IL-4/PGE-2/PF 04418948 5 µM /L-161,982 5 µM) using the Infinium HumanMethylation450 BeadChips (Illumina, Inc., San Diego, CA,). This platform allows the interrogation of >485,000 methylation sites per sample at single-nucleotide resolution, and comprises an average of 17 CpG sites per gene in the 99% of RefSeq genes. 96% of CpG islands are covered, with additional coverage in CpG island shores and the regions flanking them. The samples were hybridized in the array following the manufacturer’s instructions.
Project description:Administration of G-CSF mobilizes a unique population of CD11b+Ly6C+CD34+mature monocytes that can inhibit GVHD in murine models of BMT via an iNOS-dependent mechanism. The transcriptional profiles of flow sorted lineage-CD11b+CD34+ cells from G-CSF treated mice were compared with conventional splenic Ly6C+ and Ly6C- monocytes, progenitor cells and cultured myeloid-derived suppressor cells. Further comparisons were made with lineage-CD11b+CD34+ cells from G-CSF treated mice that had been grown in culture or that were derived from iNOS ko mice. We used microarrays to detail the global programme of gene expression underlying diffrenetiation of each of these cell types
Project description:Myeloid derived Suppressor cells (MDSC) are heterogenous popluation of cells consists of two major subsets namely the monocytic Gr-1dull/int. and granulocytic (Gr-1high). These distinct two subsets use different mechanism to inhibit T cell response. In addition, how the function of these subsets is regulated is not known yet. The Gr-1dull/int. MDSC are suppressing T cells through IFNg dependent nitric oxide dependent manner. However, the exact suppressive mechanism of Gr-1high MDSC is not clear. Here we studied the role of a cytokine IFNg on the suppressive function of Gr-1high MDSC by comparing the gene expression of Gr-1high cells cultured alone versus those cultured with T cells which donot produce IFNgamma. CD11b+Gr-1high cells were purified from the splenocyte of CT-26 colon tumor bearing mice. The purified CD11b+Gr-1high MDSCs were cultured with IFNg-/- antigen specific T cells and re- sorted after 48h and RNA was extracted and gene expression was analyzed using topic-defined PIQORTM Immunology Microarrays.
Project description:Aberrations in chromatin dynamics play a fundamental role in tumorigenesis, yet relatively little is known of the molecular mechanisms linking histone lysine methylation to neoplastic disease. ING4 (Inhibitor of Growth 4) is a native subunit of an HBO1 histone acetyltransferase (HAT) complex and a tumor suppressor protein. Here we show a critical role for the specific read-out of histone H3 trimethylated at lysine 4 (H3K4me3) by the ING4 PHD finger in mediating ING4 gene expression and tumor suppressor functions. The interaction between ING4 and H3K4me3 augments the acetylation activity of HBO1 on H3 tails, and drives H3 acetylation at ING4 target promoters to effect a DNA damage-dependent gene expression program. Further, ING4 facilitates apoptosis in response to genotoxic stress and inhibits anchorage-independent cell growth, and these functions are dependent on ING4 interactions with H3K4me3. Together, our results demonstrate a mechanism for brokering crosstalk between H3K4 methylation and histone H3 acetylation, and reveal a new molecular link between chromatin modulation and tumor suppressor mechanisms. ING4 ChIP-chip +/- Doxorubicin treatment in HT1080 cells on Nimblegen whole genome promoter array 4 samples: HT1080 cell lines stably expressing Flag-ING4 or Flag-ING4-D213A, +/- doxorubicin
Project description:Myeloid-derived suppressor cells (MDSC) are a major barrier to anticancer responses. Although much is known about how MDSC promote tumor progression, little is known about how they develop. We hypothesized that MDSC develop as a consequence of tumor-induced downregulation of interferon regulatory factor-8 (IRF-8), a key myeloid developmental transcription factor. We showed that: 1) IRF8-deficiency in mice generated myeloid populations highly homologous to tumor-induced MDSC; 2) IRF-8 overexpression in mice reduced MDSC accumulation and retarded tumor growth; 3) MDSC-inducing factors, G-CSF or GM-CSF, facilitated IRF-8 downregulation via STAT3- or STAT5-dependent pathways, respectively; and 4) IRF-8 levels in MDSC-like subsets of breast cancer patients were depressed compared to healthy donors. Altogether, our data implicate IRF-8 as a novel MDSC-dependent transcription factor. Splenic CD11b+Gr-1high cell populations from tumor-bearing mice, IRF8 knockout mice or non-tumor-bearing control mice were purified in two independent experiments by flow cytometry (> 97% purity) and subjected to whole genome expression profiling using Illumina microarrays.
Project description:Myeloid derived Suppressor cells (MDSC) are heterogenous popluation of cells consists of two major subsets namely the monocytic Gr-1dull/int. and granulocytic (Gr-1high). These distinct two subsets use different mechanism to inhibit T cell response. In addition, how the function of these subsets is regulated is not known yet. The Gr-1dull/int. MDSC are suppressing T cells through IFNg dependent nitric oxide dependent manner. However, the exact suppressive mechanism of Gr-1high MDSC is not clear. Here we studied the role of a cytokine IFNg on the suppressive function of Gr-1high MDSC by comparing the gene expression of Gr-1high cells cultured alone versus those cultured with T cells which donot produce IFNgamma.
Project description:The changes in gene expression of canine mammary neoplastic cells due to co-culture with myeloid-derived suppressor cells were assesed.
Project description:Aberrations in chromatin dynamics play a fundamental role in tumorigenesis, yet relatively little is known of the molecular mechanisms linking histone lysine methylation to neoplastic disease. ING4 (Inhibitor of Growth 4) is a native subunit of an HBO1 histone acetyltransferase (HAT) complex and a tumor suppressor protein. Here we show a critical role for the specific read-out of histone H3 trimethylated at lysine 4 (H3K4me3) by the ING4 PHD finger in mediating ING4 gene expression and tumor suppressor functions. The interaction between ING4 and H3K4me3 augments the acetylation activity of HBO1 on H3 tails, and drives H3 acetylation at ING4 target promoters to effect a DNA damage-dependent gene expression program. Further, ING4 facilitates apoptosis in response to genotoxic stress and inhibits anchorage-independent cell growth, and these functions are dependent on ING4 interactions with H3K4me3. Together, our results demonstrate a mechanism for brokering crosstalk between H3K4 methylation and histone H3 acetylation, and reveal a new molecular link between chromatin modulation and tumor suppressor mechanisms.