Project description:Gene expression was analyzed in peritoneal macrophages and TAM from mice injected with ID8 ovarian cancer cells intraperitoneally 28 days after tumor implantation. Tumor-associated macrophages (TAM) have been shown to have important roles in the malignant progression of various cancers. However, macrophages also posses intrinsic tumoricidal activity and can promote the activity of cytotoxic lymphocytes, but they rapidly adopt an alternative phenotype within tumors, associated with immune-suppression and trophic functions that support tumor growth. The mechanisms that promote TAM polarization in the tumor-microenvironment remain poorly understood, these mechanisms may represent important therapeutic targets to block the tumor-promoting functions of TAM and restore their anti-tumor potential. Here we have characterized TAM in a mouse model of metastatic ovarian cancer. We show that ovarian cancer cells promote membrane-cholesterol efflux and the depletion of lipid rafts from macrophages. Increased cholesterol efflux promoted IL-4 mediated reprogramming while inhibiting IFNg-induced gene expression. These studies reveal an unexpected role for tumor-induced membrane-cholesterol efflux in driving the IL-4 signaling and the tumor-promoting functions of TAM, while rendering them refractory to pro-inflammatory stimuli. Thus, preventing cholesterol efflux in TAM could represent a novel therapeutic strategy to block pro-tumor functions and restore anti-tumor immunity.
Project description:In order to identify gene targets of translational regulation during T cell activation, a polysome analysis was performed in a T cell receptor (TCR) transgenic model (OT-1) possessing a homogenous alpha-beta CD8 T lymphocyte population. Cells with defective TCR signal tranduction (Lck-/-, OFF) were compared to WT cells to visualise targets regulated by TCR signalling. Total cytoplasmic ribonucleoprotein was extracted from ex vivo OT-1 transgenic T lymphocytes stimulated with SIINFEKL peptide antigen for 24h, extracts were fractionated using a sucrose density gradient, and separated into a sub-polysomal and a polysomal fraction. Total RNA from each fraction was extracted, equal volume of RNA from each fraction was individually labelled (Sub-poly: Cy3; Poly: Cy5), and hybridised onto a Agilent SurePrint G3 Mouse GE v2 8x60K Microarray.
Project description:This experiment aims to study the transcriptome of activated T cells at 24h, using the same biological samples as the polysome profiling in GSE84781. A T cell receptor (TCR) transgenic mouse model (OT-1) posessing a homogenous alpha-beta CD8 T lymphocyte population was used, and cells with intact TCR signalling pathways (WT) were compared to those with defective signal transduction (Lck-/-, OFF). Ex vivo OT-1 T cells were isolated from the superficial cervicals, axillary, brachial, mesenteric, and inguinal lymph nodes and then activated for 24h with cognate peptide antigen SIINFEKL. Total RNA was extracted from the cells, labelled with Cy3, and hybridised onto an Agilent-074809 SurePrint G3 Mouse GE v2 8x60K Microarray.
Project description:To investigate if CD11b+ DCs contribute to OT-1 priming, genome transcriptome analysis was performed to compare the quality of OT-1 activation in WT or Batf3KO mice.
Project description:Gene expression was analyzed in TAM from mice injected with ID8 ovarian cancer cells intraperitoneally in ABC a1/g1 fl/fl-LysM-Cre mice. Tumor-associated macrophages (TAM) have been shown to have important roles in the malignant progression of various cancers. However, macrophages also posses intrinsic tumoricidal activity and can promote the activity of cytotoxic lymphocytes, but they rapidly adopt an alternative phenotype within tumors, associated with immune-suppression and trophic functions that support tumor growth. The mechanisms that promote TAM polarization in the tumor-microenvironment remain poorly understood, these mechanisms may represent important therapeutic targets to block the tumor-promoting functions of TAM and restore their anti-tumor potential. Here we have characterized TAM in a mouse model of metastatic ovarian cancer. We show that ovarian cancer cells promote membrane-cholesterol efflux and the depletion of lipid rafts from macrophages. Increased cholesterol efflux promoted IL-4 mediated reprogramming while inhibiting IFNg-induced gene expression. These studies reveal an unexpected role for tumor-induced membrane-cholesterol efflux in driving the IL-4 signaling and the tumor-promoting functions of TAM, while rendering them refractory to pro-inflammatory stimuli. Thus, preventing cholesterol efflux in TAM could represent a novel therapeutic strategy to block pro-tumor functions and restore anti-tumor immunity.
Project description:We conducted gene expression profile analysis by using CD45+ CD11b+ F4/80+ TAM sorted from WT or Trim24-deficient B16 bearing mouse.Scatter diagram revealed the most prominent different expression of genes altered in TAM were associated with M2 genes.