Project description:Microglia are phagocytic cells that survey the brain and perform neuroprotective functions in response to tissue damage, but their activating receptors are largely unknown. Triggering receptor expressed on myeloid cells 2 (TREM2) is a microglial immunoreceptor whose loss-of-function mutations in humans cause presenile dementia, while genetic variants are associated with increased risk of neurodegenerative diseases. In myeloid cells, TREM2 has been involved in the regulation of phagocytosis, cell proliferation and inflammatory responses in vitro. However, it is unknown how TREM2 contributes to microglia function in vivo. Here, we identify a critical role for TREM2 in the activation and function of microglia during cuprizone (CPZ)-induced demyelination. TREM2-deficient (TREM2(-/-)) mice had defective clearance of myelin debris and more axonal pathology, resulting in impaired clinical performances compared to wild-type (WT) mice. TREM2(-/-) microglia proliferated less in areas of demyelination and were less activated, displaying a more resting morphology and decreased expression of the activation markers MHC II and inducible nitric oxide synthase as compared to WT. Mechanistically, gene expression and ultrastructural analysis of microglia suggested a defect in myelin degradation and phagosome processing during CPZ intoxication in TREM2(-/-) microglia. These findings place TREM2 as a key regulator of microglia activation in vivo in response to tissue damage. Two STAGE (6weeks 12 weeks),
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:TREM-2 has been described to be a phagocytic receptor. We assessed the influence of TREM-2 on gene expression in alveolar macrophages (AM) In this data-set we characterised the differences in basal gene expression using affymetrix mouse 1.0 ST arrays between WT and TREM2-/- AM and observed TREM2 -/- AM to exhibt higher expression of opsonins 4 samples were analysed in biological duplicate (2 x WT and 2 x TREM2-/-)
Project description:We examined the role of TREM2 on microglia responses to amyloid-beta deposition in a mouse model of Alzheimer's disease Microglia were FACS-purified from 8.5 month old WT, Trem2-/-, 5XFAD, and Trem2-/- 5XFAD mice
Project description:We examined the role of TREM2 on microglia responses to demyelination Microglia were FACS-purified from WT or Trem2-/- mice fed with 0.2% cuprizone diet.
Project description:Microglia are phagocytic cells that survey the brain and perform neuroprotective functions in response to tissue damage, but their activating receptors are largely unknown. Triggering receptor expressed on myeloid cells 2 (TREM2) is a microglial immunoreceptor whose loss-of-function mutations in humans cause presenile dementia, while genetic variants are associated with increased risk of neurodegenerative diseases. In myeloid cells, TREM2 has been involved in the regulation of phagocytosis, cell proliferation and inflammatory responses in vitro. However, it is unknown how TREM2 contributes to microglia function in vivo. Here, we identify a critical role for TREM2 in the activation and function of microglia during cuprizone (CPZ)-induced demyelination. TREM2-deficient (TREM2(-/-)) mice had defective clearance of myelin debris and more axonal pathology, resulting in impaired clinical performances compared to wild-type (WT) mice. TREM2(-/-) microglia proliferated less in areas of demyelination and were less activated, displaying a more resting morphology and decreased expression of the activation markers MHC II and inducible nitric oxide synthase as compared to WT. Mechanistically, gene expression and ultrastructural analysis of microglia suggested a defect in myelin degradation and phagosome processing during CPZ intoxication in TREM2(-/-) microglia. These findings place TREM2 as a key regulator of microglia activation in vivo in response to tissue damage.
Project description:The R47H variant of TREM2 is associated with higher risk of Alzheimer's disease. We generated mice expressing the common variant or R47H variant of human TREM2 in the absence of murine TREM2 on the 5XFAD mouse model of Alzheimer's disease.
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:TREM-2 has been described to be a phagocytic receptor. We assessed the influence of TREM-2 on gene expression in alveolar macrophages (AM) In this data-set we characterised the differences in basal gene expression using affymetrix mouse 1.0 ST arrays between WT and TREM2-/- AM and observed TREM2 -/- AM to exhibt higher expression of opsonins