Myeloid-derived suppressor cells (MDSC) include immature monocytic (M-MDSC) and granulocytic (PMN-MDSC) cells that share the ability to suppress adaptive immunity and to hinder the effectiveness of anticancer treatments. Of note, in response to IFNγ, M-MDSCs release the tumor-promoting and immunosuppressive molecule nitric oxide (NO), whereas macrophages largely express antitumor properties. Investigating these opposing activities, we found that tumor-derived prostaglandin E2 (PGE2) induces nuclear accumulation of p50 NF-κB in M-MDSCs, diverting their response to IFNγ toward NO-mediated immunosuppression and reducing TNFα expression.
View Article and Find Full Text PDFAlthough tumor-associated macrophages (TAM) display a M2-skewed tumor-promoting phenotype in most cancers, in colorectal cancer, both TAM polarization and its impact remain controversial. We investigated the role of the M2-polarizing p50 NF-κB subunit in orchestrating TAM phenotype, tumor microenvironment composition, and colorectal cancer progression. We first demonstrated, by parallel studies in colitis-associated cancer (CAC) and in genetically driven Apc mouse models, that the p50-dependent inhibition of M1-polarized gut inflammation supported colorectal cancer development.
View Article and Find Full Text PDFObjectives: To provide a functional and phenotypic characterization of immune cells infiltrating small intestinal mucosa during non-IPEX autoimmune enteropathy (AIE), as to gain insights on the pathogenesis of this clinical condition.
Methods: Duodenal biopsies from a patient with AIE at baseline and following drug-induced remission were analyzed by immunohistochemistry, immunofluorescence, and flow cytometry, and results were compared with those obtained from patients with active celiac disease, ileal Crohn's disease and healthy controls. Lamina propria (LP) and intraepithelial (IELs) lymphocytes from AIE and controls were analyzed for mechanisms regulating cytokine production.
Inflammatory cells are an essential component of the tumor microenvironment. Neutrophils have emerged as important players in the orchestration and effector phase of innate and adaptive immunity. The significance of tumor-associated neutrophils (TAN) in colorectal cancer (CRC) has been the subject of conflicting reports and the present study was designed to set up a reliable methodology to assess TAN infiltration in CRC and to evaluate their clinical significance.
View Article and Find Full Text PDFCancer-driven granulo-monocytopoiesis stimulates expansion of tumor promoting myeloid populations, mostly myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs). We identified subsets of MDSCs and TAMs based on the expression of retinoic-acid-related orphan receptor (RORC1/RORγ) in human and mouse tumor bearers. RORC1 orchestrates myelopoiesis by suppressing negative (Socs3 and Bcl3) and promoting positive (C/EBPβ) regulators of granulopoiesis, as well as the key transcriptional mediators of myeloid progenitor commitment and differentiation to the monocytic/macrophage lineage (IRF8 and PU.
View Article and Find Full Text PDFPentraxin 3 (PTX3) is a fluid-phase pattern recognition molecule and a key component of the humoral arm of innate immunity. In four different models of tissue damage in mice, PTX3 deficiency was associated with increased fibrin deposition and persistence, and thicker clots, followed by increased collagen deposition, when compared with controls. Ptx3-deficient macrophages showed defective pericellular fibrinolysis in vitro.
View Article and Find Full Text PDFPTX3 is an essential component of the humoral arm of innate immunity, playing a nonredundant role in resistance against selected microbes and in the regulation of inflammation. PTX3 activates and regulates the Complement cascade by interacting with C1q and with Factor H. PTX3 deficiency was associated with increased susceptibility to mesenchymal and epithelial carcinogenesis.
View Article and Find Full Text PDFImmunity in the urinary tract has distinct and poorly understood pathophysiological characteristics and urinary tract infections (UTIs) are important causes of morbidity and mortality. We investigated the role of the soluble pattern recognition molecule pentraxin 3 (PTX3), a key component of the humoral arm of innate immunity, in UTIs. PTX3-deficient mice showed defective control of UTIs and exacerbated inflammation.
View Article and Find Full Text PDFAmyotrophic lateral sclerosis (ALS) is a progressive, fatal, neurodegenerative disorder caused by the degeneration of motor neurons in the CNS, which results in complete paralysis of skeletal muscles. Recent experimental studies have suggested that the disease could initiate in skeletal muscle, rather than in the motor neurons. To establish the timeframe of motor neuron degeneration in relation to muscle atrophy in motor neuron disease, we have used MRI to monitor changes throughout disease in brain and skeletal muscle of G93A-SOD1 mice, a purported model of ALS.
View Article and Find Full Text PDFImpairment of mitochondrial function might contribute to oxidative stress associated with neurodegeneration in amyotrophic lateral sclerosis (ALS). Glutamate levels in tissues of ALS patients are sometimes altered. In neurons, mitochondrial metabolism of exogenous glutamine is mainly responsible for the net synthesis of glutamate, which is a neurotransmitter, but it is also necessary for the synthesis of glutathione, the main endogenous antioxidant.
View Article and Find Full Text PDFBackground: Amyotrophic lateral sclerosis (ALS) is a progressive and fatal motor neuron disease, and protein aggregation has been proposed as a possible pathogenetic mechanism. However, the aggregate protein constituents are poorly characterized so knowledge on the role of aggregation in pathogenesis is limited.
Methodology/principal Findings: We carried out a proteomic analysis of the protein composition of the insoluble fraction, as a model of protein aggregates, from familial ALS (fALS) mouse model at different disease stages.
Motor neuron degeneration in amyotrophic lateral sclerosis involves oxidative damage. Glutathione (GSH) is critical as an antioxidant and a redox modulator. We used a motor neuronal cell line (NSC-34) to investigate whether wild-type and familial amyotrophic lateral sclerosis-linked G93A mutant Cu,Zn superoxide dismutase (wt/G93ASOD1) modified the GSH pool and glutamate cysteine ligase (GCL), the rate-limiting enzyme for GSH synthesis.
View Article and Find Full Text PDFMitochondrial damage induced by superoxide dismutase (SOD1) mutants has been proposed to have a causative role in the selective degeneration of motoneurons in amyotrophic lateral sclerosis (ALS). In order to investigate the basis of the tissue specificity of mutant SOD1 we compared the effect of the continuous expression of wild-type or mutant (G93A) human SOD1 on mitochondrial morphology in the NSC-34 motoneuronal-like, the N18TG2 neuroblastoma and the non-neuronal Madin-Darby Canine Kidney (MDCK) cell lines. Morphological alterations of mitochondria were observed in NSC-34 expressing the G93A mutant (NSC-G93A) but not the wild-type SOD1, whereas a ten-fold greater level of total expression of the mutant had no effect on mitochondria of non-motoneuronal cell lines.
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