The role of IL‐33/ST2 pathway in antitumor immunity is unclear. Using 4T1 breast cancer model we demonstrate time‐dependent increase of endogenous IL‐33 at both the mRNA and protein levels in primary ...tumors and metastatic lungs during cancer progression. Administration of IL‐33 accelerated tumor growth and development of lung and liver metastases, which was associated with increased intratumoral accumulation of CD11b+Gr‐1+ TGF‐β1+ myeloid‐derived suppressor cells (MDSCs) that expressed IL‐13α1R, IL‐13‐producing Lin−Sca‐1+ST2+ innate lymphoid cells (ILCs) and CD4+Foxp3+ST2+IL‐10+ Tregs compared to untreated mice. Higher incidence of monocytic vs. granulocytic MDSCs and plasmocytoid vs. conventional dendritic cells (DCs) was present in mammary tumors of IL‐33‐treated mice. Intratumoral NKp46+NKG2D+ and NKp46+FasL+ cells were markedly reduced after IL‐33 treatment, while phosphate‐buffered saline‐treated ST2‐deficient mice had increased frequencies of these tumoricidal natural killer (NK) cells compared to untreated wild‐type mice. IL‐33 promoted intratumoral cell proliferation and neovascularization, which was attenuated in the absence of ST2. Tumor‐bearing mice given IL‐33 had increased percentages of splenic MDSCs, Lin−Sca‐1+ ILCs, IL‐10‐expressing CD11c+ DCs and alternatively activated M2 macrophages and higher circulating levels of IL‐10 and IL‐13. A significantly reduced NK cell, but not CD8+ T‐cell cytotoxicity in IL‐33‐treated mice was observed and the mammary tumor progression was not affected when CD8+ T cells were in vivo depleted. We show a previously unrecognized role for IL‐33 in promoting breast cancer progression through increased intratumoral accumulation of immunosuppressive cells and by diminishing innate antitumor immunity. Therefore, IL‐33 may be considered as an important mediator in the regulation of breast cancer progression.
What's new?
This study employed a breast cancer cell line to investigate the role of interleukin‐33 in cancer progression. They found more IL‐33 in the cells as the disease advanced, and they showed that administring IL‐33 to mice accelerated growth and metastasis. The increased levels of IL‐33 sped cancer progression both by hindering antitumor immunity and by encouraging angiogenesis. Understanding the effects of IL‐33 on cancer suggests possible avenues for tumor immunotherapy.
This is the short summary of the presentation at the 2nd Belgrade Meeting on Immunoregulation entitled “
Inflammation at the interface of Innate and Acquired Immunity” held recently under the auspice ...of European Federation of Immunological Societies and organized by Medical School, University of Kragujevac.
The aim of this article is to review the immunoregulatory actions of frog skin-derived peptides in order to assess their potential as candidates for immunomodulatory or anti-inflammatory therapy. ...Frog skin peptides with demonstrable immunomodulatory properties have been isolated from skin secretions of a range of species belonging to the families Alytidae, Ascaphidae, Discoglossidae, Leptodactylidae, Pipidae and Ranidae. Their effects upon production of inflammatory and immunoregulatory cytokines by target cells have been evaluated ex vivo and effects upon cytokine expression and immune cell activity have been studied in vivo by flow cytometry after injection into mice. The naturally-occurring peptides and/or their synthetic analogues show complex and variable actions on the production of proinflammatory (TNF-α, IL-1β, IL-12, IL-23, IL-8, IFN-γ and IL-17), pleiotropic (IL-4 and IL-6) and immunosuppressive (IL-10 and TGF-β) cytokines by peripheral and spleen cells, peritoneal cells and/or isolated macrophages. The effects of frenatin 2.1S include enhancement of the activation state and homing capacity of Th1-type lymphocytes and NK cells in the mouse peritoneal cavity, as well as the promotion of their tumoricidal capacities. Overall, the diverse effects of frog skin-derived peptides on the immune system indicate their potential for development into therapeutic agents.
Obesity-induced diabetes is associated with low-grade inflammation in adipose tissue and macrophage infiltration of islets. We show that ablation of galectin-3 (Gal-3), a galactoside-binding lectin, ...accelerates high-fat diet-induced obesity and diabetes. Obese LGALS3(-/-) mice have increased body weight, amount of total visceral adipose tissue (VAT), fasting blood glucose and insulin levels, homeostasis model assessment of insulin resistance, and markers of systemic inflammation compared with diet-matched wild-type (WT) animals. VAT of obese LGALS3(-/-) mice exhibited increased incidence of type 1 T and NKT lymphocytes and proinflammatory CD11c(+)CD11b(+) macrophages and decreased CD4(+)CD25(+)FoxP3(+) regulatory T cells and M2 macrophages. Pronounced mononuclear cell infiltrate, increased expression of NLRP3 inflammasome and interleukin-1β (IL-1β) in macrophages, and increased accumulation of advanced glycation end products (AGEs) and receptor for AGE (RAGE) expression were present in pancreatic islets of obese LGALS3(-/-) animals accompanied with elevated phosphorylated nuclear factor-κB (NF-κB) p65 and mature caspase-1 protein expression in pancreatic tissue and VAT. In vitro stimulation of LGALS3(-/-) peritoneal macrophages with lipopolysaccharide (LPS) and saturated fatty acid palmitate caused increased caspase-1-dependent IL-1β production and increased phosphorylation of NF-κB p65 compared with WT cells. Transfection of LGALS3(-/-) macrophages with NLRP3 small interfering RNA attenuated IL-1β production in response to palmitate and LPS plus palmitate. Obtained results suggest important protective roles for Gal-3 in obesity-induced inflammation and diabetes.
High-mobility group box-1 (HMGB1) is a nuclear factor released by necrotic cells and by activated immune cells. HMGB1 signals via members of the toll-like receptor family and the receptor for ...advanced glycation end products (RAGE). Although HMGB1 has been implicated in ischemia/reperfusion (I/R) injury of the liver and lung, its role in I/R injury of the heart remains unclear.
Here, we demonstrate that HMGB1 acts as an early mediator of inflammation and organ damage in I/R injury of the heart. HMGB1 levels were already elevated 30 minutes after hypoxia in vitro and in ischemic injury of the heart in vivo. Treatment of mice with recombinant HMGB1 worsened I/R injury, whereas treatment with HMGB1 box A significantly reduced infarct size and markers of tissue damage. In addition, HMGB1 inhibition with recombinant HMGB1 box A suggested an involvement of the mitogen-activated protein kinases jun N-terminal kinase and extracellular signal-regulated kinase 1/2, as well as the nuclear transcription factor nuclear factor-kappaB in I/R injury. Interestingly, infarct size and markers of tissue damage were not affected by administration of recombinant HMGB1 or HMGB1 antagonists in RAGE(-/-) mice, which demonstrated significantly reduced damage in reperfused hearts compared with wild-type mice. Coincubation studies using recombinant HMGB1 in vitro induced an inflammatory response in isolated macrophages from wild-type mice but not in macrophages from RAGE(-/-) mice.
HMGB1 plays a major role in the early event of I/R injury by binding to RAGE, resulting in the activation of proinflammatory pathways and enhanced myocardial injury. Therefore, blockage of HMGB1 might represent a novel therapeutic strategy in I/R injury.
Adults with Down syndrome (DS) represent an enriched population for the development of Alzheimer's disease (AD), which could aid the study of therapeutic interventions, and in turn, could benefit ...from discoveries made in other AD populations.
1) Understand the relationship between tau pathology and age, amyloid deposition, neurodegeneration (MRI and FDG PET), and cognitive and functional performance; 2) detect and differentiate AD-specific changes from DS-specific brain changes in longitudinal MRI.
Twelve non-demented adults, ages 30 to 60, with DS were enrolled in the Down Syndrome Biomarker Initiative (DSBI), a 3-year, observational, cohort study to demonstrate the feasibility of conducting AD intervention/prevention trials in adults with DS. We collected imaging data with 18F-AV-1451 tau PET, AV-45 amyloid PET, FDG PET, and volumetric MRI, as well as cognitive and functional measures and additional laboratory measures.
All amyloid negative subjects imaged were tau-negative. Among the amyloid positive subjects, three had tau in regions associated with Braak stage VI, two at stage V, and one at stage II. Amyloid and tau burden correlated with age. The MRI analysis produced two distinct volumetric patterns. The first differentiated DS from normal (NL) and AD, did not correlate with age or amyloid, and was longitudinally stable. The second pattern reflected AD-like atrophy and differentiated NL from AD. Tau PET and MRI atrophy correlated with several cognitive and functional measures.
Tau accumulation is associated with amyloid positivity and age, as well as with progressive neurodegeneration measurable using FDG and MRI. Tau correlates with cognitive decline, as do AD-specific hypometabolism and atrophy.
Abstract Galectin 3 (Gal-3) is an antiapoptotic and a proinflammatory lectin. We hypothesized that the proinflammatory properties of Gal-3 may influence disease induction in the multiple low doses of ...streptozotocin model of diabetes. Diabetes was induced in C57BL/6 Gal-3+/+ and Gal-3−/− mice and disease monitored by blood glucose level, immuno-histology, insulin content of islets and expression of the proinflammatory cytokines, TNF-α, IFN-γ, IL-17, and iNOS in pancreatic lymph nodes. Gal-3+/+ mice developed delayed and sustained hyperglycemia, mononuclear cellular infiltration and reduced insulin content of islets accompanied with expression of proinflammatory cytokines. Gal-3− /− mice were relatively resistant to diabetogenesis as evaluated by glycemia, quantitative histology and insulin content. Further, we observed the weaker expression of IFN-γ and complete absence of TNF-α, and IL-17 in draining pancreatic lymph nodes. Macrophages, the first cells that infiltrate the islet in this model of diabetes, produce less TNF-α and NO in Gal-3−/− mice. Thus, Gal-3 is involved in immune mediated β cell damage and is required for diabetogenesis in this model of disease.
ST2 is a member of the IL‐1 receptor family and IL‐33 was recently identified as its natural ligand. The IL‐33/ST2 pathway regulates Th1/Th2 immune responses in autoimmune and inflammatory ...conditions, but the role of ST2 signaling in tumor growth and metastasis has not been investigated. We aimed to investigate whether ST2 gene deletion affects tumor appearance, growth, and metastasis, and antitumor immunity in an experimental metastatic breast cancer model. Deletion of ST2 in BALB/c mice bearing mammary carcinoma attenuated tumor growth and metastasis, which was accompanied by increased serum levels of IL‐17, IFN‐γ, and TNF‐α and decreased IL‐4. Tumor‐bearing ST2−/− mice had significantly higher percentages of activated CD27highCD11bhigh NK cells, CD69+ and KLRG− NK cells and higher cytotoxic activity of splenocytes, NK cells, and CD8+ T cells in vitro. A significantly higher number of NK cells expressing IFN‐γ were found in ST2−/− mice compared with WT recipients. In vivo depletion of CD8+ or NK cells revealed a key role for NK cells in enhanced antitumor immunity in ST2−/− mice. We report for the first time that suppressed breast cancer progression and metastasis in mice lacking ST2 corresponds mainly with enhanced cytotoxic activity of NK cells, and increased systemic Th1/Th17 cytokines.
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