144 research outputs found

    At its Heart, Homeostasis Is About T Cellsāˆ—

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    Treating inflammation in atherosclerotic cardiovascular disease: emerging therapies

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    Atherosclerosis constitutes the underlying disease to the clinical manifestations of myocardial infarction, stroke, and gangrene. Despite the success of statins, prevention of clinical events of atherosclerosis remains a major challenge in current-day cardiology. Research into the inflammatory nature of atherosclerosis has led to improved mechanistic understanding of its pathogenesis and to the identification of novel therapeutic targets discussed in this review. Recent genetic and epidemiological data document shared pathologies of chronic inflammatory diseases and atherosclerosis. Anti-inflammatory treatment regimens used in these diseases, including tumor necrosis factor-Ī± blockade, IL-1 receptor antagonism, and leukotriene blockade may be beneficial also in patients with coronary artery disease. Enhancing inherent atheroprotective immunity by expansion of regulatory T cells may emerge as a future therapeutic strategy. Immunization strategies directed against atherosclerosis-related antigens such as epitopes within the low-density lipoprotein particle have been extensively studied in animal models and may enter the clinical stage. Success of these novel therapies will be critically dependent on the adequate identification of patients and choice of appropriate clinical endpoint

    Immunotherapy with tolerogenic apolipoprotein B-100ā€“loaded dendritic cells attenuates atherosclerosis in hypercholesterolemic mice

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    BACKGROUND: Atherosclerosis is a chronic inflammatory disease characterized by a massive intimal accumulation of low-density lipoprotein that triggers chronic vascular inflammation with an autoimmune response to low-density lipoprotein components. METHODS AND RESULTS: To dampen the inflammatory component of atherosclerosis, we injected hypercholesterolemic huB100(tg) Ɨ Ldlr(-/-) mice (mice transgenic for human apolipoprotein B100 [ApoB100] and deficient for the low-density lipoprotein receptor) intravenously with dendritic cells (DCs) that had been pulsed with the low-density lipoprotein protein ApoB100 in combination with the immunosuppressive cytokine interleukin-10. DCs treated with ApoB100 and interleukin-10 reduced proliferation of effector T cells, inhibited production of interferon-Ī³, and increased de novo generation of regulatory T cells in vitro. Spleen cells from mice treated with DCs plus ApoB100 plus interleukin-10 showed diminished proliferative responses to ApoB100 and significantly dampened T-helper 1 and 2 immunity to ApoB100. Spleen CD4(+) T cells from these mice suppressed activation of ApoB100-reactive T cells in a manner characteristic of regulatory T cells, and mRNA analysis of lymphoid organs showed induction of transcripts characteristic of these cells. Treatment of huB100(tg) Ɨ Ldlr(-/-) mice with ApoB100-pulsed tolerogenic DCs led to a significant (70%) reduction of atherosclerotic lesions in the aorta, with decreased CD4(+) T-cell infiltration and signs of reduced systemic inflammation. CONCLUSIONS: Tolerogenic DCs pulsed with ApoB100 reduced the autoimmune response against low-density lipoprotein and may represent a novel possibility for treatment or prevention of atherosclerosis.Swedish Research CouncilFoundation for Strategic ResearchVinnovaSwedish Heart-Lung FoundationEuropean Union (AtheroRemo integrated project)Stockholm County CouncilPublishe

    CD1d-dependent Activation of NKT Cells Aggravates Atherosclerosis

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    Adaptive and innate immunity have been implicated in the pathogenesis of atherosclerosis. Given their abundance in the lesion, lipids might be targets of the atherosclerosis-associated immune response. Natural killer T (NKT) cells can recognize lipid antigens presented by CD1 molecules. We have explored the role of CD1d-restricted NKT cells in atherosclerosis by using apolipoprotein Eā€“deficient (apoEāˆ’/āˆ’) mice, a hypercholesterolemic mouse model that develops atherosclerosis. ApoEāˆ’/āˆ’ mice crossed with CD1dāˆ’/āˆ’ (CD1dāˆ’/āˆ’apoEāˆ’/āˆ’) mice exhibited a 25% decrease in lesion size compared with apoEāˆ’/āˆ’ mice. Administration of Ī±-galactosylceramide, a synthetic glycolipid that activates NKT cells via CD1d, induced a 50% increase in lesion size in apoEāˆ’/āˆ’ mice, whereas it did not affect lesion size in apoEāˆ’/āˆ’CD1dāˆ’/āˆ’ mice. Treatment was accompanied by an early burst of cytokines (IFNĪ³, MCP-1, TNFĪ±, IL-2, IL-4, IL-5, and IL-6) followed by sustained increases in IFNĪ³ and IL-4 transcripts in the spleen and aorta. Early activation of both T and B cells was followed by recruitment of T and NKT cells to the aorta and activation of inflammatory genes. These results show that activation of CD1d-restricted NKT cells exacerbates atherosclerosis

    Low TLR7 gene expression in atherosclerotic plaques is associated with major adverse cardio- and cerebrovascular events

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    AIMS: Processes in the development of atherosclerotic lesions can lead to plaque rupture or erosion, which can in turn elicit myocardial infarction or ischaemic stroke. The aims of this study were to determine whether Toll-like receptor 7 (TLR7) gene expression levels influence patient outcome and to explore the mechanisms linked to TLR7 expression in atherosclerosis. METHODS AND RESULTS: Atherosclerotic plaques were removed by carotid endarterectomy (CEA) and subjected to gene array expression analysis (nā€‰=ā€‰123). Increased levels of TLR7 transcript in the plaques were associated with better outcome in a follow-up study over a maximum of 8 years. Patients with higher TLR7 transcript levels had a lower risk of experiencing major cardiovascular and cerebrovascular events (MACCE) during the follow-up period after CEA (hazard ratio: 2.38, Pā€‰=ā€‰0.012, 95% CI 1.21ā€“4.67). TLR7 was expressed in all plaques by T cells, macrophages and endothelial cells in capillaries, as shown by immunohistochemistry. In short-term tissue cultures, ex vivo treatment of plaques with the TLR7 ligand imiquimod elicited dose-dependent secretion of IL-10, TNF-Ī±, GM-CSF, and IL-12/IL-23p40. This secretion was blocked with a TLR7 inhibitor. Immunofluorescent tissue analysis after TLR7 stimulation showed IL-10 expression in T cells, macrophages and vascular smooth muscle cells. TLR7 mRNA levels in the plaques were correlated with IL-10 receptor (rā€‰=ā€‰0.4031, Pā€‰<ā€‰0.0001) and GM-CSF receptor A (rā€‰=ā€‰0.4354, Pā€‰<ā€‰0.0001) transcripts. CONCLUSION: These findings demonstrate that TLR7 is abundantly expressed in human atherosclerotic plaques. TLR7 ligation elicits the secretion of pro-inflammatory and anti-inflammatory cytokines, and high TLR7 expression in plaques is associated with better patient outcome, suggesting that TLR7 is a potential therapeutic target for prevention of complications of atherosclerosis

    Tumor Genome Wide DNA Alterations Assessed by Array CGH in Patients with Poor and Excellent Survival Following Operation for Colorectal Cancer

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    Genome wide DNA alterations were evaluated by array CGH in addition to RNA expression profiling in colorectal cancer from patients with excellent and poor survival following primary operations

    MHC class II-restricted antigen presentation by plasmacytoid dendritic cells drives proatherogenic T cell immunity

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    Backgroundā€”Plasmacytoid dendritic cells (pDCs) bridge innate and adaptive immune responses and are important regulators of immuno-inflammatory diseases. However, their role in atherosclerosis remains elusive. Methods and Resultsā€”Here, we used genetic approaches to investigate the role of pDCs in atherosclerosis. Selective pDC deficiency in vivo was achieved using CD11c-Cre Ɨ Tcf4ā€“/flox bone marrow transplanted into Ldlrā€“/ā€“ mice. Compared with control Ldlrā€“/ā€“ chimeric mice, CD11c-Cre Ɨ Tcf4ā€“/flox mice had reduced atherosclerosis levels. To begin to understand the mechanisms by which pDCs regulate atherosclerosis, we studied chimeric Ldlrā€“/ā€“ mice with selective MHCII deficiency on pDCs. Significantly, these mice also developed reduced atherosclerosis compared with controls without reductions in pDC numbers or changes in conventional DCs. MHCII-deficient pDCs showed defective stimulation of apolipoprotein B100ā€“specific CD4+ T cells in response to native low-density lipoprotein, whereas production of interferon-Ī± was not affected. Finally, the atheroprotective effect of selective MHCII deficiency in pDCs was associated with significant reductions of proatherogenic T cellā€“derived interferon-Ī³ and lesional T cell infiltration, and was abrogated in CD4+ T cellā€“depleted animals. Conclusionsā€”This study supports a proatherogenic role for pDCs in murine atherosclerosis and identifies a critical role for MHCII-restricted antigen presentation by pDCs in driving proatherogenic T cell immunity

    Identification of a danger-associated peptide from apolipoprotein B100 (ApoBDS-1) that triggers innate proatherogenic responses

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    Background: Subendothelial deposited low-density lipoprotein particles are a known inflammatory factor in atherosclerosis. However, the causal components derived from low-density lipoprotein are still poorly defined. Apolipoprotein B100 (ApoB100) is the unexchangeable protein component of low-density lipoprotein, and the progression of atherosclerosis is associated with immune responses to ApoB100-derived peptides. In this study, we analyzed the proinflammatory activity of ApoB100 peptides in atherosclerosis. Methods and Results: By screening a peptide library of ApoB100, we identified a distinct native peptide referred to as ApoB100 danger-associated signal 1 (ApoBDS-1), which shows sequence-specific bioactivity in stimulation of interleukin-8, CCL2, and interleukin-6. ApoBDS-1 activates mitogen-activated protein kinase and calcium signaling, thereby effecting the expression of interleukin-8 in innate immune cells. Ex vivo stimulation of carotid plaques with ApoBDS-1 enhances interleukin-8 and prostaglandin E2 release. Furthermore, we demonstrated that ApoBDS-1ā€“positive peptide fragments are present in atherosclerotic lesions using immunoassays and that low-molecular-weight fractions isolated from plaque show ApoBDS-1 activity inducing interleukin-8 production. Conclusions: Our data show that ApoBDS-1 is a previously unrecognized peptide with robust proinflammatory activity, contributing to the disease-promoting effects of low-density lipoprotein in the pathogenesis of atherosclerosis. (Circulation. 2011;124:2433-2443.)Swedish Heart-Lung FoundationSwedish Foundation for Strategic ResearchSwedish Research CouncilCenter of Excellence for Research on Inflammation and Cardiovascular Disease Linnaeus ProgramLeducq FoundationEuropean UnionChina Scholarship Council.Publishe

    NLRP3 inflammasome expression and activation in human atherosclerosis

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    Background: The NLR family, pyrin domain containing 3 (NLRP3) inflammasome is an interleukin (IL)ā€1Ī² and ILā€18 cytokine processing complex that is activated in inflammatory conditions. The role of the NLRP3 inflammasome in the pathogenesis of atherosclerosis and myocardial infarction is not fully understood. Methods and Results: Atherosclerotic plaques were analyzed for transcripts of the NLRP3 inflammasome, and for ILā€1Ī² release. The Swedish Firstā€ever myocardial Infarction study in Acā€county (FIA) cohort consisting of DNA from 555 myocardial infarction patients and 1016 healthy individuals was used to determine the frequency of 4 single nucleotide polymorphisms (SNPs) from the downstream regulatory region of NLRP3. Expression of NLRP3, Apoptosisā€associated speckā€like protein containing a CARD (ASC), caspaseā€1 (CASP1), IL1B, and IL18 mRNA was significantly increased in atherosclerotic plaques compared to normal arteries. The expression of NLRP3 mRNA was significantly higher in plaques of symptomatic patients when compared to asymptomatic ones. CD68ā€positive macrophages were observed in the same areas of atherosclerotic lesions as NLRP3 and ASC expression. Occasionally, expression of NLRP3 and ASC was also present in smooth muscle cells. Cholesterol crystals and ATP induced ILā€1Ī² release from lipopolysaccharideā€primed human atherosclerotic lesion plaques. The minor alleles of the variants rs4266924, rs6672995, and rs10733113 were associated with NLRP3 mRNA levels in peripheral blood mononuclear cells but not with the risk of myocardial infarction. Conclusions: Our results indicate a possible role of the NLRP3 inflammasome and its genetic variants in the pathogenesis of atherosclerosis

    New trends in globalization of science and engineering education

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    Three decades ago most research and design were conducted in each country independently. But the world has become quite different since then. Global changes in technology and society changed the concept of an engineer. There is the need for engineers who can work effectively in changing global and technical environments. Less interest has been paid to the globalization of science and technology. This article reviews the stimulus, that impact the engineering profession and gives the recommendations concerning the profession of engineering, the technology and innovation
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