139 research outputs found

    Anti-CD20 Therapy Acts via FcγRIIIA to Diminish Responsiveness of Human Natural Killer Cells

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    Natural killer (NK) immune cells mediate antibody-dependent cellular cytotoxicity (ADCC) by aggregating FcγRIIIA/CD16, contributing significantly to the therapeutic effect of CD20 monoclonal antibodies (mAb). In this study, we show that CD16 ligation on primary human NK cells by the anti-CD20 mAb rituximab or ofatumumab stably impairs the spontaneous cytotoxic response attributable to cross-tolerance of several unrelated NK-activating receptors (including NKG2D, DNAM-1, NKp46, and 2B4). Similar effects were obtained from NK cells isolated from patients with chronic lymphocytic leukemia in an autologous setting. NK cells rendered hyporesponsive in this manner were deficient in the ability of these cross-tolerized receptors to phosphorylate effector signaling molecules critical for NK cytotoxicity, including SLP-76, PLCγ2, and Vav1. These effects were associated with long-lasting recruitment of the tyrosine phosphatase SHP-1 to the CD16 receptor complex. Notably, pharmacologic inhibition of SHP-1 with sodium stibogluconate counteracted CD20 mAb-induced NK hyporesponsiveness, unveiling an unrecognized role for CD16 as a bifunctional receptor capable of engendering long-lasting NK cell inhibitory signals. Our work defines a novel mechanism of immune exhaustion induced by CD20 mAb in human NK cells, with potentially negative implications in CD20 mAb-treated patients where NK cells are partly responsible for clinical efficacy. Cancer Res; 75(19); 1-12. ©2015 AACR

    Wood powders of different botanical origin as an alternative to barrel aging for red wine

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    AbstractWood powders are produced in large quantity as by-product of barrel, staves and chips industry. Differently from larger particles (chips), the use of wood powders in winemaking is not admitted (Regulation (CE) n. 934/2019); however, it could represent a cheap and sustainable alternative for the accelerated aging of red wine. To evaluate their potential use in winemaking, a comparative study on the use of wood powders from oak, chestnut and acacia wood for the accelerated aging of red wine (cv. Aglianico) was conducted. This alternative aging was compared to the aging in wood barrels from the same botanical species. The wine aged in contact with powders underwent a quicker evolution of polyphenolic fraction. After 15 days of contact, the loss of total anthocyanins was higher than that observed after 6 months of aging in barrels (from 4 to 14% with respect to the corresponding kind of barrel). The amount of polymeric pigments tannins–anthocyanins–tannins in wines aged in contact with powders was higher respect to the wines aged in barrels (from 7 to 21% with respect to the corresponding kind of barrel), while the greatest loss of total tannins was detected in the oak barrels (28% less with respect to the control). There were several differences in wine phenolic acids due to wood botanical origin, with the clearest differences being between oak and the alternative wood species (chestnut and acacia). Also, there was a significant botanical effect on sensory profiles. Indeed, both among barrels and among powders, oak wood was the one that gave the strongest wood odor character. However, all the treatments with wood powders (oak, acacia and chestnut) preserved the fruity character of wine, conferring in the meanwhile non-dominant woody notes

    Obinutuzumab-mediated high-affinity ligation of FcγRIIIA/CD16 primes NK cells for IFNγ production

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    Natural killer (NK) cell-mediated antibody-dependent cellular cytotoxicity (ADCC), based on the recognition of IgG-opsonized targets by the low-affinity receptor for IgG FcγRIIIA/CD16, represents one of the main mechanisms by which therapeutic antibodies (mAbs) mediate their antitumor effects. Besides ADCC, CD16 ligation also results in cytokine production, in particular, NK-derived IFNγ is endowed with a well-recognized role in the shaping of adaptive immune responses. Obinutuzumab is a glycoengineered anti-CD20 mAb with a modified crystallizable fragment (Fc) domain designed to increase the affinity for CD16 and consequently the killing of mAb-opsonized targets. However, the impact of CD16 ligation in optimized affinity conditions on NK functional program is not completely understood. Herein, we demonstrate that the interaction of NK cells with obinutuzumab-opsonized cells results in enhanced IFNγ production as compared with parental non-glycoengineered mAb or the reference molecule rituximab. We observed that affinity ligation conditions strictly correlate with the ability to induce CD16 down-modulation and lysosomal targeting of receptor-associated signaling elements. Indeed, a preferential degradation of FcεRIγ chain and Syk kinase was observed upon obinutuzumab stimulation independently from CD16-V158F polymorphism. Although the downregulation of FcεRIγ/Syk module leads to the impairment of cytotoxic function induced by NKp46 and NKp30 receptors, obinutuzumab-experienced cells exhibit an increased ability to produce IFNγ in response to different stimuli. These data highlight a relationship between CD16 aggregation conditions and the ability to promote a degradative pathway of CD16-coupled signaling elements associated to the shift of NK functional progra

    Ubiquitin-dependent endocytosis of NKG2D-DAP10 receptor complexes activates signaling and functions in human NK cells

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    Cytotoxic lymphocytes share the presence of the activating receptor NK receptor group 2, member D (NKG2D) and the signaling-competent adaptor DNAX-activating protein 10 (DAP10), which together play an important role in antitumor immune surveillance. Ligand stimulation induces the internalization of NKG2D-DAP10 complexes and their delivery to lysosomes for degradation. In experiments with human NK cells and cell lines, we found that the ligand-induced endocytosis of NKG2D-DAP10 depended on the ubiquitylation of DAP10, which was also required for degradation of the internalized complexes. Moreover, through combined biochemical and microscopic analyses, we showed that ubiquitin-dependent receptor endocytosis was required for the activation of extracellular signal-regulated kinase (ERK) and NK cell functions, such as the secretion of cytotoxic granules and the inflammatory cytokine interferon-γ. These results suggest that NKG2D-DAP10 endocytosis represents a means to decrease cell surface receptor abundance, as well as to control signaling outcome in cytotoxic lymphocytes

    Tamanho do habitat e ameaças antrópicas: a importância das áreas protegidas sobre macroinvertebrados de bromélias-tanque

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    Tank bromeliads may act enhancing local biodiversity providing an important habitat for varied species. We aimed to evaluate the effect of a conservation unit and anthropic threatens on the macroinvertebrate communities associated with Aechmea distichantha (Bromeliaceae) as a model to access local ecosystems studies. The survey was conducted in the Vila Velha State Park, without severe anthropic influences and at Vila Velha Farm with the presence of Pinus spp. (an exotic/invasive species), crop plantations and a road (Ponta Grossa, Paraná, Brazil). The living organisms and bromeliad parameters were evaluated from 20 bromeliads. Total abundance was higher at anthropized area and driven by the larger size of those bromeliads. Species richness also tended to be higher at the anthropized area, although the conservation unit presented higher values when rare species were excluded. The results pointed out that bromeliads from conservation unit were under minor anthropic influences, being the presence of pines considered the main disturb in the anthropized site, which may have influenced the quality and amount of detritus resulting in distinct species composition and dominance of more tolerant taxa (Chironomidae and Ceratopogonidae). So, bromeliad mesocosm may be well suited for surveys considering anthropic influences on local ecosystems.Bromélias-tanque podem atuar como promotoras da biodiversidade local abrigando uma diversa biota. Esse estudo investigou como uma unidade de conservação e uma área antropizada podem influenciar as assembleias de macroinvertebrados associadas à Aechmea distichantha Lem. (Bromeliaceae). O estudo foi conduzido no Parque Estadual de Vila Velha, local sem influências antrópicas severas e na Fazenda Vila Velha, que conta com presença de Pinus spp. (uma espécie exótica/invasora) além de outros cultivos e uma rodovia no entorno (Ponta Grossa, Paraná, Brasil). Foram amostrados os macroinvertebrados e mensurados os parâmetros estruturais de 20 bromélias. Verificou-se que as comunidades associadas às bromélias da área antropizada e da UC foram distintas, sendo a abundância total de indivíduos superior na área antropizada, possivelmente influenciada pelo maior tamanho das bromélias. A riqueza de espécies também se sobressaiu no ambiente antropizado, apesar da UC apresentar valores maiores quando as espécies raras foram excluídas da análise. Os resultados indicaram que as bromélias da unidade de conservação tiveram menor influência de ações antrópicas, sendo que o Pinus spp. pode ter influenciado a qualidade e a quantidade de detritos, resultando em distintas composições de espécies e dominância de táxons mais tolerantes (Chironomidae e Ceratopogonidae) fora da UC. Por fim, estudos envolvendo o mesocosmo bromelícola podem ser adequados para avaliar influências antrópicas sobre ecossistemas locais

    Effects of physical activity on endothelial progenitor cells (EPCs)

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    Physical activity has a therapeutic role in cardiovascular disease (CVD), through its beneficial effects on endothelial function and cardiovascular system. Circulating endothelial progenitor cells (EPCs) are bone marrow (BM) derived cells that represent a novel therapeutic target in CVD patients, because of their ability to home to sites of ischemic injury and repair the damaged vessels. Several studies show that physical activity results in a significant increase in circulating EPCs, and, in particular, there are some evidence of the beneficial exercise-induced effects on EPCs activity in CVD settings, including coronary artery disease (CAD), heart failure (HF), and peripheral artery disease (PAD). The aim of this paper is to review the current evidence about the beneficial effects of physical exercise on endothelial function and EPCs levels and activity in both healthy subjects and patients with CVD

    ICAM-1 PROMOTES THE ABNORMAL ENDOTHELIAL CELLPHENOTYPE IN CHRONIC THROMBOEMBOLIC PULMONARYHYPERTENSION

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    International audienceBACKGROUND - Pulmonary endothelial cells play a key role in the pathogenesis of ChronicThromboembolic Pulmonary Hypertension (CTEPH). Increased synthesis and/or release ofIntercellular Adhesion Molecule 1 (ICAM-1) by pulmonary endothelial cells of patients withCTEPH has been recently reported, suggesting a potential role for ICAM-1 in CTEPH.METHODS - We studied pulmonary endarterectomy specimens from 172 patients with CTEPHand pulmonary artery specimens from 97 controls undergoing lobectomy for low-stage cancerwithout metastasis.RESULTS - ICAM-1 was overexpressed in vitro in isolated and cultured endothelial cells fromendarterectomy specimens. Endothelial cell (EC) growth and apoptosis resistance weresignificantly higher in CTEPH specimens than in controls (P<0.001). Both abnormalities wereabolished by pharmacological inhibition of ICAM-1 synthesis or activity. Overexpression ofICAM-1 contributed to the acquisition and maintenance of abnormal EC growth and apoptosisresistance via phosphorylation of SRC, p38 and ERK1/2 and overproduction of Survivin.Regarding the ICAM-1 E469K polymorphism, the KE heterozygote genotype was significantlymore frequent in CTEPH than in controls, but was not associated with disease severity amongpatients with CTEPH.CONCLUSIONS - ICAM-1 contributes to maintaining the abnormal endothelial cell phenotypein CTEPH

    Proposal for screening of kidney disease in a random population based on World Kidney Day campaign

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    Despite the advances on early screening techniques, getting to know the chronic kidney disease (CKD) prevalence in Brazil and worldwide remains a challenge for researchers. Aging, diabetes and hypertension are the main CKD causes in Brazil. The aim of the study was to evaluate the presence of urinary dipstick abnormalities in World Kidney Day campaign. This is a cross-sectional studyconducted at FMABC. This study was based on the answers to a kidney disease questionnaire and urinary dipstick test. A total of 205 patients were randomly invited to collect urine samples on World Kidney Day 2013. Among the 205 studied patients, 66.34% were women with mean age of 46.32 years. Around 34.14% of the patients were hypertensive and 9.75% diabetic. Urinalysis alterations were observed in 28.29% of patients. The group with urine alterations had older individuals (51.36 years) andmore diabetes (18.96%) with higher levels of glucose (143.2 mg/dl). &nbsp;Brazilian population is getting older and diabetic which represent risk factors for the onset of CKD. The necessity of an early detection by means of specific campaigns is thus of great importance. The use of dipstick test for screening is an important tool for kidney disease diagnosis. DOI: http://dx.doi.org/10.5281/zenodo.82692

    Distal motor neuropathy associated with novel EMILIN1 mutation

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    Abstract Elastin microfibril interface-located proteins (EMILINs) are extracellular matrix glycoproteins implicated in elastogenesis and cell proliferation. Recently, a missense mutation in the EMILIN1 gene has been associated with autosomal dominant connective tissue disorder and motor-sensory neuropathy in a single family. We identified by whole exome sequencing a novel heterozygous EMILIN1 mutation c.748C>T [p.R250C] located in the coiled coil forming region of the protein, in four affected members of an autosomal dominant family presenting a distal motor neuropathy phenotype. In affected patient a sensory nerve biopsy showed slight and unspecific changes in the number and morphology of myelinated fibers. Immunofluorescence study of a motor nerve within a muscle biopsy documented the presence of EMILIN-1 in nerve structures. Skin section and skin derived fibroblasts displayed a reduced extracellular deposition of EMILIN-1 protein with a disorganized network of poorly ramified fibers in comparison with controls. Downregulation of emilin1a in zebrafish displayed developmental delay, locomotion defects, and abnormal axonal arborization from spinal cord motor neurons. The phenotype was complemented by wild-type zebrafish emilin1a, and partially the human wild-type EMILIN1 cRNA, but not by the cRNA harboring the novel c.748C>T [p.R250C]. These data suggest a role of EMILIN-1 in the pathogenesis of diseases affecting the peripheral nervous system

    Resting-state functional MRI in multicenter studies on multiple sclerosis: a report on raw data quality and functional connectivity features from the Italian Neuroimaging Network Initiative

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    The Italian Neuroimaging Network Initiative (INNI) is an expanding repository of brain MRI data from multiple sclerosis (MS) patients recruited at four Italian MRI research sites. We describe the raw data quality of resting-state functional MRI (RS-fMRI) time-series in INNI and the inter-site variability in functional connectivity (FC) features after unified automated data preprocessing. MRI datasets from 489 MS patients and 246 healthy control (HC) subjects were retrieved from the INNI database. Raw data quality metrics included temporal signal-to-noise ratio (tSNR), spatial smoothness (FWHM), framewise displacement (FD), and differential variation in signals (DVARS). Automated preprocessing integrated white-matter lesion segmentation (SAMSEG) into a standard fMRI pipeline (fMRIPrep). FC features were calculated on pre-processed data and harmonized between sites (Combat) prior to assessing general MS-related alterations. Across centers (both groups), median tSNR and FWHM ranged from 47 to 84 and from 2.0 to 2.5, and median FD and DVARS ranged from 0.08 to 0.24 and from 1.06 to 1.22. After preprocessing, only global FC-related features were significantly correlated with FD or DVARS. Across large-scale networks, age/sex/FD-adjusted and harmonized FC features exhibited both inter-site and site-specific inter-group effects. Significant general reductions were obtained for somatomotor and limbic networks in MS patients (vs. HC). The implemented procedures provide technical information on raw data quality and outcome of fully automated preprocessing that might serve as reference in future RS-fMRI studies within INNI. The unified pipeline introduced little bias across sites and appears suitable for multisite FC analyses on harmonized network estimates
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