Recalling the Biological Significance of Immune Checkpoints on NK Cells: A Chance to Overcome LAG3, PD1, and CTLA4 Inhibitory Pathways by Adoptive NK Cell Transfer?

Immune checkpoint receptors (IC) positively or negatively regulate the activation of the host immune response, preventing unwanted reactions against self-healthy tissues. In recent years the term IC has been mainly used for the inhibitory ICs, which are critical to control Natural Killer (NK) and Cytotoxic CD8(+) T cells due to its high cytotoxic potential. Due to the different nature of the signals that regulate T and NK cell activation, specific ICs have been described that mainly regulate either NK cell or T cell activity. Thus, strategies to modulate NK cell activity are raising as promising tools to treat tumors that do not respond to T cell-based immunotherapies. NK cell activation is mainly regulated by ICs and receptors from the KIR, NKG2 and NCRs families and the contribution of T cell-related ICs is less clear. Recently, NK cells have emerged as contributors to the effect of inhibitors of T cell-related ICs like CTLA4, LAG3 or the PD1/PD-L1 axes in cancer patients, suggesting that these ICs also regulate the activity of NK cells under pathological conditions. Strikingly, in contrast to NK cells from cancer patients, the level of expression of these ICs is low on most subsets of freshly isolated and in vitro activated NK cells from healthy patients, suggesting that they do not control NK cell tolerance and thus, do not act as conventional ICs under non-pathological conditions. The low level of expression of T cell-related ICs in "healthy" NK cells suggest that they should not be restricted to the detrimental effects of these inhibitory mechanisms in the cancer microenvironment. After a brief introduction of the regulatory mechanisms that control NK cell anti-tumoral activity and the conventional ICs controlling NK cell tolerance, we will critically discuss the potential role of T cell-related ICs in the control of NK cell activity under both physiological and pathological (cancer) conditions. This discussion will allow to comprehensively describe the chances and potential limitations of using allogeneic NK cells isolated from a healthy environment to overcome immune subversion by T cell-related ICs and to improve the efficacy of IC inhibitors (ICIs) in a safer way

Desenvolvimento de aveia branca em diferentes manejos fisicos e quimicos em nitossolo.

A utilização de aveia como cobertura do solo manejado em sistema plantio direto vem sendo muito empregada no sul do Brasil, contudo, impedimentos físicos e químicos do solo limitam o seu desenvolvimento radicular. O objetivo desse trabalho foi avaliar a combinação de estratégias de melhoria física e química na semeadura sobre o desenvolvimento da aveia branca em Nitossolo Vermelho sob sistema plantio direto. Os tratamentos foram distribuídos em blocos ao acaso em esquema fatorial, possuindo como fator principal o manejo mecânico e secundário o manejo químico. Os manejos mecânicos empregados foram: o SPD7 ? Sistema de Plantio Direto com sulcador da semeadora atuando a 7 cm de profundidade, como Testemunha, e a 11 cm como SPD11, esse como estratégia de manutenção do SPD; e CM ? cultivo mínimo realizado com um subsolador, como estratégia de melhoria física, porém contra os ideais do SPD. Os tipos de manejo químico foram à adição na linha de semeadura, de calcário de xisto e de calcário dolomítico. Avaliou-se a produção de massa verde e seca e a concentração mineral de nitrogênio, cálcio, magnésio, cobre e zinco. O calcário de xisto disponibilizou mais minerais para aveia resultando em maior desenvolvimento da planta, expresso pela maior massa verde e seca, bem como, a estratégia de melhoria física na semeadura, o SPD11, quando comparado ao SPD7, no entanto, o CM foi o que apresentou as maiores concentrações e massa seca da parte aérea das plantas

Las enfermedades raras en las patologías neurometabólicas

Metabolic myopathies are genetic disorders that decrease the capacity of skeletal muscle to use energy substrates and ATP. These disturbances can be classified into three categories: i) disorders of carbohydrate metabolism (glycogen and glucose), ii) defects in lipid metabolism, and iii) dysfunctions of oxidative phosphorylation -OXPHOS-. The first two are caused by enzyme deficiencies involved in the metabolic pathways of degradation and synthesis of carbohydrates and lipids, and although they show distinct clinical manifestations, exercise intolerance is a predominant symptom present in most of them. Although a good number of patients with these muscle disorders display symptoms in childhood, the diagnosis is often delayed until the second and third decades of life. Therefore, recognizing the clinical features of these deficiencies can lead to an earlier diagnosis and better treatment. Mitochondrial diseases are a group of disorders caused by an alteration of the oxidative phosphorylation system, that leads to a deficient synthesis of ATP. This system is composed of proteins codified in the two genetic systems of the cell, the nuclear and mitochondrial genomes, and, therefore, the mode of inheritance could be either Mendelian or maternal. This review will describe the special characteristics of the mitochondrial genetic system and the main mutations in mtDNA that cause human diseases.Las miopatías metabólicas son un grupo de trastornos genéticos que disminuyen la capacidad del músculo esquelético para utilizar sustratos energéticos y sintetizar ATP. Estas alteraciones pueden clasificarse en tres tipos fundamentalmente: i) trastornos del metabolismo de los carbohidratos (del glucógeno y de la glucosa), ii) defectos del metabolismo lipídico, y iii) alteraciones de la fosforilación oxidativa –OXPHOS-. Las dos primeras se deben a deficiencias enzimáticas de las rutas metabólicas de degradación y síntesis de glúcidos y lípidos y muestran diversas manifestaciones clínicas, pero una buena parte de ellas cursan con intolerancia al ejercicio. Aunque un buen número de pacientes con estos trastornos musculares presentan síntomas en la infancia, el diagnóstico normalmente se retrasa hasta la segunda y tercera década de la vida. Por tanto, reconocer las características clínicas de estas deficiencias conduce a un diagnóstico precoz y a un mejor tratamiento. Las enfermedades mitocondriales son un grupo de trastornos originados por una deficiencia en la síntesis de ATP a través del sistema de fosforilación oxidativa. Este sistema está formado por proteínas codificadas en los dos genomas de la célula (nuclear y mitocondrial) y, por tanto, pueden presentar un modelo de herencia mendeliano o materno. En esta revisión se describirán las características especiales del sistema genético mitocondrial y las principales mutaciones que causan enfermedades en humanos

Effect of age and severity of cognitive dysfunction on spontaneous activity in pet dogs - Part 1: Locomotor and exploratory behaviour

Age-related cognitive dysfunction syndrome (CDS) has been reported in dogs and it is considered a natural model for Alzheimer’s disease in humans. Changes in spontaneous activity (including locomotor and exploratory behaviour) and social responsiveness have been related to the age and cognitive status of kennel-reared Beagle dogs. The aim of this study was to assess the influence of age and severity of CDS on locomotor and exploratory behaviour of privately owned dogs. This is the first part of a two-part report on spontaneous activity in pet dogs. An open-field (OF) test and a curiosity test were administered at baseline and 6 months later to young (1–4 years, n = 9), middle-aged (5–8 years, n = 9), cognitively unimpaired aged (⩾9 years, n = 31), and cognitively impaired aged (⩾9 years, n = 36) animals. Classification of cognitive status was carried out using an owner-based observational questionnaire, and in the cognitively impaired group, the dogs were categorised as having either mild or severe cognitive impairment. Dogs were recorded during sessions in the testing room and the video-recordings were subsequently analysed. The severity of CDS (but not age) influenced locomotion and exploratory behaviour so that the more severe the impairment, the higher the locomotor activity and frequency of corner-directed (aimless) behaviours, and the lower the frequency of door-aimed activities. Curiosity directed toward novel stimuli exhibited an age-dependent decline although severely affected animals displayed more sniffing episodes directed towards the objects. OF activity did not change after 6 months. Testing aged pet dogs for spontaneous behaviour might help to better characterise cognitively affected individuals

Whole sequence of the mitochondrial DNA genome of Kearns Sayre Syndrome patients: Identification of deletions and variants

Mitochondria both produce the energy of the cell as ATP via respiration and regulate cellular metabolism. Accordingly, any deletion or mutation in the mitochondrial DNA (mtDNA) may result in a disease. One of these diseases is Kearns Sayre syndrome (KSS), described for the first time in 1958, where different large-scale deletions of different sizes and at different positions have been reported in the mitochondrial genome of patients with similar clinical symptoms. In this study, sequences of the mitochondrial genome of three patients with clinic features of KSS were analyzed. Our results revealed the position, heteroplasmy percentage, size of deletions, and their haplogroups. Two patients contained deletions reported previously and one patient showed a new deletion not reported previously. These results display for the first time a systematic analysis of mtDNA variants in the whole mtDNA genome of patients with KSS to help to understand their association with the disease

Higher platelet cytochrome oxidase specific activity in surviving than in non-surviving septic patients

Introduction: In a previous study with 96 septic patients, we found that circulating platelets in 6-months surviving septic patients showed higher activity and quantity of cytochrome c oxidase (COX) normalized by citrate synthase (CS) activity at moment of severe sepsis diagnosis than non-surviving septic patients. The objective of this study was to estimate whether COX specific activity during the first week predicts 1-month sepsis survival in a larger cohort of patients.Methods: Using a prospective, multicenter, observational study carried out in six Spanish intensive care units with 198 severe septic patients, we determined COX activity per proteins (COXact/Prot) in circulating platelets at day 1, 4 and 8 of the severe sepsis diagnosis. Endpoints were 1-month and 6-months mortality.Results: Survivor patients (n = 130) showed higher COXact/Prot (P 0.30 mOD/min/mg at day 1 (P = 0.002), 4 (P = 0.006) and 8 (P = 0.02) was associated independently with 1-month mortality. Area under the curve of COXact/Prot at day 1, 4 and 8 to predict 30-day survival were 0.70 (95% CI = 0.63-0.76; P < 0.001), 0.71 (95% CI = 0.64-0.77; P < 0.001) and 0.71 (95% CI = 0.64-0.78; P < 0.001), respectively.Conclusions: The new findings of our study, to our knowledge the largest series reporting data about mitochondrial function during follow-up in septic patients, were that septic patients that survive 1-month have a higher platelet cytochrome oxidase activity at moment of sepsis diagnosis and during the first week than non-survivors, and that platelet cytochrome oxidase activity at moment of sepsis diagnosis and during the first week could be used as biomarker to predict the clinical outcome in septic patients

All about (nk cell-mediated) death in two acts and an unexpected encore: initiation, execution and activation of adaptive immunity

NK cells are key mediators of immune cell-mediated cytotoxicity toward infected and transformed cells, being one of the main executors of cell death in the immune system. NK cells recognize target cells through an array of inhibitory and activating receptors for endogenous or exogenous pathogen-derived ligands, which together with adhesion molecules form a structure known as immunological synapse that regulates NK cell effector functions. The main and best characterized mechanisms involved in NK cell-mediated cytotoxicity are the granule exocytosis pathway (perforin/granzymes) and the expression of death ligands. These pathways are recognized as activators of different cell death programmes on the target cells leading to their destruction. However, most studies analyzing these pathways have used pure recombinant or native proteins instead of intact NK cells and, thus, extrapolation of the results to NK cell-mediated cell death might be difficult. Specially, since the activation of granule exocytosis and/or death ligands during NK cell-mediated elimination of target cells might be influenced by the stimulus received from target cells and other microenvironment components, which might affect the cell death pathways activated on target cells. Here we will review and discuss the available experimental evidence on how NK cells kill target cells, with a special focus on the different cell death modalities that have been found to be activated during NK cell-mediated cytotoxicity; including apoptosis and more inflammatory pathways like necroptosis and pyroptosis. In light of this new evidence, we will develop the new concept of cell death induced by NK cells as a new regulatory mechanism linking innate immune response with the activation of tumour adaptive T cell responses, which might be the initiating stimulus that trigger the cancer-immunity cycle. The use of the different cell death pathways and the modulation of the tumour cell molecular machinery regulating them might affect not only tumour cell elimination by NK cells but, in addition, the generation of T cell responses against the tumour that would contribute to efficient tumour elimination and generate cancer immune memory preventing potential recurrences

Rebooting the human mitochondrial phylogeny: an automated and scalable methodology with expert knowledge

<p>Abstract</p> <p>Background</p> <p>Mitochondrial DNA is an ideal source of information to conduct evolutionary and phylogenetic studies due to its extraordinary properties and abundance. Many insights can be gained from these, including but not limited to screening genetic variation to identify potentially deleterious mutations. However, such advances require efficient solutions to very difficult computational problems, a need that is hampered by the very plenty of data that confers strength to the analysis.</p> <p>Results</p> <p>We develop a systematic, automated methodology to overcome these difficulties, building from readily available, public sequence databases to high-quality alignments and phylogenetic trees. Within each stage in an autonomous workflow, outputs are carefully evaluated and outlier detection rules defined to integrate expert knowledge and automated curation, hence avoiding the manual bottleneck found in past approaches to the problem. Using these techniques, we have performed exhaustive updates to the human mitochondrial phylogeny, illustrating the power and computational scalability of our approach, and we have conducted some initial analyses on the resulting phylogenies.</p> <p>Conclusions</p> <p>The problem at hand demands careful definition of inputs and adequate algorithmic treatment for its solutions to be realistic and useful. It is possible to define formal rules to address the former requirement by refining inputs directly and through their combination as outputs, and the latter are also of help to ascertain the performance of chosen algorithms. Rules can exploit known or inferred properties of datasets to simplify inputs through partitioning, therefore cutting computational costs and affording work on rapidly growing, otherwise intractable datasets. Although expert guidance may be necessary to assist the learning process, low-risk results can be fully automated and have proved themselves convenient and valuable.</p

Revolutionizing Alzheimer\u27s disease and clinical trials through biomarkers

AbstractThe Alzheimer's Association's Research Roundtable met in May 2014 to explore recent progress in developing biomarkers to improve understanding of disease pathogenesis and expedite drug development. Although existing biomarkers have proved extremely useful for enrichment of subjects in clinical trials, there is a clear need to develop novel biomarkers that are minimally invasive and that more broadly characterize underlying pathogenic mechanisms, including neurodegeneration, neuroinflammation, and synaptic dysfunction. These may include blood-based assays and new neuropsychological testing protocols, as well as novel ligands for positron emission tomography imaging, and advanced magnetic resonance imaging methodologies. In addition, there is a need for biomarkers that can serve as theragnostic markers of response to treatment. Standardization remains a challenge, although international consortia have made substantial progress in this area and provide lessons for future standardization efforts