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1.
Exercise and immune system as modulators of intestinal microbiome: implications for the gut-muscle axis hypothesis.
Ticinesi, A, Lauretani, F, Tana, C, Nouvenne, A, Ridolo, E, Meschi, T
Exercise immunology review. 2019;:84-95
Abstract
Exercise is a possible modulator of intestinal microbiome composition, since some investigations have shown that it is associated with increased biodiversity and representation of taxa with beneficial metabolic functions. Conversely, training to exhaustion can be associated with dysbiosis of the intestinal microbiome, promoting inflammation and negative metabolic consequences. Gut microbiota can, in turn, influence the pathophysiology of several distant organs, including the skeletal muscle. A gut-muscle axis may in fact regulate muscle protein deposition and muscle function. In older individuals, this axis may be involved in the pathogenesis of muscle wasting disorders through multiple mechanisms, involving transduction of pro-anabolic stimuli from dietary nutrients, modulation of inflammation and insulin sensitivity. The immune system plays a fundamental role in these processes, being influenced by microbiome composition and at the same time contributing to shape microbial communities. In this review, we summarize the most recent literature acquisitions in this field, disentangling the complex relationships between exercise, microbiome, immune system and skeletal muscle function and proposing an interpretative framework that will need verification in future studies.
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2.
Importance of maternal diet in the training of the infant's immune system during gestation and lactation.
Jeurink, PV, Knipping, K, Wiens, F, Barańska, K, Stahl, B, Garssen, J, Krolak-Olejnik, B
Critical reviews in food science and nutrition. 2019;(8):1311-1319
Abstract
Latest forecasts predict that half of the European population will be allergic within the coming 15 years, with food allergies contributing substantially to the total burden; preventive measures are urgently needed. Unfortunately, all attempted alimentary strategies for primary prevention of allergic diseases through allergen avoidance so far have failed. This also holds true for the prevention of food allergies in breastfed infants by the common practice of excluding certain foods with allergenic potential from the maternal diet. As a preventive measure, therefore, exclusion diets should be discouraged. They can exhaust nursing mothers and negatively impact both their nutritional status as well as their motivation to breastfeed. A prolonged exclusion diet may be indicated solely in cases of doctor-diagnosed food allergy following rigid medical tests (e.g. double-blind placebo-controlled food challenges). Indicated cases usually involve exclusion of only a few food items. Continued breastfeeding is generally important for many aspects of the infant's health, including the training of the infant's immune responses to foreign compounds and avoidance of overshooting inflammatory responses. Recent studies suggest that the presence of maternal dietary proteins in amniotic fluid, cord blood, and human milk might support the induction of tolerance towards solid foods in infants. These are exactly the same species of proteins or remnants thereof that, in comparatively few cases, trigger allergic responses. However, the insight that the proteins of maternal dietary origin in human milk are more likely to be cure (or, more precise, directing prevention) than curse has still largely evaded the attention of health care professionals consulted by worried breastfeeding mothers. In this paper, we summarize recent literature on the importance of exposure to dietary proteins in the establishment of immunological tolerance and hence prevention of allergic disease. Multiple organizations have used the scientific knowledge to build (local) guidelines (e.g. AAAAI, EAACI, BSACI) that can support health care professionals to provide the best strategy to prevent the onset of allergic diseases. We thus hope to clarify existing confusion about the allergenic propensities of dietary proteins during early life, which has contributed to exaggerated fears around the diet of pregnant and breastfeeding mothers.
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3.
Altered immune system in frailty: Genetics and diet may influence inflammation.
Pansarasa, O, Pistono, C, Davin, A, Bordoni, M, Mimmi, MC, Guaita, A, Cereda, C
Ageing research reviews. 2019;:100935
Abstract
Frailty is a complex geriatric syndrome associated with biological vulnerability to stressors and decreased physiological reserve. Its etiology and pathogenesis are not completely understood, although various causes and complex pathways have been proposed. Immune system alterations (immunosenescence and "InflammAging") have been suggested to contribute to frailty, but a precise causative role of such alterations remains to be determined. Genetic studies support the suggestion of immune system involvement in frailty: genetic variants in genes involved in immune system function have been associated with the syndrome. Interestingly, nutritional status, through its effects on cellular metabolism, may also influence the immune system, i.e. hormone and cytokine (mainly adipocytokine) levels, and immune cell populations and function, increasing inflammation and contributing to frailty. This review aims to discuss the role of immune system alterations in frailty, analyzing the role of genetic factors in frailty onset and the impact of diet on inflammation and, in turn, on frailty.
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4.
Role of Zinc in Immune System and Anti-Cancer Defense Mechanisms.
Skrajnowska, D, Bobrowska-Korczak, B
Nutrients. 2019;(10)
Abstract
The human body cannot store zinc reserves, so a deficiency can arise relatively quickly, e.g., through an improper diet. Severe zinc deficiency is rare, but mild deficiencies are common around the world. Many epidemiological studies have shown a relationship between the zinc content in the diet and the risk of cancer. The anti-cancer effect of zinc is most often associated with its antioxidant properties. However, this is just one of many possibilities, including the influence of zinc on the immune system, transcription factors, cell differentiation and proliferation, DNA and RNA synthesis and repair, enzyme activation or inhibition, the regulation of cellular signaling, and the stabilization of the cell structure and membranes. This study presents selected issues regarding the current knowledge of anti-cancer mechanisms involving this element.
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5.
Origin and evolution of the plant immune system.
Han, GZ
The New phytologist. 2019;(1):70-83
Abstract
Contents Summary 70 I. Introduction 70 II. Ancient associations between plants and microbes 72 III. Evolutionary dynamics of plant-pathogen interactions 74 IV. Evolutionary signature of plant-pathogen interactions 74 V. Origin and evolution of RLK proteins 75 VI. Origin and evolution of NLR proteins 77 VII. Origin and evolution of SA signaling 78 VIII. Origin and evolution of RNA-based defense 79 IX. Perspectives 79 Acknowledgements 80 References 80 SUMMARY Microbes have engaged in antagonistic associations with plants for hundreds of millions of years. Plants, in turn, have evolved diverse immune strategies to combat microbial pathogens. The conflicts between plants and pathogens result in everchanging coevolutionary cycles known as 'Red Queen' dynamics. These ancient and ongoing plant-pathogen interactions have shaped the evolution of both plant and pathogen genomes. With the recent explosion of plant genome-scale data, comparative analyses provide novel insights into the coevolutionary dynamics of plants and pathogens. Here, we discuss the ancient associations between plants and microbes as well as the evolutionary principles underlying plant-pathogen interactions. We synthesize and review the current knowledge on the origin and evolution of key components of the plant immune system. We also highlight the importance of studying algae and nonflowering land plants in understanding the evolution of the plant immune system.
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6.
Nutrients, immune system, and exercise: Where will it take us?
Batatinha, HAP, Biondo, LA, Lira, FS, Castell, LM, Rosa-Neto, JC
Nutrition (Burbank, Los Angeles County, Calif.). 2019;:151-156
Abstract
The immune system plays a key role in controlling infections, repairing injuries, and restoring homeostasis. Immune cells are bioenergetically expensive during activation, which requires a tightly regulated control of the metabolic pathways, which is mostly regulated by two cellular energy sensors: Adenosine monophosphate-activated protein kinase and mammalian target of rapamycin. The activation and inhibition of this pathways can change cell subtype differentiation. Exercise intensity and duration and nutrient availability (especially glucose and glutamine) tightly regulate immune cell differentiation and function through Adenosine monophosphate-activated protein kinase and mammalian target of rapamycin signaling. Herein, we discuss the innate and adaptive immune-cell metabolism and how they can be affected by exercise and nutrients.
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7.
Prebiotics: Mechanisms and Preventive Effects in Allergy.
Brosseau, C, Selle, A, Palmer, DJ, Prescott, SL, Barbarot, S, Bodinier, M
Nutrients. 2019;(8)
Abstract
Allergic diseases now affect over 30% of individuals in many communities, particularly young children, underscoring the need for effective prevention strategies in early life. These allergic conditions have been linked to environmental and lifestyle changes driving the dysfunction of three interdependent biological systems: microbiota, epithelial barrier and immune system. While this is multifactorial, dietary changes are of particular interest in the altered establishment and maturation of the microbiome, including the associated profile of metabolites that modulate immune development and barrier function. Prebiotics are non-digestible food ingredients that beneficially influence the health of the host by 1) acting as a fermentable substrate for some specific commensal host bacteria leading to the release of short-chain fatty acids in the gut intestinal tract influencing many molecular and cellular processes; 2) acting directly on several compartments and specifically on different patterns of cells (epithelial and immune cells). Nutrients with prebiotic properties are therefore of central interest in allergy prevention for their potential to promote a more tolerogenic environment through these multiple pathways. Both observational studies and experimental models lend further credence to this hypothesis. In this review, we describe both the mechanisms and the therapeutic evidence from preclinical and clinical studies exploring the role of prebiotics in allergy prevention.
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8.
Nutrigenomics of Vitamin D.
Carlberg, C
Nutrients. 2019;(3)
Abstract
Nutrigenomics studies how environmental factors, such as food intake and lifestyle, influence the expression of the genome. Vitamin D₃ represents a master example of nutrigenomics, since via its metabolite 1α,25-dihydroxyvitamin D₃, which binds with high-affinity to the vitamin D receptor, the secosteroid directly affects the epigenome and transcriptome at thousands of loci within the human genome. Vitamin D is important for both cellular metabolism and immunity, as it controls calcium homeostasis and modulates the response of the innate and adaptive immune system. At sufficient UV-B exposure, humans can synthesize vitamin D₃ endogenously in their skin, but today's lifestyle often makes the molecule a true vitamin and micronutrient that needs to be taken up by diet or supplementation with pills. The individual's molecular response to vitamin D requires personalized supplementation with vitamin D₃, in order to obtain optimized clinical benefits in the prevention of osteoporosis, sarcopenia, autoimmune diseases, and possibly different types of cancer. The importance of endogenous synthesis of vitamin D₃ created an evolutionary pressure for reduced skin pigmentation, when, during the past 50,000 years, modern humans migrated from Africa towards Asia and Europe. This review will discuss different aspects of how vitamin D interacts with the human genome, focusing on nutritional epigenomics in context of immune responses. This should lead to a better understanding of the clinical benefits of vitamin D.
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9.
Interplay between early-life malnutrition, epigenetic modulation of the immune function and liver diseases.
Campisano, S, La Colla, A, Echarte, SM, Chisari, AN
Nutrition research reviews. 2019;(1):128-145
Abstract
Early-life nutrition plays a critical role in fetal growth and development. Food intake absence and excess are the two main types of energy malnutrition that predispose to the appearance of diseases in adulthood, according to the hypothesis of 'developmental origins of health and disease'. Epidemiological data have shown an association between early-life malnutrition and the metabolic syndrome in later life. Evidence has also demonstrated that nutrition during this period of life can affect the development of the immune system through epigenetic mechanisms. Thus, epigenetics has an essential role in the complex interplay between environmental factors and genetics. Altogether, this leads to the inflammatory response that is commonly seen in non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome. In conjunction, DNA methylation, covalent modification of histones and the expression of non-coding RNA are the epigenetic phenomena that affect inflammatory processes in the context of NAFLD. Here, we highlight current understanding of the mechanisms underlying developmental programming of NAFLD linked to epigenetic modulation of the immune system and environmental factors, such as malnutrition.
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10.
How does preeclampsia affect neonates? Highlights in the disease's immunity.
Marins, LR, Anizelli, LB, Romanowski, MD, Sarquis, AL
The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians. 2019;(7):1205-1212
Abstract
INTRODUCTION Preeclampsia (PE) is the primary obstetrical cause in one of the four perinatal deaths. Although the etiology and pathogenesis of preeclampsia is not fully known, a proinflammatory immune state prevails and can disrupt fetal hematopoiesis. Some of the effects on the newborn include neonatal thrombocytopenia, neutropenia, a reduction in T regulatory cells, and an increased cytotoxic natural killer cell profile. METHODS Electronic databases were searched, and defined criteria were applied to select articles for review. The review covered literature on the effects on neonatal due to maternal preeclampsia, fetal outcomes, and new treatments in research aimed at reducing morbidity and mortality of the disease. DISCUSSION The cytotoxic environment present in PE affects the development of fetal cell lineages. Neutropenia is observed in 50% of neonates and is correlated with mortality, although its treatment is not well-established. The enhancement in erythropoietin and the hypoxic setting present in the disease can also lead to thrombocytopenia. Per partum management includes platelet transfusion in order to avoid severe complications such as intraventricular hemorrhage. Regarding other cell lines, a cytotoxic profile is observed to be reflecting the milieu present in the mothers' bloodstream. This disruption alters the immune system response into a proinflammatory profile and can be correlated to neonatal necrotizing enterocolitis. An antiangiogenic environment is also part of the preeclampsia presentation and can be responsible for the enhancement of bronchopulmonary dysplasia observed in this population. Meanwhile, the reduction in angiogenic factors, such as vascular endothelial growth factor (VEGF), can be a protective mechanism for retinopathy of prematurity. Studies of the long-term effects of these observations are lacking, but lower neurodevelopmental scores and a higher cardiovascular risk are noted. New treatments in research propose a prevention of the disease during gestation in order to reduce the effects more efficiently in the fetus. Phosphodiesterase inhibitors, endothelin 1 receptor antagonists and manipulation of heme oxygenase-1 enzyme pathway are possible therapeutic alternatives. This review summarizes the current understanding of how preeclampsia affects neonates. As a conclusion, further studies are needed to build up a guideline to manage those effects. A research agenda is proposed.