Book

Environmental Influences on the Immune System

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Abstract

This book brings together articles on the overarching theme of how the environment shapes the immune system. The immune system is commonly assumed to respond to harmful pathogens such as bacteria and viruses. However, harmless bacteria, chemicals, stress, normal food and other factors can also trigger, shape or interfere with the immune system, often producing adverse effects. Yet, it is also becoming increasingly accepted that some of these interactions are physiological and necessary for a healthy immune system. Examples of negative effects include the immunosuppressive effects of UV irradiation, or the immunotoxic effects of man-made chemicals such as polycyclic aromatic hydrocarbons. Autoimmunity or allergies can be the adverse consequences of interaction between the immune system and chemical compounds such as drugs. Positive effects can come from natural exposure levels to bacteria, healthy life-style or the diet. There is a great need to understand how communication between the environment and the immune system works. This book addresses this need. It covers environmental factors (such as bacteria, sun exposure), human factors (such as age, exercise or stress), and important man-made factors (such as air pollution). A chapter on human rights complements the scientific chapters. The book is intended for immunologists, toxicologists and researchers who want to know how the immune system works and is triggered, as well as for medical doctors in environmental medicine and the general public interested in immunology.

Chapters (15)

All living organisms are in constant exchange with the environment: its climate and physical conditions, chemicals, radiation, and last but not least other organisms. Among these, pathogenic microbes are a constant threat to health. Consequently, all organisms have developed strategies to prevent damage by bacterial, viral, and fungal pathogens. In vertebrates a highly complex defense mechanism has evolved, which goes far beyond “eat-and-destroy-the-bugs” strategies of evolutionary older organisms like prokaryotes or invertebrates. This mechanism is called the immune system. The immune system is different from other organs. It is distributed across the entire body and comprises organ structures, cells, and molecules such as antibodies and cytokines. It has a vast array of functionally different cells (T and B lymphocytes, macrophages, neutrophils, mast cells, to name just a few). While some cells remain tissue bound, others can move around the body and shuttle between the blood and lymph vessels and tissues. The immune system comprises lymphoid organs such as bone marrow, thymus, lymph nodes, or the spleen, which all form developmental niches for immune and blood cell development (hematopoiesis) and act as contact centers for interaction of immune cells. Indeed, the immune system is constantly renewing itself from hematopoietic stem cells, and the highly organized differentiation of cells is an important functional feature of immune responses. The immune system is unique in its memory: it will fight pathogens better, faster, and more vigorous on a second encounter. Finally, the immune system is a paradigm of checks and balances. In order to prevent attacking and damaging its own body or overreacting to harmless environmental cues, immune responses not only entail immune activation but also spend much effort on immunosuppression. Adverse immune reactions occur when either the discernment of antigens as harmless or harmful fails or when the immune system attacks proteins of its own body as antigens. Finally, chemicals, drugs, stress, or certain environmental conditions can suppress the immune system with severe health consequences. Immunotoxicology is the discipline which deals with unwanted, adverse immune responses caused by the (chemical and physical) environment. In this chapter, I want to introduce major players of the immune system and major current concepts of its operation strategies, with a special emphasis on interactions with the environment. This shall give a framework for a better understanding of the chapters which deal with particular situations of the environment–immune system interaction.
As described in other chapters of this book, the function of the mature, fully formed immune system can be altered by a variety of environmental factors. While it is important to understand how these exposures modulate the immune system, an understudied aspect of how the environment shapes the immune system is the impact of exposures during development on the way the immune system functions later in life. Early life is a particularly susceptible time window for environmental exposures, because this is when the development and programming of multiple organs systems occurs (Nat Struct Mol Biol 20(3):282-289, 2013). In fact, some studies have shown that exposures during development lead to persistent changes in the function of other organ systems. Moreover, exposures during critical developmental periods lead to potentially permanent functional differences, as opposed to the generally transient changes that occurs after exposures during adulthood (Environ Health Perspect 120(10):1353-1361, 2012). Herein, we review the current evidence that the function of the immune system is sensitive to perturbation by developmental exposure to environmental agents. For some compounds, there is strong evidence that there are persistent immune defects associated with developmental exposures. For others, there are a handful of studies that suggest there may be immune consequences of developmental exposures. However, for many exposures little or nothing is known about whether developmental exposure has immunomodulatory effects that persist later in life. To provide an overview of current knowledge, we divide these exposures into five groups: pollutants for which a specific cellular receptor has been identified, smoke, heavy metals, pharmaceuticals, and maternal diet. Clearly, some of these agents contain a mixture of components, and metabolites of these agents may fall in to more than one category. Thus, in some situations the developing immune system is likely exposed to multiple environmental insults simultaneously. However, for brevity they are discussed in one place, acknowledging that these categories are not mutually exclusive.
The term "immunosenescence" defines gradual alterations of human immune functions associated with advancing age. Decreasing immunocompetence results in a higher susceptibility to infections and rising incidences of certain malignant and autoimmune diseases in elderly humans. As a major signature for immunosenescence, decreased vaccination efficiencies have been reported regardless of whether vaccinations were of primary or secondary nature. "Inflamm-aging", referring to the development of chronic systemic low-level inflammation, is further a key aspect of immunosenescence. Since an inflammatory aspect has been described for the pathogenesis of many major age-related diseases such as atherosclerosis and Alzheimer’s disease, the clinical impact of immunosenescence may extend far beyond diseases where a role of immunological dysfunction has been proven. A distorted immunocompetence in the elderly may result from intrinsic cellular changes as well as from external influences affecting the immunological network at all layers. So far, research efforts have found a broad variety of complex age-related alterations regarding the phenotype and the functionality of various types of immune cells, which can be associated with compromised immune functions. Chronic viral infections such as CMV have been confirmed to promote immunosenescence changes by driving exhaustive immune responses. It seems that the regenerative potential of the aged immune system is altered due to changes in the bone marrow microenvironment and a distorted functionality of hematopoietic stem cells. One of the most drastic age-associated changes for the immune system is the involution of the thymus resulting in decreased production of new T cells starting already during early adult age. Interlinking and appreciating these individual signatures is only feasible in conducting bioinformatics and system’s biology approaches. An enhanced understanding of immunosenescence alongside with the development of diagnostic and therapeutic tools to identify and treat age-related impairments in immune functions will be of great scientific and socioeconomic interest, considering the speed and magnitude of population aging worldwide.
Over the past decades, an increase of the prevalence of allergic diseases has been observed in Western countries. The hygiene hypothesis proposes that viral, bacterial, or helminth infections; environments with high levels of microbial components, such as farms; and the nutrition are preventive against the development of allergies despite the same genetic predisposition. The timing of these exposures is crucial. The critical window of time starts already in utero and ends in school age depending on the kind of exposure. The underlying immunological mechanism of such exposures seems rather to include the induction of regulatory processes to control the allergic reaction than to prevent the production of IgE. In this chapter, we review the best understood exposures together with the timing and the immunological mechanisms they induce to get the most preventive effect on the development of allergic diseases.
In this chapter, we provide an overview of how stress affects immune functioning and examine evidence in the literature regarding various intrapersonal and interpersonal factors that may exacerbate or buffer the health effects of stress and its related immune manifestations. We first review some basic information concerning the immune system to provide the reader with necessary background. We then present the primary pathways by which stress impacts the immune system, including the sympathetic nervous system, the hypothalamic-pituitary-adrenal (HPA) axis, and vagal withdrawal. Next, we discuss how the immune response varies and even goes awry, depending on the nature of the stress (acute versus chronic). Additionally, we discuss how the immune response varies depending upon the individual within whom the stress is occurring; specifically, we focus on various intrapersonal and interpersonal factors associated with immune functioning. Intrapersonal factors reviewed include rumination, emotion regulation, alexithymia, psychological stress, optimism, and positive affect. Interpersonal factors reviewed include close relationship and family processes such as negative and positive behaviors, ambivalence towards a relationship partner, social rejection and social isolation, and early life adversity. To conclude, we highlight some substantive and methodological considerations relevant to future research on the effects of stress on immunity.
This chapter is divided into three major parts. The first part covers how exercise is associated with respiratory infection. Exercise’s effect on mucosal immunity, allergic rhinitis and airway inflammation is discussed as well as how certain viruses can affect respiratory infection risk in the athletic population. In the chapter’s second section, the influence of acute exercise on our immune system is explored. More specifically, the alterations in the innate immune system and acquired immune system in response to exercise and the mechanisms leading to these alterations are elucidated. Finally, the third part is on the effects of chronic exercise on the immune system. In this part, the beneficial anti-inflammatory effect of regular physical activity and health implication that this has on prevention and treatment of various diseases, which includes cancer, dementia, cardiovascular and pulmonary diseases, is discussed. In addition, the potential harmful effects of a high-intensity training period are also addressed. There is little research in these areas with resistance-type exercise, and unless stated otherwise, the studies mentioned here are with endurance-type exercise, such as running, rowing, cycling and swimming.
The ultraviolet (UV) radiation present in sunlight is the primary cause of skin cancer, the most common form of cancer in the industrialized world. UV exposure is also immunosuppressive, and the immunosuppression induced by sunlight exposure is a major risk factor for skin cancer induction. For this reason, studying the mechanisms underlying UV-mediated immunosuppression has been an active area of research since the initial description of UV-induced immunosuppression and its role in photocarcinogenesis by Margaret Kripke in the early 1970s. Moreover, understanding how this ubiquitous and inescapable environmental agent affects the immune response provides an excellent model system for understanding how the environment influences the immune system. In this chapter I will review some of the more recent findings in this area. I will describe the mechanisms that activate systemic immunosuppression, following a photon of UV light as it penetrates the outermost layers of the skin, and activate photoreceptors, which then starts a cascade of events that ultimately transmits the suppressive signal from the skin to the immune system. I will also briefly describe some of the beneficial effects of UV-induced immunosuppression (i.e., suppressing autoimmunity). Finally, I will review studies demonstrating that applying jet fuel to the skin activates a similar mechanism to induce immunosuppression, indicating that the lessons learned from studying UV-induced immunosuppression may have broader implications for the general toxicology community.
Childhood vaccinations are of substantial public health relevance and have contributed significantly to reduced mortality and morbidity from severe infectious diseases. Persistent organic pollutants are industrially produced chemicals, which are highly persistent, bioaccumulative, and toxic to humans. As the immunological response to vaccinations is a feasible parameter and represents major immune functions, it is most relevant for the assessment of human immune suppression caused by such agents in large epidemiological studies. This chapter focuses on the limited number of environmental pollutants for which such vaccination data exists, including polychlorinated biphenyls (PCBs) and perfluorinated alkylate substances (PFAS), which are described individually. In general, elevated exposures to these compounds were associated with reduced humoral immune response to routine childhood immunizations. The prenatal and early postnatal exposure to PCB were most immunotoxic, possible through toxicity toward the developing immune system of young infants, while the contemporary exposure to PFAS reduces the antibody levels in a more direct manner. The presented results in this chapter might explain some of the wide variation in antibody responses to immunization and support the hypothesis that some people today could be immunocompromised because of their exposure to environmental pollutants. Due to their high persistence, PCBs and PFAS will remain widespread in the environment, but the presented evidence of immunotoxicity indicates that human exposure to these chemicals should be limited to protect the human immune system throughout its lifetime.
During the last two decades, engineered nanomaterial/nanoparticles have emerged in different fields of our daily life. In fact they are used for a variety of applications, such as colour pigments, solar cells, and waste water treatment. Furthermore, nanoparticles are found in consumer products that may be in contact with the human organism, e.g., food packaging, shampoos, sunscreens, toothpastes, and cigarettes. Thus, it is of great importance to evaluate how nanoparticles interact both with human beings and with the environment, considering that nanoparticles are assimilated as waste in the environment and introduced in the food chain. In assessing nanoparticle safety, their possible effects on immune responses are a major issue, since the immune system is deputed to defending and maintaining the integrity of the body, and its failure is the cause of damage and disease. This brief review will focus on the effects of nanoparticles on immunity, with a special focus on human health, but also include immunity of environmental species (such as marine and earth invertebrates) as a key tool in predicting environmental nanosafety.
The German reunification gave the unique opportunity to investigate the development of allergies in two population groups with similar genetic background but a different environment. Three surprising results were gained in epidemiological comparison studies done in Germany after 1989:1. The prevalence of allergies was higher in West than in East Germany. This was especially true for diagnoses of hay fever and birch pollen sensitization. 2. Allergies in East Germany increased after the reunification in spite of decreasing traditional outdoor air pollution with sulfur dioxide and coarse particles. 3. The change to more favorable indoor conditions in East Germany did not lead to fewer allergies. Unexpectedly unfavorable indoor conditions like single room heating and crowding were associated with less hay fever and pollen sensitization and partly explained the observed trends in allergy development. The results gained in the East–West comparison studies were driving forces for a change in the paradigms of allergy research.
Air pollution represents an important environmental risk factor for a number of health conditions. Particulate matter and gaseous compounds increase the risk of chronic and acute respiratory diseases, cardiovascular disease and lung cancer. Additional studies indicate that long-term exposure to air pollutants also contributes to the development and progression of type 2 diabetes. As the most common metabolic disease, type 2 diabetes and its chronic complications are important determinants of morbidity and mortality worldwide. This article aims to provide an overview of the currently available data on the relationship between air pollution and type 2 diabetes with specific focus on epidemiological studies. Inflammatory processes have been discussed as mechanisms that mediate this association. Therefore, we first discuss the role of subclinical inflammation in the pathogenesis of type 2 diabetes and subsequently the impact of air pollutants on the immune system. We conclude that despite accumulating evidence linking (i) air pollution and proinflammatory processes, (ii) air pollution and risk of type 2 diabetes and (iii) subclinical inflammation and type 2 diabetes, there is a surprising lack of studies addressing this complex relationship in prospective cohorts. Therefore, it is currently not possible to quantify which proportion of the risk of type 2 diabetes can be attributed to air pollution-related immune activation and to what extent the risk of type 2 diabetes can be reduced by reducing air pollution levels.
Mercury is a ubiquitous environmental contaminant. Exposures to mercury occur globally and pose significant threats to human health. Mercury toxicity to the nervous system has been extensively studied, and risks to human health as a result of mercury exposure have been evaluated on this basis, especially for exposures at high doses. Data from experimental models, such as rodent systems, suggest that mercury may also have a significant effect on the function of the immune system. However, little is known about the risks posed to human health as a result of mercury immunotoxicity, mainly due to variations in dose, route of exposure, and differences between the rodent and human immune systems. The evidence for mercury as an immunotoxic agent is reviewed here, specifically in the context of human exposures to mercury and the relevance of models of mercury immunotoxicity to human health. In light of evidence that mercury may affect the immune system, the influence of the immune system in other organ systems targeted by mercury is also reviewed.
Autoimmune diseases are comprehensive models of complex conditions in which an individual’s genetic susceptibility is necessary but not sufficient to explain disease onset, perpetuation, and severity. This is well represented by the variable but invariably incomplete concordance rates for all autoimmune diseases in monozygotic twins. In the broad group of autoimmune diseases, heritability ranges between 0.008 and 1 with median values of approximately 0.60. A complementary term coined “environmentability” may well represent the environmental influence on the individual phenotype and can include dietary habits, chemicals, or hygienic conditions via several molecular and epigenetic mechanisms. Numerous environmental factors have been proposed for systemic and organ-specific autoimmune diseases. The National Institute of Environmental Health Sciences (NIEHS) convened an expert panel workshop to review the body of literature examining the role of the environment in the development of autoimmune disease and to identify conclusions, certainties, and critical knowledge gaps in this area. The results of the workshop and the literature illustrate that several kinds of epidemiological, mechanistic, and model evidence support specific chemical and physical factors as well as infectious agents.
Well before the mechanisms were understood, pulmonary immune diseases had been associated with environmental chemicals, i.e., air contaminants. During the second half of the twentieth century, purpose and function of the different components of the immune system as well as their interactions with chemicals were extensively investigated and ultimately understood in more detail. In addition to a deeper understanding of immunological interactions and mechanisms, a series of accidents involving immunotoxic compounds pushed the development of immunotoxicological science in the last century.
National constitutions throughout the world contain enumerated rights and freedoms for individuals residing within the state’s territory or subject to its jurisdiction. In the twentieth century, the international community increasingly recognized that such constitutional guarantees sometimes prove inadequate or even illusory when military coups, armed conflicts, or repressive governments disrupt or deliberately ignore the rule of law, including constitutional limits on the exercise of power. Responding to this awareness, international and regional organizations created or reformed after the Second World War recognized that human rights must be considered a matter of international concern if individuals and groups are to be ensured their fundamental rights and freedoms. With the leadership of a group of states and strong advocacy from civil society groups, intergovernmental organizations began elaborating the international law of human rights.
... All organisms, including humans, have developed evolutionary strategies such as immunity, to prevent damage against bacterial, viral, and fungal pathogens [1,2]. The immune system is different from other organs, because it is distributed across the entire body and comprises organ structures, cells, and molecules such as antibodies and cytokines. ...
... The immune system is different from other organs, because it is distributed across the entire body and comprises organ structures, cells, and molecules such as antibodies and cytokines. It has a vast array of functionally different cells, including T and B lymphocytes, macrophages, neutrophils, mast cells [1][2][3]. The immune system, bone marrow, thymus, lymph nodes and the spleen, all form developmental niches for immune and blood cell development (hematopoiesis) and act as contact centers for interaction of immune cells. ...
... The immune system, bone marrow, thymus, lymph nodes and the spleen, all form developmental niches for immune and blood cell development (hematopoiesis) and act as contact centers for interaction of immune cells. Interestingly, the immune system is constantly renewing itself from hematopoietic stem cells, and the highly organized differentiation of cells is an important functional feature of immune responses [1][2][3]. The immune responses not only entail immune activation but also spend much effort on immunosuppression. ...
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The immune system is comprised of lymph glands, lymph nodes, thymus gland, spleen, bone marrow, lymphocytes, and molecules such as antibodies and cytokines. It has a vast array of functionally different cells such as T and B lymphocytes, macrophages, neutrophils and mast cells. The ontogenesis of the immune system is comprised of the innate immune cells and the adaptive immune cells, where innate immune cells are the first defense mechanisms to respond to pathogenic environmental factors. There are multiple components of the adaptive immune cells, including immunoglobulins (Igs), T-cell receptors (TCR), and major histocompatibility complex (MHC) responsible for adaptive immunity. However, many elements of both the innate and adaptive immune systems are conserved in our bodies. The adaptive immunity is a type of immunity that develops when a person’s immune cells respond to a pathogen such as microorganism or vaccination. Environmental factors such as pathogenic bacteria or viruses, solar exposure, age, exercise, stress, diet, sleep quality and air pollutants can influence the immune system. There may be marked decline in the immune function due to attack of COVID-19. Most patients with mild COVID-19 develop an appropriate immune response that culminates with viral clearance. However, severe disease manifestations have been linked to lymphopenia and immune hyper-responsiveness leading to cytokine storm. It has been observed that in COVID-19, alveolar macrophages are epigenetically altered after inflammation, leading to long-term lung immune paralysis. Western diets are known to have adverse effects on the immune function. However, Mediterranean-type diets rich in short- and long-chain polyunsaturated fatty acids (PUFA), vegetables, nuts and fruits, dairy products and fish and red wine, due to high content of vitamins, minerals and flavonoids may be useful in boosting immunity. Moderate physical activity may also cause an extensive increase in numerous and varied lipid super-pathway metabolites, including oxidized derivatives called oxylipins. Emerging evidence suggests that dietary supplements containing flavonoids, carotenoids, coenzyme Q10 (CoQ10), vitamins, minerals and antioxidants modulate gene and protein expression and thereby modify endogenous metabolic pathways, and consequently enhance the immunity. Mediterranean-type diet and multiple bioactive nutrients, fatty acids, amino acids, vitamins and minerals as well as moderate physical activity may be crucial for enhancing immunomodulation.
... The elemental form of mercury (Hg 0 ) is rarely present in water as this form is highly volatile and less bioavailable. Inorganic mercury includes Hg + and Hg +2 compounds generally found in dental amalgams, fungicides, cosmetic products, paints, and some tattoo dyes (Esser 2016). Inorganic mercury is converted into organic forms (such as methylmercury, ethylmercury, and phenylmercury) by either photochemical reaction or by sulfate-reducing bacteria inhabiting sediment and gill and gut of fish (Okpala et al. 2018). ...
... Intake of Hg contaminated food by the human can severely affect their vital systems. Even low concentration of Hg exposure is associated with neurological (Ursinyova et al. 2019), immunological (Esser 2016), renal (Ursinyova et al. 2019), cardiovascular, developmental (Zheng et al. 2019), and reproductive abnormalities (Zahir et al. 2005). Hg can severely affect the development of fetuses, infants, and children through mother and may cause retarded developmental and learning abilities (Zheng et al. 2019). ...
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India is the second largest fish producer in the world. This review takes into account the observations from the open literature about the metal (loid) concentrations of Indian freshwater and marine fish species. Metal (loid) concentrations in edible part (muscle) of Indian fish species were compared with the international standards, and the higher metal accumulating species were considered for bioindicator studies. The freshwater species Aorichthys aor, Heteropneustes fossilis, Labeo rohita, Mastacembelus armatus, and Triplophysa kashmirensis were regarded as bioindicator species for freshwater ecosystems of India. However, Arius parkii, Cynoglossus spp., Gerres oyena, Lates calcarifer, Liza parsia, Mugil cephalus, and Nemipterus japonicus were considered as bioindicators of Indian marine ecosystems.KeywordsIndiaFreshwaterMarineFish speciesBioindicator
... Given the homeostatic function of immune system, the immune system's balance can be abrogated by the environmental factors. These include a vast range of elements including metals, air pollution, pesticides, antibiotics, microorganism, nutrition, starvation, chronic noise, life style, sedentary behavior, chronic psychological stress, hyperthermia/ hypothermia, and trauma [1][2][3][4][5][6]. Such disturbances may selectively affect any part of the body by a yet unknown mechanism. ...
... Effects of environmental elements even can pass blood brain barrier (BBB) [6]. On this basis, it is presumed that no part of the body is out of the reach of environmental elements that along with genetic background affect functional balance of the immune system [2,5]. In this regard the relationship and connection between peripheral and central nervous system (CNS) immune response is worth noting. ...
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The brain has special importance and is known as immune privileged site to and from which trafficking of immune cells is tightly regulated. However, in Alzheimer's disease (AD) the balance of the immune system is disturbed and damages the brain. Given the anatomical and immunological barriers in the brain, we attempted to evaluate if the neuroinflammation occurred in AD is limited to the brain or is expanded to the periphery. Hence, rat model of AD was induced by intra-hippocampal injection of beta-amyloid1-42. Then, nasal, brain, cervical lymph nodes, and spleen were isolated. Then, profile of T-helper (Th)1, Th2, and Th17, represented by IFN-γ, IL-4, and IL-17, respectively, was determined. The results were compared between the organs and with the corresponding tissue in normal animals. IFN-γ and IL-17 levels in the brain, nasal tissue, and cervical lymph nodes of AD model were higher than IL-4, comparing with normal animals. Similar profile was observed in the spleen. The results suggest Alzheimer's as a systemic disease whose complication are observed locally. The possibility of epitope spreading and autoimmune nature of AD is raised again. Interestingly, although AD model was induced by injection of beta-amyloid in the brain, the cellular responses in the brain and nasal tissue were similar indicating that the nasal-brain axis is two-sided. In addition, both of IFN-γ/IL-17 and IL-4/IL-17 ratios, just in nasal tissue were markedly decreased in AD model comparing with normal animals. This suggests development of future nasal-based diagnostic approaches.
... Virtually, they can influence every physiological system including neuroendocrine interactions, neurotransmitter metabolism and neuroplasticity, thereby affecting behavioral and cognitive functioning [140]. Cytokines take center stage in orchestrating immune responses [141]. Injection of the vaccines results in a strong expression of proinflammatory cytokines. ...
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Background: Post-vaccination adverse reactions (AEs) are a reason of strong debate among scientists. Unfortunately, we often make the mistake of discussing just the epidemiology but not the molecular biology. The action mechanism of the vaccines is still not fully known despite the fact that aluminum adjuvants have been used for about 100 years. Hypothesis: We hypothesized a link between vaccinations and neuroinflammation. The peripheral proinflammatory cytokines (IL-1β, IL-6, and TNF-α), expressed after the injection of the vaccines can reach the brain and can cause neuroinflammation after microglia activation. Elevated pro-inflammatory cytokines, particularly TNF-α, have been described in studies regarding the cytokines profile in autistic children. IL-1β represents a cytokine that controls the local pro-inflammatory cascade and thereby affects the balance between protective immunity and destructive inflammation. A subgroup of children with ASD (Autism Spectrum Disorder) has developed neuroinflammation. Several postmortem studies have confirmed the activation of microglia and neuroinflammation. A recent study has shown the presence of aluminum in the brain of individuals with autism and this aluminum was also found in microglia cells. Aluminum from vaccines is redistributed to numerous organs, including brain, where it accumulates. Each vaccine adds to this tissue different level of aluminum. Aluminum, like mercury, activates microglia leading to chronic brain inflammation and neurotoxicity. Conclusion: The molecular mechanisms presented here demonstrate how peripheral cytokines, expressed after vaccination, can cause neuroinflammation in some subjects, after microglia activation, depending on the immunogenetic background and the innate immune memory.
... Exercise not only increases the supply of oxygenated blood to a metabolically expensive brain, but also increases serum neurotrophic factors and BDNF (Heisz et al. 2017;Liang et al. 2021) which, in turn, contribute to potential neurogenesis and enhanced cognitive abilities through a series of complex biochemical cascades (Horowitz et al. 2020). Moreover, exercise generally has a positive influence on the immune system, leading to a reduction in inflammatory biomarkers, and increases in antioxidant defenses (Gomes and Florida-James 2016). Finally, as reviewed by van Praag et al. (2000), exercise appears to enhance the activity of several neurotransmitter systems in rats: (1) cholinergic functioning in the hippocampus, which improves spatial learning (Fordyce and Farrar 1991), (2) opioid activity, which modulates pain (Sforzo et al. 1986), and (3) monoamine functioning (noradrenaline and serotonin), which contributes to learning and synaptic plasticity (Chaouloff 1989). ...
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The present review assesses the potential neural impact of impoverished, captive environments on large-brained mammals, with a focus on elephants and cetaceans. These species share several characteristics, including being large, wide-ranging, long-lived, cognitively sophisticated, highly social, and large-brained mammals. Although the impact of the captive environment on physical and behavioral health has been well-documented, relatively little attention has been paid to the brain itself. Here, we explore the potential neural consequences of living in captive environments, with a focus on three levels: (1) The effects of environmental impoverishment/enrichment on the brain, emphasizing the negative neural consequences of the captive/impoverished environment; (2) the neural consequences of stress on the brain, with an emphasis on corticolimbic structures; and (3) the neural underpinnings of stereotypies, often observed in captive animals, underscoring dysregulation of the basal ganglia and associated circuitry. To this end, we provide a substantive hypothesis about the negative impact of captivity on the brains of large mammals (e.g., cetaceans and elephants) and how these neural consequences are related to documented evidence for compromised physical and psychological well-being.
... Many studies from modern medical science show how fear results in breakdown of immunity -which is the only factor that matters in a fight against virus. Reed and Raison (2016), and the works cited therein, have presented a detailed analysis of how continued stress leads to dysregulation of neuroendocrine and immune systems. 4 Persistent fear leads to a Generalized Anxiety Disorder (GAD). ...
Article
This paper reflects on the current Covid-19 crisis and the emotional stress that it leads to from the Jaina perspective. It demonstrates that any pandemic like situation is concomitant with a pandemic of emotions as well; fear and stress being prominent of them. The problem of fear is grave and must be dealt with equal measures. The concept of fear is thus analysed from various perspectives as gleaned from the diverse range of Jaina texts. The paper attempts to make the philosophical texts come alive into the current situation and shows how a samyagdṛṣṭi remains unaffected (though, not absolutely) and mithyādṛṣṭi goes through constant turmoil despite facing the same circumstances. This can be further seen as a case of applied philosophy and ethics.
... There is a great communication between the environment and the immune system. Many environmental factors can be of effects on immune system such as such as bacteria, sun exposure, age, exercise, stress and air pollution (Esser, 2016). It is thought that prior exposure to moderate coronaviruses may play a part in kids' comparative COVID-19 edge over adults. ...
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COVID-19 pandemic caused by SARS-CoV-2, continues to manifest with severe acute respiratory syndrome among the adults, however, it offers a convincing indication of less severity and fatality in pedi-atric age group (0-18 years). The current trend suggests that children may get infected but are less symptomatic with less fatality, which is concordant to earlier epidemic outbreaks of SARS-CoV and
... There is a great communication between the environment and the immune system. Many environmental factors can be of effects on immune system such as such as bacteria, sun exposure, age, exercise, stress and air pollution (Esser, 2016). It is thought that prior exposure to moderate coronaviruses may play a part in kids' comparative COVID-19 edge over adults. ...
Full-text available
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COVID-19 pandemic caused by SARS-CoV-2, continues to manifest with severe acute respiratory syndrome among the adults, however, it offers a convincing indication of less severity and fatality in pediatric age group (0-18 years). The current trend suggests that children may get infected but are less symptomatic with less fatality, which is concordant to earlier epidemic outbreaks of SARS-CoV and MERS-CoV, in 2002 and 2012, respectively. According to the available data, children appear to be at lower risk for COVID-19, as adults constitute for maximum number of the confirmed cases (308,592) and deaths (13,069) as on 22nd March (https://www.worldometers.info/coronavirus). However, rapid publications and information of the adult patients with COVID-19 is in progress and published, on the contrary, almost no comprehensive data or discussion about the COVID-19 in children is available. Therefore, in this review, we outline the epidemiology, clinical symptoms, diagnosis, treatment, prevention, possible immune response and role of thymus in children to combat the COVID-19 outbreak. Keywords ChildrenCoronavirusesCOVID-19ImmunityPandemicThymus
... Воздействие токсических веществ на тимоциты может осуществляться как непосредственно, так и опосредованно через высвобождение кортикостероидов [20]. Изменения гистологического строения вилочковой железы считаются особенно информативными для определения иммунотоксичности различных веществ [12]. ...
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The aim of the article is to study the morphological features of the thymus of the white rats exposed to the inhalation of formaldehyde. Material and methods. 72 white male rats with an initial body weight of 130–150 g were were exposed to formaldehyde at a concentration of 2.766 mg/m3. Exposures were carried out once a day during 60 minutes. Exposure durations were 10, 20, 30, 60 and 90 days. We separately studied the thymus of rats, which, after 60 days of exposure to formaldehyde, were kept for 30 days in standard vivarium conditions (rehabilitation group). The structure of the thymus was studied by light microscopy. Results. The number of cells in an area of 2500 μm2 of the subcapsular zone in animals exposed to formaldehyde for 10, 20, and 30 days was 131.19±4.20, 135.65±7.74, and 135.35±10.83, respectively, which was less than the control set by 4.35%, 4.68% and 3.72%, respectively. After 40 and 60 days, this indicator was below the control by 8.90% and 9.63%. Conclusion. Inhalation of formaldehyde reduces the area of the thymus cortex. Phenomena of inversion of the cortex and the medulla are observed. Under the influence of formaldehyde, a picture of so called «starry sky» is observed in the cortical substance of the thymus. A decrease in the severity of changes in the thymus of rats belonging to the rehabilitation group, in comparison with animals that received 90 exposures, indicates that the changes are reversible.
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Wide range of Antibiotics is being used as feed additives in Animal industry in order to get rid from pathogens and as growth promoters in developing world. But after the suggested prohibition on using antibiotics, products such as probiotics are getting substantial importance in nutrition because of their non-resistant and non-residual possessions. Basic aim of the chapter is to highlight fruitful effects of Bacillus Subtilis as non-antibiotic gut modulator and growth promoter in broiler chickens. Probiotics are the living culture of microorganisms. They flourish in the gut of the host and fortify the growth of valuable commensals in the digestive tract by minimizing the destruction triggered by pathogens, boost up the immune system, supporting the integrity of the gut mucosa and maintain a stability and balance of normal microflora. Probiotics can be used as best substitute to conventional antimicrobial therapy. In addition, it has been observed that probiotics plays a role in growth enhancement by augmenting useful enzymes in the body and promote the growth of other normal commensals such as Lactobacillus and having effect on gut luminal pH. Probiotics are quite active against intestinal pathogens in several ways, viz. including improved immune elimination, competing for mucosal attachment, striving for crucial nutrients, or producing antimicrobial complexes contrary to numerous enteropathogens. It can be concluded that B. Subtilis has the ability to modulate gut and immune system histophysiology and histomorphology and can be used as safe antimicrobial candidate in poultry nutrition. Knowledge of such possessions of the B. Subtilis as probiotics and the mechanisms of action may enable the researchers to manipulate the use of such alternatives for better growth production, and safe and healthy poultry industry.
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Ecoimmunology is a rapidly developing field that explores how the environment shapes immune function, which in turn influences host–parasite relationships and disease outcomes. Host immune defence is a key fitness determinant because it underlies the capacity of animals to resist or tolerate potential infections. Importantly, immune function can be suppressed, depressed, reconfigured or stimulated by exposure to rapidly changing environmental drivers like temperature, pollutants and food availability. Thus, hosts may experience trade-offs resulting from altered investment in immune function under environmental stressors. As such, approaches in ecoimmunology can provide powerful tools to assist in the conservation of wildlife. Here, we provide case studies that explore the diverse ways that ecoimmunology can inform and advance conservation efforts, from understanding how Galapagos finches will fare with introduced parasites, to using methods from human oncology to design vaccines against a transmissible cancer in Tasmanian devils. In addition, we discuss the future of ecoimmunology and present 10 questions that can help guide this emerging field to better inform conservation decisions and biodiversity protection. From better linking changes in immune function to disease outcomes under different environmental conditions, to understanding how individual variation contributes to disease dynamics in wild populations, there is immense potential for ecoimmunology to inform the conservation of imperilled hosts in the face of new and re-emerging pathogens, in addition to improving the detection and management of emerging potential zoonoses.
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The gastrointestinal tract of humans and swine consist of a wide range of bacteria which interact with hosts metabolism. Due to the differences in co-evolution and co-adaptation, a large fraction of the gut microbiome is host-specific. In this study, we evaluated the effect of close human-animal interaction to the faecal metagenome and metabonome of swine, farmer and human control. Three distinct clusters were observed based on T-RFLP-derived faecal microbial composition. However, 16S-inferred faecal microbiota and metabolic profiles showed that only human control was significantly different from the swine (P < 0.05). The metabonome of farmers and human controls were highly similar. Notably, higher trimethylamine N-oxide (TMAO) and butyrate were detected in human control and swine, respectively. The relative abundance of TMAO was positively correlated with Prevotella copri. Overall, we compared and established the relationship between the metabolites and microbiota composition of swine, farmers and human control. Based on the data obtained, we deduced that long term occupational exposure to swine and farm environment had affected the gut bacterial composition of farmers. Nonetheless, the effect was less prominent in the metabolite profiles, suggesting the gut bacteria expressed high functional plasticity and are therefore resilience to the level of community shift detected.
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Background: The body composition and cardiorespiratory fitness are two important factors that reflect nutritional and physical activity status, respectively. An increase in body fat stores can lead to systemic inflammation. The aim of this study was investigation of relationship between plasma IL-18 and cardiorespiratory fitness, body composition, lipid profile and dietary composition. Methods: A total 90 (37 women, 53 men) employee of Islamic Azad University, Ahvaz branch (BMI> 25 kg/m2) was enrolled in present study. The bioelectrical impedance used for measurement of body composition. Cardiorespiratory fitness measured by Forestry step test. The 24-hour recall questionnaires used for evaluation of Dietary composition. The lipid profile, fasting sugar and plasma IL-18 were also evaluated. The significant level was determined p<0.05. Results: Plasma IL-18 was significantly and negatively related to VO2max (p≤0.02). Also, there is a positive significant relationship between IL-18 and BMI (p≤0.001) and WHR (p≤0.031). The dietary composition and lipid profile had no significant correlation with IL-18 and VO2max. The fat and total energy intake negatively related to plasma HDL. There is a positive significant correlation between WHR and BMI with fat and total energy intake. Conclusion: In summary, the results of present study demonstrate that high VO2max and low BMI and WHR are predictors of low IL-18 and systemic inflammation.
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This chapter provides an overview of the ontogeny and aging of the human mucosal immune system. Anatomically, the human mucosal immune system begins to develop early in gestation. Components of the system can be histologically recognized as early as 40 days of gestation. The system continues to develop throughout fetal life and into early childhood. At birth all the essential components of the mucosal immune system are present and have the potential to respond to antigenic stimulation. The development of effective mucosal immunity essentially occurs in the postnatal period. After birth the ontogeny of mucosal immunity is influenced by a number of factors, including neonatal feeding practices, nutrition and diet, vaccination, and exposure to infection, as well as maternal factors that occurred in utero and postnatally. Events during the first year of life determine the development of mucosal immunity, and links between ontogeny profiles and clinical disease are emerging. Salivary immunoglobulin A (IgA) and immunoglobulin M (IgM) levels and the incidence of transient salivary IgA deficiency in ontogeny have potential diagnostic value in predicting disease outcomes. In the elderly the acquired mucosal immune system remains competent; however, some loss of innate defenses occurs, such as decreased lysozyme levels in secretions and diminished function secondary to the physiological changes of aging. It appears that increased susceptibility to infection in the aged is primarily a consequence of environmental factors and declining systemic immunity.
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