Apoptotic Cells Induced Signaling for Immune Homeostasis in Macrophages and Dendritic Cells

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Uriel Trahtemberg

2017-10-01

Full Text Available Inefficient and abnormal clearance of apoptotic cells (efferocytosis contributes to systemic autoimmune disease in humans and mice, and inefficient chromosomal DNA degradation by DNAse II leads to systemic polyarthritis and a cytokine storm. By contrast, efficient clearance allows immune homeostasis, generally leads to a non-inflammatory state for both macrophages and dendritic cells (DCs, and contributes to maintenance of peripheral tolerance. As many as 3 × 108 cells undergo apoptosis every hour in our bodies, and one of the primary “eat me” signals expressed by apoptotic cells is phosphatidylserine (PtdSer. Apoptotic cells themselves are major contributors to the “anti-inflammatory” nature of the engulfment process, some by secreting thrombospondin-1 (TSP-1 or adenosine monophosphate and possibly other immune modulating “calm-down” signals that interact with macrophages and DCs. Apoptotic cells also produce “find me” and “tolerate me” signals to attract and immune modulate macrophages and DCs that express specific receptors for some of these signals. Neither macrophages nor DCs are uniform, and each cell type may variably express membrane proteins that function as receptors for PtdSer or for opsonins like complement or opsonins that bind to PtdSer, such as protein S and growth arrest-specific 6. Macrophages and DCs also express scavenger receptors, CD36, and integrins that function via bridging molecules such as TSP-1 or milk fat globule-EGF factor 8 protein and that differentially engage in various multi-ligand interactions between apoptotic cells and phagocytes. In this review, we describe the anti-inflammatory and pro-homeostatic nature of apoptotic cell interaction with the immune system. We do not review some forms of immunogenic cell death. We summarize the known apoptotic cell signaling events in macrophages and DCs that are related to toll-like receptors, nuclear factor kappa B, inflammasome, the lipid

How (and why) the immune system makes us sleep.

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Imeri, Luca; Opp, Mark R

2009-03-01

Good sleep is necessary for physical and mental health. For example, sleep loss impairs immune function, and sleep is altered during infection. Immune signalling molecules are present in the healthy brain, where they interact with neurochemical systems to contribute to the regulation of normal sleep. Animal studies have shown that interactions between immune signalling molecules (such as the cytokine interleukin 1) and brain neurochemical systems (such as the serotonin system) are amplified during infection, indicating that these interactions might underlie the changes in sleep that occur during infection. Why should the immune system cause us to sleep differently when we are sick? We propose that the alterations in sleep architecture during infection are exquisitely tailored to support the generation of fever, which in turn imparts survival value.

Targeting Cannabinoid Signaling in the Immune System: “High”-ly Exciting Questions, Possibilities, and Challenges

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Attila Oláh

2017-11-01

Full Text Available It is well known that certain active ingredients of the plants of Cannabis genus, i.e., the “phytocannabinoids” [pCBs; e.g., (−-trans-Δ9-tetrahydrocannabinol (THC, (−-cannabidiol, etc.] can influence a wide array of biological processes, and the human body is able to produce endogenous analogs of these substances [“endocannabinoids” (eCB, e.g., arachidonoylethanolamine (anandamide, AEA, 2-arachidonoylglycerol (2-AG, etc.]. These ligands, together with multiple receptors (e.g., CB1 and CB2 cannabinoid receptors, etc., and a complex enzyme and transporter apparatus involved in the synthesis and degradation of the ligands constitute the endocannabinoid system (ECS, a recently emerging regulator of several physiological processes. The ECS is widely expressed in the human body, including several members of the innate and adaptive immune system, where eCBs, as well as several pCBs were shown to deeply influence immune functions thereby regulating inflammation, autoimmunity, antitumor, as well as antipathogen immune responses, etc. Based on this knowledge, many in vitro and in vivo studies aimed at exploiting the putative therapeutic potential of cannabinoid signaling in inflammation-accompanied diseases (e.g., multiple sclerosis or in organ transplantation, and to dissect the complex immunological effects of medical and “recreational” marijuana consumption. Thus, the objective of the current article is (i to summarize the most recent findings of the field; (ii to highlight the putative therapeutic potential of targeting cannabinoid signaling; (iii to identify open questions and key challenges; and (iv to suggest promising future directions for cannabinoid-based drug development.

The essential role of G protein-coupled receptor (GPCR) signaling in regulating T cell immunity.

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Wang, Dashan

2018-06-01

The aim of this paper is to clarify the critical role of GPCR signaling in T cell immunity. The G protein-coupled receptors (GPCRs) are the most common targets in current pharmaceutical industry, and represent the largest and most versatile family of cell surface communicating molecules. GPCRs can be activated by a diverse array of ligands including neurotransmitters, chemokines as well as sensory stimuli. Therefore, GPCRs are involved in many key cellular and physiological processes, such as sense of light, taste and smell, neurotransmission, metabolism, endocrine and exocrine secretion. In recent years, GPCRs have been found to play an important role in immune system. T cell is an important type of immune cell, which plays a central role in cell-mediated immunity. A variety of GPCRs and their signaling mediators (RGS proteins, GRKs and β-arrestin) have been found to express in T cells and involved T cell-mediated immunity. We will summarize the role of GPCR signaling and their regulatory molecules in T cell activation, homeostasis and function in this article. GPCR signaling plays an important role in T cell activation, homeostasis and function. GPCR signaling is critical in regulating T cell immunity.

Network modeling reveals prevalent negative regulatory relationships between signaling sectors in Arabidopsis immune signaling.

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Masanao Sato

Full Text Available Biological signaling processes may be mediated by complex networks in which network components and network sectors interact with each other in complex ways. Studies of complex networks benefit from approaches in which the roles of individual components are considered in the context of the network. The plant immune signaling network, which controls inducible responses to pathogen attack, is such a complex network. We studied the Arabidopsis immune signaling network upon challenge with a strain of the bacterial pathogen Pseudomonas syringae expressing the effector protein AvrRpt2 (Pto DC3000 AvrRpt2. This bacterial strain feeds multiple inputs into the signaling network, allowing many parts of the network to be activated at once. mRNA profiles for 571 immune response genes of 22 Arabidopsis immunity mutants and wild type were collected 6 hours after inoculation with Pto DC3000 AvrRpt2. The mRNA profiles were analyzed as detailed descriptions of changes in the network state resulting from the genetic perturbations. Regulatory relationships among the genes corresponding to the mutations were inferred by recursively applying a non-linear dimensionality reduction procedure to the mRNA profile data. The resulting static network model accurately predicted 23 of 25 regulatory relationships reported in the literature, suggesting that predictions of novel regulatory relationships are also accurate. The network model revealed two striking features: (i the components of the network are highly interconnected; and (ii negative regulatory relationships are common between signaling sectors. Complex regulatory relationships, including a novel negative regulatory relationship between the early microbe-associated molecular pattern-triggered signaling sectors and the salicylic acid sector, were further validated. We propose that prevalent negative regulatory relationships among the signaling sectors make the plant immune signaling network a "sector

METHODS OF PROVIDING NOISE IMMUNITY IN AUTOMOBILE ANTI-THEFT SYSTEM CONTROL

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Frolov, V.

2013-06-01

Full Text Available In modern ani-theft systems they use frequency and phase modulation. Since the width of the signal is limited, it is possible to intercept the signal and then switch off the alarm at the right time.To ensure the noise immunity and secrecy manufacturers use more sophisticated codes using the methods of cryptography. Significant increase in noise immunity in modern ani-theft systems is possible using broadband signals.

Viral subversion of the immune system

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Gillet, L.; Vanderplasschen, A.

2005-01-01

The continuous interactions between host and viruses during their co-evolution have shaped not only the immune system but also the countermeasures used by viruses. Studies in the last decade have described the diverse arrays of pathways and molecular targets that are used by viruses to elude immune detection or destruction, or both. These include targeting of pathways for major histocompatibility complex class I and class II antigen presentation, natural killer cell recognition, apoptosis, cytokine signalling, and complement activation. This paper provides an overview of the viral immune-evasion mechanisms described to date. It highlights the contribution of this field to our understanding of the immune system, and the importance of understanding this aspect of the biology of viral infection to develop efficacious and safe vaccines. (author)

Regulation of vitamin D homeostasis: implications for the immune system.

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van Etten, Evelyne; Stoffels, Katinka; Gysemans, Conny; Mathieu, Chantal; Overbergh, Lut

2008-10-01

Vitamin D homeostasis in the immune system is the focus of this review. The production of both the activating (25- and 1alpha-hydroxylase) and the metabolizing (24-hydroxylase) enzymes by cells of the immune system itself, indicates that 1,25(OH)(2)D(3) can be produced locally in immune reaction sites. Moreover, the strict regulation of these enzymes by immune signals is highly suggestive for an autocrine/paracrine role in the immune system, and opens new treatment possibilities.

Cyclic Dinucleotides in the Scope of the Mammalian Immune System.

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Mankan, Arun K; Müller, Martina; Witte, Gregor; Hornung, Veit

2017-01-01

First discovered in prokaryotes and more recently in eukaryotes, cyclic dinucleotides (CDNs) constitute a unique branch of second messenger signaling systems. Within prokaryotes CDNs regulate a wide array of different biological processes, whereas in the vertebrate system CDN signaling is largely dedicated to activation of the innate immune system. In this book chapter we summarize the occurrence and signaling pathways of these small-molecule second messengers, most importantly in the scope of the mammalian immune system. In this regard, our main focus is the role of the cGAS-STING axis in the context of microbial infection and sterile inflammation and its implications for therapeutic applications.

Metabolic signals and innate immune activation in obesity and exercise.

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Ringseis, Robert; Eder, Klaus; Mooren, Frank C; Krüger, Karsten

2015-01-01

The combination of a sedentary lifestyle and excess energy intake has led to an increased prevalence of obesity which constitutes a major risk factor for several co-morbidities including type 2 diabetes and cardiovascular diseases. Intensive research during the last two decades has revealed that a characteristic feature of obesity linking it to insulin resistance is the presence of chronic low-grade inflammation being indicative of activation of the innate immune system. Recent evidence suggests that activation of the innate immune system in the course of obesity is mediated by metabolic signals, such as free fatty acids (FFAs), being elevated in many obese subjects, through activation of pattern recognition receptors thereby leading to stimulation of critical inflammatory signaling cascades, like IκBα kinase/nuclear factor-κB (IKK/NF- κB), endoplasmic reticulum (ER) stress-induced unfolded protein response (UPR) and NOD-like receptor P3 (NLRP3) inflammasome pathway, that interfere with insulin signaling. Exercise is one of the main prescribed interventions in obesity management improving insulin sensitivity and reducing obesity- induced chronic inflammation. This review summarizes current knowledge of the cellular recognition mechanisms for FFAs, the inflammatory signaling pathways triggered by excess FFAs in obesity and the counteractive effects of both acute and chronic exercise on obesity-induced activation of inflammatory signaling pathways. A deeper understanding of the effects of exercise on inflammatory signaling pathways in obesity is useful to optimize preventive and therapeutic strategies to combat the increasing incidence of obesity and its comorbidities. Copyright © 2015 International Society of Exercise and Immunology. All rights reserved.

[Zinc signaling : a novel regulatory system on bone homeostasis, and immune and allergic responses].

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Fukada, Toshiyuki; Nishida, Keigo; Yamasaki, Satoru; Hojyo, Shintaro

2012-11-01

Zinc (Zn) is an essential trace element that is required for proliferation, differentiation, and variety of cellular functions, and unbalanced homeostasis of Zn ion (Zn(2 + )) results in health problems such as abnormal bone formation and immunodeficiency. Recent studies have shed light on important roles of Zn(2 + )as a signaling mediator, called Zn signal. Zn(2 + )homeostasis is regulated through Zn transporters and cation channels. Advances of genetic and molecular approaches have revealed that Zn signal regulates mammalian physiology and pathogenesis. We will address that Zn signal undoubtedly contributes to our health, by highlighting it in bone homeostasis and immune regulation, and discuss that the "Zn signal axis" selectively controls intracellular signal transduction to fine-tune cellular functions.

Ageing and the immune system: focus on macrophages.

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Linehan, E; Fitzgerald, D C

2015-03-01

A fully functioning immune system is essential in order to maintain good health. However, the immune system deteriorates with advancing age, and this contributes to increased susceptibility to infection, autoimmunity, and cancer in the older population. Progress has been made in identifying age-related defects in the adaptive immune system. In contrast, relatively little research has been carried out on the impact of ageing on the innate immune response. This area requires further research as the innate immune system plays a crucial role in protection against infection and represents a first line of defence. Macrophages are central effector cells of the innate immune system and have many diverse functions. As a result, age-related impairments in macrophage function are likely to have important consequences for the health of the older population. It has been reported that ageing in macrophages impacts on many processes including toll-like receptor signalling, polarisation, phagocytosis, and wound repair. A detailed understanding of the impact of ageing on macrophages is required in order to develop therapeutics that will boost immune responses in the older population.

Danger Signals Activating the Immune Response after Trauma

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Stefanie Hirsiger

2012-01-01

Full Text Available Sterile injury can cause a systemic inflammatory response syndrome (SIRS that resembles the host response during sepsis. The inflammatory response following trauma comprises various systems of the human body which are cross-linked with each other within a highly complex network of inflammation. Endogenous danger signals (danger-associated molecular patterns; DAMPs; alarmins as well as exogenous pathogen-associated molecular patterns (PAMPs play a crucial role in the initiation of the immune response. With popularization of the “danger theory,” numerous DAMPs and PAMPs and their corresponding pathogen-recognition receptors have been identified. In this paper, we highlight the role of the DAMPs high-mobility group box protein 1 (HMGB1, interleukin-1α (IL-1α, and interleukin-33 (IL-33 as unique dual-function mediators as well as mitochondrial danger signals released upon cellular trauma and necrosis.

TGFβ signaling in the brain increases with aging and signals to astrocytes and innate immune cells in the weeks after stroke

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Buckwalter Marion S

2010-10-01

Full Text Available Abstract Background TGFβ is both neuroprotective and a key immune system modulator and is likely to be an important target for future stroke therapy. The precise function of increased TGF-β1 after stroke is unknown and its pleiotropic nature means that it may convey a neuroprotective signal, orchestrate glial scarring or function as an important immune system regulator. We therefore investigated the time course and cell-specificity of TGFβ signaling after stroke, and whether its signaling pattern is altered by gender and aging. Methods We performed distal middle cerebral artery occlusion strokes on 5 and 18 month old TGFβ reporter mice to get a readout of TGFβ responses after stroke in real time. To determine which cell type is the source of increased TGFβ production after stroke, brain sections were stained with an anti-TGFβ antibody, colocalized with markers for reactive astrocytes, neurons, and activated microglia. To determine which cells are responding to TGFβ after stroke, brain sections were double-labelled with anti-pSmad2, a marker of TGFβ signaling, and markers of neurons, oligodendrocytes, endothelial cells, astrocytes and microglia. Results TGFβ signaling increased 2 fold after stroke, beginning on day 1 and peaking on day 7. This pattern of increase was preserved in old animals and absolute TGFβ signaling in the brain increased with age. Activated microglia and macrophages were the predominant source of increased TGFβ after stroke and astrocytes and activated microglia and macrophages demonstrated dramatic upregulation of TGFβ signaling after stroke. TGFβ signaling in neurons and oligodendrocytes did not undergo marked changes. Conclusions We found that TGFβ signaling increases with age and that astrocytes and activated microglia and macrophages are the main cell types that undergo increased TGFβ signaling in response to post-stroke increases in TGFβ. Therefore increased TGFβ after stroke likely regulates glial

TGFβ signaling in the brain increases with aging and signals to astrocytes and innate immune cells in the weeks after stroke.

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Doyle, Kristian P; Cekanaviciute, Egle; Mamer, Lauren E; Buckwalter, Marion S

2010-10-11

TGFβ is both neuroprotective and a key immune system modulator and is likely to be an important target for future stroke therapy. The precise function of increased TGF-β1 after stroke is unknown and its pleiotropic nature means that it may convey a neuroprotective signal, orchestrate glial scarring or function as an important immune system regulator. We therefore investigated the time course and cell-specificity of TGFβ signaling after stroke, and whether its signaling pattern is altered by gender and aging. We performed distal middle cerebral artery occlusion strokes on 5 and 18 month old TGFβ reporter mice to get a readout of TGFβ responses after stroke in real time. To determine which cell type is the source of increased TGFβ production after stroke, brain sections were stained with an anti-TGFβ antibody, colocalized with markers for reactive astrocytes, neurons, and activated microglia. To determine which cells are responding to TGFβ after stroke, brain sections were double-labelled with anti-pSmad2, a marker of TGFβ signaling, and markers of neurons, oligodendrocytes, endothelial cells, astrocytes and microglia. TGFβ signaling increased 2 fold after stroke, beginning on day 1 and peaking on day 7. This pattern of increase was preserved in old animals and absolute TGFβ signaling in the brain increased with age. Activated microglia and macrophages were the predominant source of increased TGFβ after stroke and astrocytes and activated microglia and macrophages demonstrated dramatic upregulation of TGFβ signaling after stroke. TGFβ signaling in neurons and oligodendrocytes did not undergo marked changes. We found that TGFβ signaling increases with age and that astrocytes and activated microglia and macrophages are the main cell types that undergo increased TGFβ signaling in response to post-stroke increases in TGFβ. Therefore increased TGFβ after stroke likely regulates glial scar formation and the immune response to stroke.

MenTORing Immunity: mTOR Signaling in the Development and Function of Tissue-Resident Immune Cells.

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Jones, Russell G; Pearce, Edward J

2017-05-16

Tissue-resident immune cells must balance survival in peripheral tissues with the capacity to respond rapidly upon infection or tissue damage, and in turn couple these responses with intrinsic metabolic control and conditions in the tissue microenvironment. The serine/threonine kinase mammalian/mechanistic target of rapamycin (mTOR) is a central integrator of extracellular and intracellular growth signals and cellular metabolism and plays important roles in both innate and adaptive immune responses. This review discusses the function of mTOR signaling in the differentiation and function of tissue-resident immune cells, with focus on the role of mTOR as a metabolic sensor and its impact on metabolic regulation in innate and adaptive immune cells. We also discuss the impact of metabolic constraints in tissues on immune homeostasis and disease, and how manipulating mTOR activity with drugs such as rapamycin can modulate immunity in these contexts. Copyright © 2017. Published by Elsevier Inc.

The Role of the Immune System in Obesity and Insulin Resistance

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Payal S. Patel

2013-01-01

Full Text Available The innate immune system provides organisms with rapid and well-coordinated protection from foreign pathogens. However, under certain conditions of metabolic dysfunction, components of the innate immune system may be activated in the absence of external pathogens, leading to pathologic consequences. Indeed, there appears to be an intimate relationship between metabolic diseases and immune dysfunction; for example, macrophages are prime players in the initiation of a chronic inflammatory state in obesity which leads to insulin resistance. In response to increases in free fatty acid release from obese adipose depots, M1-polarized macrophages infiltrate adipose tissues. These M1 macrophages trigger inflammatory signaling and stress responses within cells that signal through JNK or IKKβ pathways, leading to insulin resistance. If overnutrition persists, mechanisms that counteract inflammation (such as M2 macrophages and PPAR signaling are suppressed, and the inflammation becomes chronic. Although macrophages are a principal constituent of obese adipose tissue inflammation, other components of the immune system such as lymphocytes and mast cells also contribute to the inflammatory cascade. Thus it is not merely an increased mass of adipose tissue that directly leads to attenuation of insulin action, but rather adipose tissue inflammation activated by the immune system in obese individuals that leads to insulin resistance.

Vitamin D signaling in intestinal innate immunity and homeostasis.

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Dimitrov, Vassil; White, John H

2017-09-15

The lumen of the gut hosts a plethora of microorganisms that participate in food assimilation, inactivation of harmful particles and in vitamin synthesis. On the other hand, enteric flora, a number of food antigens, and toxins are capable of triggering immune responses causing inflammation, which, when unresolved, may lead to chronic conditions such as inflammatory bowel disease (IBD). It is important, therefore, to contain the gut bacteria within the lumen, control microbial load and composition, as well as ensure adequate innate and adaptive immune responses to pathogenic threats. There is growing evidence that vitamin D signaling has impacts on all these aspects of intestinal physiology, contributing to healthy enteric homeostasis. VD was first discovered as the curative agent for nutritional rickets, and its classical actions are associated with calcium absorption and bone health. However, vitamin D exhibits a number of extra-skeletal effects, particularly in innate immunity. Notably, it stimulates production of pattern recognition receptors, anti-microbial peptides, and cytokines, which are at the forefront of innate immune responses. They play a role in sensing the microbiota, in preventing excessive bacterial overgrowth, and complement the actions of vitamin D signaling in enhancing intestinal barrier function. Vitamin D also favours tolerogenic rather than inflammogenic T cell differentiation and function. Compromised innate immune function and overactive adaptive immunity, as well as defective intestinal barrier function, have been associated with IBD. Importantly, observational and intervention studies support a beneficial role of vitamin D supplementation in patients with Crohn's disease, a form of IBD. This review summarizes the effects of vitamin D signaling on barrier integrity and innate and adaptive immunity in the gut, as well as on microbial load and composition. Collectively, studies to date reveal that vitamin D signaling has widespread effects

Trauma equals danger—damage control by the immune system

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Stoecklein, Veit M.; Osuka, Akinori; Lederer, James A.

2012-01-01

Traumatic injuries induce a complex host response that disrupts immune system homeostasis and predisposes patients to opportunistic infections and inflammatory complications. The response to injuries varies considerably by type and severity, as well as by individual variables, such as age, sex, and genetics. These variables make studying the impact of trauma on the immune system challenging. Nevertheless, advances have been made in understanding how injuries influence immune system function as well as the immune cells and pathways involved in regulating the response to injuries. This review provides an overview of current knowledge about how traumatic injuries affect immune system phenotype and function. We discuss the current ideas that traumatic injuries induce a unique type of a response that may be triggered by a combination of endogenous danger signals, including alarmins, DAMPs, self-antigens, and cytokines. Additionally, we review and propose strategies for redirecting injury responses to help restore immune system homeostasis. PMID:22654121

High-resolution mass spectrometry driven discovery of peptidic danger signals in insect immunity.

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Arton Berisha

Full Text Available The 'danger model' is an alternative concept for immune response postulating that the immune system reacts to entities that do damage (danger associated molecular patterns, DAMP and not only to entities that are foreign (pathogen-associated molecular patterns, PAMP as proposed by classical immunology concepts. In this study we used Galleria mellonella to validate the danger model in insects. Hemolymph of G. mellonella was digested with thermolysin (as a representative for virulence-associated metalloproteinases produced by humanpathogens followed by chromatographic fractionation. Immune-stimulatory activity was tested by measuring lysozyme activity with the lytic zone assays against Micrococcus luteus cell wall components. Peptides were analyzed by nano-scale liquid chromatography coupled to high-resolution Fourier transform mass spectrometers. Addressing the lack of a genome sequence we complemented the rudimentary NCBI protein database with a recently established transcriptome and de novo sequencing methods for peptide identification. This approach led to identification of 127 peptides, 9 of which were identified in bioactive fractions. Detailed MS/MS experiments in comparison with synthetic analogues confirmed the amino acid sequence of all 9 peptides. To test the potential of these putative danger signals to induce immune responses we injected the synthetic analogues into G. mellonella and monitored the anti-bacterial activity against living Micrococcus luteus. Six out of 9 peptides identified in the bioactive fractions exhibited immune-stimulatory activity when injected. Hence, we provide evidence that small peptides resulting from thermolysin-mediated digestion of hemolymph proteins function as endogenous danger signals which can set the immune system into alarm. Consequently, our study indicates that the danger model also plays a role in insect immunity.

The molecular mechanisms of signaling by cooperative assembly formation in innate immunity pathways.

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Vajjhala, Parimala R; Ve, Thomas; Bentham, Adam; Stacey, Katryn J; Kobe, Bostjan

2017-06-01

The innate immune system is the first line of defense against infection and responses are initiated by pattern recognition receptors (PRRs) that detect pathogen-associated molecular patterns (PAMPs). PRRs also detect endogenous danger-associated molecular patterns (DAMPs) that are released by damaged or dying cells. The major PRRs include the Toll-like receptor (TLR) family members, the nucleotide binding and oligomerization domain, leucine-rich repeat containing (NLR) family, the PYHIN (ALR) family, the RIG-1-like receptors (RLRs), C-type lectin receptors (CLRs) and the oligoadenylate synthase (OAS)-like receptors and the related protein cyclic GMP-AMP synthase (cGAS). The different PRRs activate specific signaling pathways to collectively elicit responses including the induction of cytokine expression, processing of pro-inflammatory cytokines and cell-death responses. These responses control a pathogenic infection, initiate tissue repair and stimulate the adaptive immune system. A central theme of many innate immune signaling pathways is the clustering of activated PRRs followed by sequential recruitment and oligomerization of adaptors and downstream effector enzymes, to form higher-order arrangements that amplify the response and provide a scaffold for proximity-induced activation of the effector enzymes. Underlying the formation of these complexes are co-operative assembly mechanisms, whereby association of preceding components increases the affinity for downstream components. This ensures a rapid immune response to a low-level stimulus. Structural and biochemical studies have given key insights into the assembly of these complexes. Here we review the current understanding of assembly of immune signaling complexes, including inflammasomes initiated by NLR and PYHIN receptors, the myddosomes initiated by TLRs, and the MAVS CARD filament initiated by RIG-1. We highlight the co-operative assembly mechanisms during assembly of each of these complexes. Copyright �

The Immune System Bridges the Gut Microbiota with Systemic Energy Homeostasis: Focus on TLRs, Mucosal Barrier, and SCFAs.

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Spiljar, Martina; Merkler, Doron; Trajkovski, Mirko

2017-01-01

The gut microbiota is essential for the development and regulation of the immune system and the metabolism of the host. Germ-free animals have altered immunity with increased susceptibility to immunologic diseases and show metabolic alterations. Here, we focus on two of the major immune-mediated microbiota-influenced components that signal far beyond their local environment. First, the activation or suppression of the toll-like receptors (TLRs) by microbial signals can dictate the tone of the immune response, and they are implicated in regulation of the energy homeostasis. Second, we discuss the intestinal mucosal surface is an immunologic component that protects the host from pathogenic invasion, is tightly regulated with regard to its permeability and can influence the systemic energy balance. The short chain fatty acids are a group of molecules that can both modulate the intestinal barrier and escape the gut to influence systemic health. As modulators of the immune response, the microbiota-derived signals influence functions of distant organs and can change susceptibility to metabolic diseases.

Signaling pathways and immune evasion mechanisms in classical Hodgkin lymphoma.

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Liu, W Robert; Shipp, Margaret A

2017-11-23

Classical Hodgkin lymphoma (cHL) is an unusual B-cell-derived malignancy in which rare malignant Hodgkin and Reed-Sternberg (HRS) cells are surrounded by an extensive but ineffective inflammatory/immune cell infiltrate. This striking feature suggests that malignant HRS cells escape immunosurveillance and interact with immune cells in the cancer microenvironment for survival and growth. We previously found that cHLs have a genetic basis for immune evasion: near-uniform copy number alterations of chromosome 9p24.1 and the associated PD-1 ligand loci, CD274/PD-L1 and PDCD1LG2/PD-L2, and copy number-dependent increased expression of these ligands. HRS cells expressing PD-1 ligands are thought to engage PD-1 receptor-positive immune effectors in the tumor microenvironment and induce PD-1 signaling and associated immune evasion. The genetic bases of enhanced PD-1 signaling in cHL make these tumors uniquely sensitive to PD-1 blockade. © 2017 by The American Society of Hematology.

Met1-linked Ubiquitination in Immune Signalling

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Fiil, Berthe Katrine; Gyrd-Hansen, Mads

2014-01-01

Methionine 1-linked ubiquitin chains (Met1-Ub), or linear ubiquitin, has emerged as a central post-translational modification in innate immune signalling. Molecular machinery that assembles, senses and, more recently, disassembles Met1-Ub has been identified, and technical advances have enabled...... identification of physiological substrates for Met1-Ub in response to activation of innate immune receptors. These discoveries have significantly advanced our understanding of how non-degradative ubiquitin modifications control pro-inflammatory responses mediated by nuclear factor κB and mitogen...

Crosstalk between bone niche and immune system: osteoimmunology signaling as a potential target for cancer treatment.

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Criscitiello, Carmen; Viale, Giulia; Gelao, Lucia; Esposito, Angela; De Laurentiis, Michele; De Placido, Sabino; Santangelo, Michele; Goldhirsch, Aron; Curigliano, Giuseppe

2015-02-01

There is a well recognized link between the bone and the immune system and in recent years there has been a major effort to elucidate the multiple functions of the molecules expressed in both bone and immune cells. Several molecules that were initially identified and studied in the immune system have been shown to have essential functions also in the bone. An interdisciplinary field embracing immune and bone biology has been brought together and called "osteoimmunology". The co-regulation of the skeletal and immune systems strikingly exemplifies the extreme complexity of such an interaction. Their interdependency must be considered in designing therapeutic approaches for either of the two systems. In other words, it is necessary to think of the osteoimmune system as a complex physiological unit. Denosumab was originally introduced to specifically target bone resorption, but it is now under evaluation for its effect on the long term immune response. Similarly, our current and still growing knowledge of the intimate link between the immune system and bone will be beneficial for the safety of drugs targeting either of these integrated systems. Given the large number of molecules exerting functions on both the skeletal and immune systems, osteoimmunological understanding is becoming increasingly important. Both bone and immune systems are frequently disrupted in cancer; and they may be crucial in regulating tumor growth and progression. Some therapies - such as bisphosphonates and receptor activator of NF-κB ligand (RANKL) targeted drugs - that aim at reducing pathologic osteolysis in cancer may interact with the immune system, thus providing potential favorable effects on survival. Copyright © 2014 Elsevier Ltd. All rights reserved.

JAK/STAT signaling pathway-mediated immune response in silkworm (Bombyx mori) challenged by Beauveria bassiana.

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Geng, Tao; Lv, Ding-Ding; Huang, Yu-Xia; Hou, Cheng-Xiang; Qin, Guang-Xing; Guo, Xi-Jie

2016-12-20

Innate immunity was critical in insects defensive system and able to be induced by Janus kinase/signal transducer and activator of transcription cascade transduction (JAK/STAT) signaling pathway. Currently, it had been identified many JAK/STAT signaling pathway-related genes in silkworm, but little function was known on insect innate immunity. To explore the roles of JAK/STAT pathway in antifungal immune response in silkworm (Bombyx mori) against Beauveria bassiana infection, the expression patterns of B. mori C-type lectin 5 (BmCTL5) and genes encoding 6 components of JAK/STAT signaling pathway in silkworm challenged by B. bassiana were analyzed using quantitative real time PCR. Meanwhile the activation of JAK/STAT signaling pathway by various pathogenic micro-organisms and the affect of JAK/STAT signaling pathway inhibitors on antifungal activity in silkworm hemolymph was also detected. Moreover, RNAi assay of BmCTL5 and the affect on expression levels of signaling factors were also analyzed. We found that JAK/STAT pathway could be obviously activated in silkworm challenged with B. bassiana and had no response to bacteria and B. mori cytoplasmic polyhedrosis virus (BmCPV). However, the temporal expression patterns of JAK/STAT signaling pathway related genes were significantly different. B. mori downstream receptor kinase (BmDRK) might be a positive regulator of JAK/STAT signaling pathway in silkworm against B. bassiana infection. Moreover, antifungal activity assay showed that the suppression of JAK/STAT signaling pathway by inhibitors could significantly inhibit the antifungal activity in hemolymph and resulted in increased sensitivity of silkworm to B. bassiana infection, indicating that JAK/STAT signaling pathway might be involved in the synthesis and secretion of antifungal substances. The results of RNAi assays suggested that BmCTL5 might be one pattern recognition receptors for JAK/STAT signaling pathway in silkworm. These findings yield insights for better

Differential effects of interleukin-17 receptor signaling on innate and adaptive immunity during central nervous system bacterial infection

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Vidlak Debbie

2012-06-01

Full Text Available Abstract Although IL-17A (commonly referred to as IL-17 has been implicated in the pathogenesis of central nervous system (CNS autoimmune disease, its role during CNS bacterial infections remains unclear. To evaluate the broader impact of IL-17 family members in the context of CNS infection, we utilized IL-17 receptor (IL-17R knockout (KO mice that lack the ability to respond to IL-17, IL-17F and IL-17E (IL-25. In this article, we demonstrate that IL-17R signaling regulates bacterial clearance as well as natural killer T (NKT cell and gamma-delta (γδ T cell infiltrates during Staphylococcus aureus-induced brain abscess formation. Specifically, when compared with wild-type (WT animals, IL-17R KO mice exhibited elevated bacterial burdens at days 7 and 14 following S. aureus infection. Additionally, IL-17R KO animals displayed elevated neutrophil chemokine production, revealing the ability to compensate for the lack of IL-17R activity. Despite these differences, innate immune cell recruitment into brain abscesses was similar in IL-17R KO and WT mice, whereas IL-17R signaling exerted a greater influence on adaptive immune cell recruitment. In particular, γδ T cell influx was increased in IL-17R KO mice at day 7 post-infection. In addition, NK1.1high infiltrates were absent in brain abscesses of IL-17R KO animals and, surprisingly, were rarely detected in the livers of uninfected IL-17R KO mice. Although IL-17 is a key regulator of neutrophils in other infection models, our data implicate an important role for IL-17R signaling in regulating adaptive immunity during CNS bacterial infection.

Immune-Modulating Perspectives for Low Frequency Electromagnetic Fields in Innate Immunity

Directory of Open Access Journals (Sweden)

Maria Manuela Rosado

2018-03-01

Full Text Available In recent years, the effects of electromagnetic fields (EMFs on the immune system have received a considerable interest, not only to investigate possible negative health impact but also to explore the possibility to favorably modulate immune responses. To generate beneficial responses, the immune system should eradicate pathogens while “respecting” the organism and tolerating irrelevant antigens. According to the current view, damage-associated molecules released by infected or injured cells, or secreted by innate immune cells generate danger signals activating an immune response. These signals are also relevant to the subsequent activation of homeostatic mechanisms that control the immune response in pro- or anti-inflammatory reactions, a feature that allows modulation by therapeutic treatments. In the present review, we describe and discuss the effects of extremely low frequency (ELF-EMF and pulsed EMF on cell signals and factors relevant to the activation of danger signals and innate immunity cells. By discussing the EMF modulating effects on cell functions, we envisage the use of EMF as a therapeutic agent to regulate immune responses associated with wound healing.

Conducted Interference Immunity Characteristics to High-speed Power Line Communication System

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Tokuda, Masamitsu; Hosoya, Satoshi; Yamagata, Toru; Matsuo, Takashi

In this paper, we measured the immunity characteristics to the conducted interference wave, from the aspect of PHY rate (physical layer data rate) of PLC (Power Line Communication) system, and compared with simulation results by MATLAB/ Simulink. When the interference signal is impressed to the OFDM (Orthogonal Frequency Division Multiplexing) signal, the PHY rate decrease rapidly below C/I (Carrier / Interference) = 25dB and become nearly zero around C/I = -35dB, and so it turns out that the PLC System with OFDM signal has a good narrowband interference immunity characteristic. In addition, it is revealed that the PHY rate of PLC modem can be calculated by MATLAB/Simulink even when the narrowband interference signal is impressed through the power line. Furthermore, we examined the improving effect of the notch band for the immunity characteristics to the conducted interference wave. As a result, it is revealed that the PHY rate normalized by the maximum value increases by 15∼25% by inserting the notch when impressing the interference signal in the notch band and C/I is improved by 10∼15dB by inserting the notch.

DMPD: Innate immune responses: crosstalk of signaling and regulation of genetranscription. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 16753195 Innate immune responses: crosstalk of signaling and regulation of genetran...l) (.csml) Show Innate immune responses: crosstalk of signaling and regulation of genetranscription. PubmedI...D 16753195 Title Innate immune responses: crosstalk of signaling and regulation o

Ebola Virus Altered Innate and Adaptive Immune Response Signalling Pathways: Implications for Novel Therapeutic Approaches.

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Kumar, Anoop

2016-01-01

Ebola virus (EBOV) arise attention for their impressive lethality by the poor immune response and high inflammatory reaction in the patients. It causes a severe hemorrhagic fever with case fatality rates of up to 90%. The mechanism underlying this lethal outcome is poorly understood. In 2014, a major outbreak of Ebola virus spread amongst several African countries, including Leone, Sierra, and Guinea. Although infections only occur frequently in Central Africa, but the virus has the potential to spread globally. Presently, there is no vaccine or treatment is available to counteract Ebola virus infections due to poor understanding of its interaction with the immune system. Accumulating evidence indicates that the virus actively alters both innate and adaptive immune responses and triggers harmful inflammatory responses. In the literature, some reports have shown that alteration of immune signaling pathways could be due to the ability of EBOV to interfere with dendritic cells (DCs), which link innate and adaptive immune responses. On the other hand, some reports have demonstrated that EBOV, VP35 proteins act as interferon antagonists. So, how the Ebola virus altered the innate and adaptive immune response signaling pathways is still an open question for the researcher to be explored. Thus, in this review, I try to summarize the mechanisms of the alteration of innate and adaptive immune response signaling pathways by Ebola virus which will be helpful for designing effective drugs or vaccines against this lethal infection. Further, potential targets, current treatment and novel therapeutic approaches have also been discussed.

The role of innate signaling in the homeostasis of tolerance and immunity in the intestine.

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Wells, Jerry M; Loonen, Linda M P; Karczewski, Jurgen M

2010-01-01

In the intestine innate recognition of microbes is achieved through pattern recognition receptor (PRR) families expressed in immune cells and different cell lineages of the intestinal epithelium. Toll-like receptor (TLR) and nucleotide-binding and oligomerization domain-like receptor (NLR) families are emerging as key mediators of immunity through their role as maturation factors of immune cells and triggers for the production of cytokines and chemokines and antimicrobial factors. At the mucosal surface chronic activation of the immune system is avoided through the epithelial production of a glycocalyx, steady-state production of antimicrobial factors as well as the selective expression and localization of PRRs. Additionally, the polarization of epithelial TLR signaling and suppression of NF-kappaB activation by luminal commensals appears to contribute to the homeostasis of tolerance and immunity. Several studies have demonstrated that TLR signaling in epithelial cells contributes to a range of homeostatic mechanisms including proliferation, wound healing, epithelial integrity, and regulation of mucosal immune functions. The intestinal epithelium appears to have uniquely evolved to maintain mucosal tolerance and immunity, and future efforts to further understand the molecular mechanisms of intestinal homeostasis may have a major impact on human health. Copyright 2009 Elsevier GmbH. All rights reserved.

Our Immune System

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Our Immune System A story for children with primary immunodeficiency diseases Written by Sara LeBien IMMUNE DEFICIENCY FOUNDATION A note ... who are immune deficient to better understand their immune system. What is a “ B-cell, ” a “ T-cell, ” ...

Immune System Quiz

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... Safe Videos for Educators Search English Español Quiz: Immune System KidsHealth / For Kids / Quiz: Immune System Print How much do you know about your immune system? Find out by taking this quiz! About Us ...

GDSL LIPASE1 Modulates Plant Immunity through Feedback Regulation of Ethylene Signaling1[W

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Kim, Hye Gi; Kwon, Sun Jae; Jang, Young Jin; Nam, Myung Hee; Chung, Joo Hee; Na, Yun-Cheol; Guo, Hongwei; Park, Ohkmae K.

2013-01-01

Ethylene is a key signal in the regulation of plant defense responses. It is required for the expression and function of GDSL LIPASE1 (GLIP1) in Arabidopsis (Arabidopsis thaliana), which plays an important role in plant immunity. Here, we explore molecular mechanisms underlying the relationship between GLIP1 and ethylene signaling by an epistatic analysis of ethylene response mutants and GLIP1-overexpressing (35S:GLIP1) plants. We show that GLIP1 expression is regulated by ethylene signaling components and, further, that GLIP1 expression or application of petiole exudates from 35S:GLIP1 plants affects ethylene signaling both positively and negatively, leading to ETHYLENE RESPONSE FACTOR1 activation and ETHYLENE INSENSITIVE3 (EIN3) down-regulation, respectively. Additionally, 35S:GLIP1 plants or their exudates increase the expression of the salicylic acid biosynthesis gene SALICYLIC ACID INDUCTION-DEFICIENT2, known to be inhibited by EIN3 and EIN3-LIKE1. These results suggest that GLIP1 regulates plant immunity through positive and negative feedback regulation of ethylene signaling, and this is mediated by its activity to accumulate a systemic signal(s) in the phloem. We propose a model explaining how GLIP1 regulates the fine-tuning of ethylene signaling and ethylene-salicylic acid cross talk. PMID:24170202

Signaling by myeloid C-type lectin receptors in immunity and homeostasis.

Science.gov (United States)

Sancho, David; Reis e Sousa, Caetano

2012-01-01

Myeloid cells are key drivers of physiological responses to pathogen invasion or tissue damage. Members of the C-type lectin receptor (CLR) family stand out among the specialized receptors utilized by myeloid cells to orchestrate these responses. CLR ligands include carbohydrate, protein, and lipid components of both pathogens and self, which variably trigger endocytic, phagocytic, proinflammatory, or anti-inflammatory reactions. These varied outcomes rely on a versatile system for CLR signaling that includes tyrosine-based motifs that recruit kinases, phosphatases, or endocytic adaptors as well as nontyrosine-based signals that modulate the activation of other pathways or couple to the uptake machinery. Here, we review the signaling properties of myeloid CLRs and how they impact the role of myeloid cells in innate and adaptive immunity.

DMPD: IRAK1: a critical signaling mediator of innate immunity. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 17890055 IRAK1: a critical signaling mediator of innate immunity. Gottipati S, Rao ...IRAK1: a critical signaling mediator of innate immunity. PubmedID 17890055 Title IRAK1: a critical signaling mediator

Role of neuropilin-2 in the immune system.

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Schellenburg, S; Schulz, A; Poitz, D M; Muders, M H

2017-10-01

Neuropilins (NRPs) are single transmembrane receptors with short cytoplasmic tails and are dependent on receptors like VEGF receptors or Plexins for signal transduction. NRPs are known to be important in angiogenesis, lymphangiogenesis, and axon guidance. The Neuropilin-family consists of two members, Neuropilin-1 (NRP1) and Neuropilin-2 (NRP2). They are up to 44 % homologous and conserved in all vertebrates. High levels of NRP2 are found on immune cells. Current research is very limited regarding the functions of NRP2 on these cells. Recent evidence suggests that NRP2 is important for migration, antigen presentation, phagocytosis and cell-cell contact within the immune system. Additionally, posttranslational NRP2 modifications like polysialylation are crucial for the function of some immune cells. This review is an overview about expression and functions of NRP2 in the immune system. Copyright © 2017 Elsevier Ltd. All rights reserved.

Trauma: the role of the innate immune system

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Rijkers GT

2006-05-01

Full Text Available Abstract Immune dysfunction can provoke (multiple organ failure in severely injured patients. This dysfunction manifests in two forms, which follow a biphasic pattern. During the first phase, in addition to the injury by trauma, organ damage is caused by the immune system during a systemic inflammatory response. During the second phase the patient is more susceptible for sepsis due to host defence failure (immune paralysis. The pathophysiological model outlined in this review encompasses etiological factors and the contribution of the innate immune system in the end organ damage. The etiological factors can be divided into intrinsic (genetic predisposition and physiological status and extrinsic components (type of injury or "traumaload" and surgery or "intervention load". Of all the factors, the intervention load is the only one which, can be altered by the attending emergency physician. Adjustment of the therapeutic approach and choice of the most appropriate treatment strategy can minimize the damage caused by the immune response and prevent the development of immunological paralysis. This review provides a pathophysiological basis for the damage control concept, in which a staged approach of surgery and post-traumatic immunomonitoring have become important aspects of the treatment protocol. The innate immune system is the main objective of immunomonitoring as it has the most prominent role in organ failure after trauma. Polymorphonuclear phagocytes and monocytes are the main effector-cells of the innate immune system in the processes that lead to organ failure. These cells are controlled by cytokines, chemokines, complement factors and specific tissue signals. The contribution of tissue barrier integrity and its interaction with the innate immune system is further evaluated.

The Immune System, Cytokines, and Biomarkers in Autism Spectrum Disorder

Institute of Scientific and Technical Information of China (English)

Anne Masi; Nicholas Glozier; Russell Dale; Adam J.Guastella

2017-01-01

Autism Spectrum Disorder (ASD) is a pervasive neurodevelopmental condition characterized by variable impairments in communication and social interaction as well as restricted interests and repetitive behaviors.Heterogeneity of presentation is a hallmark.Investigations of immune system problems in ASD,including aberrations in cytokine profiles and signaling,have been increasing in recent times and are the subject of ongoing interest.With the aim of establishing whether cytokines have utility as potential biomarkers that may define a subgroup of ASD,or function as an objective measure of response to treatment,this review summarizes the role of the immune system,discusses the relationship between the immune system,the brain,and behavior,and presents previouslyidentified immune system abnormalities in ASD,specifically addressing the role of cytokines in these aberrations.The roles and identification of biomarkers are also addressed,particularly with respect to cytokine profiles in ASD.

The Immune System, Cytokines, and Biomarkers in Autism Spectrum Disorder.

Science.gov (United States)

Masi, Anne; Glozier, Nicholas; Dale, Russell; Guastella, Adam J

2017-04-01

Autism Spectrum Disorder (ASD) is a pervasive neurodevelopmental condition characterized by variable impairments in communication and social interaction as well as restricted interests and repetitive behaviors. Heterogeneity of presentation is a hallmark. Investigations of immune system problems in ASD, including aberrations in cytokine profiles and signaling, have been increasing in recent times and are the subject of ongoing interest. With the aim of establishing whether cytokines have utility as potential biomarkers that may define a subgroup of ASD, or function as an objective measure of response to treatment, this review summarizes the role of the immune system, discusses the relationship between the immune system, the brain, and behavior, and presents previously-identified immune system abnormalities in ASD, specifically addressing the role of cytokines in these aberrations. The roles and identification of biomarkers are also addressed, particularly with respect to cytokine profiles in ASD.

Immune Homeostasis in Epithelial Cells: Evidence and Role of Inflammasome Signaling Reviewed.

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Peeters, Paul M; Wouters, Emiel F; Reynaert, Niki L

2015-01-01

The epithelium regulates the interaction between the noxious xenogenous, as well as the microbial environment and the immune system, not only by providing a barrier but also by expressing a number of immunoregulatory membrane receptors, and intracellular danger sensors and their downstream effectors. Amongst these are a number of inflammasome sensor subtypes, which have been initially characterized in myeloid cells and described to be activated upon assembly into multiprotein complexes by microbial and environmental triggers. This review compiles a vast amount of literature that supports a pivotal role for inflammasomes in the various epithelial barriers of the human body as essential factors maintaining immune signaling and homeostasis.

Keeping the immune system in check: a role for mitophagy.

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Lazarou, Michael

2015-01-01

Mitochondria play a central role in many facets of cellular function including energy production, control of cell death and immune signaling. Breakdown of any of these pathways because of mitochondrial deficits or excessive reactive oxygen species production has detrimental consequences for immune system function and cell viability. Maintaining the functional integrity of mitochondria is therefore a critical challenge for the cell. Surveillance systems that monitor mitochondrial status enable the cell to identify and either repair or eliminate dysfunctional mitochondria. Mitophagy is a selective form of autophagy that eliminates dysfunctional mitochondria from the population to maintain overall mitochondrial health. This review covers the major players involved in mitophagy and explores the role mitophagy plays to support the immune system.

DMPD: Regulation of innate immunity by suppressor of cytokine signaling (SOCS)proteins. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 18406369 Regulation of innate immunity by suppressor of cytokine signaling (SOCS)proteins...svg) (.html) (.csml) Show Regulation of innate immunity by suppressor of cytokine signaling (SOCS)proteins. ...PubmedID 18406369 Title Regulation of innate immunity by suppressor of cytokine signaling (SOCS)proteins

Implications of central immune signaling caused by drugs of abuse: mechanisms, mediators and new therapeutic approaches for prediction and treatment of drug dependence.

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Coller, Janet K; Hutchinson, Mark R

2012-05-01

In the past two decades a trickle of manuscripts examining the non-neuronal central nervous system immune consequences of the drugs of abuse has now swollen to a significant body of work. Initially, these studies reported associative evidence of central nervous system proinflammation resulting from exposure to the drugs of abuse demonstrating key implications for neurotoxicity and disease progression associated with, for example, HIV infection. However, more recently this drug-induced activation of central immune signaling is now understood to contribute substantially to the pharmacodynamic actions of the drugs of abuse, by enhancing the engagement of classical mesolimbic dopamine reward pathways and withdrawal centers. This review will highlight the key in vivo animal, human, biological and molecular evidence of these central immune signaling actions of opioids, alcohol, cocaine, methamphetamine, and 3,4-methylenedioxymethamphetamine (MDMA). Excitingly, this new appreciation of central immune signaling activity of drugs of abuse provides novel therapeutic interventions and opportunities to identify 'at risk' individuals through the use of immunogenetics. Discussion will also cover the evidence of modulation of this signaling by existing clinical and pre-clinical drug candidates, and novel pharmacological targets. Finally, following examination of the breadth of central immune signaling actions of the drugs of abuse highlighted here, the current known common immune signaling components will be outlined and their impact on established addiction neurocircuitry discussed, thereby synthesizing a common neuroimmune hypothesis of addiction. Copyright © 2012 Elsevier Inc. All rights reserved.

The role of the immune system in the generation of neuropathic pain.

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Calvo, Margarita; Dawes, John M; Bennett, David L H

2012-07-01

Persistent pain is a sequela of several neurological conditions with a primary immune basis, such as Guillain-Barré syndrome and multiple sclerosis. Additionally, diverse forms of injury to the peripheral or the central nervous systems--whether traumatic, metabolic, or toxic--result in substantial recruitment and activation of immune cells. This response involves the innate immune system, but evidence also exists of T-lymphocyte recruitment, and in some patient cohorts antibodies to neuronal antigens have been reported. Mediators released by immune cells, such as cytokines, sensitise nociceptive signalling in the peripheral and central nervous systems. Preclinical data suggest an immune pathogenesis of neuropathic pain, but clinical evidence of a central role of the immune system is less clear. An important challenge for the future is to establish to what extent this immune response initiates or maintains neuropathic pain in patients and thus whether it is amenable to therapy. Copyright © 2012 Elsevier Ltd. All rights reserved.

Promoting tissue regeneration by modulating the immune system.

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Julier, Ziad; Park, Anthony J; Briquez, Priscilla S; Martino, Mikaël M

2017-04-15

The immune system plays a central role in tissue repair and regeneration. Indeed, the immune response to tissue injury is crucial in determining the speed and the outcome of the healing process, including the extent of scarring and the restoration of organ function. Therefore, controlling immune components via biomaterials and drug delivery systems is becoming an attractive approach in regenerative medicine, since therapies based on stem cells and growth factors have not yet proven to be broadly effective in the clinic. To integrate the immune system into regenerative strategies, one of the first challenges is to understand the precise functions of the different immune components during the tissue healing process. While remarkable progress has been made, the immune mechanisms involved are still elusive, and there is indication for both negative and positive roles depending on the tissue type or organ and life stage. It is well recognized that the innate immune response comprising danger signals, neutrophils and macrophages modulates tissue healing. In addition, it is becoming evident that the adaptive immune response, in particular T cell subset activities, plays a critical role. In this review, we first present an overview of the basic immune mechanisms involved in tissue repair and regeneration. Then, we highlight various approaches based on biomaterials and drug delivery systems that aim at modulating these mechanisms to limit fibrosis and promote regeneration. We propose that the next generation of regenerative therapies may evolve from typical biomaterial-, stem cell-, or growth factor-centric approaches to an immune-centric approach. Most regenerative strategies have not yet proven to be safe or reasonably efficient in the clinic. In addition to stem cells and growth factors, the immune system plays a crucial role in the tissue healing process. Here, we propose that controlling the immune-mediated mechanisms of tissue repair and regeneration may support

[Immune system and tumors].

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Terme, Magali; Tanchot, Corinne

2017-02-01

Despite having been much debated, it is now well established that the immune system plays an essential role in the fight against cancer. In this article, we will highlight the implication of the immune system in the control of tumor growth and describe the major components of the immune system involved in the antitumoral immune response. The immune system, while exerting pressure on tumor cells, also will play a pro-tumoral role by sculpting the immunogenicity of tumors cells as they develop. Finally, we will illustrate the numerous mechanisms of immune suppression that take place within the tumoral microenvironment which allow tumor cells to escape control from the immune system. The increasingly precise knowledge of the brakes to an effective antitumor immune response allows the development of immunotherapy strategies more and more innovating and promising of hope. Copyright © 2016. Published by Elsevier Masson SAS.

Complement: a key system for immune surveillance and homeostasis.

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Ricklin, Daniel; Hajishengallis, George; Yang, Kun; Lambris, John D

2010-09-01

Nearly a century after the significance of the human complement system was recognized, we have come to realize that its functions extend far beyond the elimination of microbes. Complement acts as a rapid and efficient immune surveillance system that has distinct effects on healthy and altered host cells and foreign intruders. By eliminating cellular debris and infectious microbes, orchestrating immune responses and sending 'danger' signals, complement contributes substantially to homeostasis, but it can also take action against healthy cells if not properly controlled. This review describes our updated view of the function, structure and dynamics of the complement network, highlights its interconnection with immunity at large and with other endogenous pathways, and illustrates its multiple roles in homeostasis and disease.

Molecular mechanisms of aging and immune system regulation in Drosophila.

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Eleftherianos, Ioannis; Castillo, Julio Cesar

2012-01-01

Aging is a complex process that involves the accumulation of deleterious changes resulting in overall decline in several vital functions, leading to the progressive deterioration in physiological condition of the organism and eventually causing disease and death. The immune system is the most important host-defense mechanism in humans and is also highly conserved in insects. Extensive research in vertebrates has concluded that aging of the immune function results in increased susceptibility to infectious disease and chronic inflammation. Over the years, interest has grown in studying the molecular interaction between aging and the immune response to pathogenic infections. The fruit fly Drosophila melanogaster is an excellent model system for dissecting the genetic and genomic basis of important biological processes, such as aging and the innate immune system, and deciphering parallel mechanisms in vertebrate animals. Here, we review the recent advances in the identification of key players modulating the relationship between molecular aging networks and immune signal transduction pathways in the fly. Understanding the details of the molecular events involved in aging and immune system regulation will potentially lead to the development of strategies for decreasing the impact of age-related diseases, thus improving human health and life span.

Comparative Genomics Reveals the Origins and Diversity of Arthropod Immune Systems.

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Palmer, William J; Jiggins, Francis M

2015-08-01

Insects are an important model for the study of innate immune systems, but remarkably little is known about the immune system of other arthropod groups despite their importance as disease vectors, pests, and components of biological diversity. Using comparative genomics, we have characterized the immune system of all the major groups of arthropods beyond insects for the first time--studying five chelicerates, a myriapod, and a crustacean. We found clear traces of an ancient origin of innate immunity, with some arthropods having Toll-like receptors and C3-complement factors that are more closely related in sequence or structure to vertebrates than other arthropods. Across the arthropods some components of the immune system, such as the Toll signaling pathway, are highly conserved. However, there is also remarkable diversity. The chelicerates apparently lack the Imd signaling pathway and beta-1,3 glucan binding proteins--a key class of pathogen recognition receptors. Many genes have large copy number variation across species, and this may sometimes be accompanied by changes in function. For example, we find that peptidoglycan recognition proteins have frequently lost their catalytic activity and switch between secreted and intracellular forms. We also find that there has been widespread and extensive duplication of the cellular immune receptor Dscam (Down syndrome cell adhesion molecule), which may be an alternative way to generate the high diversity produced by alternative splicing in insects. In the antiviral short interfering RNAi pathway Argonaute 2 evolves rapidly and is frequently duplicated, with a highly variable copy number. Our results provide a detailed analysis of the immune systems of several important groups of animals for the first time and lay the foundations for functional work on these groups. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Metabolic gene expression changes in astrocytes in Multiple Sclerosis cerebral cortex are indicative of immune-mediated signaling

KAUST Repository

Zeis, T.

2015-04-01

Emerging as an important correlate of neurological dysfunction in Multiple Sclerosis (MS), extended focal and diffuse gray matter abnormalities have been found and linked to clinical manifestations such as seizures, fatigue and cognitive dysfunction. To investigate possible underlying mechanisms we analyzed the molecular alterations in histopathological normal appearing cortical gray matter (NAGM) in MS. By performing a differential gene expression analysis of NAGM of control and MS cases we identified reduced transcription of astrocyte specific genes involved in the astrocyte–neuron lactate shuttle (ANLS) and the glutamate–glutamine cycle (GGC). Additional quantitative immunohistochemical analysis demonstrating a CX43 loss in MS NAGM confirmed a crucial involvement of astrocytes and emphasizes their importance in MS pathogenesis. Concurrently, a Toll-like/IL-1β signaling expression signature was detected in MS NAGM, indicating that immune-related signaling might be responsible for the downregulation of ANLS and GGC gene expression in MS NAGM. Indeed, challenging astrocytes with immune stimuli such as IL-1β and LPS reduced their ANLS and GGC gene expression in vitro. The detected upregulation of IL1B in MS NAGM suggests inflammasome priming. For this reason, astrocyte cultures were treated with ATP and ATP/LPS as for inflammasome activation. This treatment led to a reduction of ANLS and GGC gene expression in a comparable manner. To investigate potential sources for ANLS and GGC downregulation in MS NAGM, we first performed an adjuvant-driven stimulation of the peripheral immune system in C57Bl/6 mice in vivo. This led to similar gene expression changes in spinal cord demonstrating that peripheral immune signals might be one source for astrocytic gene expression changes in the brain. IL1B upregulation in MS NAGM itself points to a possible endogenous signaling process leading to ANLS and GGC downregulation. This is supported by our findings that, among others

On Modelling an Immune System

OpenAIRE

Monroy, Raúl; Saab, Rosa; Godínez, Fernando

2004-01-01

Immune systems of live forms have been an abundant source of inspiration to contemporary computer scientists. Problem solving strategies, stemming from known immune system phenomena, have been successfully applied to challenging problems of modern computing. However, research in artificial immune systems has overlooked establishing a coherent model of known immune system behaviour. This paper aims reports on an preliminary computer model of an immune system, where each immune system component...

Molecular dialogues between the ischemic brain and the peripheral immune system: Dualistic roles in injury and repair

Science.gov (United States)

An, Chengrui; Shi, Yejie; Li, Peiying; Hu, Xiaoming; Gan, Yu; Stetler, Ruth A.; Leak, Rehana K.; Gao, Yanqin; Sun, Bao-Liang; Zheng, Ping; Chen, Jun

2014-01-01

Immune and inflammatory responses actively modulate the pathophysiological processes of acute brain injuries such as stroke. Soon after the onset of stroke, signals such as brain-derived antigens, danger-associated molecular patterns (DAMPs), cytokines, and chemokines are released from the injured brain into the systemic circulation. The injured brain also communicates with peripheral organs through the parasympathetic and sympathetic branches of the autonomic nervous system. Many of these diverse signals not only activate resident immune cells in the brain, but also trigger robust immune responses in the periphery. Peripheral immune cells then migrate toward the site of injury and release additional cytokines, chemokines, and other molecules, causing further disruptive or protective effects in the ischemic brain. Bidirectional communication between the injured brain and the peripheral immune system is now known to regulate the progression of stroke pathology as well as tissue repair. In the end, this exquisitely coordinated crosstalk helps determine the fate of animals after stroke. This article reviews the literature on ischemic brain-derived signals through which peripheral immune responses are triggered, and the potential impact of these peripheral responses on brain injury and repair. Pharmacological strategies and cell-based therapies that target the dialogue between the brain and peripheral immune system show promise as potential novel treatments for stroke. PMID:24374228

Evolution of JAK-STAT pathway components: mechanisms and role in immune system development.

Directory of Open Access Journals (Sweden)

Clifford Liongue

Full Text Available BACKGROUND: Lying downstream of a myriad of cytokine receptors, the Janus kinase (JAK-Signal transducer and activator of transcription (STAT pathway is pivotal for the development and function of the immune system, with additional important roles in other biological systems. To gain further insight into immune system evolution, we have performed a comprehensive bioinformatic analysis of the JAK-STAT pathway components, including the key negative regulators of this pathway, the SH2-domain containing tyrosine phosphatase (SHP, Protein inhibitors against Stats (PIAS, and Suppressor of cytokine signaling (SOCS proteins across a diverse range of organisms. RESULTS: Our analysis has demonstrated significant expansion of JAK-STAT pathway components co-incident with the emergence of adaptive immunity, with whole genome duplication being the principal mechanism for generating this additional diversity. In contrast, expansion of upstream cytokine receptors appears to be a pivotal driver for the differential diversification of specific pathway components. CONCLUSION: Diversification of JAK-STAT pathway components during early vertebrate development occurred concurrently with a major expansion of upstream cytokine receptors and two rounds of whole genome duplications. This produced an intricate cell-cell communication system that has made a significant contribution to the evolution of the immune system, particularly the emergence of adaptive immunity.

Skin innate immune system

Directory of Open Access Journals (Sweden)

Berna Aksoy

2013-06-01

Full Text Available All multicellular organisms protect themselves from external universe and microorganisms by innate immune sytem that is constitutively present. Skin innate immune system has several different components composed of epithelial barriers, humoral factors and cellular part. In this review information about skin innate immune system and its components are presented to the reader. Innate immunity, which wasn’t adequately interested in previously, is proven to provide a powerfull early protection system, control many infections before the acquired immunity starts and directs acquired immunity to develop optimally

Single-cell network profiling of peripheral blood mononuclear cells from healthy donors reveals age- and race-associated differences in immune signaling pathway activation.

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Longo, Diane M; Louie, Brent; Putta, Santosh; Evensen, Erik; Ptacek, Jason; Cordeiro, James; Wang, Ena; Pos, Zoltan; Hawtin, Rachael E; Marincola, Francesco M; Cesano, Alessandra

2012-02-15

A greater understanding of the function of the human immune system at the single-cell level in healthy individuals is critical for discerning aberrant cellular behavior that occurs in settings such as autoimmunity, immunosenescence, and cancer. To achieve this goal, a systems-level approach capable of capturing the response of the interdependent immune cell types to external stimuli is required. In this study, an extensive characterization of signaling responses in multiple immune cell subpopulations within PBMCs from a cohort of 60 healthy donors was performed using single-cell network profiling (SCNP). SCNP is a multiparametric flow cytometry-based approach that enables the simultaneous measurement of basal and evoked signaling in multiple cell subsets within heterogeneous populations. In addition to establishing the interindividual degree of variation within a broad panel of immune signaling responses, the possible association of any observed variation with demographic variables including age and race was investigated. Using half of the donors as a training set, multiple age- and race-associated variations in signaling responses in discrete cell subsets were identified, and several were subsequently confirmed in the remaining samples (test set). Such associations may provide insight into age-related immune alterations associated with high infection rates and diminished protection following vaccination and into the basis for ethnic differences in autoimmune disease incidence and treatment response. SCNP allowed for the generation of a functional map of healthy immune cell signaling responses that can provide clinically relevant information regarding both the mechanisms underlying immune pathological conditions and the selection and effect of therapeutics.

Functional comparison of innate immune signaling pathways in primates.

Directory of Open Access Journals (Sweden)

Luis B Barreiro

2010-12-01

Full Text Available Humans respond differently than other primates to a large number of infections. Differences in susceptibility to infectious agents between humans and other primates are probably due to inter-species differences in immune response to infection. Consistent with that notion, genes involved in immunity-related processes are strongly enriched among recent targets of positive selection in primates, suggesting that immune responses evolve rapidly, yet providing only indirect evidence for possible inter-species functional differences. To directly compare immune responses among primates, we stimulated primary monocytes from humans, chimpanzees, and rhesus macaques with lipopolysaccharide (LPS and studied the ensuing time-course regulatory responses. We find that, while the universal Toll-like receptor response is mostly conserved across primates, the regulatory response associated with viral infections is often lineage-specific, probably reflecting rapid host-virus mutual adaptation cycles. Additionally, human-specific immune responses are enriched for genes involved in apoptosis, as well as for genes associated with cancer and with susceptibility to infectious diseases or immune-related disorders. Finally, we find that chimpanzee-specific immune signaling pathways are enriched for HIV-interacting genes. Put together, our observations lend strong support to the notion that lineage-specific immune responses may help explain known inter-species differences in susceptibility to infectious diseases.

Cyclic GMP-AMP as an Endogenous Second Messenger in Innate Immune Signaling by Cytosolic DNA.

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Kato, Kazuki; Omura, Hiroki; Ishitani, Ryuichiro; Nureki, Osamu

2017-06-20

The innate immune system functions as the first line of defense against invading bacteria and viruses. In this context, the cGAS/STING [cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) synthase/STING] signaling axis perceives the nonself DNA associated with bacterial and viral infections, as well as the leakage of self DNA by cellular dysfunction and stresses, to elicit the host's immune responses. In this pathway, the noncanonical cyclic dinucleotide 2',3'-cyclic GMP-AMP (2',3'-cGAMP) functions as a second messenger for signal transduction: 2',3'-cGAMP is produced by the enzyme cGAS upon its recognition of double-stranded DNA, and then the 2',3'-cGAMP is recognized by the receptor STING to induce the phosphorylation of downstream factors, including TBK1 (TANK binding kinase 1) and IRF3 (interferon regulatory factor 3). Numerous crystal structures of the components of this cGAS/STING signaling axis have been reported and these clarify the structural basis for their signal transduction mechanisms. In this review, we summarize recent progress made in the structural dissection of this signaling pathway and indicate possible directions of forthcoming research.

Quantitative Evaluation of Stomatal Cytoskeletal Patterns during the Activation of Immune Signaling in Arabidopsis thaliana.

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Masaki Shimono

Full Text Available Historically viewed as primarily functioning in the regulation of gas and water vapor exchange, it is now evident that stomata serve an important role in plant immunity. Indeed, in addition to classically defined functions related to cell architecture and movement, the actin cytoskeleton has emerged as a central component of the plant immune system, underpinning not only processes related to cell shape and movement, but also receptor activation and signaling. Using high resolution quantitative imaging techniques, the temporal and spatial changes in the actin microfilament array during diurnal cycling of stomatal guard cells has revealed a highly orchestrated transition from random arrays to ordered bundled filaments. While recent studies have demonstrated that plant stomata close in response to pathogen infection, an evaluation of stimulus-induced changes in actin cytoskeletal dynamics during immune activation in the guard cell, as well as the relationship of these changes to the function of the actin cytoskeleton and stomatal aperture, remains undefined. In the current study, we employed quantitative cell imaging and hierarchical clustering analyses to define the response of the guard cell actin cytoskeleton to pathogen infection and the elicitation of immune signaling. Using this approach, we demonstrate that stomatal-localized actin filaments respond rapidly, and specifically, to both bacterial phytopathogens and purified pathogen elicitors. Notably, we demonstrate that higher order temporal and spatial changes in the filament array show distinct patterns of organization during immune activation, and that changes in the naïve diurnal oscillations of guard cell actin filaments are perturbed by pathogens, and that these changes parallel pathogen-induced stomatal gating. The data presented herein demonstrate the application of a highly tractable and quantifiable method to assign transitions in actin filament organization to the activation of

Design principles of paradoxical signaling in the immune system

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Hart, Yuval

A widespread feature of cell-cell signaling systems is paradoxical pleiotropy: the same secreted signaling molecule can induce opposite effects in the responding cells. For example, the cytokine IL-2 can promote proliferation and death of T-cells. The role of such paradoxical signaling remains unclear. We suggest that this mechanism provides homeostatic concentration of cells, independent of initial conditions. The crux of the paradoxical mechanism is the combination of a positive and a negative feedback loops creating two stable states - an OFF state and an ON state. Experimentally, we found that CD4 + cells grown in culture with a 30-fold difference in initial concentrations reached a homeostatic concentration nearly independent of initial cell levels (ON-state). Below an initial threshold, cell density decayed to extinction (OFF-state). Mathematical modeling explained the observed cell and cytokine dynamics and predicted conditions that shifted cell fate from homeostasis to the OFF-state. We suggest that paradoxical signaling provides cell circuits with specific dynamical features that are robust to environmental perturbations.

DMPD: Peptidoglycan signaling in innate immunity and inflammatory disease. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 15802263 Peptidoglycan signaling in innate immunity and inflammatory disease. McDon...ald C, Inohara N, Nunez G. J Biol Chem. 2005 May 27;280(21):20177-80. Epub 2005 Mar 31. (.png) (.svg) (.html) (.csml) Show Peptidog...lycan signaling in innate immunity and inflammatory disease. PubmedID 15802263 Title Peptidog

Molecular dialogs between the ischemic brain and the peripheral immune system: dualistic roles in injury and repair.

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An, Chengrui; Shi, Yejie; Li, Peiying; Hu, Xiaoming; Gan, Yu; Stetler, Ruth A; Leak, Rehana K; Gao, Yanqin; Sun, Bao-Liang; Zheng, Ping; Chen, Jun

2014-04-01

Immune and inflammatory responses actively modulate the pathophysiological processes of acute brain injuries such as stroke. Soon after the onset of stroke, signals such as brain-derived antigens, danger-associated molecular patterns (DAMPs), cytokines, and chemokines are released from the injured brain into the systemic circulation. The injured brain also communicates with peripheral organs through the parasympathetic and sympathetic branches of the autonomic nervous system. Many of these diverse signals not only activate resident immune cells in the brain, but also trigger robust immune responses in the periphery. Peripheral immune cells then migrate toward the site of injury and release additional cytokines, chemokines, and other molecules, causing further disruptive or protective effects in the ischemic brain. Bidirectional communication between the injured brain and the peripheral immune system is now known to regulate the progression of stroke pathology as well as tissue repair. In the end, this exquisitely coordinated crosstalk helps determine the fate of animals after stroke. This article reviews the literature on ischemic brain-derived signals through which peripheral immune responses are triggered, and the potential impact of these peripheral responses on brain injury and repair. Pharmacological strategies and cell-based therapies that target the dialog between the brain and peripheral immune system show promise as potential novel treatments for stroke. Published by Elsevier Ltd.

Intestinal epithelial cell-specific RARα depletion results in aberrant epithelial cell homeostasis and underdeveloped immune system.

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Jijon, H B; Suarez-Lopez, L; Diaz, O E; Das, S; De Calisto, J; Yaffe, M B; Pittet, M J; Mora, J R; Belkaid, Y; Xavier, R J; Villablanca, E J

2018-05-01

Retinoic acid (RA), a dietary vitamin A metabolite, is crucial in maintaining intestinal homeostasis. RA acts on intestinal leukocytes to modulate their lineage commitment and function. Although the role of RA has been characterized in immune cells, whether intestinal epithelial cells (IECs) rely on RA signaling to exert their immune-regulatory function has not been examined. Here we demonstrate that lack of RA receptor α (RARα) signaling in IECs results in deregulated epithelial lineage specification, leading to increased numbers of goblet cells and Paneth cells. Mechanistically, lack of RARα resulted in increased KLF4 + goblet cell precursors in the distal bowel, whereas RA treatment inhibited klf4 expression and goblet cell differentiation in zebrafish. These changes in secretory cells are associated with increased Reg3g, reduced luminal bacterial detection, and an underdeveloped intestinal immune system, as evidenced by an almost complete absence of lymphoid follicles and gut resident mononuclear phagocytes. This underdeveloped intestinal immune system shows a decreased ability to clear infection with Citrobacter rodentium. Collectively, our findings indicate that epithelial cell-intrinsic RARα signaling is critical to the global development of the intestinal immune system.

Group 3 Innate Lymphoid Cells: Communications Hubs of the Intestinal Immune System.

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Withers, David R; Hepworth, Matthew R

2017-01-01

The maintenance of mammalian health requires the generation of appropriate immune responses against a broad range of environmental and microbial challenges, which are continually encountered at barrier tissue sites including the skin, lung, and gastrointestinal tract. Dysregulated barrier immune responses result in inflammation, both locally and systemically in peripheral organs. Group 3 innate lymphoid cells (ILC3) are constitutively present at barrier sites and appear to be highly specialized in their ability to sense a range of environmental and host-derived signals. Under homeostatic conditions, ILC3 respond to local cues to maintain tissue homeostasis and restrict inflammatory responses. In contrast, perturbations in the tissue microenvironment resulting from disease, infection, or tissue damage can drive dysregulated pro-inflammatory ILC3 responses and contribute to immunopathology. The tone of the ILC3 response is dictated by a balance of "exogenous" signals, such as dietary metabolites and commensal microbes, and "endogenous" host-derived signals from stromal cells, immune cells, and the nervous system. ILC3 must therefore have the capacity to simultaneously integrate a wide array of complex and dynamic inputs in order to regulate barrier function and tissue health. In this review, we discuss the concept of ILC3 as a "communications hub" in the intestinal tract and associated lymphoid tissues and address the variety of signals, derived from multiple biological systems, which are interpreted by ILC3 to modulate the release of downstream effector molecules and regulate cell-cell crosstalk. Successful integration of environmental cues by ILC3 and downstream propagation to the broader immune system is required to maintain a tolerogenic and anti-inflammatory tone and reinforce barrier function, whereas dysregulation of ILC3 responses can contribute to the onset or progression of clinically relevant chronic inflammatory diseases.

Group 3 Innate Lymphoid Cells: Communications Hubs of the Intestinal Immune System

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David R. Withers

2017-10-01

Full Text Available The maintenance of mammalian health requires the generation of appropriate immune responses against a broad range of environmental and microbial challenges, which are continually encountered at barrier tissue sites including the skin, lung, and gastrointestinal tract. Dysregulated barrier immune responses result in inflammation, both locally and systemically in peripheral organs. Group 3 innate lymphoid cells (ILC3 are constitutively present at barrier sites and appear to be highly specialized in their ability to sense a range of environmental and host-derived signals. Under homeostatic conditions, ILC3 respond to local cues to maintain tissue homeostasis and restrict inflammatory responses. In contrast, perturbations in the tissue microenvironment resulting from disease, infection, or tissue damage can drive dysregulated pro-inflammatory ILC3 responses and contribute to immunopathology. The tone of the ILC3 response is dictated by a balance of “exogenous” signals, such as dietary metabolites and commensal microbes, and “endogenous” host-derived signals from stromal cells, immune cells, and the nervous system. ILC3 must therefore have the capacity to simultaneously integrate a wide array of complex and dynamic inputs in order to regulate barrier function and tissue health. In this review, we discuss the concept of ILC3 as a “communications hub” in the intestinal tract and associated lymphoid tissues and address the variety of signals, derived from multiple biological systems, which are interpreted by ILC3 to modulate the release of downstream effector molecules and regulate cell–cell crosstalk. Successful integration of environmental cues by ILC3 and downstream propagation to the broader immune system is required to maintain a tolerogenic and anti-inflammatory tone and reinforce barrier function, whereas dysregulation of ILC3 responses can contribute to the onset or progression of clinically relevant chronic inflammatory diseases.

Group 3 Innate Lymphoid Cells: Communications Hubs of the Intestinal Immune System

Science.gov (United States)

Withers, David R.; Hepworth, Matthew R.

2017-01-01

The maintenance of mammalian health requires the generation of appropriate immune responses against a broad range of environmental and microbial challenges, which are continually encountered at barrier tissue sites including the skin, lung, and gastrointestinal tract. Dysregulated barrier immune responses result in inflammation, both locally and systemically in peripheral organs. Group 3 innate lymphoid cells (ILC3) are constitutively present at barrier sites and appear to be highly specialized in their ability to sense a range of environmental and host-derived signals. Under homeostatic conditions, ILC3 respond to local cues to maintain tissue homeostasis and restrict inflammatory responses. In contrast, perturbations in the tissue microenvironment resulting from disease, infection, or tissue damage can drive dysregulated pro-inflammatory ILC3 responses and contribute to immunopathology. The tone of the ILC3 response is dictated by a balance of “exogenous” signals, such as dietary metabolites and commensal microbes, and “endogenous” host-derived signals from stromal cells, immune cells, and the nervous system. ILC3 must therefore have the capacity to simultaneously integrate a wide array of complex and dynamic inputs in order to regulate barrier function and tissue health. In this review, we discuss the concept of ILC3 as a “communications hub” in the intestinal tract and associated lymphoid tissues and address the variety of signals, derived from multiple biological systems, which are interpreted by ILC3 to modulate the release of downstream effector molecules and regulate cell–cell crosstalk. Successful integration of environmental cues by ILC3 and downstream propagation to the broader immune system is required to maintain a tolerogenic and anti-inflammatory tone and reinforce barrier function, whereas dysregulation of ILC3 responses can contribute to the onset or progression of clinically relevant chronic inflammatory diseases. PMID:29085366

Signalling through C-type lectin receptors: shaping immune responses

NARCIS (Netherlands)

Geijtenbeek, Teunis B. H.; Gringhuis, Sonja I.

2009-01-01

C-type lectin receptors (CLRs) expressed by dendritic cells are crucial for tailoring immune responses to pathogens. Following pathogen binding, CLRs trigger distinct signalling pathways that induce the expression of specific cytokines which determine T cell polarization fates. Some CLRs can induce

Cancer-Targeted Oncolytic Adenoviruses for Modulation of the Immune System.

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Cerullo, Vincenzo; Capasso, Cristian; Vaha-Koskela, Markus; Hemminki, Otto; Hemminki, Akseli

2018-01-01

Adenovirus is one of the most commonly used vectors for gene therapy and it is the first approved virus-derived drug for treatment of cancer. As an oncolytic agent, it can induce lysis of infected cells, but it can also engage the immune system, promoting activation and maturation of antigen- presenting cells (APCs). In essence, oncolysis combined with the associated immunostimulatory actions result in a "personalized in situ vaccine" for each patient. In order to take full advantage of these features, we should try to understand how adenovirus interacts with the immune system, what are the receptors involved in triggering subsequent signals and which kind of responses they elicit. Tackling these questions will give us further insight in how to manipulate adenovirus-mediated immune responses for enhancement of anti-tumor efficacy. In this review, we first highlight how oncolytic adenovirus interacts with the innate immune system and its receptors such as Toll-like receptors, nucleotide-binding and oligomerization domain (NOD)- like receptors and other immune sensors. Then we describe the effect of these interactions on the adaptive immune system and its cells, especially B and T lymphocytes. Finally, we summarize the most significant preclinical and clinical results in the field of gene therapy where researchers have engineered adenovirus to manipulate the host immune system by expressing cytokines and signalingmediators. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Immune System

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A properly functioning immune system is essential to good health. It defends the body against infectious agents and in some cases tumor cells. Individuals with immune deficiencies resulting from genetic defects, diseases (e.g., AIDS, leukemia), or drug therapies are more suscepti...

Weakened Immune Systems

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... Issues Health Issues Health Issues Conditions Injuries & Emergencies Vaccine Preventable Diseases ... Children > Safety & Prevention > Immunizations > Weakened Immune Systems Safety & Prevention ...

The TLR13-MyD88-NF-κB signalling pathway of Cyclina sinensis plays vital roles in innate immune responses.

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Ren, Yipeng; Ding, Dan; Pan, Baoping; Bu, Wenjun

2017-11-01

Toll-like receptors, the best known pattern recognition receptors, play important roles in recognizing non-self molecules and binding pathogen-associated molecular patterns in the innate immune system. In the present research, the cDNA and protein characterization of the TLR signalling pathway genes including IRAK4, TRAK6 and IKKα (named CsIRAK4, CsTRAF6 and CsIKKα, respectively) with the typical motifs from Cyclina sinensis showed significant similarity with their homologues from other shellfish. Furthermore, the mRNA transcripts of these three genes are ubiquitously expressed in all tissues tested and are dominantly expressed in C. sinensis haemocytes (P sinensis by RNA interference and immune challenges. The results suggested the mRNA expression patterns of CsMyD88, CsIRAK4, CsTRAF6, CsIKKα, CsIκB, CsNF-κB, CsC-LYZ and CsAMP were all down-regulated (P sinensis haemocytes, revealing the involvement of the TLR13-MyD88-NF-κB signalling pathway in innate immunity by positively adjusting internal signalling factors and immune-related genes. In summary, a TLR13-MyD88-NF-κB signalling pathway exists and plays vital roles in innate immune responses in C. sinensis. These findings collectively lay the foundation for studying the functional characterization of internal signalling factors and establishing a regulatory network for the TLR signalling pathway in molluscs. Copyright © 2017 Elsevier Ltd. All rights reserved.

DMPD: Innate immune sensing of pathogens and danger signals by cell surface Toll-likereceptors. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 17275324 Innate immune sensing of pathogens and danger signals by cell surface Toll... Show Innate immune sensing of pathogens and danger signals by cell surface Toll-likereceptors. PubmedID 172...75324 Title Innate immune sensing of pathogens and danger signals by cell surface

Aberrant T Cell Signaling and Subsets in Systemic Lupus Erythematosus

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Takayuki Katsuyama

2018-05-01

Full Text Available Systemic lupus erythematosus (SLE is a chronic multi-organ debilitating autoimmune disease, which mainly afflicts women in the reproductive years. A complex interaction of genetics, environmental factors and hormones result in the breakdown of immune tolerance to “self” leading to damage and destruction of multiple organs, such as the skin, joints, kidneys, heart and brain. Both innate and adaptive immune systems are critically involved in the misguided immune response against self-antigens. Dendritic cells, neutrophils, and innate lymphoid cells are important in initiating antigen presentation and propagating inflammation at lymphoid and peripheral tissue sites. Autoantibodies produced by B lymphocytes and immune complex deposition in vital organs contribute to tissue damage. T lymphocytes are increasingly being recognized as key contributors to disease pathogenesis. CD4 T follicular helper cells enable autoantibody production, inflammatory Th17 subsets promote inflammation, while defects in regulatory T cells lead to unchecked immune responses. A better understanding of the molecular defects including signaling events and gene regulation underlying the dysfunctional T cells in SLE is necessary to pave the path for better management, therapy, and perhaps prevention of this complex disease. In this review, we focus on the aberrations in T cell signaling in SLE and highlight therapeutic advances in this field.

Aberrant T Cell Signaling and Subsets in Systemic Lupus Erythematosus

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Katsuyama, Takayuki; Tsokos, George C.; Moulton, Vaishali R.

2018-01-01

Systemic lupus erythematosus (SLE) is a chronic multi-organ debilitating autoimmune disease, which mainly afflicts women in the reproductive years. A complex interaction of genetics, environmental factors and hormones result in the breakdown of immune tolerance to “self” leading to damage and destruction of multiple organs, such as the skin, joints, kidneys, heart and brain. Both innate and adaptive immune systems are critically involved in the misguided immune response against self-antigens. Dendritic cells, neutrophils, and innate lymphoid cells are important in initiating antigen presentation and propagating inflammation at lymphoid and peripheral tissue sites. Autoantibodies produced by B lymphocytes and immune complex deposition in vital organs contribute to tissue damage. T lymphocytes are increasingly being recognized as key contributors to disease pathogenesis. CD4 T follicular helper cells enable autoantibody production, inflammatory Th17 subsets promote inflammation, while defects in regulatory T cells lead to unchecked immune responses. A better understanding of the molecular defects including signaling events and gene regulation underlying the dysfunctional T cells in SLE is necessary to pave the path for better management, therapy, and perhaps prevention of this complex disease. In this review, we focus on the aberrations in T cell signaling in SLE and highlight therapeutic advances in this field. PMID:29868033

Immune system simulation online

DEFF Research Database (Denmark)

Rapin, Nicolas; Lund, Ole; Castiglione, Filippo

2011-01-01

MOTIVATION: The recognition of antigenic peptides is a major event of an immune response. In current mesoscopic-scale simulators of the immune system, this crucial step has been modeled in a very approximated way. RESULTS: We have equipped an agent-based model of the immune system with immuno...

Deletion of the innate immune NLRP3 receptor abolishes cardiac ischemic preconditioning and is associated with decreased Il-6/STAT3 signaling

NARCIS (Netherlands)

Zuurbier, C.J.; Jong, W.M.; Eerbeek, O.; Koeman, A.; Pulskens, W.P.C.; Butter, L.M.; Leemans, J.C.; Hollmann, M.W.

2012-01-01

OBJECTIVE: Recent studies indicate that the innate immune system is not only triggered by exogenous pathogens and pollutants, but also by endogenous danger signals released during ischemia and necrosis. As triggers for the innate immune NLRP3 inflammasome protein complex appear to overlap with those

Geometric Distribution-Based Readers Scheduling Optimization Algorithm Using Artificial Immune System

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Litian Duan

2016-11-01

Full Text Available In the multiple-reader environment (MRE of radio frequency identification (RFID system, multiple readers are often scheduled to interrogate the randomized tags via operating at different time slots or frequency channels to decrease the signal interferences. Based on this, a Geometric Distribution-based Multiple-reader Scheduling Optimization Algorithm using Artificial Immune System (GD-MRSOA-AIS is proposed to fairly and optimally schedule the readers operating from the viewpoint of resource allocations. GD-MRSOA-AIS is composed of two parts, where a geometric distribution function combined with the fairness consideration is first introduced to generate the feasible scheduling schemes for reader operation. After that, artificial immune system (including immune clone, immune mutation and immune suppression quickly optimize these feasible ones as the optimal scheduling scheme to ensure that readers are fairly operating with larger effective interrogation range and lower interferences. Compared with the state-of-the-art algorithm, the simulation results indicate that GD-MRSOA-AIS could efficiently schedules the multiple readers operating with a fairer resource allocation scheme, performing in larger effective interrogation range.

Quantifying adaptive evolution in the Drosophila immune system.

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Darren J Obbard

2009-10-01

Full Text Available It is estimated that a large proportion of amino acid substitutions in Drosophila have been fixed by natural selection, and as organisms are faced with an ever-changing array of pathogens and parasites to which they must adapt, we have investigated the role of parasite-mediated selection as a likely cause. To quantify the effect, and to identify which genes and pathways are most likely to be involved in the host-parasite arms race, we have re-sequenced population samples of 136 immunity and 287 position-matched non-immunity genes in two species of Drosophila. Using these data, and a new extension of the McDonald-Kreitman approach, we estimate that natural selection fixes advantageous amino acid changes in immunity genes at nearly double the rate of other genes. We find the rate of adaptive evolution in immunity genes is also more variable than other genes, with a small subset of immune genes evolving under intense selection. These genes, which are likely to represent hotspots of host-parasite coevolution, tend to share similar functions or belong to the same pathways, such as the antiviral RNAi pathway and the IMD signalling pathway. These patterns appear to be general features of immune system evolution in both species, as rates of adaptive evolution are correlated between the D. melanogaster and D. simulans lineages. In summary, our data provide quantitative estimates of the elevated rate of adaptive evolution in immune system genes relative to the rest of the genome, and they suggest that adaptation to parasites is an important force driving molecular evolution.

The interplay between the immune system and chemotherapy: emerging methods for optimizing therapy.

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Ghiringhelli, François; Apetoh, Lionel

2014-01-01

Preclinical studies have revealed an unexpected ability of the immune system to contribute to the success of chemotherapy and radiotherapy. Anticancer therapies can trigger immune system activation by promoting the release of danger signals from dying tumor cells and/or the elimination of immunosuppressive cells. We have, however, recently discovered that some chemotherapies, such as 5-fluorouracil and gemcitabine, exert conflicting effects on anticancer immune responses. Although 5-fluorouracil and Gem selectively eliminated myeloid-derived suppressive cells in tumor-bearing rodents, these chemotherapies promoted the release of IL-1β and the development of pro-angiogenic IL-17-producing CD4 T cells. The ambivalent effects of chemotherapy on immune responses should thus be carefully considered to design effective combination therapies based on chemotherapy and immune modulators. Herein, we discuss how the initial findings underscoring the key role of the immune system in mediating the antitumor efficacy of anticancer agents could begin to translate into effective therapies in humans.

Adrenergic Signaling: A Targetable Checkpoint Limiting Development of the Antitumor Immune Response

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Qiao, Guanxi; Chen, Minhui; Bucsek, Mark J.; Repasky, Elizabeth A.; Hylander, Bonnie L.

2018-01-01

An immune response must be tightly controlled so that it will be commensurate with the level of response needed to protect the organism without damaging normal tissue. The roles of cytokines and chemokines in orchestrating these processes are well known, but although stress has long been thought to also affect immune responses, the underlying mechanisms were not as well understood. Recently, the role of nerves and, specifically, the sympathetic nervous system, in regulating immune responses is being revealed. Generally, an acute stress response is beneficial but chronic stress is detrimental because it suppresses the activities of effector immune cells while increasing the activities of immunosuppressive cells. In this review, we first discuss the underlying biology of adrenergic signaling in cells of both the innate and adaptive immune system. We then focus on the effects of chronic adrenergic stress in promoting tumor growth, giving examples of effects on tumor cells and immune cells, explaining the methods commonly used to induce stress in preclinical mouse models. We highlight how this relates to our observations that mandated housing conditions impose baseline chronic stress on mouse models, which is sufficient to cause chronic immunosuppression. This problem is not commonly recognized, but it has been shown to impact conclusions of several studies of mouse physiology and mouse models of disease. Moreover, the fact that preclinical mouse models are chronically immunosuppressed has critical ramifications for analysis of any experiments with an immune component. Our group has found that reducing adrenergic stress by housing mice at thermoneutrality or treating mice housed at cooler temperatures with β-blockers reverses immunosuppression and significantly improves responses to checkpoint inhibitor immunotherapy. These observations are clinically relevant because there are numerous retrospective epidemiological studies concluding that cancer patients who were

Immunization Information System and Informatics to Promote Immunizations: Perspective From Minnesota Immunization Information Connection.

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Muscoplat, Miriam Halstead; Rajamani, Sripriya

2017-01-01

The vision for management of immunization information is availability of real-time consolidated data and services for all ages, to clinical, public health, and other stakeholders. This is being executed through Immunization Information Systems (IISs), which are population-based and confidential computerized systems present in most US states and territories. Immunization Information Systems offer many functionalities, such as immunization assessment reports, client follow-up, reminder/recall feature, vaccine management tools, state-supplied vaccine ordering, comprehensive immunization history, clinical decision support/vaccine forecasting and recommendations, data processing, and data exchange. This perspective article will present various informatics tools in an IIS, in the context of the Minnesota Immunization Information Connection.

Phosphoproteomics-based systems analysis of signal transduction networks

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Hiroko eKozuka-Hata

2012-01-01

Full Text Available Signal transduction systems coordinate complex cellular information to regulate biological events such as cell proliferation and differentiation. Although the accumulating evidence on widespread association of signaling molecules has revealed essential contribution of phosphorylation-dependent interaction networks to cellular regulation, their dynamic behavior is mostly yet to be analyzed. Recent technological advances regarding mass spectrometry-based quantitative proteomics have enabled us to describe the comprehensive status of phosphorylated molecules in a time-resolved manner. Computational analyses based on the phosphoproteome dynamics accelerate generation of novel methodologies for mathematical analysis of cellular signaling. Phosphoproteomics-based numerical modeling can be used to evaluate regulatory network elements from a statistical point of view. Integration with transcriptome dynamics also uncovers regulatory hubs at the transcriptional level. These omics-based computational methodologies, which have firstly been applied to representative signaling systems such as the epidermal growth factor receptor pathway, have now opened up a gate for systems analysis of signaling networks involved in immune response and cancer.

Dissecting Phaseolus vulgaris innate immune system against Colletotrichum lindemuthianum infection.

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Paula Rodrigues Oblessuc

Full Text Available BACKGROUND: The genus Colletotrichum is one of the most economically important plant pathogens, causing anthracnose on a wide range of crops including common beans (Phaseolus vulgaris L.. Crop yield can be dramatically decreased depending on the plant cultivar used and the environmental conditions. This study aimed to identify potential genetic components of the bean immune system to provide environmentally friendly control measures against this fungus. METHODOLOGY AND PRINCIPAL FINDINGS: As the common bean is not amenable to reverse genetics to explore functionality and its genome is not fully curated, we used putative Arabidopsis orthologs of bean expressed sequence tag (EST to perform bioinformatic analysis and experimental validation of gene expression to identify common bean genes regulated during the incompatible interaction with C. lindemuthianum. Similar to model pathosystems, Gene Ontology (GO analysis indicated that hormone biosynthesis and signaling in common beans seem to be modulated by fungus infection. For instance, cytokinin and ethylene responses were up-regulated and jasmonic acid, gibberellin, and abscisic acid responses were down-regulated, indicating that these hormones may play a central role in this pathosystem. Importantly, we have identified putative bean gene orthologs of Arabidopsis genes involved in the plant immune system. Based on experimental validation of gene expression, we propose that hypersensitive reaction as part of effector-triggered immunity may operate, at least in part, by down-regulating genes, such as FLS2-like and MKK5-like, putative orthologs of the Arabidopsis genes involved in pathogen perception and downstream signaling. CONCLUSIONS/SIGNIFICANCE: We have identified specific bean genes and uncovered metabolic processes and pathways that may be involved in the immune response against pathogens. Our transcriptome database is a rich resource for mining novel defense-related genes, which enabled us to

Innate immune signalling at the intestinal epithelium in homeostasis and disease

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Pott, Johanna; Hornef, Mathias

2012-01-01

The intestinal epithelium—which constitutes the interface between the enteric microbiota and host tissues—actively contributes to the maintenance of mucosal homeostasis and defends against pathogenic microbes. The recognition of conserved microbial products by cytosolic or transmembrane pattern recognition receptors in epithelial cells initiates signal transduction and influences effector cell function. However, the signalling pathways, effector molecules and regulatory mechanisms involved are not yet fully understood, and the functional outcome is poorly defined. This review analyses the complex and dynamic role of intestinal epithelial innate immune recognition and signalling, on the basis of results in intestinal epithelial cell-specific transgene or gene-deficient animals. This approach identifies specific epithelial cell functions within the diverse cellular composition of the mucosal tissue, in the presence of the complex and dynamic gut microbiota. These insights have thus provided a more comprehensive understanding of the role of the intestinal epithelium in innate immunity during homeostasis and disease. PMID:22801555

Gut Microbiota-Immune System Crosstalk and Pancreatic Disorders

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D. Pagliari

2018-01-01

Full Text Available Gut microbiota is key to the development and modulation of the mucosal immune system. It plays a central role in several physiological functions, in the modulation of inflammatory signaling and in the protection against infections. In healthy states, there is a perfect balance between commensal and pathogens, and microbiota and the immune system interact to maintain gut homeostasis. The alteration of such balance, called dysbiosis, determines an intestinal bacterial overgrowth which leads to the disruption of the intestinal barrier with systemic translocation of pathogens. The pancreas does not possess its own microbiota, and it is believed that inflammatory and neoplastic processes affecting the gland may be linked to intestinal dysbiosis. Increasing research evidence testifies a correlation between intestinal dysbiosis and various pancreatic disorders, but it remains unclear whether dysbiosis is the cause or an effect. The analysis of specific alterations in the microbiome profile may permit to develop novel tools for the early detection of several pancreatic disorders, utilizing samples, such as blood, saliva, and stools. Future studies will have to elucidate the mechanisms by which gut microbiota is modulated and how it tunes the immune system, in order to be able to develop innovative treatment strategies for pancreatic disorders.

The activation of the adaptive immune system: cross-talk between antigen-presenting cells, T cells and B cells.

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den Haan, Joke M M; Arens, Ramon; van Zelm, Menno C

2014-12-01

The adaptive immune system consists of T and B cells that express clonally distributed antigen receptors. To achieve functional adaptive immune responses, antigen-specific T cell populations are stimulated by professional antigen-presenting cells like dendritic cells (DCs), which provide crucial stimulatory signals for efficient expansion and development of effector functions. Antigen-specific B cells receive costimulatory signals from helper T cells to stimulate affinity maturation and isotype switching. Here we elaborate on the interactions between DCs, T cells and B cells, and on the important signals for efficient induction of adaptive immune responses. Copyright © 2014 Elsevier B.V. All rights reserved.

Innate immune receptor Toll-like receptor 4 signalling in neuropsychiatric diseases.

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García Bueno, B; Caso, J R; Madrigal, J L M; Leza, J C

2016-05-01

The innate immunity is a stereotyped first line of defense against pathogens and unspecified damage signals. One of main actors of innate immunity are the Toll-like receptors (TLRs), and one of the better characterized members of this family is TLR-4, that it is mainly activated by Gram-negative bacteria lipopolysaccharide. In brain, TLR-4 organizes innate immune responses against infections or cellular damage, but also possesses other physiological functions. In the last years, some evidences suggest a role of TLR-4 in stress and stress-related neuropsychiatric diseases. Peripheral and brain TLR-4 activation triggers sickness behavior, and its expression is a risk factor of depression. Some elements of the TLR-4 signaling pathway are up-regulated in peripheral samples and brain post-mortem tissue from depressed and suicidal patients. The "leaky gut" hypothesis of neuropsychiatric diseases is based on the existence of an increase of the intestinal permeability which results in bacterial translocation able to activate TLR-4. Enhanced peripheral TLR-4 expression/activity has been described in subjects diagnosed with schizophrenia, bipolar disorder and in autistic children. A role for TLR-4 in drugs abuse has been also proposed. The therapeutic potential of pharmacological/genetic modulation of TLRs signaling pathways in neuropsychiatry is promising, but a great preclinical/clinical scientific effort is still needed. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Neuromodulation of the Intestinal Immune System and Its Relevance in Inflammatory Bowel Disease.

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Di Giovangiulio, Martina; Verheijden, Simon; Bosmans, Goele; Stakenborg, Nathalie; Boeckxstaens, Guy E; Matteoli, Gianluca

2015-01-01

One of the main tasks of the immune system is to discriminate and appropriately react to "danger" or "non-danger" signals. This is crucial in the gastrointestinal tract, where the immune system is confronted with a myriad of food antigens and symbiotic microflora that are in constant contact with the mucosa, in addition to any potential pathogens. This large number of antigens and commensal microflora, which are essential for providing vital nutrients, must be tolerated by the intestinal immune system to prevent aberrant inflammation. Hence, the balance between immune activation versus tolerance should be tightly regulated to maintain intestinal homeostasis and to prevent immune activation indiscriminately against all luminal antigens. Loss of this delicate equilibrium can lead to chronic activation of the intestinal immune response resulting in intestinal disorders, such as inflammatory bowel diseases (IBD). In order to maintain homeostasis, the immune system has evolved diverse regulatory strategies including additional non-immunological actors able to control the immune response. Accumulating evidence strongly indicates a bidirectional link between the two systems in which the brain modulates the immune response via the detection of circulating cytokines and via direct afferent input from sensory fibers and from enteric neurons. In the current review, we will highlight the most recent findings regarding the cross-talk between the nervous system and the mucosal immune system and will discuss the potential use of these neuronal circuits and neuromediators as novel therapeutic tools to reestablish immune tolerance and treat intestinal chronic inflammation.

Alternative Immune Systems

Directory of Open Access Journals (Sweden)

Luis Fernando Cadavid Gutierrez

2011-09-01

Full Text Available The immune system in animals is a complex network of molecules, cells and tissues that coordinately maintain the physiological and genetic integrity of the organism. Traditionally, two classes of immunity have been considered, the innate immunity and the adaptive immunity. The former is ancestral, with limited variability and low discrimination. The latter is highly variable, specific and limited to jawed vertebrates. Adaptive immunity is based on antigen receptors that rearrange somatically to generate a nearly unlimited diversity of molecules. Likely, this mechanism of somatic recombination arose as a consequence of a horizontal transfer of transposons and transposases from bacterial genomes in the ancestor of jawed vertebrates. The recent discovery in jawless vertebrates and invertebrates of alternative adaptive immune mechanisms, suggests during evolution different animal groups have found alternative solutions to the problem of immune recognition.

The twilight of immunity: emerging concepts in aging of the immune system.

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Nikolich-Žugich, Janko

2018-01-01

Immunosenescence is a series of age-related changes that affect the immune system and, with time, lead to increased vulnerability to infectious diseases. This Review addresses recent developments in the understanding of age-related changes that affect key components of immunity, including the effect of aging on cells of the (mostly adaptive) immune system, on soluble molecules that guide the maintenance and function of the immune system and on lymphoid organs that coordinate both the maintenance of lymphocytes and the initiation of immune responses. I further address the effect of the metagenome and exposome as key modifiers of immune-system aging and discuss a conceptual framework in which age-related changes in immunity might also affect the basic rules by which the immune system operates.

Role of the immune system in regeneration and its dynamic interplay with adult stem cells.

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Abnave, Prasad; Ghigo, Eric

2018-04-09

The immune system plays an indispensable role in the process of tissue regeneration following damage as well as during homeostasis. Inflammation and immune cell recruitment are signs of early onset injury. At the wound site, immune cells not only help to clear debris but also secrete numerous signalling molecules that induce appropriate cell proliferation and differentiation programmes essential for successful regeneration. However, the immune system does not always perform a complementary role in regeneration and several reports have suggested that increased inflammation can inhibit the regeneration process. Successful regeneration requires a balanced immune cell response, with the recruitment of accurately polarised immune cells in an appropriate quantity. The regulatory interactions of the immune system with regeneration are not unidirectional. Stem cells, as key players in regeneration, can also modulate the immune system in several ways to facilitate regeneration. In this review, we will focus on recent research demonstrating the key role of immune system in the regeneration process as well as the immunomodulatory effects of stem cells. Finally, we propose that research investigating the interplay between the immune system and stem cells within highly regenerating animals can benefit the identification of the key interactions and molecules required for successful regeneration. Copyright © 2018 Elsevier Ltd. All rights reserved.

Modulation of innate immune responses by Yersinia type III secretion system translocators and effectors.

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Bliska, James B; Wang, Xiaoying; Viboud, Gloria I; Brodsky, Igor E

2013-10-01

The innate immune system of mammals responds to microbial infection through detection of conserved molecular determinants called 'pathogen-associated molecular patterns' (PAMPs). Pathogens use virulence factors to counteract PAMP-directed responses. The innate immune system can in turn recognize signals generated by virulence factors, allowing for a heightened response to dangerous pathogens. Many Gram-negative bacterial pathogens encode type III secretion systems (T3SSs) that translocate effector proteins, subvert PAMP-directed responses and are critical for infection. A plasmid-encoded T3SS in the human-pathogenic Yersinia species translocates seven effectors into infected host cells. Delivery of effectors by the T3SS requires plasma membrane insertion of two translocators, which are thought to form a channel called a translocon. Studies of the Yersinia T3SS have provided key advances in our understanding of how innate immune responses are generated by perturbations in plasma membrane and other signals that result from translocon insertion. Additionally, studies in this system revealed that effectors function to inhibit innateimmune responses resulting from insertion of translocons into plasma membrane. Here, we review these advances with the goal of providing insight into how a T3SS can activate and inhibit innate immune responses, allowing a virulent pathogen to bypass host defences. © 2013 John Wiley & Sons Ltd.

Immune System (For Parents)

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... of the Immune System Print en español El sistema inmunitario The immune system, which is made up ... of Use Notice of Nondiscrimination Visit the Nemours Web site. Note: All information on KidsHealth® is for ...

Immune System and Disorders

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Your immune system is a complex network of cells, tissues, and organs that work together to defend against germs. It ... t, to find and destroy them. If your immune system cannot do its job, the results can be ...

Immune System Dysfunction in the Elderly.

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Fuentes, Eduardo; Fuentes, Manuel; Alarcón, Marcelo; Palomo, Iván

2017-01-01

Human aging is characterized by both physical and physiological frailty that profoundly affects the immune system. In this context aging is associated with declines in adaptive and innate immunity established as immunosenescence. Immunosenescence is a new concept that reflects the age-associated restructuring changes of innate and adaptive immune functions. Thus elderly individuals usually present chronic low-level inflammation, higher infection rates and chronic diseases. A study of alterations in the immune system during aging could provide a potentially useful biomarker for the evaluation of immune senescence treatment. The immune system is the result of the interplay between innate and adaptive immunity, yet the impact of aging on this function is unclear. In this article the function of the immune system during aging is explored.

Retinoic acid signaling in B-cells is essential for oral immunization and microflora composition

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Pantazi, Eirini; Marks, Ellen; Stolarczyk, Emilie; Lycke, Nils; Noelle, Randolph J.; Elgueta, Raul

2015-01-01

Retinoic acid (RA)3 is a critical regulator of the intestinal adaptive immune response. However, the intrinsic impact of RA on B cell differentiation in the regulation of gut humoral immunity in vivo has never been directly shown. To address this issue, we have been able to generate a mouse model where B-cells specifically express a dominant negative receptor α for RA. Here, we show that the silencing of RA signaling in B-cells reduces the numbers of IgA+ antibody secreting cells (ASC) both in vitro and in vivo, suggesting that RA has a direct effect on IgA plasma cell (PC) differentiation. Moreover, the lack of RA signaling in B-cells abrogates Ag-specific IgA responses after oral immunization and affects the microbiota composition. In conclusion, these results suggest that RA signaling in B-cells through the RA receptor α is important to generate an effective gut humoral response and to maintain a normal microbiota composition. PMID:26163586

Immune regulation by microbiome metabolites.

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Kim, Chang H

2018-03-22

Commensal microbes and the host immune system have been co-evolved for mutual regulation. Microbes regulate the host immune system, in part, by producing metabolites. A mounting body of evidence indicates that diverse microbial metabolites profoundly regulate the immune system via host receptors and other target molecules. Immune cells express metabolite-specific receptors such as P2X 7 , GPR41, GPR43, GPR109A, aryl hydrocarbon receptor precursor (AhR), pregnane X receptor (PXR), farnesoid X receptor (FXR), TGR5 and other molecular targets. Microbial metabolites and their receptors form an extensive array of signals to respond to changes in nutrition, health and immunological status. As a consequence, microbial metabolite signals contribute to nutrient harvest from diet, and regulate host metabolism and the immune system. Importantly, microbial metabolites bidirectionally function to promote both tolerance and immunity to effectively fight infection without developing inflammatory diseases. In pathogenic conditions, adverse effects of microbial metabolites have been observed as well. Key immune-regulatory functions of the metabolites, generated from carbohydrates, proteins and bile acids, are reviewed in this article. © 2018 John Wiley & Sons Ltd.

Arthropod Innate Immune Systems and Vector-Borne Diseases.

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Baxter, Richard H G; Contet, Alicia; Krueger, Kathryn

2017-02-21

Arthropods, especially ticks and mosquitoes, are the vectors for a number of parasitic and viral human diseases, including malaria, sleeping sickness, Dengue, and Zika, yet arthropods show tremendous individual variation in their capacity to transmit disease. A key factor in this capacity is the group of genetically encoded immune factors that counteract infection by the pathogen. Arthropod-specific pattern recognition receptors and protease cascades detect and respond to infection. Proteins such as antimicrobial peptides, thioester-containing proteins, and transglutaminases effect responses such as lysis, phagocytosis, melanization, and agglutination. Effector responses are initiated by damage signals such as reactive oxygen species signaling from epithelial cells and recognized by cell surface receptors on hemocytes. Antiviral immunity is primarily mediated by siRNA pathways but coupled with interferon-like signaling, antimicrobial peptides, and thioester-containing proteins. Molecular mechanisms of immunity are closely linked to related traits of longevity and fertility, and arthropods have the capacity for innate immunological memory. Advances in understanding vector immunity can be leveraged to develop novel control strategies for reducing the rate of transmission of both ancient and emerging threats to global health.

Immune evasion of porcine enteric coronaviruses and viral modulation of antiviral innate signaling.

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Zhang, Qingzhan; Yoo, Dongwan

2016-12-02

Porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV) are emerged and reemerging viruses in pigs, and together with transmissible gastroenteritis virus (TGEV), pose significant economic concerns to the swine industry. These viruses infect epithelial cells of the small intestine and cause watery diarrhea, dehydration, and a high mortality in neonatal piglets. Type I interferons (IFN-α/β) are major antiviral cytokines forming host innate immunity, and in turn, these enteric coronaviruses have evolved to modulate the host innate immune signaling during infection. Accumulating evidence however suggests that IFN induction and signaling in the intestinal epithelial cells differ from other epithelial cells, largely due to distinct features of the gut epithelial mucosal surface and commensal microflora, and it appears that type III interferon (IFN-λ) plays a key role to maintain the antiviral state in the gut. This review describes the recent understanding on the immune evasion strategies of porcine enteric coronaviruses and the role of different types of IFNs for intestinal antiviral innate immunity. Copyright © 2016 Elsevier B.V. All rights reserved.

The neonicotinoid insecticide Clothianidin adversely affects immune signaling in a human cell line.

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Di Prisco, Gennaro; Iannaccone, Marco; Ianniello, Flora; Ferrara, Rosalba; Caprio, Emilio; Pennacchio, Francesco; Capparelli, Rosanna

2017-10-18

Clothianidin is a widely used neonicotinoid insecticide, which is a potent agonist of the nicotinic acetylcholine receptor in insects. This neurotoxic compound has a negative impact on insect immunity, as it down-regulates the activation of the transcription factor NF-κB. Given the evolutionary conserved role of NF-κB in the modulation of the immune response in the animal kingdom, here we want to assess any effect of Clothianidin on vertebrate defense barriers. In presence of this neonicotinoid insecticide, a pro-inflammatory challenge with LPS on the human monocytic cell line THP-1 results both in a reduced production of the cytokine TNF-α and in a down-regulation of a reporter gene under control of NF-κB promoter. This finding is corroborated by a significant impact of Clothianidin on the transcription levels of different immune genes, characterized by a core disruption of TRAF4 and TRAF6 that negatively influences NF-κB signaling. Moreover, exposure to Clothianidin concurrently induces a remarkable up-regulation of NGFR, which supports the occurrence of functional ties between the immune and nervous systems. These results suggest a potential risk of immunotoxicity that neonicotinoids may have on vertebrates, which needs to be carefully assessed at the organism level.

Conceptual Spaces of the Immune System.

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Fierz, Walter

2016-01-01

The immune system can be looked at as a cognitive system. This is often done in analogy to the neuro-psychological system. Here, it is demonstrated that the cognitive functions of the immune system can be properly described within a new theory of cognitive science. Gärdenfors' geometrical framework of conceptual spaces is applied to immune cognition. Basic notions, like quality dimensions, natural properties and concepts, similarities, prototypes, saliences, etc., are related to cognitive phenomena of the immune system. Constraints derived from treating the immune system within a cognitive theory, like Gärdenfors' conceptual spaces, might well prove to be instrumental for the design of vaccines, immunological diagnostic tests, and immunotherapy.

Immune System and Kidney Transplantation.

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Shrestha, Badri Man

2017-01-01

The immune system recognises a transplanted kidney as foreign body and mounts immune response through cellular and humoral mechanisms leading to acute or chronic rejection, which ultimately results in graft loss. Over the last five decades, there have been significant advances in the understanding of the immune responses to transplanted organs in both experimental and clinical transplant settings. Modulation of the immune response by using immunosuppressive agents has led to successful outcomes after kidney transplantation. The paper provides an overview of the general organisation and function of human immune system, immune response to kidney transplantation, and the current practice of immunosuppressive therapy in kidney transplantation in the United Kingdom.

Interactions between adipose tissue and the immune system in health and malnutrition.

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Wensveen, Felix M; Valentić, Sonja; Šestan, Marko; Wensveen, Tamara Turk; Polić, Bojan

2015-09-01

Adipose tissue provides the body with a storage depot of nutrients that is drained during times of starvation and replenished when food sources are abundant. As such, it is the primary sensor for nutrient availability in the milieu of an organism, which it communicates to the body through the excretion of hormones. Adipose tissue regulates a multitude of body functions associated with metabolism, such as gluconeogenesis, feeding and nutrient uptake. The immune system forms a vital layer of protection against micro-organisms that try to gain access to the nutrients contained in the body. Because infections need to be resolved as quickly as possible, speed is favored over energy-efficiency in an immune response. Especially when immune cells are activated, they switch to fast, but energy-inefficient anaerobic respiration to fulfill their energetic needs. Despite the necessity for an effective immune system, it is not given free rein in its energy expenditure. Signals derived from adipose tissue limit immune cell numbers and activity under conditions of nutrient shortage, whereas they allow proper immune cell activity when food sources are sufficiently available. When excessive fat accumulation occurs, such as in diet-induced obesity, adipose tissue becomes the site of pathological immune cell activation, causing chronic low-grade systemic inflammation. Obesity is therefore associated with a number of disorders in which the immune system plays a central role, such as atherosclerosis and non-alcoholic steatohepatitis. In this review, we will discuss the way in which adipose tissue regulates activity of the immune system under healthy and pathological conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dynamics of immune system vulnerabilities

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Stromberg, Sean P.

The adaptive immune system can be viewed as a complex system, which adapts, over time, to reflect the history of infections experienced by the organism. Understanding its operation requires viewing it in terms of tradeoffs under constraints and evolutionary history. It typically displays "robust, yet fragile" behavior, meaning common tasks are robust to small changes but novel threats or changes in environment can have dire consequences. In this dissertation we use mechanistic models to study several biological processes: the immune response, the homeostasis of cells in the lymphatic system, and the process that normally prevents autoreactive cells from entering the lymphatic system. Using these models we then study the effects of these processes interacting. We show that the mechanisms that regulate the numbers of cells in the immune system, in conjunction with the immune response, can act to suppress autoreactive cells from proliferating, thus showing quantitatively how pathogenic infections can suppress autoimmune disease. We also show that over long periods of time this same effect can thin the repertoire of cells that defend against novel threats, leading to an age correlated vulnerability. This vulnerability is shown to be a consequence of system dynamics, not due to degradation of immune system components with age. Finally, modeling a specific tolerance mechanism that normally prevents autoimmune disease, in conjunction with models of the immune response and homeostasis we look at the consequences of the immune system mistakenly incorporating pathogenic molecules into its tolerizing mechanisms. The signature of this dynamic matches closely that of the dengue virus system.

The eye: A window to the soul of the immune system.

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Perez, V L; Saeed, A M; Tan, Y; Urbieta, M; Cruz-Guilloty, F

2013-09-01

The eye is considered as an immune privileged site, and with good reason. It has evolved a variety of molecular and cellular mechanisms that limit immune responses to preserve vision. For example, the cornea is mainly protected from autoimmunity by the lack of blood and lymphatic vessels, whereas the retina-blood barrier is maintained in an immunosuppressive state by the retinal pigment epithelium. However, there are several scenarios in which immune privilege is altered and the eye becomes susceptible to immune attack. In this review, we highlight the role of the immune system in two clinical conditions that affect the anterior and posterior segments of the eye: corneal transplantation and age-related macular degeneration. Interestingly, crosstalk between the innate and adaptive immune systems is critical in both acute and chronic inflammatory responses in the eye, with T cells playing a central role in combination with neutrophils and macrophages. In addition, we emphasize the advantage of using the eye as a model for in vivo longitudinal imaging of the immune system in action. Through this technique, it has been possible to identify functionally distinct intra-graft motility patterns of responding T cells, as well as the importance of chemokine signaling in situ for T cell activation. The detailed study of ocular autoimmunity could provide novel therapeutic strategies for blinding diseases while also providing more general information on acute versus chronic inflammation. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Immune System: Basis of so much Health and Disease: 3. Adaptive Immunity.

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Scully, Crispian; Georgakopoulou, Eleni A; Hassona, Yazan

2017-04-01

The immune system is the body’s primary defence mechanism against infections, and disturbances in the system can cause disease if the system fails in defence functions (in immunocompromised people), or if the activity is detrimental to the host (as in auto-immune and auto-inflammatory states). A healthy immune system is also essential to normal health of dental and oral tissues. This series presents the basics for the understanding of the immune system; this article covers adaptive immunity. Clinical relevance: Dental clinicians need a basic understanding of the immune system as it underlies health and disease.

Gaseous 3-pentanol primes plant immunity against a bacterial speck pathogen, Pseudomonas syringae pv. tomato via salicylic acid and jasmonic acid-dependent signaling pathways in Arabidopsis.

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Song, Geun C; Choi, Hye K; Ryu, Choong-Min

2015-01-01

3-Pentanol is an active organic compound produced by plants and is a component of emitted insect sex pheromones. A previous study reported that drench application of 3-pentanol elicited plant immunity against microbial pathogens and an insect pest in crop plants. Here, we evaluated whether 3-pentanol and the derivatives 1-pentanol and 2-pentanol induced plant systemic resistance using the in vitro I-plate system. Exposure of Arabidopsis seedlings to 10 μM and 100 nM 3-pentanol evaporate elicited an immune response to Pseudomonas syringae pv. tomato DC3000. We performed quantitative real-time PCR to investigate the 3-pentanol-mediated Arabidopsis immune responses by determining Pathogenesis-Related (PR) gene expression levels associated with defense signaling through salicylic acid (SA), jasmonic acid (JA), and ethylene signaling pathways. The results show that exposure to 3-pentanol and subsequent pathogen challenge upregulated PDF1.2 and PR1 expression. Selected Arabidopsis mutants confirmed that the 3-pentanol-mediated immune response involved SA and JA signaling pathways and the NPR1 gene. Taken together, this study indicates that gaseous 3-pentanol triggers induced resistance in Arabidopsis by priming SA and JA signaling pathways. To our knowledge, this is the first report that a volatile compound of an insect sex pheromone triggers plant systemic resistance against a bacterial pathogen.

Gaseous 3-pentanol primes plant immunity against a bacterial speck pathogen, Pseudomonas syringae pv. tomato via salicylic acid and jasmonic acid-dependent signaling pathways in Arabidopsis

Directory of Open Access Journals (Sweden)

Geun Cheol eSong

2015-10-01

Full Text Available 3-Pentanol is an active organic compound produced by plants and is a component of emitted insect sex pheromones. A previous study reported that drench application of 3-pentanol elicited plant immunity against microbial pathogens and an insect pest in crop plants. Here, we evaluated whether 3-pentanol and the derivatives 1-pentanol and 2-pentanol induced plant systemic resistance using the in vitro I-plate system. Exposure of Arabidopsis seedlings to 10 M and 100 nM 3-pentanol evaporate elicited an immune response to Pseudomonas syringae pv. tomato DC3000. We performed quantitative real-time PCR to investigate the 3-pentanol-mediated Arabidopsis immune responses by determining Pathogenesis-Related (PR gene expression levels associated with defense signaling through SA, JA, and ethylene signaling pathways. The results show that exposure to 3-pentanol and subsequent pathogen challenge upregulated PDF1.2 and PR1 expression. Selected Arabidopsis mutants confirmed that the 3-pentanol-mediated immune response involved salicylic acid (SA and jasmonic acid (JA signaling pathways and the NPR1 gene. Taken together, this study indicates that gaseous 3-pentanol triggers induced resistance in Arabidopsis by priming SA and JA signaling pathways. To our knowledge, this is the first report that a volatile compound of an insect sex pheromone triggers plant systemic resistance against a bacterial pathogen.

Regulation of TGFβ in the immune system: an emerging role for integrins and dendritic cells.

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Worthington, John J; Fenton, Thomas M; Czajkowska, Beata I; Klementowicz, Joanna E; Travis, Mark A

2012-12-01

Regulation of an immune response requires complex crosstalk between cells of the innate and adaptive immune systems, via both cell-cell contact and secretion of cytokines. An important cytokine with a broad regulatory role in the immune system is transforming growth factor-β (TGF-β). TGF-β is produced by and has effects on many different cells of the immune system, and plays fundamental roles in the regulation of immune responses during homeostasis, infection and disease. Although many cells can produce TGFβ, it is always produced as an inactive complex that must be activated to bind to the TGFβ receptor complex and promote downstream signalling. Thus, regulation of TGFβ activation is a crucial step in controlling TGFβ function. This review will discuss how TGFβ controls diverse immune responses and how TGFβ function is regulated, with a focus on recent work highlighting a critical role for the integrin αvβ8 expressed by dendritic cells in activating TGFβ. Copyright © 2012 Elsevier GmbH. All rights reserved.

Ovarian cancer and the immune system - The role of targeted therapies.

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Turner, Taylor B; Buchsbaum, Donald J; Straughn, J Michael; Randall, Troy D; Arend, Rebecca C

2016-08-01

The majority of patients with epithelial ovarian cancer are diagnosed with advanced disease. While many of these patients will respond initially to chemotherapy, the majority will relapse and die of their disease. Targeted therapies that block or activate specific intracellular signaling pathways have been disappointing. In the past 15years, the role of the immune system in ovarian cancer has been investigated. Patients with a more robust immune response, as documented by the presence of lymphocytes infiltrating within their tumor, have increased survival and better response to chemotherapy. In addition, a strong immunosuppressive environment often accompanies ovarian cancer. Recent research has identified potential therapies that leverage the immune system to identify and destroy tumor cells that previously evaded immunosurveillance mechanisms. In this review, we discuss the role of the immune system in ovarian cancer and focus on specific pathways and molecules that show a potential for targeted therapy. We also review the ongoing clinical trials using targeted immunotherapy in ovarian cancer. The role of targeted immunotherapy in patients with ovarian cancer represents a field of growing research and clinical importance. Copyright © 2016 Elsevier Inc. All rights reserved.

Honest sexual signaling in turtles: experimental evidence of a trade-off between immune response and coloration in red-eared sliders Trachemys scripta elegans.

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Ibáñez, Alejandro; Polo-Cavia, Nuria; López, Pilar; Martín, José

2014-10-01

Sexual signals can be evolutionarily stable if they are honest and condition dependent or costly to the signaler. One possible cost is the existence of a trade-off between maintaining the immune system and the elaboration of ornaments. This hypothesis has been experimentally tested in some groups of animals but not in others such as turtles. We experimentally challenged the immune system of female red-eared sliders Trachemys scripta elegans, with a bacterial antigen (lipopolysaccharide (LPS)) without pathogenic effects to explore whether the immune activation affected visual colorful ornaments of the head. The LPS injection altered the reflectance patterns of color ornaments. In comparison to the control animals, the yellow chin stripes of injected animals exhibited (1) reduced brightness, (2) lower long wavelength (>470 nm) reflectance, and (3) lower values for carotenoid chroma. The postorbital patches of injected individuals also showed reduced very long wavelength (>570 nm) reflectance but did not change in carotenoid chroma. Thus, experimental turtles showed darker and less "yellowish" chin stripes and less "reddish" postorbital patches at the end of the experiment, whereas control turtles did not change their coloration. This is the first experimental evidence supporting the existence of a trade-off between the immune system and the expression of visual ornaments in turtles. We suggest that this trade-off may allow turtles to honestly signal individual quality via characteristics of coloration, which may have an important role in intersexual selection processes.

Honest sexual signaling in turtles: experimental evidence of a trade-off between immune response and coloration in red-eared sliders Trachemys scripta elegans

Science.gov (United States)

Ibáñez, Alejandro; Polo-Cavia, Nuria; López, Pilar; Martín, José

2014-10-01

Sexual signals can be evolutionarily stable if they are honest and condition dependent or costly to the signaler. One possible cost is the existence of a trade-off between maintaining the immune system and the elaboration of ornaments. This hypothesis has been experimentally tested in some groups of animals but not in others such as turtles. We experimentally challenged the immune system of female red-eared sliders Trachemys scripta elegans, with a bacterial antigen (lipopolysaccharide (LPS)) without pathogenic effects to explore whether the immune activation affected visual colorful ornaments of the head. The LPS injection altered the reflectance patterns of color ornaments. In comparison to the control animals, the yellow chin stripes of injected animals exhibited (1) reduced brightness, (2) lower long wavelength (>470 nm) reflectance, and (3) lower values for carotenoid chroma. The postorbital patches of injected individuals also showed reduced very long wavelength (>570 nm) reflectance but did not change in carotenoid chroma. Thus, experimental turtles showed darker and less "yellowish" chin stripes and less "reddish" postorbital patches at the end of the experiment, whereas control turtles did not change their coloration. This is the first experimental evidence supporting the existence of a trade-off between the immune system and the expression of visual ornaments in turtles. We suggest that this trade-off may allow turtles to honestly signal individual quality via characteristics of coloration, which may have an important role in intersexual selection processes.

The Immune System Game

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Work, Kirsten A.; Gibbs, Melissa A.; Friedman, Erich J.

2015-01-01

We describe a card game that helps introductory biology students understand the basics of the immune response to pathogens. Students simulate the steps of the immune response with cards that represent the pathogens and the cells and molecules mobilized by the immune system. In the process, they learn the similarities and differences between the…

A Plant Phytosulfokine Peptide Initiates Auxin-Dependent Immunity through Cytosolic Ca2+ Signaling in Tomato.

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Zhang, Huan; Hu, Zhangjian; Lei, Cui; Zheng, Chenfei; Wang, Jiao; Shao, Shujun; Li, Xin; Xia, Xiaojian; Cai, Xinzhong; Zhou, Jie; Zhou, Yanhong; Yu, Jingquan; Foyer, Christine H; Shi, Kai

2018-03-01

Phytosulfokine (PSK) is a disulfated pentapeptide that is an important signaling molecule. Although it has recently been implicated in plant defenses to pathogen infection, the mechanisms involved remain poorly understood. Using surface plasmon resonance and gene silencing approaches, we showed that the tomato ( Solanum lycopersicum ) PSK receptor PSKR1, rather than PSKR2, functioned as the major PSK receptor in immune responses. Silencing of PSK signaling genes rendered tomato more susceptible to infection by the economically important necrotrophic pathogen Botrytis cinerea Analysis of tomato mutants defective in either defense hormone biosynthesis or signaling demonstrated that PSK-induced immunity required auxin biosynthesis and associated defense pathways. Here, using aequorin-expressing tomato plants, we provide evidence that PSK perception by tomato PSKR1 elevated cytosolic [Ca 2+ ], leading to auxin-dependent immune responses via enhanced binding activity between calmodulins and the auxin biosynthetic YUCs. Thus, our data demonstrate that PSK acts as a damage-associated molecular pattern and is perceived mainly by PSKR1, which increases cytosolic [Ca 2+ ] and activates auxin-mediated pathways that enhance immunity of tomato plants to B. cinerea . © 2018 American Society of Plant Biologists. All rights reserved.

Immune regulation in gut and cord : opportunities for directing the immune system

NARCIS (Netherlands)

de Roock, S.

2012-01-01

The gut is an important organ for the immune system. Microbes and immune cells interact directly or via epithelial cells. Both TH17 and Treg cells mature in this environment. The composition of the microbiota has an important influence on the immune homeostasis. Influencing the immune system via the

Local and systemic tumor immune dynamics

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Enderling, Heiko

Tumor-associated antigens, stress proteins, and danger-associated molecular patterns are endogenous immune adjuvants that can both initiate and continually stimulate an immune response against a tumor. In retaliation, tumors can hijack intrinsic immune regulatory programs that are intended to prevent autoimmune disease, thereby facilitating continued growth despite the activated antitumor immune response. In metastatic disease, this ongoing tumor-immune battle occurs at each site. Adding an additional layer of complexity, T cells activated at one tumor site can cycle through the blood circulation system and extravasate in a different anatomic location to surveil a distant metastasis. We propose a mathematical modeling framework that incorporates the trafficking of activated T cells between metastatic sites. We extend an ordinary differential equation model of tumor-immune system interactions to multiple metastatic sites. Immune cells are activated in response to tumor burden and tumor cell death, and are recruited from tumor sites elsewhere in the body. A model of T cell trafficking throughout the circulatory system can inform the tumor-immune interaction model about the systemic distribution and arrival of T cells at specific tumor sites. Model simulations suggest that metastases not only contribute to immune surveillance, but also that this contribution varies between metastatic sites. Such information may ultimately help harness the synergy of focal therapy with the immune system to control metastatic disease.

The Notch Signaling Pathway Is Balancing Type 1 Innate Lymphoid Cell Immune Functions

Directory of Open Access Journals (Sweden)

Thibaut Perchet

2018-06-01

Full Text Available The Notch pathway is one of the canonical signaling pathways implicated in the development of various solid tumors. During carcinogenesis, the Notch pathway dysregulation induces tumor expression of Notch receptor ligands participating to escape the immune surveillance. The Notch pathway conditions both the development and the functional regulation of lymphoid subsets. Its importance on T cell subset polarization has been documented contrary to its action on innate lymphoid cells (ILC. We aim to analyze the effect of the Notch pathway on type 1 ILC polarization and functions after disruption of the RBPJk-dependent Notch signaling cascade. Indeed, type 1 ILC comprises conventional NK (cNK cells and type 1 helper innate lymphoid cells (ILC1 that share Notch-related functional characteristics such as the IFNg secretion downstream of T-bet expression. cNK cells have strong antitumor properties. However, data are controversial concerning ILC1 functions during carcinogenesis with models showing antitumoral capacities and others reporting ILC1 inability to control tumor growth. Using various mouse models of Notch signaling pathway depletion, we analyze the effects of its absence on type 1 ILC differentiation and cytotoxic functions. We also provide clues into its role in the maintenance of immune homeostasis in tissues. We show that modulating the Notch pathway is not only acting on tumor-specific T cell activity but also on ILC immune subset functions. Hence, our study uncovers the intrinsic Notch signaling pathway in ILC1/cNK populations and their response in case of abnormal Notch ligand expression. This study help evaluating the possible side effects mediated by immune cells different from T cells, in case of multivalent forms of the Notch receptor ligand delta 1 treatments. In definitive, it should help determining the best novel combination of therapeutic strategies in case of solid tumors.

Technique Selectively Represses Immune System

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... Research Matters December 3, 2012 Technique Selectively Represses Immune System Myelin (green) encases and protects nerve fibers (brown). A new technique prevents the immune system from attacking myelin in a mouse model of ...

[Saccharomyces boulardii CNCM I-745 influences the gut-associated immune system].

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Stier, Heike; Bischoff, Stephan C

2017-06-01

The impact of the intestinal microbiome is increasing steadily with regard to the immune function und the defense against pathogens. The medicinal yeast Saccharomyces boulardii CNCM I-745 (S. boulardii) has been used as probiotic for the prevention and treatment of infectious diarrhea since more than 50 years. Meta-analyses confirm the clinical efficacy of S. boulardii to treat diarrhea of various origins in children and adults. This review article summarizes experimental studies on molecular and immunological mechanisms which explain the proven clinical efficacy of S. boulardii. Thereby the focus is on the gut-associated immune system. S. boulardii stimulates the release of immunoglobulins and cytokines and also induces the maturation of immune cells. This suggests that S. boulardii is capable of activating the unspecific immune system. In case of an infection, S. boulardii is able to bind pathogenic bacteria and to neutralize their toxins. Moreover, the medicinal yeast can attenuate the overreacting inflammatory immune response, by interfering with the signaling cascade, which is induced by the infection, and that way influences the innate and adaptive immune system. Thanks to these mechanisms the pathogens' potential of adhesion is lessened. Thus the intestinal epithelial layer is protected and diarrhea-induced fluid loss is reduced. The different molecular and immunological mechanisms investigated in the experimental studies prove the already confirmed very good clinical efficacy of S. boulardii in infectious diarrhea caused by pathogens such as bacteria, viruses, and fungi.

Play the Immune System Defender Game

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... Questionnaire The Immune System Play the Immune System Game About the game Granulocytes, macrophages and dendritic cells are immune cells ... last will in Paris. Play the Blood Typing Game Try to save some patients and learn about ...

Mechanism for maintaining homeostasis in the immune system of the intestine.

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Taniguchi, Yoshie; Yoshioka, Noriko; Nakata, Kazue; Nishizawa, Takashi; Inagawa, Hiroyuki; Kohchi, Chie; Soma, Gen-Ichiro

2009-11-01

Every organism possesses a mechanism for maintaining homeostasis. We have focused on the immune system as a system that helps maintain homeostasis of the body, and particularly on the intestine as the largest organ of immunity in the body. We have also focused our research on the mechanism that responds to foreign substances in the intestine, especially the toll-like receptors (TLR). The activation of myeloid differentiation primary response gene 88 (MyD88) signal transduction as a response to TLR in the intestine is believed to contribute to the maintenance of homeostasis of the body through the homeostasis of the intestine. Furthermore, significant findings were reported in which signal transduction from TLR4 was essential for the maintenance and regulation of the intestine. These results strongly suggest the possibility that homeostasis in the intestine is maintained by TLR4, and signaling by TLR4 after exposure to lipopolysaccharide (LPS) probably has a role in regulating homeostasis. It is expected that the prevention and treatment of various diseases using TLR4 will continue to develop. As LPS is a substance that enhances the activity of TLR4, it will also attract attention as a valuable substance in its own right.

Effects of PM2.5 exposure on the Notch signaling pathway and immune imbalance in chronic obstructive pulmonary disease

International Nuclear Information System (INIS)

Gu, Xing-yu; Chu, Xu; Zeng, Xiao-Li; Bao, Hai-Rong; Liu, Xiao-Ju

2017-01-01

Chronic Obstructive Pulmonary Disease (COPD) is associated with T lymphocytes subset (Th1/Th2, Th17/Treg) imbalance. Notch signaling pathway plays a key role in the development of the adaptive immunity. The immune disorder induced by fine particulate matter (PM2.5) is related to COPD. The aim of this study was to investigate the mechanism by which PM2.5 influences the Notch signaling pathway leading to worsening immune disorder and accelerating COPD development. A COPD mouse model was established by cigarette smoke exposure. PM2.5 exposure was performed by aerosol inhalation. γ-secretase inhibitor (GSI) was given using intraperitoneal injection. Splenic T lymphocytes were purified using a density gradient centrifugation method. CD4 + T lymphocyte subsets (Th1/Th2, Th17/Treg) were detected using flow cytometry. mRNA and proteins of Notch1/2/3/4, Hes1/5, and Hey1 were detected using RT-PCR and Western blot. Serum INF-γ, IL-4, IL-17 and IL-10 concentrations were measured using ELISA. The results showed that in COPD mice Th1% and Th17%, Th1/Th2 and Th17/Treg were increased, and the levels of mRNA and protein in Notch1/2/3/4, Hes1/5, and Hey1 and serum INF-γ and IL-17 concentrations were significantly increased, and Th2%, Treg%, and serum IL-4 and IL-10 concentrations were significantly decreased. COPD Mice have Th1- and Th17-mediated immune disorder, and the Notch signaling pathway is in an overactivated state. PM2.5 promotes the overactivation of the Notch signaling pathway and aggravates the immune disorder of COPD. GSI can partially inhibit the activation of the Notch signaling pathway and alleviate the immune disorder under basal state and the immune disorder of COPD caused by PM2.5. This result suggests that PM2.5 is involved in the immune disorder of mice with COPD by affecting the Notch signaling pathway and that PM2.5 aggravates COPD. - Highlights: • The COPD mice demonstrated Th1 and Th17 dominant immune imbalance. • PM2.5 aggravates the Th1/Th2 and Th

HIF-mediated innate immune responses: cell signaling and therapeutic implications

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Harris AJ

2014-05-01

Full Text Available Alison J Harris, AA Roger Thompson, Moira KB Whyte, Sarah R Walmsley Academic Unit of Respiratory Medicine, Department of Infection and Immunity, University of Sheffield, Sheffield, UK Abstract: Leukocytes recruited to infected, damaged, or inflamed tissues during an immune response must adapt to oxygen levels much lower than those in the circulation. Hypoxia inducible factors (HIFs are key mediators of cellular responses to hypoxia and, as in other cell types, HIFs are critical for the upregulation of glycolysis, which enables innate immune cells to produce adenosine triphosphate anaerobically. An increasing body of evidence demonstrates that hypoxia also regulates many other innate immunological functions, including cell migration, apoptosis, phagocytosis of pathogens, antigen presentation and production of cytokines, chemokines, and angiogenic and antimicrobial factors. Many of these functions are mediated by HIFs, which are not only stabilized posttranslationally by hypoxia, but also transcriptionally upregulated by inflammatory signals. Here, we review the role of HIFs in the responses of innate immune cells to hypoxia, both in vitro and in vivo, with a particular focus on myeloid cells, on which the majority of studies have so far been carried out. Keywords: hypoxia, neutrophils, monocytes, macrophages

Immune Evasion, Immunopathology and the Regulation of the Immune System

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Bruno Faivre

2013-02-01

Full Text Available Costs and benefits of the immune response have attracted considerable attention in the last years among evolutionary biologists. Given the cost of parasitism, natural selection should favor individuals with the most effective immune defenses. Nevertheless, there exists huge variation in the expression of immune effectors among individuals. To explain this apparent paradox, it has been suggested that an over-reactive immune system might be too costly, both in terms of metabolic resources and risks of immune-mediated diseases, setting a limit to the investment into immune defenses. Here, we argue that this view neglects one important aspect of the interaction: the role played by evolving pathogens. We suggest that taking into account the co-evolutionary interactions between the host immune system and the parasitic strategies to overcome the immune response might provide a better picture of the selective pressures that shape the evolution of immune functioning. Integrating parasitic strategies of host exploitation can also contribute to understand the seemingly contradictory results that infection can enhance, but also protect from, autoimmune diseases. In the last decades, the incidence of autoimmune disorders has dramatically increased in wealthy countries of the northern hemisphere with a concomitant decrease of most parasitic infections. Experimental work on model organisms has shown that this pattern may be due to the protective role of certain parasites (i.e., helminths that rely on the immunosuppression of hosts for their persistence. Interestingly, although parasite-induced immunosuppression can protect against autoimmunity, it can obviously favor the spread of other infections. Therefore, we need to think about the evolution of the immune system using a multidimensional trade-off involving immunoprotection, immunopathology and the parasitic strategies to escape the immune response.

Nanobody-Based Biologics for Modulating Purinergic Signaling in Inflammation and Immunity

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Stephan Menzel

2018-03-01

Full Text Available Adenosine triphosphate (ATP and nicotinamide adenine dinucleotide (NAD+ are released as danger signals from cells during infection and sterile inflammation. In the extracellular compartment ATP is converted by CD39, CD73, and other ecto-enzymes into metabolites that modulate the activity of T cells and macrophages. While ATP mediates pro-inflammatory signals via P2X7 and other P2 receptors, adenosine triggers anti-inflammatory signaling via the adenosine 2a receptor (Adora2a and other P1 receptors. The latter also plays a role in maintaining an immunosuppressive tumor microenvironment. NAD+ is converted by CD38, CD203 and other ecto-enzymes to the Ca2+ mobilizing messengers cyclic ADP-ribose and ADP-ribose, and to adenosine. Recent findings on the roles of CD38, CD39, CD73, CD203, P2X7, and Adora2a in inflammation and immunity underscore the potential of these proteins as drug targets. However, available small molecule inhibitors often lack specificity and mediate unwanted off-target toxicity. Nanobodies – single domain antibodies derived from heavy chain antibodies that naturally occur in camelids – display a propensity to bind functional epitopes not accessible to conventional antibodies. Like conventional antibodies, nanobodies and nanobody-based biologics are highly specific and have well-understood, tunable in vivo pharmacodynamics with little if any toxicity. Nanobodies thus represent attractive alternatives to small molecule inhibitors for modulating purinergic signaling in inflammation and immunity. Here we review recent progress made in developing nanobodies against key targets of purinergic signaling.

Nanobody-Based Biologics for Modulating Purinergic Signaling in Inflammation and Immunity.

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Menzel, Stephan; Schwarz, Nicole; Haag, Friedrich; Koch-Nolte, Friedrich

2018-01-01

Adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide (NAD + ) are released as danger signals from cells during infection and sterile inflammation. In the extracellular compartment ATP is converted by CD39, CD73, and other ecto-enzymes into metabolites that modulate the activity of T cells and macrophages. While ATP mediates pro-inflammatory signals via P2X7 and other P2 receptors, adenosine triggers anti-inflammatory signaling via the adenosine 2a receptor (Adora2a) and other P1 receptors. The latter also plays a role in maintaining an immunosuppressive tumor microenvironment. NAD + is converted by CD38, CD203 and other ecto-enzymes to the Ca 2+ mobilizing messengers cyclic ADP-ribose and ADP-ribose, and to adenosine. Recent findings on the roles of CD38, CD39, CD73, CD203, P2X7, and Adora2a in inflammation and immunity underscore the potential of these proteins as drug targets. However, available small molecule inhibitors often lack specificity and mediate unwanted off-target toxicity. Nanobodies - single domain antibodies derived from heavy chain antibodies that naturally occur in camelids - display a propensity to bind functional epitopes not accessible to conventional antibodies. Like conventional antibodies, nanobodies and nanobody-based biologics are highly specific and have well-understood, tunable in vivo pharmacodynamics with little if any toxicity. Nanobodies thus represent attractive alternatives to small molecule inhibitors for modulating purinergic signaling in inflammation and immunity. Here we review recent progress made in developing nanobodies against key targets of purinergic signaling.

Always one step ahead: How pathogenic bacteria use the type III secretion system to manipulate the intestinal mucosal immune system

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Marchès Olivier

2011-05-01

Full Text Available Abstract The intestinal immune system and the epithelium are the first line of defense in the gut. Constantly exposed to microorganisms from the environment, the gut has complex defense mechanisms to prevent infections, as well as regulatory pathways to tolerate commensal bacteria and food antigens. Intestinal pathogens have developed strategies to regulate intestinal immunity and inflammation in order to establish or prolong infection. The organisms that employ a type III secretion system use a molecular syringe to deliver effector proteins into the cytoplasm of host cells. These effectors target the host cell cytoskeleton, cell organelles and signaling pathways. This review addresses the multiple mechanisms by which the type III secretion system targets the intestinal immune response, with a special focus on pathogenic E. coli.

Protein Kinase C Enzymes in the Hematopoietic and Immune Systems.

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Altman, Amnon; Kong, Kok-Fai

2016-05-20

The protein kinase C (PKC) family, discovered in the late 1970s, is composed of at least 10 serine/threonine kinases, divided into three groups based on their molecular architecture and cofactor requirements. PKC enzymes have been conserved throughout evolution and are expressed in virtually all cell types; they represent critical signal transducers regulating cell activation, differentiation, proliferation, death, and effector functions. PKC family members play important roles in a diverse array of hematopoietic and immune responses. This review covers the discovery and history of this enzyme family, discusses the roles of PKC enzymes in the development and effector functions of major hematopoietic and immune cell types, and points out gaps in our knowledge, which should ignite interest and further exploration, ultimately leading to better understanding of this enzyme family and, above all, its role in the many facets of the immune system.

SUMO-, MAPK- and resistance protein-signaling converge at transcription complexes that regulate plant innate immunity

NARCIS (Netherlands)

Burg, van den H.A.; Takken, F.L.W.

2010-01-01

Upon pathogen perception plant innate immune receptors activate various signaling pathways that trigger host defenses. PAMP-triggered defense signaling requires mitogen-activated protein kinase (MAPK) pathways, which modulate the activity of transcription factors through phosphorylation. Here, we

SUMO-, MAPK-, and resistance protein-signaling converge at transcription complexes that regulate plant innate immunity

NARCIS (Netherlands)

van den Burg, H.A.; Takken, F.L.W.

2010-01-01

Upon pathogen perception plant innate immune receptors activate various signaling pathways that trigger host defenses. PAMP-triggered defense signaling requires mitogen-activated protein kinase (MAPK) pathways, which modulate the activity of transcription factors through phosphorylation. Here, we

Mapping the Fetomaternal Peripheral Immune System at Term Pregnancy.

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Fragiadakis, Gabriela K; Baca, Quentin J; Gherardini, Pier Federico; Ganio, Edward A; Gaudilliere, Dyani K; Tingle, Martha; Lancero, Hope L; McNeil, Leslie S; Spitzer, Matthew H; Wong, Ronald J; Shaw, Gary M; Darmstadt, Gary L; Sylvester, Karl G; Winn, Virginia D; Carvalho, Brendan; Lewis, David B; Stevenson, David K; Nolan, Garry P; Aghaeepour, Nima; Angst, Martin S; Gaudilliere, Brice L

2016-12-01

Preterm labor and infections are the leading causes of neonatal deaths worldwide. During pregnancy, immunological cross talk between the mother and her fetus is critical for the maintenance of pregnancy and the delivery of an immunocompetent neonate. A precise understanding of healthy fetomaternal immunity is the important first step to identifying dysregulated immune mechanisms driving adverse maternal or neonatal outcomes. This study combined single-cell mass cytometry of paired peripheral and umbilical cord blood samples from mothers and their neonates with a graphical approach developed for the visualization of high-dimensional data to provide a high-resolution reference map of the cellular composition and functional organization of the healthy fetal and maternal immune systems at birth. The approach enabled mapping of known phenotypical and functional characteristics of fetal immunity (including the functional hyperresponsiveness of CD4 + and CD8 + T cells and the global blunting of innate immune responses). It also allowed discovery of new properties that distinguish the fetal and maternal immune systems. For example, examination of paired samples revealed differences in endogenous signaling tone that are unique to a mother and her offspring, including increased ERK1/2, MAPK-activated protein kinase 2, rpS6, and CREB phosphorylation in fetal Tbet + CD4 + T cells, CD8 + T cells, B cells, and CD56 lo CD16 + NK cells and decreased ERK1/2, MAPK-activated protein kinase 2, and STAT1 phosphorylation in fetal intermediate and nonclassical monocytes. This highly interactive functional map of healthy fetomaternal immunity builds the core reference for a growing data repository that will allow inferring deviations from normal associated with adverse maternal and neonatal outcomes. Copyright © 2016 by The American Association of Immunologists, Inc.

Plant immune and growth receptors share common signalling components but localise to distinct plasma membrane nanodomains.

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Bücherl, Christoph A; Jarsch, Iris K; Schudoma, Christian; Segonzac, Cécile; Mbengue, Malick; Robatzek, Silke; MacLean, Daniel; Ott, Thomas; Zipfel, Cyril

2017-03-06

Cell surface receptors govern a multitude of signalling pathways in multicellular organisms. In plants, prominent examples are the receptor kinases FLS2 and BRI1, which activate immunity and steroid-mediated growth, respectively. Intriguingly, despite inducing distinct signalling outputs, both receptors employ common downstream signalling components, which exist in plasma membrane (PM)-localised protein complexes. An important question is thus how these receptor complexes maintain signalling specificity. Live-cell imaging revealed that FLS2 and BRI1 form PM nanoclusters. Using single-particle tracking we could discriminate both cluster populations and we observed spatiotemporal separation between immune and growth signalling platforms. This finding was confirmed by visualising FLS2 and BRI1 within distinct PM nanodomains marked by specific remorin proteins and differential co-localisation with the cytoskeleton. Our results thus suggest that signalling specificity between these pathways may be explained by the spatial separation of FLS2 and BRI1 with their associated signalling components within dedicated PM nanodomains.

Comprehensive Transcriptome Profiling and Functional Analysis of the Frog (Bombina maxima) Immune System

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Zhao, Feng; Yan, Chao; Wang, Xuan; Yang, Yang; Wang, Guangyin; Lee, Wenhui; Xiang, Yang; Zhang, Yun

2014-01-01

Amphibians occupy a key phylogenetic position in vertebrates and evolution of the immune system. But, the resources of its transcriptome or genome are still little now. Bombina maxima possess strong ability to survival in very harsh environment with a more mature immune system. We obtained a comprehensive transcriptome by RNA-sequencing technology. 14.3% of transcripts were identified to be skin-specific genes, most of which were not isolated from skin secretion in previous works or novel non-coding RNAs. 27.9% of transcripts were mapped into 242 predicted KEGG pathways and 6.16% of transcripts related to human disease and cancer. Of 39 448 transcripts with the coding sequence, at least 1501 transcripts (570 genes) related to the immune system process. The molecules of immune signalling pathway were almost presented, several transcripts with high expression in skin and stomach. Experiments showed that lipopolysaccharide or bacteria challenge stimulated pro-inflammatory cytokine production and activation of pro-inflammatory caspase-1. These frog's data can remarkably expand the existing genome or transcriptome resources of amphibians, especially immunity data. The entity of the data provides a valuable platform for further investigation on more detailed immune response in B. maxima and a comparative study with other amphibians. PMID:23942912

Microbial-immune cross-talk and regulation of the immune system.

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Cahenzli, Julia; Balmer, Maria L; McCoy, Kathy D

2013-01-01

We are all born germ-free. Following birth we enter into a lifelong relationship with microbes residing on our body's surfaces. The lower intestine is home to the highest microbial density in our body, which is also the highest microbial density known on Earth (up to 10(12) /g of luminal contents). With our indigenous microbial cells outnumbering our human cells by an order of magnitude our body is more microbial than human. Numerous immune adaptations confine these microbes within the mucosa, enabling most of us to live in peaceful homeostasis with our intestinal symbionts. Intestinal epithelial cells not only form a physical barrier between the bacteria-laden lumen and the rest of the body but also function as multi-tasking immune cells that sense the prevailing microbial (apical) and immune (basolateral) milieus, instruct the underlying immune cells, and adapt functionally. In the constant effort to ensure intestinal homeostasis, the immune system becomes educated to respond appropriately and in turn immune status can shape the microbial consortia. Here we review how the dynamic immune-microbial dialogue underlies maturation and regulation of the immune system and discuss recent findings on the impact of diet on both microbial ecology and immune function. © 2012 The Authors. Immunology © 2012 Blackwell Publishing Ltd.

In immune defense: redefining the role of the immune system in chronic disease.

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Rubinow, Katya B; Rubinow, David R

2017-03-01

The recognition of altered immune system function in many chronic disease states has proven to be a pivotal advance in biomedical research over the past decade. For many metabolic and mood disorders, this altered immune activity has been characterized as inflammation, with the attendant assumption that the immune response is aberrant. However, accumulating evidence challenges this assumption and suggests that the immune system may be mounting adaptive responses to chronic stressors. Further, the inordinate complexity of immune function renders a simplistic, binary model incapable of capturing critical mechanistic insights. In this perspective article, we propose alternative paradigms for understanding the role of the immune system in chronic disease. By invoking allostasis or systems biology rather than inflammation, we can ascribe greater functional significance to immune mediators, gain newfound appreciation of the adaptive facets of altered immune activity, and better avoid the potentially disastrous effects of translating erroneous assumptions into novel therapeutic strategies.

Unfolded protein response (UPR) signaling regulates arsenic trioxide-mediated macrophage innate immune function disruption

International Nuclear Information System (INIS)

Srivastava, Ritesh K.; Li, Changzhao; Chaudhary, Sandeep C.; Ballestas, Mary E.; Elmets, Craig A.; Robbins, David J.; Matalon, Sadis; Deshane, Jessy S.; Afaq, Farrukh; Bickers, David R.; Athar, Mohammad

2013-01-01

Arsenic exposure is known to disrupt innate immune functions in humans and in experimental animals. In this study, we provide a mechanism by which arsenic trioxide (ATO) disrupts macrophage functions. ATO treatment of murine macrophage cells diminished internalization of FITC-labeled latex beads, impaired clearance of phagocytosed fluorescent bacteria and reduced secretion of pro-inflammatory cytokines. These impairments in macrophage functions are associated with ATO-induced unfolded protein response (UPR) signaling pathway characterized by the enhancement in proteins such as GRP78, p-PERK, p-eIF2α, ATF4 and CHOP. The expression of these proteins is altered both at transcriptional and translational levels. Pretreatment with chemical chaperon, 4-phenylbutyric acid (PBA) attenuated the ATO-induced activation in UPR signaling and afforded protection against ATO-induced disruption of macrophage functions. This treatment also reduced ATO-mediated reactive oxygen species (ROS) generation. Interestingly, treatment with antioxidant N-acetylcysteine (NAC) prior to ATO exposure, not only reduced ROS production and UPR signaling but also improved macrophage functions. These data demonstrate that UPR signaling and ROS generation are interdependent and are involved in the arsenic-induced pathobiology of macrophage. These data also provide a novel strategy to block the ATO-dependent impairment in innate immune responses. - Highlights: • Inorganic arsenic to humans and experimental animals disrupt innate immune responses. • The mechanism underlying arsenic impaired macrophage functions involves UPR signaling. • Chemical chaperon attenuates arsenic-mediated macrophage function impairment. • Antioxidant, NAC blocks impairment in arsenic-treated macrophage functions

Unfolded protein response (UPR) signaling regulates arsenic trioxide-mediated macrophage innate immune function disruption

Energy Technology Data Exchange (ETDEWEB)

Srivastava, Ritesh K.; Li, Changzhao; Chaudhary, Sandeep C. [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL (United States); Ballestas, Mary E. [Department of Pediatrics Infectious Disease, Children' s of Alabama, School of Medicine, University of Alabama at Birmingham, AL (United States); Elmets, Craig A. [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL (United States); Robbins, David J. [Department of Surgery, Molecular Oncology Program, Miller School of Medicine, University of Miami, Miami (United States); Matalon, Sadis [Department of Anesthesiology, University of Alabama at Birmingham, Birmingham, AL (United States); Deshane, Jessy S. [Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL (United States); Afaq, Farrukh [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL (United States); Bickers, David R. [Department of Dermatology, Columbia University Medical Center, New York (United States); Athar, Mohammad, E-mail: mathar@uab.edu [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL (United States)

2013-11-01

Arsenic exposure is known to disrupt innate immune functions in humans and in experimental animals. In this study, we provide a mechanism by which arsenic trioxide (ATO) disrupts macrophage functions. ATO treatment of murine macrophage cells diminished internalization of FITC-labeled latex beads, impaired clearance of phagocytosed fluorescent bacteria and reduced secretion of pro-inflammatory cytokines. These impairments in macrophage functions are associated with ATO-induced unfolded protein response (UPR) signaling pathway characterized by the enhancement in proteins such as GRP78, p-PERK, p-eIF2α, ATF4 and CHOP. The expression of these proteins is altered both at transcriptional and translational levels. Pretreatment with chemical chaperon, 4-phenylbutyric acid (PBA) attenuated the ATO-induced activation in UPR signaling and afforded protection against ATO-induced disruption of macrophage functions. This treatment also reduced ATO-mediated reactive oxygen species (ROS) generation. Interestingly, treatment with antioxidant N-acetylcysteine (NAC) prior to ATO exposure, not only reduced ROS production and UPR signaling but also improved macrophage functions. These data demonstrate that UPR signaling and ROS generation are interdependent and are involved in the arsenic-induced pathobiology of macrophage. These data also provide a novel strategy to block the ATO-dependent impairment in innate immune responses. - Highlights: • Inorganic arsenic to humans and experimental animals disrupt innate immune responses. • The mechanism underlying arsenic impaired macrophage functions involves UPR signaling. • Chemical chaperon attenuates arsenic-mediated macrophage function impairment. • Antioxidant, NAC blocks impairment in arsenic-treated macrophage functions.

Immune System

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... of the Immune System Print en español El sistema inmunitario Whether you're stomping through the showers ... of Use Notice of Nondiscrimination Visit the Nemours Web site. Note: All information on TeensHealth® is for ...

Linear ubiquitination signals in adaptive immune responses.

Science.gov (United States)

Ikeda, Fumiyo

2015-07-01

Ubiquitin can form eight different linkage types of chains using the intrinsic Met 1 residue or one of the seven intrinsic Lys residues. Each linkage type of ubiquitin chain has a distinct three-dimensional topology, functioning as a tag to attract specific signaling molecules, which are so-called ubiquitin readers, and regulates various biological functions. Ubiquitin chains linked via Met 1 in a head-to-tail manner are called linear ubiquitin chains. Linear ubiquitination plays an important role in the regulation of cellular signaling, including the best-characterized tumor necrosis factor (TNF)-induced canonical nuclear factor-κB (NF-κB) pathway. Linear ubiquitin chains are specifically generated by an E3 ligase complex called the linear ubiquitin chain assembly complex (LUBAC) and hydrolyzed by a deubiquitinase (DUB) called ovarian tumor (OTU) DUB with linear linkage specificity (OTULIN). LUBAC linearly ubiquitinates critical molecules in the TNF pathway, such as NEMO and RIPK1. The linear ubiquitin chains are then recognized by the ubiquitin readers, including NEMO, which control the TNF pathway. Accumulating evidence indicates an importance of the LUBAC complex in the regulation of apoptosis, development, and inflammation in mice. In this article, I focus on the role of linear ubiquitin chains in adaptive immune responses with an emphasis on the TNF-induced signaling pathways. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The Pathology of Orthopedic Implant Failure Is Mediated by Innate Immune System Cytokines

Directory of Open Access Journals (Sweden)

Stefan Landgraeber

2014-01-01

Full Text Available All of the over 1 million total joint replacements implanted in the US each year are expected to eventually fail after 15–25 years of use, due to slow progressive subtle inflammation at the bone implant interface. This inflammatory disease state is caused by implant debris acting, primarily, on innate immune cells, that is, macrophages. This slow progressive pathological bone loss or “aseptic loosening” is a potentially life-threatening condition due to the serious complications in older people (>75 yrs of total joint replacement revision surgery. In some people implant debris (particles and ions from metals can influence the adaptive immune system as well, giving rise to the concept of metal sensitivity. However, a consensus of studies agrees that the dominant form of this response is due to innate reactivity by macrophages to implant debris where both danger (DAMP and pathogen (PAMP signalling elicit cytokine-based inflammatory responses. This paper discusses implant debris induced release of the cytokines and chemokines due to activation of the innate (and the adaptive immune system and the subsequent formation of osteolysis. Different mechanisms of implant-debris reactivity related to the innate immune system are detailed, for example, danger signalling (e.g., IL-1β, IL-18, IL-33, etc., toll-like receptor activation (e.g., IL-6, TNF-α, etc., apoptosis (e.g., caspases 3–9, bone catabolism (e.g., TRAP5b, and hypoxia responses (Hif1-α. Cytokine-based clinical and basic science studies are in progress to provide diagnosis and therapeutic intervention strategies.

The Pathology of Orthopedic Implant Failure Is Mediated by Innate Immune System Cytokines

Science.gov (United States)

Landgraeber, Stefan; Jäger, Marcus; Jacobs, Joshua J.; Hallab, Nadim James

2014-01-01

All of the over 1 million total joint replacements implanted in the US each year are expected to eventually fail after 15–25 years of use, due to slow progressive subtle inflammation at the bone implant interface. This inflammatory disease state is caused by implant debris acting, primarily, on innate immune cells, that is, macrophages. This slow progressive pathological bone loss or “aseptic loosening” is a potentially life-threatening condition due to the serious complications in older people (>75 yrs) of total joint replacement revision surgery. In some people implant debris (particles and ions from metals) can influence the adaptive immune system as well, giving rise to the concept of metal sensitivity. However, a consensus of studies agrees that the dominant form of this response is due to innate reactivity by macrophages to implant debris where both danger (DAMP) and pathogen (PAMP) signalling elicit cytokine-based inflammatory responses. This paper discusses implant debris induced release of the cytokines and chemokines due to activation of the innate (and the adaptive) immune system and the subsequent formation of osteolysis. Different mechanisms of implant-debris reactivity related to the innate immune system are detailed, for example, danger signalling (e.g., IL-1β, IL-18, IL-33, etc.), toll-like receptor activation (e.g., IL-6, TNF-α, etc.), apoptosis (e.g., caspases 3–9), bone catabolism (e.g., TRAP5b), and hypoxia responses (Hif1-α). Cytokine-based clinical and basic science studies are in progress to provide diagnosis and therapeutic intervention strategies. PMID:24891761

Interleukin-21 receptor signalling is important for innate immune protection against HSV-2 infections.

Directory of Open Access Journals (Sweden)

Sine K Kratholm

Full Text Available Interleukin (IL -21 is produced by Natural Killer T (NKT cells and CD4(+ T cells and is produced in response to virus infections, where IL-21 has been shown to be essential in adaptive immune responses. Cells from the innate immune system such as Natural Killer (NK cells and macrophages are also important in immune protection against virus. These cells express the IL-21 receptor (IL-21R and respond to IL-21 with increased cytotoxicity and cytokine production. Currently, however it is not known whether IL-21 plays a significant role in innate immune responses to virus infections. The purpose of this study was to investigate the role of IL-21 and IL-21R in the innate immune response to a virus infection. We used C57BL/6 wild type (WT and IL-21R knock out (KO mice in a murine vaginal Herpes Simplex Virus type 2 (HSV-2 infection model to show that IL-21 - IL-21R signalling is indeed important in innate immune responses against HSV-2. We found that the IL-21R was expressed in the vaginal epithelium in uninfected (u.i WT mice, and expression increased early after HSV-2 infection. IL-21R KO mice exhibited increased vaginal viral titers on day 2 and 3 post infection (p.i. and subsequently developed significantly higher disease scores and a lower survival rate compared to WT mice. In addition, WT mice infected with HSV-2 receiving intra-vaginal pre-treatment with murine recombinant IL-21 (mIL-21 had decreased vaginal viral titers on day 2 p.i., significantly lower disease scores, and a higher survival rate compared to infected untreated WT controls. Collectively our data demonstrate the novel finding that the IL-21R plays a critical role in regulating innate immune responses against HSV-2 infection.

Approaches Mediating Oxytocin Regulation of the Immune System.

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Li, Tong; Wang, Ping; Wang, Stephani C; Wang, Yu-Feng

2016-01-01

The hypothalamic neuroendocrine system is mainly composed of the neural structures regulating hormone secretion from the pituitary gland and has been considered as the higher regulatory center of the immune system. Recently, the hypothalamo-neurohypophysial system (HNS) emerged as an important component of neuroendocrine-immune network, wherein the oxytocin (OT)-secreting system (OSS) plays an essential role. The OSS, consisting of OT neurons in the supraoptic nucleus, paraventricular nucleus, their several accessory nuclei and associated structures, can integrate neural, endocrine, metabolic, and immune information and plays a pivotal role in the development and functions of the immune system. The OSS can promote the development of thymus and bone marrow, perform immune surveillance, strengthen immune defense, and maintain immune homeostasis. Correspondingly, OT can inhibit inflammation, exert antibiotic-like effect, promote wound healing and regeneration, and suppress stress-associated immune disorders. In this process, the OSS can release OT to act on immune system directly by activating OT receptors or through modulating activities of other hypothalamic-pituitary-immune axes and autonomic nervous system indirectly. However, our understandings of the role of the OSS in neuroendocrine regulation of immune system are largely incomplete, particularly its relationship with other hypothalamic-pituitary-immune axes and the vasopressin-secreting system that coexists with the OSS in the HNS. In addition, it remains unclear about the relationship between the OSS and peripherally produced OT in immune regulation, particularly intrathymic OT that is known to elicit central immunological self-tolerance of T-cells to hypophysial hormones. In this work, we provide a brief review of current knowledge of the features of OSS regulation of the immune system and of potential approaches that mediate OSS coordination of the activities of entire neuroendocrine-immune network.

Immune System Toxicity and Immunotoxicity Hazard Identification

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Exposure to chemicals may alter immune system health, increasing the risk of infections, allergy and autoimmune diseases. The chapter provides a concise overview of the immune system, host factors that affect immune system heal, and the effects that xenobiotic exposure may have ...

Aggression, Social Stress, and the Immune System in Humans and Animal Models

Directory of Open Access Journals (Sweden)

Aki Takahashi

2018-03-01

Full Text Available Social stress can lead to the development of psychological problems ranging from exaggerated anxiety and depression to antisocial and violence-related behaviors. Increasing evidence suggests that the immune system is involved in responses to social stress in adulthood. For example, human studies show that individuals with high aggression traits display heightened inflammatory cytokine levels and dysregulated immune responses such as slower wound healing. Similar findings have been observed in patients with depression, and comorbidity of depression and aggression was correlated with stronger immune dysregulation. Therefore, dysregulation of the immune system may be one of the mediators of social stress that produces aggression and/or depression. Similar to humans, aggressive animals also show increased levels of several proinflammatory cytokines, however, unlike humans these animals are more protected from infectious organisms and have faster wound healing than animals with low aggression. On the other hand, subordinate animals that receive repeated social defeat stress have been shown to develop escalated and dysregulated immune responses such as glucocorticoid insensitivity in monocytes. In this review we synthesize the current evidence in humans, non-human primates, and rodents to show a role for the immune system in responses to social stress leading to psychiatric problems such as aggression or depression. We argue that while depression and aggression represent two fundamentally different behavioral and physiological responses to social stress, it is possible that some overlapped, as well as distinct, pattern of immune signaling may underlie both of them. We also argue the necessity of studying animal models of maladaptive aggression induced by social stress (i.e., social isolation for understanding neuro-immune mechanism of aggression, which may be relevant to human aggression.

Aggression, Social Stress, and the Immune System in Humans and Animal Models.

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Takahashi, Aki; Flanigan, Meghan E; McEwen, Bruce S; Russo, Scott J

2018-01-01

Social stress can lead to the development of psychological problems ranging from exaggerated anxiety and depression to antisocial and violence-related behaviors. Increasing evidence suggests that the immune system is involved in responses to social stress in adulthood. For example, human studies show that individuals with high aggression traits display heightened inflammatory cytokine levels and dysregulated immune responses such as slower wound healing. Similar findings have been observed in patients with depression, and comorbidity of depression and aggression was correlated with stronger immune dysregulation. Therefore, dysregulation of the immune system may be one of the mediators of social stress that produces aggression and/or depression. Similar to humans, aggressive animals also show increased levels of several proinflammatory cytokines, however, unlike humans these animals are more protected from infectious organisms and have faster wound healing than animals with low aggression. On the other hand, subordinate animals that receive repeated social defeat stress have been shown to develop escalated and dysregulated immune responses such as glucocorticoid insensitivity in monocytes. In this review we synthesize the current evidence in humans, non-human primates, and rodents to show a role for the immune system in responses to social stress leading to psychiatric problems such as aggression or depression. We argue that while depression and aggression represent two fundamentally different behavioral and physiological responses to social stress, it is possible that some overlapped, as well as distinct, pattern of immune signaling may underlie both of them. We also argue the necessity of studying animal models of maladaptive aggression induced by social stress (i.e., social isolation) for understanding neuro-immune mechanism of aggression, which may be relevant to human aggression.

Curating the innate immunity interactome.

LENUS (Irish Health Repository)

Lynn, David J

2010-01-01

The innate immune response is the first line of defence against invading pathogens and is regulated by complex signalling and transcriptional networks. Systems biology approaches promise to shed new light on the regulation of innate immunity through the analysis and modelling of these networks. A key initial step in this process is the contextual cataloguing of the components of this system and the molecular interactions that comprise these networks. InnateDB (http:\\/\\/www.innatedb.com) is a molecular interaction and pathway database developed to facilitate systems-level analyses of innate immunity.

The commensal microbiota drives immune homeostasis

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Marie-Claire eArrieta

2012-03-01

Full Text Available For millions of years, microbes have coexisted with eukaryotic cells at the mucosal surfaces of vertebrates in a complex, yet usually harmonious symbiosis. An ever-expanding number of reports describe how eliminating or shifting the intestinal microbiota has profound effects on the development and functionality of the mucosal and systemic immune systems. Here, we examine some of the mechanisms by which bacterial signals affect immune homeostasis. Focusing on the strategies that microbes use to keep our immune system healthy, as opposed to trying to correct the immune imbalances caused by dysbiosis, may prove to be a more astute and efficient way of treating immune-mediated disease.

Immune system and melanoma biology: a balance between immunosurveillance and immune escape.

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Passarelli, Anna; Mannavola, Francesco; Stucci, Luigia Stefania; Tucci, Marco; Silvestris, Francesco

2017-12-01

Melanoma is one of the most immunogenic tumors and its relationship with host immune system is currently under investigation. Many immunomodulatory mechanisms, favoring melanomagenesis and progression, have been described to interfere with the disablement of melanoma recognition and attack by immune cells resulting in immune resistance and immunosuppression. This knowledge produced therapeutic advantages, such as immunotherapy, aiming to overcome the immune evasion. Here, we review the current advances in cancer immunoediting and focus on melanoma immunology, which involves a dynamic interplay between melanoma and immune system, as well as on effects of "targeted therapies" on tumor microenvironment for combination strategies.

Parallels between immune driven-hematopoiesis and T cell activation: 3 signals that relay inflammatory stress to the bone marrow

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Libregts, Sten F.W.M.; Nolte, Martijn A., E-mail: m.nolte@sanquin.nl

2014-12-10

Quiescence, self-renewal, lineage commitment and differentiation of hematopoietic stem cells (HSCs) towards fully mature blood cells are a complex process that involves both intrinsic and extrinsic signals. During steady-state conditions, most hematopoietic signals are provided by various resident cells inside the bone marrow (BM), which establish the HSC micro-environment. However, upon infection, the hematopoietic process is also affected by pathogens and activated immune cells, which illustrates an effective feedback mechanism to hematopoietic stem and progenitor cells (HSPCs) via immune-mediated signals. Here, we review the impact of pathogen-associated molecular patterns (PAMPs), damage-associated molecular patterns (DAMPs), costimulatory molecules and pro-inflammatory cytokines on the quiescence, proliferation and differentiation of HSCs and more committed progenitors. As modulation of HSPC function via these immune-mediated signals holds an interesting parallel with the “three-signal-model” described for the activation and differentiation of naïve T-cells, we propose a novel “three-signal” concept for immune-driven hematopoiesis. In this model, the recognition of PAMPs and DAMPs will activate HSCs and induce proliferation, while costimulatory molecules and pro-inflammatory cytokines confer a second and third signal, respectively, which further regulate expansion, lineage commitment and differentiation of HSPCs. We review the impact of inflammatory stress on hematopoiesis along these three signals and we discuss whether they act independently from each other or that concurrence of these signals is important for an adequate response of HSPCs upon infection. - Highlights: • Inflammation and infection have a direct impact on hematopoiesis in the bone marrow. • We draw a striking parallel between immune-driven hematopoiesis and T cell activation. • We review how PAMPs and DAMPs, costimulation and cytokines influence HSPC function.

Parallels between immune driven-hematopoiesis and T cell activation: 3 signals that relay inflammatory stress to the bone marrow

International Nuclear Information System (INIS)

Libregts, Sten F.W.M.; Nolte, Martijn A.

2014-01-01

Quiescence, self-renewal, lineage commitment and differentiation of hematopoietic stem cells (HSCs) towards fully mature blood cells are a complex process that involves both intrinsic and extrinsic signals. During steady-state conditions, most hematopoietic signals are provided by various resident cells inside the bone marrow (BM), which establish the HSC micro-environment. However, upon infection, the hematopoietic process is also affected by pathogens and activated immune cells, which illustrates an effective feedback mechanism to hematopoietic stem and progenitor cells (HSPCs) via immune-mediated signals. Here, we review the impact of pathogen-associated molecular patterns (PAMPs), damage-associated molecular patterns (DAMPs), costimulatory molecules and pro-inflammatory cytokines on the quiescence, proliferation and differentiation of HSCs and more committed progenitors. As modulation of HSPC function via these immune-mediated signals holds an interesting parallel with the “three-signal-model” described for the activation and differentiation of naïve T-cells, we propose a novel “three-signal” concept for immune-driven hematopoiesis. In this model, the recognition of PAMPs and DAMPs will activate HSCs and induce proliferation, while costimulatory molecules and pro-inflammatory cytokines confer a second and third signal, respectively, which further regulate expansion, lineage commitment and differentiation of HSPCs. We review the impact of inflammatory stress on hematopoiesis along these three signals and we discuss whether they act independently from each other or that concurrence of these signals is important for an adequate response of HSPCs upon infection. - Highlights: • Inflammation and infection have a direct impact on hematopoiesis in the bone marrow. • We draw a striking parallel between immune-driven hematopoiesis and T cell activation. • We review how PAMPs and DAMPs, costimulation and cytokines influence HSPC function

Molecular Pathways for Immune Recognition of Preproinsulin Signal Peptide in Type 1 Diabetes.

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Kronenberg-Versteeg, Deborah; Eichmann, Martin; Russell, Mark A; de Ru, Arnoud; Hehn, Beate; Yusuf, Norkhairin; van Veelen, Peter A; Richardson, Sarah J; Morgan, Noel G; Lemberg, Marius K; Peakman, Mark

2018-04-01

The signal peptide region of preproinsulin (PPI) contains epitopes targeted by HLA-A-restricted (HLA-A0201, A2402) cytotoxic T cells as part of the pathogenesis of β-cell destruction in type 1 diabetes. We extended the discovery of the PPI epitope to disease-associated HLA-B*1801 and HLA-B*3906 (risk) and HLA-A*1101 and HLA-B*3801 (protective) alleles, revealing that four of six alleles present epitopes derived from the signal peptide region. During cotranslational translocation of PPI, its signal peptide is cleaved and retained within the endoplasmic reticulum (ER) membrane, implying it is processed for immune recognition outside of the canonical proteasome-directed pathway. Using in vitro translocation assays with specific inhibitors and gene knockout in PPI-expressing target cells, we show that PPI signal peptide antigen processing requires signal peptide peptidase (SPP). The intramembrane protease SPP generates cytoplasm-proximal epitopes, which are transporter associated with antigen processing (TAP), ER-luminal epitopes, which are TAP independent, each presented by different HLA class I molecules and N-terminal trimmed by ER aminopeptidase 1 for optimal presentation. In vivo, TAP expression is significantly upregulated and correlated with HLA class I hyperexpression in insulin-containing islets of patients with type 1 diabetes. Thus, PPI signal peptide epitopes are processed by SPP and loaded for HLA-guided immune recognition via pathways that are enhanced during disease pathogenesis. © 2018 by the American Diabetes Association.

Maternal immunity enhances systemic recall immune responses upon oral immunization of piglets with F4 fimbriae.

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Nguyen, Ut V; Melkebeek, Vesna; Devriendt, Bert; Goetstouwers, Tiphanie; Van Poucke, Mario; Peelman, Luc; Goddeeris, Bruno M; Cox, Eric

2015-06-23

F4 enterotoxigenic Escherichia coli (ETEC) cause diarrhoea and mortality in piglets leading to severe economic losses. Oral immunization of piglets with F4 fimbriae induces a protective intestinal immune response evidenced by an F4-specific serum and intestinal IgA response. However, successful oral immunization of pigs with F4 fimbriae in the presence of maternal immunity has not been demonstrated yet. In the present study we aimed to evaluate the effect of maternal immunity on the induction of a systemic immune response upon oral immunization of piglets. Whereas F4-specific IgG and IgA could be induced by oral immunization of pigs without maternal antibodies and by intramuscular immunization of pigs with maternal antibodies, no such response was seen in the orally immunized animals with maternal antibodies. Since maternal antibodies can mask an antibody response, we also looked by ELIspot assays for circulating F4-specific antibody secreting cells (ASCs). Enumerating the F4-specific ASCs within the circulating peripheral blood mononuclear cells, and the number of F4-specific IgA ASCs within the circulating IgA(+) B-cells revealed an F4-specific immune response in the orally immunized animals with maternal antibodies. Interestingly, results suggest a more robust IgA booster response by oral immunization of pigs with than without maternal antibodies. These results demonstrate that oral immunization of piglets with F4-specific maternal antibodies is feasible and that these maternal antibodies seem to enhance the secondary systemic immune response. Furthermore, our ELIspot assay on enriched IgA(+) B-cells could be used as a screening procedure to optimize mucosal immunization protocols in pigs with maternal immunity.

Specific recycling receptors are targeted to the immune synapse by the intraflagellar transport system

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Finetti, Francesca; Patrussi, Laura; Masi, Giulia; Onnis, Anna; Galgano, Donatella; Lucherini, Orso Maria; Pazour, Gregory J.; Baldari, Cosima T.

2014-01-01

ABSTRACT T cell activation requires sustained signaling at the immune synapse, a specialized interface with the antigen-presenting cell (APC) that assembles following T cell antigen receptor (TCR) engagement by major histocompatibility complex (MHC)-bound peptide. Central to sustained signaling is the continuous recruitment of TCRs to the immune synapse. These TCRs are partly mobilized from an endosomal pool by polarized recycling. We have identified IFT20, a component of the intraflagellar transport (IFT) system that controls ciliogenesis, as a central regulator of TCR recycling to the immune synapse. Here, we have investigated the interplay of IFT20 with the Rab GTPase network that controls recycling. We found that IFT20 forms a complex with Rab5 and the TCR on early endosomes. IFT20 knockdown (IFT20KD) resulted in a block in the recycling pathway, leading to a build-up of recycling TCRs in Rab5+ endosomes. Recycling of the transferrin receptor (TfR), but not of CXCR4, was disrupted by IFT20 deficiency. The IFT components IFT52 and IFT57 were found to act together with IFT20 to regulate TCR and TfR recycling. The results provide novel insights into the mechanisms that control TCR recycling and immune synapse assembly, and underscore the trafficking-related function of the IFT system beyond ciliogenesis. PMID:24554435

Molecular Mechanisms Underlying β-Adrenergic Receptor-Mediated Cross-Talk between Sympathetic Neurons and Immune Cells

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Dianne Lorton

2015-03-01

Full Text Available Cross-talk between the sympathetic nervous system (SNS and immune system is vital for health and well-being. Infection, tissue injury and inflammation raise firing rates of sympathetic nerves, increasing their release of norepinephrine (NE in lymphoid organs and tissues. NE stimulation of β2-adrenergic receptors (ARs in immune cells activates the cAMP-protein kinase A (PKA intracellular signaling pathway, a pathway that interfaces with other signaling pathways that regulate proliferation, differentiation, maturation and effector functions in immune cells. Immune–SNS cross-talk is required to maintain homeostasis under normal conditions, to develop an immune response of appropriate magnitude after injury or immune challenge, and subsequently restore homeostasis. Typically, β2-AR-induced cAMP is immunosuppressive. However, many studies report actions of β2-AR stimulation in immune cells that are inconsistent with typical cAMP–PKA signal transduction. Research during the last decade in non-immune organs, has unveiled novel alternative signaling mechanisms induced by β2-AR activation, such as a signaling switch from cAMP–PKA to mitogen-activated protein kinase (MAPK pathways. If alternative signaling occurs in immune cells, it may explain inconsistent findings of sympathetic regulation of immune function. Here, we review β2-AR signaling, assess the available evidence for alternative signaling in immune cells, and provide insight into the circumstances necessary for “signal switching” in immune cells.

Bim: guardian of tissue homeostasis and critical regulator of the immune system, tumorigenesis and bone biology.

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Akiyama, Toru; Tanaka, Sakae

2011-08-01

One of the most important roles of apoptosis is the maintenance of tissue homeostasis. Impairment of apoptosis leads to a number of pathological conditions. In response to apoptotic signals, various proteins are activated in a pathway and signal-specific manner. Recently, the pro-apoptotic molecule Bim has attracted increasing attention as a pivotal regulator of tissue homeostasis. The Bim expression level is strictly controlled in both transcriptional and post-transcriptional levels. This control is dependent on cell, tissue and apoptotic stimuli. The phenotype of Bim-deficient mice is a systemic lupus erythematosus-like autoimmune disease with an abnormal accumulation of hematopoietic cells. Bim is thus a critical regulator of hematopoietic cells and immune system. Further studies have revealed the critical roles of Bim in various normal and pathological conditions, including bone homeostasis and tumorigenesis. The current understanding of Bim signaling and roles in the maintenance of tissue homeostasis is reviewed in this paper, focusing on the immune system, bone biology and tumorigenesis to illustrate the diversified role of Bim.

Colorectal cancer cells suppress CD4+ T cells immunity through canonical Wnt signaling.

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Sun, Xuan; Liu, Suoning; Wang, Daguang; Zhang, Yang; Li, Wei; Guo, Yuchen; Zhang, Hua; Suo, Jian

2017-02-28

Understanding how colorectal cancer escapes from immunosurveillance and immune attack is important for developing novel immunotherapies for colorectal cancer. In this study we evaluated the role of canonical Wnt signaling in the regulation of T cell function in a mouse colorectal cancer model. We found that colorectal cancer cells expressed abundant Wnt ligands, and intratumoral T cells expressed various Frizzled proteins. Meanwhile, both active β-catenin and total β-catenin were elevated in intratumoral T cells. In vitro study indicated that colorectal cancer cells suppressed IFN-γ expression and increased IL-17a expression in activated CD4+ T cells. However, the cytotoxic activity of CD8+ T cells was not altered by colorectal cancer cells. To further evaluate the importance of Wnt signaling for CD4+ T cell-mediated cancer immunity, β-catenin expression was enforced in CD4+ T cells using lentiviral transduction. In an adoptive transfer model, enforced expression of β-catenin in intratumoral CD4+ T cells increased IL-17a expression, enhanced proliferation and inhibited apoptosis of colorectal cancer cells. Taken together, our study disclosed a new mechanism by which colorectal cancer impairs T cell immunity.

Innate immunity in the pathogenesis of psoriasis.

LENUS (Irish Health Repository)

Sweeney, Cheryl M

2011-12-01

Psoriasis is a common, immune-mediated inflammatory skin disorder. T helper(h)1 and Th17 lymphocytes contribute to the pathogenesis of psoriasis through the release of inflammatory cytokines that promote further recruitment of immune cells, keratinocyte proliferation and sustained inflammation. The innate immune system is the first line of defence against infection and plays a crucial role in the initiation of the adaptive immune response. The presence of innate immune cells and their products in psoriatic skin plaques suggests a role for innate immunity in this disease. In addition, the innate immune system can direct the development of pathogenic Th cells in psoriasis. In this article, we will summarise the role of the innate immune system in psoriasis with particular emphasis on the role of cytokines, signalling pathways and cells of the innate immune system.

A systems biology approach reveals that tissue tropism to West Nile virus is regulated by antiviral genes and innate immune cellular processes.

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Mehul S Suthar

2013-02-01

Full Text Available The actions of the RIG-I like receptor (RLR and type I interferon (IFN signaling pathways are essential for a protective innate immune response against the emerging flavivirus West Nile virus (WNV. In mice lacking RLR or IFN signaling pathways, WNV exhibits enhanced tissue tropism, indicating that specific host factors of innate immune defense restrict WNV infection and dissemination in peripheral tissues. However, the immune mechanisms by which the RLR and IFN pathways coordinate and function to impart restriction of WNV infection are not well defined. Using a systems biology approach, we defined the host innate immune response signature and actions that restrict WNV tissue tropism. Transcriptional profiling and pathway modeling to compare WNV-infected permissive (spleen and nonpermissive (liver tissues showed high enrichment for inflammatory responses, including pattern recognition receptors and IFN signaling pathways, that define restriction of WNV replication in the liver. Assessment of infected livers from Mavs(-/- × Ifnar(-/- mice revealed the loss of expression of several key components within the natural killer (NK cell signaling pathway, including genes associated with NK cell activation, inflammatory cytokine production, and NK cell receptor signaling. In vivo analysis of hepatic immune cell infiltrates from WT mice demonstrated that WNV infection leads to an increase in NK cell numbers with enhanced proliferation, maturation, and effector action. In contrast, livers from Mavs(-/- × Ifnar(-/- infected mice displayed reduced immune cell infiltration, including a significant reduction in NK cell numbers. Analysis of cocultures of dendritic and NK cells revealed both cell-intrinsic and -extrinsic roles for the RLR and IFN signaling pathways to regulate NK cell effector activity. Taken together, these observations reveal a complex innate immune signaling network, regulated by the RLR and IFN signaling pathways, that drives tissue

Cutting Edge: Retinoic Acid Signaling in B Cells Is Essential for Oral Immunization and Microflora Composition.

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Pantazi, Eirini; Marks, Ellen; Stolarczyk, Emilie; Lycke, Nils; Noelle, Randolph J; Elgueta, Raul

2015-08-15

Retinoic acid (RA) is a critical regulator of the intestinal adaptive immune response. However, the intrinsic impact of RA on B cell differentiation in the regulation of gut humoral immunity in vivo has never been directly shown. To address this issue, we have been able to generate a mouse model where B cells specifically express a dominant-negative receptor α for RA. In this study, we show that the silencing of RA signaling in B cells reduces the numbers of IgA(+) Ab-secreting cells both in vitro and in vivo, suggesting that RA has a direct effect on IgA plasma cell differentiation. Moreover, the lack of RA signaling in B cells abrogates Ag-specific IgA responses after oral immunization and affects the microbiota composition. In conclusion, these results suggest that RA signaling in B cells through the RA receptor α is important to generate an effective gut humoral response and to maintain a normal microbiota composition. Copyright © 2015 by The American Association of Immunologists, Inc.

Innate immune signalling of the zebrafish embryo

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Stockhammer, Oliver W.

2010-01-01

In the last decade the study of the innate immune system has gained renewed scientific momentum as a result of the discovery of essential receptor families, such as the Toll-like receptor (TLR) family, that are required for pathogen recognition. These receptors detect specific molecular structures

Feeding Our Immune System: Impact on Metabolism

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Isabelle Wolowczuk

2008-01-01

Full Text Available Endogenous intestinal microflora and environmental factors, such as diet, play a central role in immune homeostasis and reactivity. In addition, microflora and diet both influence body weight and insulin-resistance, notably through an action on adipose cells. Moreover, it is known since a long time that any disturbance in metabolism, like obesity, is associated with immune alteration, for example, inflammation. The purpose of this review is to provide an update on how nutrients-derived factors (mostly focusing on fatty acids and glucose impact the innate and acquired immune systems, including the gut immune system and its associated bacterial flora. We will try to show the reader how the highly energy-demanding immune cells use glucose as a main source of fuel in a way similar to that of insulin-responsive adipose tissue and how Toll-like receptors (TLRs of the innate immune system, which are found on immune cells, intestinal cells, and adipocytes, are presently viewed as essential actors in the complex balance ensuring bodily immune and metabolic health. Understanding more about these links will surely help to study and understand in a more fundamental way the common observation that eating healthy will keep you and your immune system healthy.

Weakened Immune System and Adult Vaccination

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... Basics Adult Vaccination Resources for Healthcare Professionals Weakened Immune System and Adult Vaccination Recommend on Facebook Tweet Share ... people with health conditions such as a weakened immune system. If you have cancer or other immunocompromising conditions, ...

Recent Advances in Aptamers Targeting Immune System.

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Hu, Piao-Ping

2017-02-01

The immune system plays important role in protecting the organism by recognizing non-self molecules from pathogen such as bacteria, parasitic worms, and viruses. When the balance of the host defense system is disturbed, immunodeficiency, autoimmunity, and inflammation occur. Nucleic acid aptamers are short single-stranded DNA (ssDNA) or RNA ligands that interact with complementary molecules with high specificity and affinity. Aptamers that target the molecules involved in immune system to modulate their function have great potential to be explored as new diagnostic and therapeutic agents for immune disorders. This review summarizes recent advances in the development of aptamers targeting immune system. The selection of aptamers with superior chemical and biological characteristics will facilitate their application in the diagnosis and treatment of immune disorders.

Transport modeling: An artificial immune system approach

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Teodorović Dušan

2006-01-01

Full Text Available This paper describes an artificial immune system approach (AIS to modeling time-dependent (dynamic, real time transportation phenomenon characterized by uncertainty. The basic idea behind this research is to develop the Artificial Immune System, which generates a set of antibodies (decisions, control actions that altogether can successfully cover a wide range of potential situations. The proposed artificial immune system develops antibodies (the best control strategies for different antigens (different traffic "scenarios". This task is performed using some of the optimization or heuristics techniques. Then a set of antibodies is combined to create Artificial Immune System. The developed Artificial Immune transportation systems are able to generalize, adapt, and learn based on new knowledge and new information. Applications of the systems are considered for airline yield management, the stochastic vehicle routing, and real-time traffic control at the isolated intersection. The preliminary research results are very promising.

Molecular mechanism and function of CD40/CD40L engagement in the immune system.

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Elgueta, Raul; Benson, Micah J; de Vries, Victor C; Wasiuk, Anna; Guo, Yanxia; Noelle, Randolph J

2009-05-01

During the generation of a successful adaptive immune response, multiple molecular signals are required. A primary signal is the binding of cognate antigen to an antigen receptor expressed by T and B lymphocytes. Multiple secondary signals involve the engagement of costimulatory molecules expressed by T and B lymphocytes with their respective ligands. Because of its essential role in immunity, one of the best characterized of the costimulatory molecules is the receptor CD40. This receptor, a member of the tumor necrosis factor receptor family, is expressed by B cells, professional antigen-presenting cells, as well as non-immune cells and tumors. CD40 binds its ligand CD40L, which is transiently expressed on T cells and other non-immune cells under inflammatory conditions. A wide spectrum of molecular and cellular processes is regulated by CD40 engagement including the initiation and progression of cellular and humoral adaptive immunity. In this review, we describe the downstream signaling pathways initiated by CD40 and overview how CD40 engagement or antagonism modulates humoral and cellular immunity. Lastly, we discuss the role of CD40 as a target in harnessing anti-tumor immunity. This review underscores the essential role CD40 plays in adaptive immunity.

Early Microbes Modify Immune System Development and Metabolic Homeostasis-The "Restaurant" Hypothesis Revisited.

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Nash, Michael J; Frank, Daniel N; Friedman, Jacob E

2017-01-01

The developing infant gut microbiome affects metabolism, maturation of the gastrointestinal tract, immune system function, and brain development. Initial seeding of the neonatal microbiota occurs through maternal and environmental contact. Maternal diet, antibiotic use, and cesarean section alter the offspring microbiota composition, at least temporarily. Nutrients are thought to regulate initial perinatal microbial colonization, a paradigm known as the "Restaurant" hypothesis. This hypothesis proposes that early nutritional stresses alter both the initial colonizing bacteria and the development of signaling pathways controlled by microbial mediators. These stresses fine-tune the immune system and metabolic homeostasis in early life, potentially setting the stage for long-term metabolic and immune health. Dysbiosis, an imbalance or a maladaptation in the microbiota, can be caused by several factors including dietary alterations and antibiotics. Dysbiosis can alter biological processes in the gut and in tissues and organs throughout the body. Misregulated development and activity of both the innate and adaptive immune systems, driven by early dysbiosis, could have long-lasting pathologic consequences such as increased autoimmunity, increased adiposity, and non-alcoholic fatty liver disease (NAFLD). This review will focus on factors during pregnancy and the neonatal period that impact a neonate's gut microbiome, as well as the mechanisms and possible links from early infancy that can drive increased risk for diseases including obesity and NAFLD. The complex pathways that connect diet, the microbiota, immune system development, and metabolism, particularly in early life, present exciting new frontiers for biomedical research.

Melatonin: Buffering the Immune System

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Juan M. Guerrero

2013-04-01

Full Text Available Melatonin modulates a wide range of physiological functions with pleiotropic effects on the immune system. Despite the large number of reports implicating melatonin as an immunomodulatory compound, it still remains unclear how melatonin regulates immunity. While some authors argue that melatonin is an immunostimulant, many studies have also described anti-inflammatory properties. The data reviewed in this paper support the idea of melatonin as an immune buffer, acting as a stimulant under basal or immunosuppressive conditions or as an anti-inflammatory compound in the presence of exacerbated immune responses, such as acute inflammation. The clinical relevance of the multiple functions of melatonin under different immune conditions, such as infection, autoimmunity, vaccination and immunosenescence, is also reviewed.

Melatonin: Buffering the Immune System

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Carrillo-Vico, Antonio; Lardone, Patricia J.; Álvarez-Sánchez, Nuria; Rodríguez-Rodríguez, Ana; Guerrero, Juan M.

2013-01-01

Melatonin modulates a wide range of physiological functions with pleiotropic effects on the immune system. Despite the large number of reports implicating melatonin as an immunomodulatory compound, it still remains unclear how melatonin regulates immunity. While some authors argue that melatonin is an immunostimulant, many studies have also described anti-inflammatory properties. The data reviewed in this paper support the idea of melatonin as an immune buffer, acting as a stimulant under basal or immunosuppressive conditions or as an anti-inflammatory compound in the presence of exacerbated immune responses, such as acute inflammation. The clinical relevance of the multiple functions of melatonin under different immune conditions, such as infection, autoimmunity, vaccination and immunosenescence, is also reviewed. PMID:23609496

The immune system, adaptation, and machine learning

Science.gov (United States)

Farmer, J. Doyne; Packard, Norman H.; Perelson, Alan S.

1986-10-01

The immune system is capable of learning, memory, and pattern recognition. By employing genetic operators on a time scale fast enough to observe experimentally, the immune system is able to recognize novel shapes without preprogramming. Here we describe a dynamical model for the immune system that is based on the network hypothesis of Jerne, and is simple enough to simulate on a computer. This model has a strong similarity to an approach to learning and artificial intelligence introduced by Holland, called the classifier system. We demonstrate that simple versions of the classifier system can be cast as a nonlinear dynamical system, and explore the analogy between the immune and classifier systems in detail. Through this comparison we hope to gain insight into the way they perform specific tasks, and to suggest new approaches that might be of value in learning systems.

Connecting the immune system, systemic chronic inflammation and the gut microbiome: The role of sex.

Science.gov (United States)

Rizzetto, Lisa; Fava, Francesca; Tuohy, Kieran M; Selmi, Carlo

2018-05-31

Unresolved low grade systemic inflammation represents the underlying pathological mechanism driving immune and metabolic pathways involved in autoimmune diseases (AID). Mechanistic studies in animal models of AID and observational studies in patients have found alterations in gut microbiota communities and their metabolites, suggesting a microbial contribution to the onset or progression of AID. The gut microbiota and its metabolites have been shown to influence immune functions and immune homeostasis both within the gut and systematically. Microbial derived-short chain fatty acid (SCFA) and bio-transformed bile acid (BA) have been shown to influence the immune system acting as ligands specific cell signaling receptors like GPRCs, TGR5 and FXR, or via epigenetic processes. Similarly, intestinal permeability (leaky gut) and bacterial translocation are important contributors to chronic systemic inflammation and, without repair of the intestinal barrier, might represent a continuous inflammatory stimulus capable of triggering autoimmune processes. Recent studies indicate gender-specific differences in immunity, with the gut microbiota shaping and being concomitantly shaped by the hormonal milieu governing differences between the sexes. A bi-directional cross-talk between microbiota and the endocrine system is emerging with bacteria being able to produce hormones (e.g. serotonin, dopamine and somatostatine), respond to host hormones (e.g. estrogens) and regulate host hormones' homeostasis (e.g by inhibiting gene prolactin transcription or converting glucocorticoids to androgens). We review herein how gut microbiota and its metabolites regulate immune function, intestinal permeability and possibly AID pathological processes. Further, we describe the dysbiosis within the gut microbiota observed in different AID and speculate how restoring gut microbiota composition and its regulatory metabolites by dietary intervention including prebiotics and probiotics could help in

The role of glycans in immune evasion: the human fetoembryonic defence system hypothesis revisited.

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Clark, Gary F

2014-03-01

Emerging data suggest that mechanisms to evade the human immune system may be shared by the conceptus, tumour cells, persistent pathogens and viruses. It is therefore timely to revisit the human fetoembryonic defense system (Hu-FEDS) hypothesis that was proposed in two papers in the 1990s. The initial paper suggested that glycoconjugates expressed in the human reproductive system inhibited immune responses directed against gametes and the developing human by employing their carbohydrate sequences as functional groups. These glycoconjugates were proposed to block specific binding interactions and interact with lectins linked to signal transduction pathways that modulated immune cell functions. The second article suggested that aggressive tumour cells and persistent pathogens (HIV, H. pylori, schistosomes) either mimicked or acquired the same carbohydrate functional groups employed in this system to evade immune responses. This subterfuge enabled these pathogens and tumour cells to couple their survival to the human reproductive imperative. The Hu-FEDS model has been repeatedly tested since its inception. Data relevant to this model have also been obtained in other studies. Herein, the Hu-FEDS hypothesis is revisited in the context of these more recent findings. Far more supportive evidence for this model now exists than when it was first proposed, and many of the original predictions have been validated. This type of subterfuge by pathogens and tumour cells likely applies to all sexually reproducing metazoans that must protect their gametes from immune responses. Intervention in these pathological states will likely remain problematic until this system of immune evasion is fully understood and appreciated.

The Immune System and Bodily Defence

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 2. The Immune System and Bodily Defence How Do Parasites and the Immune System Choose their Dances? Vineeta Bal Satyajit Rath. Series Article Volume 2 Issue 2 February 1997 pp 17-24 ...

The Immune System and Bodily Defence

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 9. The Immune System and Bodily Defence How Does the Immune System Recognize Everything Under the Sun? Vineeta Bal Satyajit Rath. Series Article Volume 2 Issue 9 September 1997 pp 6-10 ...

Immune inhibitory receptors in viral infection and cancer

NARCIS (Netherlands)

Karnam, G.

2014-01-01

We are protected from external and internal dangers by our immune system. Immune responses need to be balanced to prevent uncontrolled inflammation and/or autoimmunity. Cell growth inhibition, apoptosis, and down regulation of receptor signals are all part of the inhibitory tools used by the immune

The S(c)ensory Immune System Theory.

Science.gov (United States)

Veiga-Fernandes, Henrique; Freitas, António A

2017-10-01

Viewpoints on the immune system have evolved across different paradigms, including the clonal selection theory, the idiotypic network, and the danger and tolerance models. Herein, we propose that in multicellular organisms, where panoplies of cells from different germ layers interact and immune cells are constantly generated, the behavior of the immune system is defined by the rules governing cell survival, systems physiology and organismic homeostasis. Initially, these rules were imprinted at the single cell-protist level, but supervened modifications in the transition to multicellular organisms. This context determined the emergence of the 'sensory immune system', which operates in a s(c)ensor mode to ensure systems physiology, organismic homeostasis, and perpetuation of its replicating molecules. Copyright © 2017 Elsevier Ltd. All rights reserved.

Immune genes undergo more adaptive evolution than non-immune system genes in Daphnia pulex

Directory of Open Access Journals (Sweden)

McTaggart Seanna J

2012-05-01

Full Text Available Abstract Background Understanding which parts of the genome have been most influenced by adaptive evolution remains an unsolved puzzle. Some evidence suggests that selection has the greatest impact on regions of the genome that interact with other evolving genomes, including loci that are involved in host-parasite co-evolutionary processes. In this study, we used a population genetic approach to test this hypothesis by comparing DNA sequences of 30 putative immune system genes in the crustacean Daphnia pulex with 24 non-immune system genes. Results In support of the hypothesis, results from a multilocus extension of the McDonald-Kreitman (MK test indicate that immune system genes as a class have experienced more adaptive evolution than non-immune system genes. However, not all immune system genes show evidence of adaptive evolution. Additionally, we apply single locus MK tests and calculate population genetic parameters at all loci in order to characterize the mode of selection (directional versus balancing in the genes that show the greatest deviation from neutral evolution. Conclusions Our data are consistent with the hypothesis that immune system genes undergo more adaptive evolution than non-immune system genes, possibly as a result of host-parasite arms races. The results of these analyses highlight several candidate loci undergoing adaptive evolution that could be targeted in future studies.

Signaling through IL-17C/IL-17RE is dispensable for immunity to systemic, oral and cutaneous candidiasis.

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Conti, Heather R; Whibley, Natasha; Coleman, Bianca M; Garg, Abhishek V; Jaycox, Jillian R; Gaffen, Sarah L

2015-01-01

Candida albicans is a commensal fungal microbe of the human orogastrointestinal tract and skin. C. albicans causes multiple forms of disease in immunocompromised patients, including oral, vaginal, dermal and disseminated candidiasis. The cytokine IL-17 (IL-17A) and its receptor subunits, IL-17RA and IL-17RC, are required for protection to most forms of candidiasis. The importance of the IL-17R pathway has been observed not only in knockout mouse models, but also in humans with rare genetic mutations that impact generation of Th17 cells or the IL-17 signaling pathway, including Hyper-IgE Syndrome (STAT3 or TYK2 mutations) or IL17RA or ACT1 gene deficiency. The IL-17 family of cytokines is a distinct subclass of cytokines with unique structural and signaling properties. IL-17A is the best-characterized member of the IL-17 family to date, but far less is known about other IL-17-related cytokines. In this study, we sought to determine the role of a related IL-17 cytokine, IL-17C, in protection against oral, dermal and disseminated forms of C. albicans infection. IL-17C signals through a heterodimeric receptor composed of the IL-17RA and IL-17RE subunits. We observed that IL-17C mRNA was induced following oral C. albicans infection. However, mice lacking IL-17C or IL-17RE cleared C. albicans infections in the oral mucosa, skin and bloodstream at rates similar to WT littermate controls. Moreover, these mice demonstrated similar gene transcription profiles and recovery kinetics as WT animals. These findings indicate that IL-17C and IL-17RE are dispensable for immunity to the forms of candidiasis evaluated, and illustrate a surprisingly limited specificity of the IL-17 family of cytokines with respect to systemic, oral and cutaneous Candida infections.

Signaling through IL-17C/IL-17RE Is Dispensable for Immunity to Systemic, Oral and Cutaneous Candidiasis

Science.gov (United States)

Conti, Heather R.; Whibley, Natasha; Coleman, Bianca M.; Garg, Abhishek V.; Jaycox, Jillian R.; Gaffen, Sarah L.

2015-01-01

Candida albicans is a commensal fungal microbe of the human orogastrointestinal tract and skin. C. albicans causes multiple forms of disease in immunocompromised patients, including oral, vaginal, dermal and disseminated candidiasis. The cytokine IL-17 (IL-17A) and its receptor subunits, IL-17RA and IL-17RC, are required for protection to most forms of candidiasis. The importance of the IL-17R pathway has been observed not only in knockout mouse models, but also in humans with rare genetic mutations that impact generation of Th17 cells or the IL-17 signaling pathway, including Hyper-IgE Syndrome (STAT3 or TYK2 mutations) or IL17RA or ACT1 gene deficiency. The IL-17 family of cytokines is a distinct subclass of cytokines with unique structural and signaling properties. IL-17A is the best-characterized member of the IL-17 family to date, but far less is known about other IL-17-related cytokines. In this study, we sought to determine the role of a related IL-17 cytokine, IL-17C, in protection against oral, dermal and disseminated forms of C. albicans infection. IL-17C signals through a heterodimeric receptor composed of the IL-17RA and IL-17RE subunits. We observed that IL-17C mRNA was induced following oral C. albicans infection. However, mice lacking IL-17C or IL-17RE cleared C. albicans infections in the oral mucosa, skin and bloodstream at rates similar to WT littermate controls. Moreover, these mice demonstrated similar gene transcription profiles and recovery kinetics as WT animals. These findings indicate that IL-17C and IL-17RE are dispensable for immunity to the forms of candidiasis evaluated, and illustrate a surprisingly limited specificity of the IL-17 family of cytokines with respect to systemic, oral and cutaneous Candida infections. PMID:25849644

Unique aspects of the perinatal immune system.

Science.gov (United States)

Zhang, Xiaoming; Zhivaki, Dania; Lo-Man, Richard

2017-08-01

The early stages of life are associated with increased susceptibility to infection, which is in part due to an ineffective immune system. In the context of infection, the immune system must be stimulated to provide efficient protection while avoiding insufficient or excessive activation. Yet, in early life, age-dependent immune regulation at molecular and cellular levels contributes to a reduced immunological fitness in terms of pathogen clearance and response to vaccines. To enable microbial colonization to be tolerated at birth, epigenetic immune cell programming and early life-specific immune regulatory and effector mechanisms ensure that vital functions and organ development are supported and that tissue damage is avoided. Advancement in our understanding of age-related remodelling of immune networks and the consequent tuning of immune responsiveness will open up new possibilities for immune intervention and vaccine strategies that are designed specifically for early life.

Prenatal Alcohol Exposure and the Developing Immune System.

Science.gov (United States)

Gauthier, Theresa W

2015-01-01

Evidence from research in humans and animals suggest that ingesting alcohol during pregnancy can disrupt the fetal immune system and result in an increased risk of infections and disease in newborns that may persist throughout life. Alcohol may have indirect effects on the immune system by increasing the risk of premature birth, which itself is a risk factor for immune-related problems. Animal studies suggest that alcohol exposure directly disrupts the developing immune system. A comprehensive knowledge of the mechanisms underlying alcohol's effects on the developing immune system only will become clear once researchers establish improved methods for identifying newborns exposed to alcohol in utero.

Anopheles gambiae antiviral immune response to systemic O'nyong-nyong infection.

Directory of Open Access Journals (Sweden)

Joanna Waldock

Full Text Available Mosquito-borne viral diseases cause significant burden in much of the developing world. Although host-virus interactions have been studied extensively in the vertebrate host, little is known about mosquito responses to viral infection. In contrast to mosquitoes of the Aedes and Culex genera, Anopheles gambiae, the principal vector of human malaria, naturally transmits very few arboviruses, the most important of which is O'nyong-nyong virus (ONNV. Here we have investigated the A. gambiae immune response to systemic ONNV infection using forward and reverse genetic approaches.We have used DNA microarrays to profile the transcriptional response of A. gambiae inoculated with ONNV and investigate the antiviral function of candidate genes through RNAi gene silencing assays. Our results demonstrate that A. gambiae responses to systemic viral infection involve genes covering all aspects of innate immunity including pathogen recognition, modulation of immune signalling, complement-mediated lysis/opsonisation and other immune effector mechanisms. Patterns of transcriptional regulation and co-infections of A. gambiae with ONNV and the rodent malaria parasite Plasmodium berghei suggest that hemolymph immune responses to viral infection are diverted away from melanisation. We show that four viral responsive genes encoding two putative recognition receptors, a galectin and an MD2-like receptor, and two effector lysozymes, function in limiting viral load.This study is the first step in elucidating the antiviral mechanisms of A. gambiae mosquitoes, and has revealed interesting differences between A. gambiae and other invertebrates. Our data suggest that mechanisms employed by A. gambiae are distinct from described invertebrate antiviral immunity to date, and involve the complement-like branch of the humoral immune response, supressing the melanisation response that is prominent in anti-parasitic immunity. The antiviral immune response in A. gambiae is thus

Review of the systems biology of the immune system using agent-based models.

Science.gov (United States)

Shinde, Snehal B; Kurhekar, Manish P

2018-06-01

The immune system is an inherent protection system in vertebrate animals including human beings that exhibit properties such as self-organisation, self-adaptation, learning, and recognition. It interacts with the other allied systems such as the gut and lymph nodes. There is a need for immune system modelling to know about its complex internal mechanism, to understand how it maintains the homoeostasis, and how it interacts with the other systems. There are two types of modelling techniques used for the simulation of features of the immune system: equation-based modelling (EBM) and agent-based modelling. Owing to certain shortcomings of the EBM, agent-based modelling techniques are being widely used. This technique provides various predictions for disease causes and treatments; it also helps in hypothesis verification. This study presents a review of agent-based modelling of the immune system and its interactions with the gut and lymph nodes. The authors also review the modelling of immune system interactions during tuberculosis and cancer. In addition, they also outline the future research directions for the immune system simulation through agent-based techniques such as the effects of stress on the immune system, evolution of the immune system, and identification of the parameters for a healthy immune system.

The immune system strikes back: cellular immune responses against indoleamine 2,3-dioxygenase

DEFF Research Database (Denmark)

Sørensen, Rikke Baek; Berge-Hansen, Linda; Junker, Niels

2009-01-01

BACKGROUND: The enzyme indoleamine 2,3-dioxygenase (IDO) exerts an well established immunosuppressive function in cancer. IDO is expressed within the tumor itself as well as in antigen-presenting cells in tumor-draining lymph nodes, where it promotes the establishment of peripheral immune tolerance...... to tumor antigens. In the present study, we tested the notion whether IDO itself may be subject to immune responses. METHODS AND FINDINGS: The presence of naturally occurring IDO-specific CD8 T cells in cancer patients was determined by MHC/peptide stainings as well as ELISPOT. Antigen specific cytotoxic T...... of the major immune suppressive cell populations. CONCLUSION: IDO may serve as an important and widely applicable target for anti-cancer immunotherapeutic strategies. Furthermore, as emerging evidence suggests that IDO constitutes a significant counter-regulatory mechanism induced by pro-inflammatory signals...

Interleukin-36 cytokines may overcome microbial immune evasion strategies that inhibit interleukin-1 family signaling.

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Jensen, Liselotte E

2017-08-15

Pathogens deploy immune evasion strategies to successfully establish infections within their hosts. Naturally, the host responds by acquiring mechanisms to counter these strategies. There is increasing evidence that the three interleukin-36 (IL-36) cytokines, IL-36α, IL-36β and IL-36γ, play important roles in host immunity. With a focus on the skin as a target for microbial and viral invasion, the current knowledge of IL-36 functions is reviewed. Furthermore, the hypothesis that the IL-36s have evolved to counteract virulence factors is presented using viruses as an example. The IL-36s are related to IL-1α, IL-1β, IL-18, and IL-33. Numerous viruses affecting the skin have developed immune evasion strategies that neutralize IL-1α, IL-1β, or IL-18 signaling or combinations of these pathways. Through small differences in activation mechanisms and receptor utilization, it is possible that IL-36 signaling may proceed unhindered in the presence of these viral inhibitors. Thus, one physiological function of the IL-36s may be to counteract microbial immune evasion. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Role of the immune system in pancreatic cancer progression and immune modulating treatment strategies.

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Sideras, K; Braat, H; Kwekkeboom, J; van Eijck, C H; Peppelenbosch, M P; Sleijfer, S; Bruno, M

2014-05-01

Traditional chemotherapeutics have largely failed to date to produce significant improvements in pancreatic cancer survival. One of the reasons for the resilience of pancreatic cancer towards intensive treatment is that the cancer is capable of high jacking the immune system: during disease progression the immune system is converted from a system that attacks tumor cells into a support structure for the cancer, exerting trophic actions on the cancer cells. This turn-around of immune system action is achieved through mobilization and activation of regulatory T cells, myeloid derived suppressor cells, tumor-associated macrophages and fibroblasts, all of which suppress CD8 T cells and NK cells. This immune suppression occurs both through the expression of tolerance-inducing cell surface molecules, such as PD-L1, as well as through the production of "tolerogenic" cytokines, such as IL-10 and TGF-β. Based on the accumulating insight into the importance of the immune system for the outcome of pancreatic cancer patients multiple new immunotherapeutic approaches against pancreatic cancer are being currently tested in clinical trials. In this review we give an overview of both the immune escaping mechanisms of pancreatic cancer as well as the new immune related therapeutic strategies currently being tested in pancreatic cancer clinical trials. Copyright © 2013 Elsevier Ltd. All rights reserved.

Zinc as a Gatekeeper of Immune Function

Directory of Open Access Journals (Sweden)

Inga Wessels

2017-11-01

Full Text Available After the discovery of zinc deficiency in the 1960s, it soon became clear that zinc is essential for the function of the immune system. Zinc ions are involved in regulating intracellular signaling pathways in innate and adaptive immune cells. Zinc homeostasis is largely controlled via the expression and action of zinc “importers” (ZIP 1–14, zinc “exporters” (ZnT 1–10, and zinc-binding proteins. Anti-inflammatory and anti-oxidant properties of zinc have long been documented, however, underlying mechanisms are still not entirely clear. Here, we report molecular mechanisms underlying the development of a pro-inflammatory phenotype during zinc deficiency. Furthermore, we describe links between altered zinc homeostasis and disease development. Consequently, the benefits of zinc supplementation for a malfunctioning immune system become clear. This article will focus on underlying mechanisms responsible for the regulation of cellular signaling by alterations in zinc homeostasis. Effects of fast zinc flux, intermediate “zinc waves”, and late homeostatic zinc signals will be discriminated. Description of zinc homeostasis-related effects on the activation of key signaling molecules, as well as on epigenetic modifications, are included to emphasize the role of zinc as a gatekeeper of immune function.

The Immune System and Bodily Defence

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 6. The Immune System and Bodily Defence How Does the Immune System Organize Itself so as to Connect Target Recognition to Expected Functions? Vineeta Bal Satyajit Rath. Series Article Volume 2 Issue 6 June 1997 pp 25-38 ...

Bacteria-triggered systemic immunity in barley is associated with WRKY and ETHYLENE RESPONSIVE FACTORs but not with salicylic acid.

Science.gov (United States)

Dey, Sanjukta; Wenig, Marion; Langen, Gregor; Sharma, Sapna; Kugler, Karl G; Knappe, Claudia; Hause, Bettina; Bichlmeier, Marlies; Babaeizad, Valiollah; Imani, Jafargholi; Janzik, Ingar; Stempfl, Thomas; Hückelhoven, Ralph; Kogel, Karl-Heinz; Mayer, Klaus F X; Vlot, A Corina

2014-12-01

Leaf-to-leaf systemic immune signaling known as systemic acquired resistance is poorly understood in monocotyledonous plants. Here, we characterize systemic immunity in barley (Hordeum vulgare) triggered after primary leaf infection with either Pseudomonas syringae pathovar japonica (Psj) or Xanthomonas translucens pathovar cerealis (Xtc). Both pathogens induced resistance in systemic, uninfected leaves against a subsequent challenge infection with Xtc. In contrast to systemic acquired resistance in Arabidopsis (Arabidopsis thaliana), systemic immunity in barley was not associated with NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 or the local or systemic accumulation of salicylic acid. Instead, we documented a moderate local but not systemic induction of abscisic acid after infection of leaves with Psj. In contrast to salicylic acid or its functional analog benzothiadiazole, local applications of the jasmonic acid methyl ester or abscisic acid triggered systemic immunity to Xtc. RNA sequencing analysis of local and systemic transcript accumulation revealed unique gene expression changes in response to both Psj and Xtc and a clear separation of local from systemic responses. The systemic response appeared relatively modest, and quantitative reverse transcription-polymerase chain reaction associated systemic immunity with the local and systemic induction of two WRKY and two ETHYLENE RESPONSIVE FACTOR (ERF)-like transcription factors. Systemic immunity against Xtc was further associated with transcriptional changes after a secondary/systemic Xtc challenge infection; these changes were dependent on the primary treatment. Taken together, bacteria-induced systemic immunity in barley may be mediated in part by WRKY and ERF-like transcription factors, possibly facilitating transcriptional reprogramming to potentiate immunity. © 2014 American Society of Plant Biologists. All Rights Reserved.

The Role of Epigenetic Regulation in Transcriptional Memory in the Immune System.

Science.gov (United States)

Woodworth, A M; Holloway, A F

The immune system is exquisitely poised to identify, respond to, and eradicate pathogens from the body, as well as to produce a more rapid and augmented response to a subsequent encounter with the pathogen. These cellular responses rely on the highly coordinated and rapid activation of gene expression programs as well as the ability of the cell to retain a memory of the initial gene response. It is clear that chromatin structure and epigenetic mechanisms play a crucial role in determining these gene responses, and in fact the immune system has proved an instructive model for investigating the multifaceted mechanisms through which the chromatin landscape contributes to gene expression programs. These mechanisms include modifications to the DNA and histone proteins, the positioning, composition, and remodeling of nucleosomes, as well as the formation of higher-order chromatin structures. Moreover, it is now apparent that epigenetic mechanisms also provide an instrument by which cells can retain memory of the initial transcriptional response, "priming" the genome so that it can respond more quickly to subsequent exposure to the signal. Here, we use the immune system as a model to demonstrate the complex interplay between transcription factors and the chromatin landscape required to orchestrate precise gene responses to external stimuli and further to demonstrate how these interactions can establish memory of past transcriptional events. We focus on what we have learnt from the immune system and how this can inform our understanding of other cellular systems. © 2017 Elsevier Inc. All rights reserved.

Investigating immune system aging: system dynamics and agent-based modeling

OpenAIRE

Figueredo, Grazziela; Aickelin, Uwe

2010-01-01

System dynamics and agent based simulation models can\\ud both be used to model and understand interactions of entities within a population. Our modeling work presented here is concerned with understanding the suitability of the different types of simulation for the immune system aging problems and comparing their results. We are trying to answer questions such as: How fit is the immune system given a certain age? Would an immune boost be of therapeutic value, e.g. to improve the effectiveness...

Immune activation affects chemical sexual ornaments of male Iberian wall lizards

Science.gov (United States)

López, Pilar; Gabirot, Marianne; Martín, José

2009-01-01

Many animals use chemical signals in sexual selection, but it is not clear how these sexual traits might have evolved to signal honestly male condition. It is possible that there is a trade-off between maintaining the immune system and the elaboration of ornaments. We experimentally challenged the immune system of male Iberian wall lizards, Podarcis hispanica, with a bacterial antigen (lipopolysaccharide), without pathogenic effects, to explore whether the immune activation affected chemical ornaments. Immune activation resulted in decreased proportions of a major chemical in femoral secretions (cholesta-5,7-dien-3-ol = provitamin D3) known to be selected in scent of males by females and which active form (vitamin D) has a variety of important effects on immune system function. This result suggests the existence of a potential trade-off between physiological regulation of the immune system and the allocation of essential nutrients (vitamins) to sexual chemical ornaments in male lizards.

Prenatal Alcohol Exposure and the Developing Immune System

OpenAIRE

Gauthier, Theresa W.

2015-01-01

Evidence from research in humans and animals suggest that ingesting alcohol during pregnancy can disrupt the fetal immune system and result in an increased risk of infections and disease in newborns that may persist throughout life. Alcohol may have indirect effects on the immune system by increasing the risk of premature birth, which itself is a risk factor for immune-related problems. Animal studies suggest that alcohol exposure directly disrupts the developing immune system. A comprehensiv...

Signaling mechanisms underlying the robustness and tunability of the plant immune network

Science.gov (United States)

Kim, Yungil; Tsuda, Kenichi; Igarashi, Daisuke; Hillmer, Rachel A.; Sakakibara, Hitoshi; Myers, Chad L.; Katagiri, Fumiaki

2014-01-01

Summary How does robust and tunable behavior emerge in a complex biological network? We sought to understand this for the signaling network controlling pattern-triggered immunity (PTI) in Arabidopsis. A dynamic network model containing four major signaling sectors, the jasmonate, ethylene, PAD4, and salicylate sectors, which together explain up to 80% of the PTI level, was built using data for dynamic sector activities and PTI levels under exhaustive combinatorial sector perturbations. Our regularized multiple regression model had a high level of predictive power and captured known and unexpected signal flows in the network. The sole inhibitory sector in the model, the ethylene sector, was central to the network robustness via its inhibition of the jasmonate sector. The model's multiple input sites linked specific signal input patterns varying in strength and timing to different network response patterns, indicating a mechanism enabling tunability. PMID:24439900

Role for sumoylation in systemic inflammation and immune homeostasis in Drosophila larvae.

Directory of Open Access Journals (Sweden)

Indira Paddibhatla

2010-12-01

Full Text Available To counter systemic risk of infection by parasitic wasps, Drosophila larvae activate humoral immunity in the fat body and mount a robust cellular response resulting in encapsulation of the wasp egg. Innate immune reactions are tightly regulated and are resolved within hours. To understand the mechanisms underlying activation and resolution of the egg encapsulation response and examine if failure of the latter develops into systemic inflammatory disease, we correlated parasitic wasp-induced changes in the Drosophila larva with systemic chronic conditions in sumoylation-deficient mutants. We have previously reported that loss of either Cactus, the Drosophila (IκB protein or Ubc9, the SUMO-conjugating enzyme, leads to constitutive activation of the humoral and cellular pathways, hematopoietic overproliferation and tumorogenesis. Here we report that parasite infection simultaneously activates NF-κB-dependent transcription of Spätzle processing enzyme (SPE and cactus. Endogenous Spätzle protein (the Toll ligand is expressed in immune cells and excessive SPE or Spätzle is pro-inflammatory. Consistent with this function, loss of Spz suppresses Ubc9⁻ defects. In contrast to the pro-inflammatory roles of SPE and Spätzle, Cactus and Ubc9 exert an anti-inflammatory effect. We show that Ubc9 maintains steady state levels of Cactus protein. In a series of immuno-genetic experiments, we demonstrate the existence of a robust bidirectional interaction between blood cells and the fat body and propose that wasp infection activates Toll signaling in both compartments via extracellular activation of Spätzle. Within each organ, the IκB/Ubc9-dependent inhibitory feedback resolves immune signaling and restores homeostasis. The loss of this feedback leads to chronic inflammation. Our studies not only provide an integrated framework for understanding the molecular basis of the evolutionary arms race between insect hosts and their parasites, but also offer

Nutritional components regulate the gut immune system and its association with intestinal immune disease development.

Science.gov (United States)

Lamichhane, Aayam; Kiyono, Hiroshi; Kunisawa, Jun

2013-12-01

The gut is equipped with a unique immune system for maintaining immunological homeostasis, and its functional immune disruption can result in the development of immune diseases such as food allergy and intestinal inflammation. Accumulating evidence has demonstrated that nutritional components play an important role in the regulation of gut immune responses and also in the development of intestinal immune diseases. In this review, we focus on the immunological functions of lipids, vitamins, and nucleotides in the regulation of the intestinal immune system and as potential targets for the control of intestinal immune diseases. © 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

Early Microbes Modify Immune System Development and Metabolic Homeostasis—The “Restaurant” Hypothesis Revisited

Science.gov (United States)

Nash, Michael J.; Frank, Daniel N.; Friedman, Jacob E.

2017-01-01

The developing infant gut microbiome affects metabolism, maturation of the gastrointestinal tract, immune system function, and brain development. Initial seeding of the neonatal microbiota occurs through maternal and environmental contact. Maternal diet, antibiotic use, and cesarean section alter the offspring microbiota composition, at least temporarily. Nutrients are thought to regulate initial perinatal microbial colonization, a paradigm known as the “Restaurant” hypothesis. This hypothesis proposes that early nutritional stresses alter both the initial colonizing bacteria and the development of signaling pathways controlled by microbial mediators. These stresses fine-tune the immune system and metabolic homeostasis in early life, potentially setting the stage for long-term metabolic and immune health. Dysbiosis, an imbalance or a maladaptation in the microbiota, can be caused by several factors including dietary alterations and antibiotics. Dysbiosis can alter biological processes in the gut and in tissues and organs throughout the body. Misregulated development and activity of both the innate and adaptive immune systems, driven by early dysbiosis, could have long-lasting pathologic consequences such as increased autoimmunity, increased adiposity, and non-alcoholic fatty liver disease (NAFLD). This review will focus on factors during pregnancy and the neonatal period that impact a neonate’s gut microbiome, as well as the mechanisms and possible links from early infancy that can drive increased risk for diseases including obesity and NAFLD. The complex pathways that connect diet, the microbiota, immune system development, and metabolism, particularly in early life, present exciting new frontiers for biomedical research. PMID:29326657

Learning and Memory... and the Immune System

Science.gov (United States)

Marin, Ioana; Kipnis, Jonathan

2013-01-01

The nervous system and the immune system are two main regulators of homeostasis in the body. Communication between them ensures normal functioning of the organism. Immune cells and molecules are required for sculpting the circuitry and determining the activity of the nervous system. Within the parenchyma of the central nervous system (CNS),…

Physical Activities, Exercises, and Their Effects to the Immune System

OpenAIRE

Nurmasitoh, Titis

2015-01-01

Every systems in human body correlate to maintain homeostasis. One of those systems which contribute to maintain homeostasis is the immune system. The immune system defends physiological functions against foreign substances and cancer cells through a complex and multilayered mechanism. The ability to defend against foreign substances and abnormal cells is done by two types of immune system, which are Innate immune system and adaptive/acquired immune system. There are also certain factors that...

Impact of the Innate Immune Response in the Actions of Ethanol on the Central Nervous System.

Science.gov (United States)

Montesinos, Jorge; Alfonso-Loeches, Silvia; Guerri, Consuelo

2016-11-01

The innate immune response in the central nervous system (CNS) participates in both synaptic plasticity and neural damage. Emerging evidence from human and animal studies supports the role of the neuroimmune system response in many actions of ethanol (EtOH) on the CNS. Research studies have shown that alcohol stimulates brain immune cells, microglia, and astrocytes, by activating innate immune receptors Toll-like receptors (TLRs) and NOD-like receptors (inflammasome NLRs) triggering signaling pathways, which culminate in the production of pro-inflammatory cytokines and chemokines that lead to neuroinflammation. This review focuses on evidence that indicates the participation of TLRs and the inflammasome NLRs signaling response in many effects of EtOH on the CNS, such as neuroinflammation associated with brain damage, cognitive and behavioral dysfunction, and adolescent brain development alterations. It also reviews findings that indicate the role of TLR4-dependent signaling immune molecules in alcohol consumption, reward, and addiction. The research data suggest that overactivation of TLR4 or NLRs increases pro-inflammatory cytokines and mediators to cause neural damage in the cerebral cortex and hippocampus, while modest TLR4 activation, along with the generation of certain cytokines and chemokines in specific brain areas (e.g., amygdala, ventral tegmental area), modulate neurotransmission, alcohol drinking, and alcohol rewards. Elimination of TLR4 and NLRP3 abolishes many neuroimmune effects of EtOH. Despite much progress being made in this area, there are some research gaps and unanswered questions that this review discusses. Finally, potential therapies that target neuroimmune pathways to treat neuropathological and behavioral consequences of alcohol abuse are also evaluated. Copyright © 2016 by the Research Society on Alcoholism.

Diffuse endocrine system, neuroendocrine tumors and immunity: what's new?

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Ameri, Pietro; Ferone, Diego

2012-01-01

During the last two decades, research into the modulation of immunity by the neuroendocrine system has flourished, unravelling significant effects of several neuropeptides, including somatostatin (SRIH), and especially cortistatin (CST), on immune cells. Scientists have learnt that the diffuse neuroendocrine system can regulate the immune system at all its levels: innate immunity, adaptive immunity, and maintenance of immune tolerance. Compelling studies with animal models have demonstrated that some neuropeptides may be effective in treating inflammatory disorders, such as sepsis, and T helper 1-driven autoimmune diseases, like Crohn's disease and rheumatoid arthritis. Here, the latest findings concerning the neuroendocrine control of the immune system are discussed, with emphasis on SRIH and CST. The second part of the review deals with the immune response to neuroendocrine tumors (NETs). The anti-NET immune response has been described in the last years and it is still being characterized, similarly to what is happening for several other types of cancer. In parallel with investigations addressing the mechanisms by which the immune system contrasts NET growth and spreading, ground-breaking clinical trials of dendritic cell vaccination as immunotherapy for metastatic NETs have shown in principle that the immune reaction to NETs can be exploited for treatment. Copyright © 2012 S. Karger AG, Basel.

CYLD Limits Lys63- and Met1-Linked Ubiquitin at Receptor Complexes to Regulate Innate Immune Signaling

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Matous Hrdinka

2016-03-01

Full Text Available Innate immune signaling relies on the deposition of non-degradative polyubiquitin at receptor-signaling complexes, but how these ubiquitin modifications are regulated by deubiquitinases remains incompletely understood. Met1-linked ubiquitin (Met1-Ub is assembled by the linear ubiquitin assembly complex (LUBAC, and this is counteracted by the Met1-Ub-specific deubiquitinase OTULIN, which binds to the catalytic LUBAC subunit HOIP. In this study, we report that HOIP also interacts with the deubiquitinase CYLD but that CYLD does not regulate ubiquitination of LUBAC components. Instead, CYLD limits extension of Lys63-Ub and Met1-Ub conjugated to RIPK2 to restrict signaling and cytokine production. Accordingly, Met1-Ub and Lys63-Ub were individually required for productive NOD2 signaling. Our study thus suggests that LUBAC, through its associated deubiquitinases, coordinates the deposition of not only Met1-Ub but also Lys63-Ub to ensure an appropriate response to innate immune receptor activation.

Measuring the immune system: a comprehensive approach for the analysis of immune functions in humans.

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Claus, Maren; Dychus, Nicole; Ebel, Melanie; Damaschke, Jürgen; Maydych, Viktoriya; Wolf, Oliver T; Kleinsorge, Thomas; Watzl, Carsten

2016-10-01

The immune system is essential to provide protection from infections and cancer. Disturbances in immune function can therefore directly affect the health of the affected individual. Many extrinsic and intrinsic factors such as exposure to chemicals, stress, nutrition and age have been reported to influence the immune system. These influences can affect various components of the immune system, and we are just beginning to understand the causalities of these changes. To investigate such disturbances, it is therefore essential to analyze the different components of the immune system in a comprehensive fashion. Here, we demonstrate such an approach which provides information about total number of leukocytes, detailed quantitative and qualitative changes in the composition of lymphocyte subsets, cytokine levels in serum and functional properties of T cells, NK cells and monocytes. Using samples from a cohort of 24 healthy volunteers, we demonstrate the feasibility of our approach to detect changes in immune functions.

The Immune System in Irritable Bowel Syndrome

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Cremon, Cesare; Carini, Giovanni; Bellacosa, Lara; Zecchi, Lisa; De Giorgio, Roberto; Corinaldesi, Roberto; Stanghellini, Vincenzo

2011-01-01

The potential relevance of systemic and gastrointestinal immune activation in the pathophysiology and symptom generation in the irritable bowel syndrome (IBS) is supported by a number of observations. Infectious gastroenteritis is the strongest risk factor for the development of IBS and increased rates of IBS-like symptoms have been detected in patients with inflammatory bowel disease in remission or in celiac disease patients on a gluten free diet. The number of T cells and mast cells in the small and large intestine of patients with IBS is increased in a large proportion of patients with IBS over healthy controls. Mediators released by immune cells and likely from other non-immune competent cells impact on the function of enteric and sensory afferent nerves as well as on epithelial tight junctions controlling mucosal barrier of recipient animals, isolated human gut tissues or cell culture systems. Antibodies against microbiota antigens (bacterial flagellin), and increased levels of cytokines have been detected systemically in the peripheral blood advocating the existence of abnormal host-microbial interactions and systemic immune responses. Nonetheless, there is wide overlap of data obtained in healthy controls; in addition, the subsets of patients showing immune activation have yet to be clearly identified. Gender, age, geographic differences, genetic predisposition, diet and differences in the intestinal microbiota likely play a role and further research has to be done to clarify their relevance as potential mechanisms in the described immune system dysregulation. Immune activation has stimulated interest for the potential identification of biomarkers useful for clinical and research purposes and the development of novel therapeutic approaches. PMID:22148103

Natural evolution, disease, and localization in the immune system

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Deem, Michael

2004-03-01

Adaptive vertebrate immune system is a wonder of modern evolution. Under most circumstances, the dynamics of the immune system is well-matched to the dynamics of pathogen growth during a typical infection. Some pathogens, however, have evolved escape mechanisms that interact in subtle ways with the immune system dynamics. In addition, negative interactions the immune system, which has evolved over 400 000 000 years, and vaccination,which has been practiced for only 200 years, are possible. For example,vaccination against the flu can actually increase susceptibility to the flu in the next year. As another example, vaccination against one of the four strains of dengue fever typically increases susceptibility against the other three strains. Immunodominance also arises in the immune system control of nascent tumors--the immune system recognizes only a small subset of the tumor specific antigens, and the rest are free to grow and cause tumor growth. In this talk, I present a physical theory of original antigenic sin and immunodominance. How localization in the immune system leads to the observed phenomena is discussed. 1) M. W. Deem and H. Y. Lee, ``Sequence Space Localization in the Immune System Response to Vaccination and Disease,'' Phys. Rev. Lett. 91 (2003) 068101

Immune response induction in the central nervous system

DEFF Research Database (Denmark)

Owens, Trevor; Babcock, Alicia

2002-01-01

The primary function of the immune response is protection of the host against infection with pathogens, including viruses. Since viruses can infect any tissue of the body, including the central nervous system (CNS), it is logical that cells of the immune system should equally have access to all...... tissues. Nevertheless, the brain and spinal cord are noted for their lack of immune presence. Relative to other organ systems, the CNS appears immunologically privileged. Furthermore, when immune responses do occur in the CNS, they are frequently associated with deleterious effects such as inflammatory...

The role of the immune system in kidney disease.

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Tecklenborg, J; Clayton, D; Siebert, S; Coley, S M

2018-05-01

The immune system and the kidneys are closely linked. In health the kidneys contribute to immune homeostasis, while components of the immune system mediate many acute forms of renal disease and play a central role in progression of chronic kidney disease. A dysregulated immune system can have either direct or indirect renal effects. Direct immune-mediated kidney diseases are usually a consequence of autoantibodies directed against a constituent renal antigen, such as collagen IV in anti-glomerular basement membrane disease. Indirect immune-mediated renal disease often follows systemic autoimmunity with immune complex formation, but can also be due to uncontrolled activation of the complement pathways. Although the range of mechanisms of immune dysregulation leading to renal disease is broad, the pathways leading to injury are similar. Loss of immune homeostasis in renal disease results in perpetual immune cell recruitment and worsening damage to the kidney. Uncoordinated attempts at tissue repair, after immune-mediated disease or non-immune mediated injury, result in fibrosis of structures important for renal function, leading eventually to kidney failure. As renal disease often manifests clinically only when substantial damage has already occurred, new diagnostic methods and indeed treatments must be identified to inhibit further progression and promote appropriate tissue repair. Studying cases in which immune homeostasis is re-established may reveal new treatment possibilities. © 2018 British Society for Immunology.

Dengue vaccine safety signal: Immune enhancement, waning immunity, or chance occurrence?

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Gessner, Bradford D; Halsey, Neal

2017-06-14

A new dengue vaccine was associated with increased risk of hospitalized virologically-confirmed disease during year 3 of follow-up among children age 2-5years. Among hypotheses to explain this finding, we could not distinguish definitively between antibody dependent enhancement, waning immunity, or chance occurrence. However, any theory must account for the following: (a) the signal occurred mainly because of decreased dengue among controls rather than increased dengue among vaccinees; (b) among 48 data points, a statistically significant increase in hospitalization among vaccinated children occurred for only one age group, during one year, and in one region; (c) cumulative risk was similar for vaccinated vs. control children age 2-5years at the end of year 5 and lower for vaccinated vs. control children among older age groups; (d) the protective effect of vaccine against hospitalization decreased from years 1-2 to years 3-5 of follow-up for all age groups and regions. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

CRISPR-based immune systems of the Sulfolobales: complexity and diversity

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Garrett, Roger Antony; Shah, Shiraz Ali; Vestergaard, Gisle Alberg

2011-01-01

CRISPR (cluster of regularly interspaced palindromic repeats)/Cas and CRISPR/Cmr systems of Sulfolobus, targeting DNA and RNA respectively of invading viruses or plasmids are complex and diverse. We address their classification and functional diversity, and the wide sequence diversity of RAMP...... (repeat-associated mysterious protein)-motif containing proteins encoded in Cmr modules. Factors influencing maintenance of partially impaired CRISPR-based systems are discussed. The capacity for whole CRISPR transcripts to be generated despite the uptake of transcription signals within spacer sequences...... is considered. Targeting of protospacer regions of invading elements by Cas protein-crRNA (CRISPR RNA) complexes exhibit relatively low sequence stringency, but the integrity of protospacer-associated motifs appears to be important. Different mechanisms for circumventing or inactivating the immune systems...

Alcohol resistance in Drosophila is modulated by the Toll innate immune pathway.

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Troutwine, B R; Ghezzi, A; Pietrzykowski, A Z; Atkinson, N S

2016-04-01

A growing body of evidence has shown that alcohol alters the activity of the innate immune system and that changes in innate immune system activity can influence alcohol-related behaviors. Here, we show that the Toll innate immune signaling pathway modulates the level of alcohol resistance in Drosophila. In humans, a low level of response to alcohol is correlated with increased risk of developing an alcohol use disorder. The Toll signaling pathway was originally discovered in, and has been extensively studied in Drosophila. The Toll pathway is a major regulator of innate immunity in Drosophila, and mammalian Toll-like receptor signaling has been implicated in alcohol responses. Here, we use Drosophila-specific genetic tools to test eight genes in the Toll signaling pathway for effects on the level of response to ethanol. We show that increasing the activity of the pathway increases ethanol resistance whereas decreasing the pathway activity reduces ethanol resistance. Furthermore, we show that gene products known to be outputs of innate immune signaling are rapidly induced following ethanol exposure. The interaction between the Toll signaling pathway and ethanol is rooted in the natural history of Drosophila melanogaster. © 2016 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

DNA Damage Response and Immune Defence: Links and Mechanisms

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Björn Schumacher

2016-08-01

Full Text Available DNA damage plays a causal role in numerous human pathologies including cancer, premature aging and chronic inflammatory conditions. In response to genotoxic insults, the DNA damage response (DDR orchestrates DNA damage checkpoint activation and facilitates the removal of DNA lesions. The DDR can also arouse the immune system by for example inducing the expression of antimicrobial peptides as well as ligands for receptors found on immune cells. The activation of immune signalling is triggered by different components of the DDR including DNA damage sensors, transducer kinases, and effectors. In this review, we describe recent advances on the understanding of the role of DDR in activating immune signalling. We highlight evidence gained into (i which molecular and cellular pathways of DDR activate immune signalling, (ii how DNA damage drives chronic inflammation, and (iii how chronic inflammation causes DNA damage and pathology in humans.

The adaptor molecule RIAM integrates signaling events critical for integrin-mediated control of immune function and cancer progression.

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Patsoukis, Nikolaos; Bardhan, Kankana; Weaver, Jessica D; Sari, Duygu; Torres-Gomez, Alvaro; Li, Lequn; Strauss, Laura; Lafuente, Esther M; Boussiotis, Vassiliki A

2017-08-22

Lymphocyte activation requires adhesion to antigen-presenting cells. This is a critical event linking innate and adaptive immunity. Lymphocyte adhesion is accomplished through LFA-1, which must be activated by a process referred to as inside-out integrin signaling. Among the few signaling molecules that have been implicated in inside-out integrin activation in hematopoietic cells are the small guanosine triphosphatase (GTPase) Rap1 and its downstream effector Rap1-interacting molecule (RIAM), a multidomain protein that defined the Mig10-RIAM-lamellipodin (MRL) class of adaptor molecules. Through its various domains, RIAM is a critical node of signal integration for activation of T cells, recruits monomeric and polymerized actin to drive actin remodeling and cytoskeletal reorganization, and promotes inside-out integrin signaling in T cells. As a regulator of inside-out integrin activation, RIAM affects multiple functions of innate and adaptive immunity. The effects of RIAM on cytoskeletal reorganization and integrin activation have implications in cell migration and trafficking of cancer cells. We provide an overview of the structure and interactions of RIAM, and we discuss the implications of RIAM functions in innate and adaptive immunity and cancer. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Nutritional support for the infant's immune system

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Niers, L.; Stasse-Wolthuis, M.; Rombouts, F.M.; Rijkers, G.T.

2007-01-01

Newborn babies possess a functional but immature immune system as a defense against a world teeming with microorganisms. Breast milk contains a number of biological, active compounds that support the infant's immune system. These include secretory immunoglobulin A (IgA), which confers specific

The Commensal Microbiota Drives Immune Homeostasis

OpenAIRE

Arrieta, Marie-Claire; Finlay, Barton Brett

2012-01-01

For millions of years, microbes have coexisted with eukaryotic cells at the mucosal surfaces of vertebrates in a complex, yet usually harmonious symbiosis. An ever-expanding number of reports describe how eliminating or shifting the intestinal microbiota has profound effects on the development and functionality of the mucosal and systemic immune systems. Here, we examine some of the mechanisms by which bacterial signals affect immune homeostasis. Focusing on the strategies that microbes use t...

GYF-21, an Epoxide 2-(2-Phenethyl-Chromone Derivative, Suppresses Innate and Adaptive Immunity via Inhibiting STAT1/3 and NF-κB Signaling Pathways

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Ran Guo

2017-05-01

Full Text Available Multiple sclerosis is a chronic inflammatory autoimmune disease of the central nervous system characterized by demyelinating plaques and axonal loss. Inhibition on over activation of innate and adaptive immunity provides a rationale strategy for treatment of multiple sclerosis. In the present study, we investigated the inhibitory effects of GYF-21, an epoxide 2-(2-phenethyl-chromone derivative isolated from Chinese agarwood, on innate and adaptive immunity for revealing its potential to treat multiple sclerosis. The results showed that GYF-21 markedly inhibited the activation of microglia, and dendritic cells as well as neutrophils, all of which play important roles in innate immunity. Furthermore, GYF-21 significantly suppressed adaptive immunity via inhibiting the differentiation of naive CD4+ T cells into T helper 1 (Th1 and T helper 17 (Th17 cells, and suppressing the activation, proliferation, and IFN-γ secretion of CD8+ T cells. The mechanism study showed that GYF-21 evidently inhibited the activation of STAT1/3 and NF-κB signaling pathways in microglia. In conclusion, we demonstrated that GYF-21 can significantly inhibit innate and adaptive immunity via suppressing STAT1/3 and NF-κB signaling pathways, and has potential to be developed into therapeutic drug for multiple sclerosis.

Influence of Saccharomyces boulardii CNCM I-745on the gut-associated immune system.

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Stier, Heike; Bischoff, Stephan C

2016-01-01

The probiotic Saccharomyces boulardii CNCM I-745 (also known as Saccharomyces cerevisiae HANSEN CBS 5926; in the following S. boulardii ) has proven its effectiveness in preventive and therapeutic treatment of many gastrointestinal diseases, especially diseases associated with acute diarrhea. In particular, antibiotic-associated diarrhea, Clostridium difficile -associated diarrhea, traveller's diarrhea, as well as acute diarrhea due to common viral and bacterial infections in children and adults. The aim of this review is to summarize the experimental studies elucidating the molecular and immunological mechanisms by which these clinically proven effects are archived, with an emphasis on the gut-associated immune system. The main focus is laid on anti-inflammatory and immune-modulatory action of S. boulardii involved in bacterial or enterotoxin-mediated diarrhea and inflammation. An attempt is made to differentiate between the effects associated with cellular versus soluble factors and between prophylactic and therapeutic effects. A literature search was performed in PubMed/PubMed Central for the effects of S. boulardii on the gut-associated immune system (focus acute diarrhea). S. boulardii exhibits its positive effect by the direct effects on pathogens or their toxins as well as by influencing the host's infection-induced signaling cascades and its innate and adaptive immune system. The combination of these mechanisms results in a reduction of the pathogens' ability for adhesion or colonization and an attenuation of the overreacting inflammatory immune response. Thereby, the integrity of the intestinal epithelial cell layer is preserved or restored, and the diarrheic leakage of fluids into the intestinal lumen is attenuated.

La protéine CG4572 de Drosophile et la propagation du signal ARNi immun antiviral

OpenAIRE

Karlikow , Margot

2015-01-01

During viral infection, cell survival will depend on adequately giving, receiving and processing information to establish an efficient antiviral immune response. Cellular communication is therefore essential to allow the propagation of immune signals that will confer protection to the entire organism.The major antiviral defense in insects is the RNA interference (RNAi) mechanism that is activated by detection of viral double-stranded RNA (dsRNA). The antiviral RNAi mechanism can be divided in...

The CD47-SIRPα signaling axis as an innate immune checkpoint in cancer.

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Matlung, Hanke L; Szilagyi, Katka; Barclay, Neil A; van den Berg, Timo K

2017-03-01

Immune checkpoint inhibitors, including those targeting CTLA-4/B7 and the PD-1/PD-L1 inhibitory pathways, are now available for clinical use in cancer patients, with other interesting checkpoint inhibitors being currently in development. Most of these have the purpose to promote adaptive T cell-mediated immunity against cancer. Here, we review another checkpoint acting to potentiate the activity of innate immune cells towards cancer. This innate immune checkpoint is composed of what has become known as the 'don't-eat me' signal CD47, which is a protein broadly expressed on normal cells and often overexpressed on cancer cells, and its counter-receptor, the myeloid inhibitory immunoreceptor SIRPα. Blocking CD47-SIRPα interactions has been shown to promote the destruction of cancer cells by phagocytes, including macrophages and neutrophils. Furthermore, there is growing evidence that targeting of the CD47-SIRPα axis may also promote antigen-presenting cell function and thereby stimulate adaptive T cell-mediated anti-cancer immunity. The development of CD47-SIRPα checkpoint inhibitors and the potential side effects that these may have are discussed. Collectively, this identifies the CD47-SIRPα axis as a promising innate immune checkpoint in cancer, and with data of the first clinical studies with CD47-SIRPα checkpoint inhibitors expected within the coming years, this is an exciting and rapidly developing field. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Evaluation of mucosal and systemic immune responses elicited by GPI-0100- adjuvanted influenza vaccine delivered by different immunization strategies.

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Heng Liu

Full Text Available Vaccines for protection against respiratory infections should optimally induce a mucosal immune response in the respiratory tract in addition to a systemic immune response. However, current parenteral immunization modalities generally fail to induce mucosal immunity, while mucosal vaccine delivery often results in poor systemic immunity. In order to find an immunization strategy which satisfies the need for induction of both mucosal and systemic immunity, we compared local and systemic immune responses elicited by two mucosal immunizations, given either by the intranasal (IN or the intrapulmonary (IPL route, with responses elicited by a mucosal prime followed by a systemic boost immunization. The study was conducted in BALB/c mice and the vaccine formulation was an influenza subunit vaccine supplemented with GPI-0100, a saponin-derived adjuvant. While optimal mucosal antibody titers were obtained after two intrapulmonary vaccinations, optimal systemic antibody responses were achieved by intranasal prime followed by intramuscular boost. The latter strategy also resulted in the best T cell response, yet, it was ineffective in inducing nose or lung IgA. Successful induction of secretory IgA, IgG and T cell responses was only achieved with prime-boost strategies involving intrapulmonary immunization and was optimal when both immunizations were given via the intrapulmonary route. Our results underline that immunization via the lungs is particularly effective for priming as well as boosting of local and systemic immune responses.

Evaluation of Mucosal and Systemic Immune Responses Elicited by GPI-0100- Adjuvanted Influenza Vaccine Delivered by Different Immunization Strategies

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Liu, Heng; Patil, Harshad P.; de Vries-Idema, Jacqueline; Wilschut, Jan; Huckriede, Anke

2013-01-01

Vaccines for protection against respiratory infections should optimally induce a mucosal immune response in the respiratory tract in addition to a systemic immune response. However, current parenteral immunization modalities generally fail to induce mucosal immunity, while mucosal vaccine delivery often results in poor systemic immunity. In order to find an immunization strategy which satisfies the need for induction of both mucosal and systemic immunity, we compared local and systemic immune responses elicited by two mucosal immunizations, given either by the intranasal (IN) or the intrapulmonary (IPL) route, with responses elicited by a mucosal prime followed by a systemic boost immunization. The study was conducted in BALB/c mice and the vaccine formulation was an influenza subunit vaccine supplemented with GPI-0100, a saponin-derived adjuvant. While optimal mucosal antibody titers were obtained after two intrapulmonary vaccinations, optimal systemic antibody responses were achieved by intranasal prime followed by intramuscular boost. The latter strategy also resulted in the best T cell response, yet, it was ineffective in inducing nose or lung IgA. Successful induction of secretory IgA, IgG and T cell responses was only achieved with prime-boost strategies involving intrapulmonary immunization and was optimal when both immunizations were given via the intrapulmonary route. Our results underline that immunization via the lungs is particularly effective for priming as well as boosting of local and systemic immune responses. PMID:23936066

Early Microbes Modify Immune System Development and Metabolic Homeostasis—The “Restaurant” Hypothesis Revisited

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Michael J. Nash

2017-12-01

Full Text Available The developing infant gut microbiome affects metabolism, maturation of the gastrointestinal tract, immune system function, and brain development. Initial seeding of the neonatal microbiota occurs through maternal and environmental contact. Maternal diet, antibiotic use, and cesarean section alter the offspring microbiota composition, at least temporarily. Nutrients are thought to regulate initial perinatal microbial colonization, a paradigm known as the “Restaurant” hypothesis. This hypothesis proposes that early nutritional stresses alter both the initial colonizing bacteria and the development of signaling pathways controlled by microbial mediators. These stresses fine-tune the immune system and metabolic homeostasis in early life, potentially setting the stage for long-term metabolic and immune health. Dysbiosis, an imbalance or a maladaptation in the microbiota, can be caused by several factors including dietary alterations and antibiotics. Dysbiosis can alter biological processes in the gut and in tissues and organs throughout the body. Misregulated development and activity of both the innate and adaptive immune systems, driven by early dysbiosis, could have long-lasting pathologic consequences such as increased autoimmunity, increased adiposity, and non-alcoholic fatty liver disease (NAFLD. This review will focus on factors during pregnancy and the neonatal period that impact a neonate’s gut microbiome, as well as the mechanisms and possible links from early infancy that can drive increased risk for diseases including obesity and NAFLD. The complex pathways that connect diet, the microbiota, immune system development, and metabolism, particularly in early life, present exciting new frontiers for biomedical research.

Signaling through IL-17C/IL-17RE is dispensable for immunity to systemic, oral and cutaneous candidiasis.

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Heather R Conti

Full Text Available Candida albicans is a commensal fungal microbe of the human orogastrointestinal tract and skin. C. albicans causes multiple forms of disease in immunocompromised patients, including oral, vaginal, dermal and disseminated candidiasis. The cytokine IL-17 (IL-17A and its receptor subunits, IL-17RA and IL-17RC, are required for protection to most forms of candidiasis. The importance of the IL-17R pathway has been observed not only in knockout mouse models, but also in humans with rare genetic mutations that impact generation of Th17 cells or the IL-17 signaling pathway, including Hyper-IgE Syndrome (STAT3 or TYK2 mutations or IL17RA or ACT1 gene deficiency. The IL-17 family of cytokines is a distinct subclass of cytokines with unique structural and signaling properties. IL-17A is the best-characterized member of the IL-17 family to date, but far less is known about other IL-17-related cytokines. In this study, we sought to determine the role of a related IL-17 cytokine, IL-17C, in protection against oral, dermal and disseminated forms of C. albicans infection. IL-17C signals through a heterodimeric receptor composed of the IL-17RA and IL-17RE subunits. We observed that IL-17C mRNA was induced following oral C. albicans infection. However, mice lacking IL-17C or IL-17RE cleared C. albicans infections in the oral mucosa, skin and bloodstream at rates similar to WT littermate controls. Moreover, these mice demonstrated similar gene transcription profiles and recovery kinetics as WT animals. These findings indicate that IL-17C and IL-17RE are dispensable for immunity to the forms of candidiasis evaluated, and illustrate a surprisingly limited specificity of the IL-17 family of cytokines with respect to systemic, oral and cutaneous Candida infections.

Noise immunity of optimal tracking demodulators

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Uriadnikov, Iu. F.; Vasilev, N. A.

1982-05-01

The noise immunity of optimal discrete tracking demodulators, used in space communication systems, is analyzed in the case of an arbitrary relationship between the signal pulse repetition period and the interval of message correlation. Expressions are obtained which are then used to compare the noise immunities of discrete and continuous tracking demodulators, used for the transmission of messages with spectra approximated by Butterworth polynomials. It is shown that the noise immunity of the discrete demodulator significantly deteriorates

Psychological Stress and the Cutaneous Immune Response: Roles of the HPA Axis and the Sympathetic Nervous System in Atopic Dermatitis and Psoriasis

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Jessica M. F. Hall

2012-01-01

Full Text Available Psychological stress, an evolutionary adaptation to the fight-or-flight response, triggers a number of physiological responses that can be deleterious under some circumstances. Stress signals activate the hypothalamus-pituitary-adrenal (HPA axis and the sympathetic nervous system. Elements derived from those systems (e.g., cortisol, catecholamines and neuropeptides can impact the immune system and possible disease states. Skin provides a first line of defense against many environmental insults. A number of investigations have indicated that the skin is especially sensitive to psychological stress, and experimental evidence shows that the cutaneous innate and adaptive immune systems are affected by stressors. For example, psychological stress has been shown to reduce recovery time of the stratum corneum barrier after its removal (innate immunity and alters antigen presentation by epidermal Langerhans cells (adaptive immunity. Moreover, psychological stress may trigger or exacerbate immune mediated dermatological disorders. Understanding how the activity of the psyche-nervous -immune system axis impinges on skin diseases may facilitate coordinated treatment strategies between dermatologists and psychiatrists. Herein, we will review the roles of the HPA axis and the sympathetic nervous system on the cutaneous immune response. We will selectively highlight how the interplay between psychological stress and the immune system affects atopic dermatitis and psoriasis.

Defective chemokine signal integration in leukocytes lacking activator of G protein signaling 3 (AGS3).

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Branham-O'Connor, Melissa; Robichaux, William G; Zhang, Xian-Kui; Cho, Hyeseon; Kehrl, John H; Lanier, Stephen M; Blumer, Joe B

2014-04-11

Activator of G-protein signaling 3 (AGS3, gene name G-protein signaling modulator-1, Gpsm1), an accessory protein for G-protein signaling, has functional roles in the kidney and CNS. Here we show that AGS3 is expressed in spleen, thymus, and bone marrow-derived dendritic cells, and is up-regulated upon leukocyte activation. We explored the role of AGS3 in immune cell function by characterizing chemokine receptor signaling in leukocytes from mice lacking AGS3. No obvious differences in lymphocyte subsets were observed. Interestingly, however, AGS3-null B and T lymphocytes and bone marrow-derived dendritic cells exhibited significant chemotactic defects as well as reductions in chemokine-stimulated calcium mobilization and altered ERK and Akt activation. These studies indicate a role for AGS3 in the regulation of G-protein signaling in the immune system, providing unexpected venues for the potential development of therapeutic agents that modulate immune function by targeting these regulatory mechanisms.

Effects of engineered nanoparticles on the innate immune system.

Science.gov (United States)

Liu, Yuanchang; Hardie, Joseph; Zhang, Xianzhi; Rotello, Vincent M

2017-12-01

Engineered nanoparticles (NPs) have broad applications in industry and nanomedicine. When NPs enter the body, interactions with the immune system are unavoidable. The innate immune system, a non-specific first line of defense against potential threats to the host, immediately interacts with introduced NPs and generates complicated immune responses. Depending on their physicochemical properties, NPs can interact with cells and proteins to stimulate or suppress the innate immune response, and similarly activate or avoid the complement system. NPs size, shape, hydrophobicity and surface modification are the main factors that influence the interactions between NPs and the innate immune system. In this review, we will focus on recent reports about the relationship between the physicochemical properties of NPs and their innate immune response, and their applications in immunotherapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Immune Signaling and Antimicrobial Peptide Expression in Lepidoptera

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Heidi Goodrich-Blair

2013-07-01

Full Text Available Many lepidopteran insects are agricultural pests that affect stored grains, food and fiber crops. These insects have negative ecological and economic impacts since they lower crop yield, and pesticides are expensive and can have off-target effects on beneficial arthropods. A better understanding of lepidopteran immunity will aid in identifying new targets for the development of specific insect pest management compounds. A fundamental aspect of immunity, and therefore a logical target for control, is the induction of antimicrobial peptide (AMP expression. These peptides insert into and disrupt microbial membranes, thereby promoting pathogen clearance and insect survival. Pathways leading to AMP expression have been extensively studied in the dipteran Drosophila melanogaster. However, Diptera are an important group of pollinators and pest management strategies that target their immune systems is not recommended. Recent advances have facilitated investigation of lepidopteran immunity, revealing both conserved and derived characteristics. Although the general pathways leading to AMP expression are conserved, specific components of these pathways, such as recognition proteins have diverged. In this review we highlight how such comparative immunology could aid in developing pest management strategies that are specific to agricultural insect pests.

Notch1 Signaling Regulates the Th17/Treg Immune Imbalance in Patients with Psoriasis Vulgaris.

Science.gov (United States)

Ma, Lei; Xue, HaiBo; Gao, Tianqin; Gao, MeiLan; Zhang, YuJie

2018-01-01

To evaluate the regulating effect of Notch1 signaling on Th17/Treg immune imbalance in psoriasis vulgaris (PV). Notch1, Hes-1, ROR γ t, Foxp3, IL-17, and IL-10 mRNA expression, as well as Th17 and Treg cell percentages in peripheral CD4 + T cells, were detected by real-time quantitative RT-PCR and flow cytometry, and serum concentrations of IL-17 and IL-10 were detected by ELISA in 36 PV patients and 32 healthy controls. Additionally, CD4 + T cells from 12 PV patients were treated with γ -secretase inhibitor DAPT, and the above indexes were measured. PV patients presented distinct Th17/Treg immune imbalance and highly expressed Notch1 and Hes-1 mRNA levels, which were positively correlated with psoriasis area and severity index (PASI) and the ratios of Th17/Treg and ROR γ t/Foxp3. DAPT treatment resulted in the obvious downregulation of Th17 cell percentage in cocultured CD4 + T cells, ROR γ t and IL-17 mRNA levels, and IL-17 concentration in cell-free supernatant from cocultured CD4 + T cells of PV patients in a dose-dependent manner, while there was no significant influence on Treg cell percentage, Foxp3, and IL-10 expression, therefore leading to the recovery of Th17/Treg immune imbalance. Notch1 signaling may contribute to the pathogenesis of PV by regulating Th17/Treg immune imbalance.

Role of Osmolytes in Regulating Immune System.

Science.gov (United States)

Kumar, Tarun; Yadav, Manisha; Singh, Laishram Rajendrakumar

2016-01-01

The immune system has evolved to protect the host organism from diverse range of pathogenic microbes that are themselves constantly evolving. It is a complex network of cells, humoral factors, chemokines and cytokines. Dysregulation of immune system results in various kinds of immunological disorders. There are several external agents which govern the regulation of immune system. Recent studies have indicated the role of osmolytes in regulation of various immunological processes such as Ag-Ab interaction, Ig assembly, Ag presentation etc. In this present review, we have systematically discussed the role of osmolytes involved in regulation of several key immunological processes. Osmolytes are involved in the regulation of several key immunological processes such as immunoglobulin assembly and folding, immune cells proliferation, regulation of immune cells function, Ag-Ab interaction, antigen presentation, inflammatory response and protection against photo-immunosuppression. Hence, osmolytes and their transporters might be used as potential drug and drug targets respectively. This review is therefore designed to help clinicians in development of osmolyte based therapeutic strategies in the treatment of various immunological disorders. Appropriate future perspectives have also been included.

Radiation-induced effects and the immune system in cancer

Energy Technology Data Exchange (ETDEWEB)

Kaur, Punit; Asea, Alexzander, E-mail: aasea@msm.edu [Department of Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, Atlanta, GA (United States)

2012-12-17

Chemotherapy and radiation therapy (RT) are standard therapeutic modalities for patients with cancers, and could induce various tumor cell death modalities, releasing tumor-derived antigens as well as danger signals that could either be captured for triggering anti-tumor immune response. Historic studies examining tissue and cellular responses to RT have predominantly focused on damage caused to proliferating malignant cells leading to their death. However, there is increasing evidence that RT also leads to significant alterations in the tumor microenvironment, particularly with respect to effects on immune cells and infiltrating tumors. This review will focus on immunologic consequences of RT and discuss the therapeutic reprogramming of immune responses in tumors and how it regulates efficacy and durability to RT.

Methyl salicylate is a critical mobile signal for plant systemic acquired resistance.

Science.gov (United States)

Park, Sang-Wook; Kaimoyo, Evans; Kumar, Dhirendra; Mosher, Stephen; Klessig, Daniel F

2007-10-05

In plants, the mobile signal for systemic acquired resistance (SAR), an organism-wide state of enhanced defense to subsequent infections, has been elusive. By stimulating immune responses in mosaic tobacco plants created by grafting different genetic backgrounds, we showed that the methyl salicylate (MeSA) esterase activity of salicylic acid-binding protein 2 (SABP2), which converts MeSA into salicylic acid (SA), is required for SAR signal perception in systemic tissue, the tissue that does not receive the primary (initial) infection. Moreover, in plants expressing mutant SABP2 with unregulated MeSA esterase activity in SAR signal-generating, primary infected leaves, SAR was compromised and the associated increase in MeSA levels was suppressed in primary infected leaves, their phloem exudates, and systemic leaves. SAR was also blocked when SA methyl transferase (which converts SA to MeSA) was silenced in primary infected leaves, and MeSA treatment of lower leaves induced SAR in upper untreated leaves. Therefore, we conclude that MeSA is a SAR signal in tobacco.

Exploring the Homeostatic and Sensory Roles of the Immune System.

Science.gov (United States)

Marques, Rafael Elias; Marques, Pedro Elias; Guabiraba, Rodrigo; Teixeira, Mauro Martins

2016-01-01

Immunology developed under the notion of the immune system exists to fight pathogens. Recently, the discovery of interactions with commensal microbiota that are essential to human health initiated a change in this old paradigm. Here, we argue that the immune system has major physiological roles extending far beyond defending the host. Immune and inflammatory responses share the core property of sensing, defining the immune system also as a sensory system. The inference with the immune system collects, interprets, and stores information, while creating an identity of self, places it in close relationship to the nervous system, which suggests that these systems may have a profound evolutionary connection.

SMAD regulatory networks construct a balanced immune system.

Science.gov (United States)

Malhotra, Nidhi; Kang, Joonsoo

2013-05-01

A balanced immune response requires combating infectious assaults while striving to maintain quiescence towards the self. One of the central players in this process is the pleiotropic cytokine transforming growth factor-β (TGF-β), whose deficiency results in spontaneous systemic autoimmunity in mice. The dominant function of TGF-β is to regulate the peripheral immune homeostasis, particularly in the microbe-rich and antigen-rich environment of the gut. To maintain intestinal integrity, the epithelial cells, myeloid cells and lymphocytes that inhabit the gut secrete TGF-β, which acts in both paracrine and autocrine fashions to activate its signal transducers, the SMAD transcription factors. The SMAD pathway regulates the production of IgA by B cells, maintains the protective mucosal barrier and promotes the balanced differentiation of CD4(+) T cells into inflammatory T helper type 17 cells and suppressive FOXP3(+) T regulatory cells. While encounters with pathogenic microbes activate SMAD proteins to evoke a protective inflammatory immune response, SMAD activation and synergism with immunoregulatory factors such as the vitamin A metabolite retinoic acid enforce immunosuppression toward commensal microbes and innocuous food antigens. Such complementary context-dependent functions of TGF-β are achieved by the co-operation of SMAD proteins with distinct dominant transcription activators and accessory chromatin modifiers. This review highlights recent advances in unravelling the molecular basis for the multi-faceted functions of TGF-β in the gut that are dictacted by fluid orchestrations of SMADs and their myriad partners. © 2013 Blackwell Publishing Ltd.

Strengthening health system to improve immunization for migrants in China.

Science.gov (United States)

Fang, Hai; Yang, Li; Zhang, Huyang; Li, Chenyang; Wen, Liankui; Sun, Li; Hanson, Kara; Meng, Qingyue

2017-07-01

Immunization is the most cost-effective method to prevent and control vaccine-preventable diseases. Migrant population in China has been rising rapidly, and their immunization status is poor. China has tried various strategies to strengthen its health system, which has significantly improved immunization for migrants. This study applied a qualitative retrospective review method aiming to collect, analyze and synthesize health system strengthening experiences and practices about improving immunizations for migrants in China. A conceptual framework of Theory of Change was used to extract the searched literatures. 11 searched literatures and 4 national laws and policies related to immunizations for migrant children were carefully studied. China mainly employed 3 health system strengthening strategies to significantly improve immunization for migrant population: stop charging immunization fees or immunization insurance, manage immunization certificates well, and pay extra attentions on immunization for special children including migrant children. These health system strengthening strategies were very effective, and searched literatures show that up-to-date and age-appropriate immunization rates were significantly improved for migrant children. Economic development led to higher migrant population in China, but immunization for migrants, particularly migrant children, were poor. Fortunately various health system strengthening strategies were employed to improve immunization for migrants in China and they were rather successful. The experiences and lessons of immunization for migrant population in China might be helpful for other developing countries with a large number of migrant population.

Metallothioneins: Emerging Modulators in Immunity and Infection

Directory of Open Access Journals (Sweden)

Kavitha Subramanian Vignesh

2017-10-01

Full Text Available Metallothioneins (MTs are a family of metal-binding proteins virtually expressed in all organisms including prokaryotes, lower eukaryotes, invertebrates and mammals. These proteins regulate homeostasis of zinc (Zn and copper (Cu, mitigate heavy metal poisoning, and alleviate superoxide stress. In recent years, MTs have emerged as an important, yet largely underappreciated, component of the immune system. Innate and adaptive immune cells regulate MTs in response to stress stimuli, cytokine signals and microbial challenge. Modulation of MTs in these cells in turn regulates metal ion release, transport and distribution, cellular redox status, enzyme function and cell signaling. While it is well established that the host strictly regulates availability of metal ions during microbial pathogenesis, we are only recently beginning to unravel the interplay between metal-regulatory pathways and immunological defenses. In this perspective, investigation of mechanisms that leverage the potential of MTs to orchestrate inflammatory responses and antimicrobial defenses has gained momentum. The purpose of this review, therefore, is to illumine the role of MTs in immune regulation. We discuss the mechanisms of MT induction and signaling in immune cells and explore the therapeutic potential of the MT-Zn axis in bolstering immune defenses against pathogens.

The sterile immune response during hepatic ischemia/reperfusion

NARCIS (Netherlands)

van Golen, Rowan F.; van Gulik, Thomas M.; Heger, Michal

2012-01-01

Hepatic ischemia and reperfusion elicits an immune response that lacks a microbial constituent yet poses a potentially lethal threat to the host. In this sterile setting, the immune system is alarmed by endogenous danger signals that are release by stressed and dying liver cells. The detection of

A model system for targeted drug release triggered by biomolecular signals logically processed through enzyme logic networks.

Science.gov (United States)

Mailloux, Shay; Halámek, Jan; Katz, Evgeny

2014-03-07

A new Sense-and-Act system was realized by the integration of a biocomputing system, performing analytical processes, with a signal-responsive electrode. A drug-mimicking release process was triggered by biomolecular signals processed by different logic networks, including three concatenated AND logic gates or a 3-input OR logic gate. Biocatalytically produced NADH, controlled by various combinations of input signals, was used to activate the electrochemical system. A biocatalytic electrode associated with signal-processing "biocomputing" systems was electrically connected to another electrode coated with a polymer film, which was dissolved upon the formation of negative potential releasing entrapped drug-mimicking species, an enzyme-antibody conjugate, operating as a model for targeted immune-delivery and consequent "prodrug" activation. The system offers great versatility for future applications in controlled drug release and personalized medicine.

Hepatitis B virus polymerase blocks pattern recognition receptor signaling via interaction with DDX3: implications for immune evasion.

Directory of Open Access Journals (Sweden)

Haifeng Wang

Full Text Available Viral infection leads to induction of pattern-recognition receptor signaling, which leads to interferon regulatory factor (IRF activation and ultimately interferon (IFN production. To establish infection, many viruses have strategies to evade the innate immunity. For the hepatitis B virus (HBV, which causes chronic infection in the liver, the evasion strategy remains uncertain. We now show that HBV polymerase (Pol blocks IRF signaling, indicating that HBV Pol is the viral molecule that effectively counteracts host innate immune response. In particular, HBV Pol inhibits TANK-binding kinase 1 (TBK1/IkappaB kinase-epsilon (IKKepsilon, the effector kinases of IRF signaling. Intriguingly, HBV Pol inhibits TBK1/IKKepsilon activity by disrupting the interaction between IKKepsilon and DDX3 DEAD box RNA helicase, which was recently shown to augment TBK1/IKKepsilon activity. This unexpected role of HBV Pol may explain how HBV evades innate immune response in the early phase of the infection. A therapeutic implication of this work is that a strategy to interfere with the HBV Pol-DDX3 interaction might lead to the resolution of life-long persistent infection.

Crosstalk between cancer and the neuro-immune system.

Science.gov (United States)

Kuol, Nyanbol; Stojanovska, Lily; Apostolopoulos, Vasso; Nurgali, Kulmira

2018-02-15

In the last decade, understanding of cancer initiation and progression has been given much attention with studies mainly focusing on genetic abnormalities. Importantly, cancer cells can influence their microenvironment and bi-directionally communicate with other systems such as the immune system. The nervous system plays a fundamental role in regulating immune responses to a range of disease states including cancer. Its dysfunction influences the progression of cancer. The role of the immune system in tumor progression is of relevance to the nervous system since they can bi-directionally communicate via neurotransmitters and neuropeptides, common receptors, and, cytokines. However, cross-talk between these cells is highly complex in nature, and numerous variations are possible according to the type of cancer involved. The neuro-immune interaction is essential in influencing cancer development and progression. Copyright © 2017 Elsevier B.V. All rights reserved.

Up in arms: Immune and nervous system response to sea star wasting disease

Science.gov (United States)

Fuess, Lauren E; Eiselord, Morgan E.; Closek, Collin J.; Tracy, Allison M.; Mauntz, Ruth; Gignoux-Wolfsohn, Sarah; Moritsch, Monica M; Yoshioka, Reyn; Burge, Colleen A.; Harvell, Drew; Friedman, Carolyn S.; Hershberger, Paul K.; Roberts, Steven B.

2015-01-01

Echinoderms, positioned taxonomically at the base of deuterostomes, provide an important system for the study of the evolution of the immune system. However, there is little known about the cellular components and genes associated with echinoderm immunity. The 2013–2014 sea star wasting disease outbreak is an emergent, rapidly spreading disease, which has led to large population declines of asteroids in the North American Pacific. While evidence suggests that the signs of this disease, twisting arms and lesions, may be attributed to a viral infection, the host response to infection is still poorly understood. In order to examine transcriptional responses of the sea star Pycnopodia helianthoides to sea star wasting disease, we injected a viral sized fraction (0.2 μm) homogenate prepared from symptomatic P. helianthoides into apparently healthy stars. Nine days following injection, when all stars were displaying signs of the disease, specimens were sacrificed and coelomocytes were extracted for RNA-seq analyses. A number of immune genes, including those involved in Toll signaling pathways, complement cascade, melanization response, and arachidonic acid metabolism, were differentially expressed. Furthermore, genes involved in nervous system processes and tissue remodeling were also differentially expressed, pointing to transcriptional changes underlying the signs of sea star wasting disease. The genomic resources presented here not only increase understanding of host response to sea star wasting disease, but also provide greater insight into the mechanisms underlying immune function in echinoderms.

Immune system alterations in amyotrophic lateral sclerosis

DEFF Research Database (Denmark)

Hovden, H; Frederiksen, J L; Pedersen, S W

2013-01-01

Amyotrophic lateral sclerosis is a disease of which the underlying cause and pathogenesis are unknown. Cumulatative data clearly indicates an active participation by the immune system in the disease. An increasingly recognized theory suggests a non-cell autonomous mechanism, meaning that multiple...... cells working together are necessary for the pathogenesis of the disease. Observed immune system alterations could indicate an active participation in this mechanism. Damaged motor neurons are able to activate microglia, astrocytes and the complement system, which further can influence each other...... and contribute to neurodegeneration. Infiltrating peripheral immune cells appears to correlate with disease progression, but their significance and composition is unclear. The deleterious effects of this collaborating system of cells appear to outweigh the protective aspects, and revealing this interplay might...

Modeling evolution and immune system by cellular automata

International Nuclear Information System (INIS)

Bezzi, M.

2001-01-01

In this review the behavior of two different biological systems is investigated using cellular automata. Starting from this spatially extended approach it is also tried, in some cases, to reduce the complexity of the system introducing mean-field approximation, and solving (or trying to solve) these simplified systems. It is discussed the biological meaning of the results, the comparison with experimental data (if available) and the different features between spatially extended and mean-field versions. The biological systems considered in this review are the following: Darwinian evolution in simple ecosystems and immune system response. In the first section the main features of molecular evolution are introduced, giving a short survey of genetics for physicists and discussing some models for prebiotic systems and simple ecosystems. It is also introduced a cellular automaton model for studying a set of evolving individuals in a general fitness landscape, considering also the effects of co-evolution. In particular the process of species formation (speciation) is described in sect. 5. The second part deals with immune system modeling. The biological features of immune response are discussed, as well as it is introduced the concept of shape space and of idiotypic network. More detailed reviews which deal with immune system models (mainly focused on idiotypic network models) can be found. Other themes here discussed: the applications of CA to immune system modeling, two complex cellular automata for humoral and cellular immune response. Finally, it is discussed the biological data and the general conclusions are drawn in the last section

CD95-CD95L: can the brain learn from the immune system?

DEFF Research Database (Denmark)

Becher, B; Barker, P A; Owens, T

1998-01-01

being recognized that CD95 signaling by immune cells mediates effects other than apoptosis, such as cell survival and under inflammatory conditions expression of this protein promotes neural-immune interactions. Both neuroscientists and immunologists can contribute to defining the mechanisms underlying...

Aryl hydrocarbon receptor signaling modulates antiviral immune responses: ligand metabolism rather than chemical source is the stronger predictor of outcome.

Science.gov (United States)

Boule, Lisbeth A; Burke, Catherine G; Jin, Guang-Bi; Lawrence, B Paige

2018-01-29

The aryl hydrocarbon receptor (AHR) offers a compelling target to modulate the immune system. AHR agonists alter adaptive immune responses, but the consequences differ across studies. We report here the comparison of four agents representing different sources of AHR ligands in mice infected with influenza A virus (IAV): TCDD, prototype exogenous AHR agonist; PCB126, pollutant with documented human exposure; ITE, novel pharmaceutical; and FICZ, degradation product of tryptophan. All four compounds diminished virus-specific IgM levels and increased the proportion of regulatory T cells. TCDD, PCB126 and ITE, but not FICZ, reduced virus-specific IgG levels and CD8 + T cell responses. Similarly, ITE, PCB126, and TCDD reduced Th1 and Tfh cells, whereas FICZ increased their frequency. In Cyp1a1-deficient mice, all compounds, including FICZ, reduced the response to IAV. Conditional Ahr knockout mice revealed that all four compounds require AHR within hematopoietic cells. Thus, differences in the immune response to IAV likely reflect variances in quality, magnitude, and duration of AHR signaling. This indicates that binding affinity and metabolism may be stronger predictors of immune effects than a compound's source of origin, and that harnessing AHR will require finding a balance between dampening immune-mediated pathologies and maintaining sufficient host defenses against infection.

The influence of pregnancy on systemic immunity.

Science.gov (United States)

Pazos, Michael; Sperling, Rhoda S; Moran, Thomas M; Kraus, Thomas A

2012-12-01

Adaptations in maternal systemic immunity are presumed to be responsible for observed alterations in disease susceptibility and severity as pregnancy progresses. Epidemiological evidence as well as animal studies have shown that influenza infections are more severe during the second and third trimesters of pregnancy, resulting in greater morbidity and mortality, although the reason for this is still unclear. Our laboratory has taken advantage of 20 years of experience studying the murine immune response to respiratory viruses to address questions of altered immunity during pregnancy. With clinical studies and unique animal model systems, we are working to define the mechanisms responsible for altered immune responses to influenza infection during pregnancy and what roles hormones such as estrogen or progesterone play in these alterations.

The ubiquitin editing enzyme A20 maintains immune homeostasis and prevents autoimmunity

OpenAIRE

Tavares, Rita M.

2010-01-01

Dissertation presented to obtain the Doctorate degree (Ph.D.) in Biology at Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa The immune system is vital to ensure the surveillance of organisms against pathogens or malignant cells. However, the negative regulation of the immune system is equally essential, and defects in the termination of immune signals can result in autoimmunity and other pathologies. The functioning of the immune system results from the integrati...

State of immune system lesions eymeriozo turkey-invasions histomonoznoyu

OpenAIRE

CHARIV I.

2011-01-01

The immune system of animals and birds provides resistance against bacterial and viral infections. In the intestinal mucosa and eymeriyi histomonady produce metabolic products that are toxic to different systems and tissues of turkeys. They parasitizing in the intestine, suppress specific phase of immunity provided by antibodies (humoral type), reduce activity sensitized cells (cell type), slow phase of nonspecific immunity, which is represented by various immune cells.

The Role of the Immune System Beyond the Fight Against Infection.

Science.gov (United States)

Sattler, Susanne

2017-01-01

The immune system was identified as a protective factor during infectious diseases over a century ago. Current definitions and textbook information are still largely influenced by these early observations, and the immune system is commonly presented as a defence machinery. However, host defence is only one manifestation of the immune system's overall function in the maintenance of tissue homeostasis and system integrity. In fact, the immune system is integral part of fundamental physiological processes such as development, reproduction and wound healing, and a close crosstalk between the immune system and other body systems such as metabolism, the central nervous system and the cardiovascular system is evident. Research and medical professionals in an expanding range of areas start to recognise the implications of the immune system in their respective fields.This chapter provides a brief historical perspective on how our understanding of the immune system has evolved from a defence system to an overarching surveillance machinery to maintain tissue integrity. Current perspectives on the non-defence functions of classical immune cells and factors will also be discussed.

The role of intestinal microbiota and the immune system.

Science.gov (United States)

Purchiaroni, F; Tortora, A; Gabrielli, M; Bertucci, F; Gigante, G; Ianiro, G; Ojetti, V; Scarpellini, E; Gasbarrini, A

2013-02-01

The human gut is an ecosystem consisting of a great number of commensal bacteria living in symbiosis with the host. Several data confirm that gut microbiota is engaged in a dynamic interaction with the intestinal innate and adaptive immune system, affecting different aspects of its development and function. To review the immunological functions of gut microbiota and improve knowledge of its therapeutic implications for several intestinal and extra-intestinal diseases associated to dysregulation of the immune system. Significant articles were identified by literature search and selected based on content, including atopic diseases, inflammatory bowel diseases and treatment of these conditions with probiotics. Accumulating evidence indicates that intestinal microflora has protective, metabolic, trophic and immunological functions and is able to establish a "cross-talk" with the immune component of mucosal immunity, comprising cellular and soluble elements. When one or more steps in this fine interaction fail, autoimmune or auto-inflammatory diseases may occur. Furthermore, it results from the data that probiotics, used for the treatment of the diseases caused by the dysregulation of the immune system, can have a beneficial effect by different mechanisms. Gut microbiota interacts with both innate and adaptive immune system, playing a pivotal role in maintenance and disruption of gut immune quiescence. A cross talk between the mucosal immune system and endogenous microflora favours a mutual growth, survival and inflammatory control of the intestinal ecosystem. Based on these evidences, probiotics can be used as an ecological therapy in the treatment of immune diseases.  

[The liver and the immune system].

Science.gov (United States)

Jakab, Lajos

2015-07-26

The liver is known to be the metabolic centre of the organism and is under the control of the central nervous system. It has a peculiar tissue structure and its anatomic localisation defines it as part of the immune system having an individual role in the defence of the organism. The determinant of its particular tissue build-up is the sinusoid system. In addition to hepatocytes, one cell row "endothelium", stellate cells close to the external surface, Kupffer cells tightly to its inner surface, as well as dendritic cells and other cell types (T and B lymphocytes, natural killer and natural killer T-cells, mast cells, granulocytes) are present. The multitudes and variety of cells make it possible to carry out the tasks according to the assignment of the organism. The liver is a member of the immune system having immune cells largely in an activated state. Its principal tasks are the assurance of the peripheral immune tolerance of the organism with the help of the haemopoetic cells and transforming growth factor-β. The liver takes part in the determination of the manner of the non-specific immune response of the organism. In addition to acute phase reaction of the organism, the liver has a role in the adaptive/specific immune response. These functions include retardation of the T and B lymphocytes and the defence against harmful pathogens. With the collaboration of transforming growth factor-β, immunoglobulins and their subclasses are inhibited just as the response of the T lymphocytes. The only exception is the undisturbed immunoglobulin A production. Particularly important is the intensive participation of the liver in the acute phase reaction of the organism, which is organised and guided by the coordinated functions of the cortico-hypothalamo-hypophysis-adrenal axis. Beside cellular elements, hormones, adhesion molecules, chemokines and cytokines are also involved in the cooperation with the organs. Acute phase reactants play a central role in these processes

Nociception and role of immune system in pain.

Science.gov (United States)

Verma, Vivek; Sheikh, Zeeshan; Ahmed, Ahad S

2015-09-01

Both pain and inflammation are protective responses. However, these self-limiting conditions (with well-established negative feedback loops) become pathological if left uncontrolled. Both pain and inflammation can interact with each other in a multi-dimensional manner. These interactions are known to create an array of 'difficult to manage' pathologies. This review explains in detail the role of immune system and the related cells in peripheral sensitization and neurogenic inflammation. Various neuro-immune interactions are analyzed at peripheral, sensory and central nervous system levels. Innate immunity plays a critical role in central sensitization and in establishing acute pain as chronic condition. Moreover, inflammatory mediators also exhibit psychological effects, thus contributing towards the emotional elements associated with pain. However, there is also a considerable anti-inflammatory and analgesic role of immune system. This review also attempts to enlist various novel pharmacological approaches that exhibit their actions through modification of neuro-immune interface.

Phospholipase C-β in immune cells.

Science.gov (United States)

Kawakami, Toshiaki; Xiao, Wenbin

2013-09-01

Great progress has recently been made in structural and functional research of phospholipase C (PLC)-β. We now understand how PLC-β isoforms (β1-β4) are activated by GTP-bound Gαq downstream of G protein-coupled receptors. Numerous studies indicate that PLC-βs participate in the differentiation and activation of immune cells that control both the innate and adaptive immune systems. The PLC-β3 isoform also interplays with tyrosine kinase-based signaling pathways, to inhibit Stat5 activation by recruiting the protein-tyrosine phosphatase SHP-1, with which PLC-β3 and Stat5 form a multi-molecular signaling platform, named SPS complex. The SPS complex has important regulatory roles in tumorigenesis and immune cell activation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Assessment of geometry in 2D immune systems using high accuracy laser-based bioprinting techniques (Conference Presentation)

Science.gov (United States)

Lauzurica, Sara; Márquez, Andrés.; Molpeceres, Carlos; Notario, Laura; Gómez-Fontela, Miguel; Lauzurica, Pilar

2017-02-01

The immune system is a very complex system that comprises a network of genetic and signaling pathways subtending a network of interacting cells. The location of the cells in a network, along with the gene products they interact with, rules the behavior of the immune system. Therefore, there is a great interest in understanding properly the role of a cell in such networks to increase our knowledge of the immune system response. In order to acquire a better understanding of these processes, cell printing with high spatial resolution emerges as one of the promising approaches to organize cells in two and three-dimensional patterns to enable the study the geometry influence in these interactions. In particular, laser assisted bio-printing techniques using sub-nanosecond laser sources have better characteristics for application in this field, mainly due to its higher spatial resolution, cell viability percentage and process automation. This work presents laser assisted bio-printing of antigen-presenting cells (APCs) in two-dimensional geometries, placing cellular components on a matrix previously generated on demand, permitting to test the molecular interactions between APCs and lymphocytes; as well as the generation of two-dimensional structures designed ad hoc in order to study the mechanisms of mobilization of immune system cells. The use of laser assisted bio-printing, along with APCs and lymphocytes emulate the structure of different niches of the immune system so that we can analyse functional requirement of these interaction.

Integration of the immune system: a complex adaptive supersystem

Science.gov (United States)

Crisman, Mark V.

2001-10-01

Immunity to pathogenic organisms is a complex process involving interacting factors within the immune system including circulating cells, tissues and soluble chemical mediators. Both the efficiency and adaptive responses of the immune system in a dynamic, often hostile, environment are essential for maintaining our health and homeostasis. This paper will present a brief review of one of nature's most elegant, complex adaptive systems.

The deconvolution of complex spectra by artificial immune system

Science.gov (United States)

Galiakhmetova, D. I.; Sibgatullin, M. E.; Galimullin, D. Z.; Kamalova, D. I.

2017-11-01

An application of the artificial immune system method for decomposition of complex spectra is presented. The results of decomposition of the model contour consisting of three components, Gaussian contours, are demonstrated. The method of artificial immune system is an optimization method, which is based on the behaviour of the immune system and refers to modern methods of search for the engine optimization.

Role of Cortistatin in the Stressed Immune System.

Science.gov (United States)

Delgado, Mario; Gonzalez-Rey, Elena

2017-01-01

The immune system is faced with the daunting job of defending the organism against invading pathogens, while at the same time preserving the body integrity and maintaining tolerance to its own tissues. Loss of self-tolerance compromises immune homeostasis and leads to the onset of autoimmune disorders. The identification of endogenous factors that control immune tolerance and inflammation is a key goal for immunologists. Evidences from the last decade indicate that the neuropeptide cortistatin is one of the endogenous factors. Cortistatin is produced by immune cells and through its binding to various receptors, it exerts potent anti-inflammatory actions and participates in the maintenance of immune tolerance at multiple levels, especially in immunological disorders. Cortistatin emerges as a key element in the bidirectional communication between the neuroendocrine and immune systems aimed at regulating body homeostasis. © 2017 S. Karger AG, Basel.

Bacteria-Triggered Systemic Immunity in Barley Is Associated with WRKY and ETHYLENE RESPONSIVE FACTORs But Not with Salicylic Acid1[C][W

Science.gov (United States)

Dey, Sanjukta; Wenig, Marion; Langen, Gregor; Sharma, Sapna; Kugler, Karl G.; Knappe, Claudia; Hause, Bettina; Bichlmeier, Marlies; Babaeizad, Valiollah; Imani, Jafargholi; Janzik, Ingar; Stempfl, Thomas; Hückelhoven, Ralph; Kogel, Karl-Heinz; Mayer, Klaus F.X.

2014-01-01

Leaf-to-leaf systemic immune signaling known as systemic acquired resistance is poorly understood in monocotyledonous plants. Here, we characterize systemic immunity in barley (Hordeum vulgare) triggered after primary leaf infection with either Pseudomonas syringae pathovar japonica (Psj) or Xanthomonas translucens pathovar cerealis (Xtc). Both pathogens induced resistance in systemic, uninfected leaves against a subsequent challenge infection with Xtc. In contrast to systemic acquired resistance in Arabidopsis (Arabidopsis thaliana), systemic immunity in barley was not associated with NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 or the local or systemic accumulation of salicylic acid. Instead, we documented a moderate local but not systemic induction of abscisic acid after infection of leaves with Psj. In contrast to salicylic acid or its functional analog benzothiadiazole, local applications of the jasmonic acid methyl ester or abscisic acid triggered systemic immunity to Xtc. RNA sequencing analysis of local and systemic transcript accumulation revealed unique gene expression changes in response to both Psj and Xtc and a clear separation of local from systemic responses. The systemic response appeared relatively modest, and quantitative reverse transcription-polymerase chain reaction associated systemic immunity with the local and systemic induction of two WRKY and two ETHYLENE RESPONSIVE FACTOR (ERF)-like transcription factors. Systemic immunity against Xtc was further associated with transcriptional changes after a secondary/systemic Xtc challenge infection; these changes were dependent on the primary treatment. Taken together, bacteria-induced systemic immunity in barley may be mediated in part by WRKY and ERF-like transcription factors, possibly facilitating transcriptional reprogramming to potentiate immunity. PMID:25332505

Endoplasmic reticulum stress pathway required for immune homeostasis is neurally controlled by arrestin-1.

Science.gov (United States)

Singh, Varsha; Aballay, Alejandro

2012-09-28

In response to pathogen infection, the host innate immune system activates microbial killing pathways and cellular stress pathways that need to be balanced because insufficient or excessive immune responses have deleterious consequences. Recent studies demonstrate that two G protein-coupled receptors (GPCRs) in the nervous system of Caenorhabditis elegans control immune homeostasis. To investigate further how GPCR signaling controls immune homeostasis at the organismal level, we studied arrestin-1 (ARR-1), which is the only GPCR adaptor protein in C. elegans. The results indicate that ARR-1 is required for GPCR signaling in ASH, ASI, AQR, PQR, and URX neurons, which control the unfolded protein response and a p38 mitogen-activated protein kinase signaling pathway required for innate immunity. ARR-1 activity also controlled immunity through ADF chemosensory and AFD thermosensory neurons that regulate longevity. Furthermore, we found that although ARR-1 played a key role in the control of immunity by AFD thermosensory neurons, it did not control longevity through these cells. However, ARR-1 partially controlled longevity through ADF neurons.

Gut-Associated Lymphoid Tissue: A Key Tissue Inside the Mucosal Immune System of Hens Immunized with Escherichia coli F4.

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Peralta, Maria F; Magnoli, Alejandra; Alustiza, Fabrisio; Nilson, Armando; Miazzo, Raúl; Vivas, Adriana

2017-01-01

Immunoglobulin Y (IgY) is the predominant antibody found in hen's ( Gallus domesticus ) egg yolk. This antibody, developed against several microorganisms in hen egg yolk, has been successfully used as an alternative to immunoglobulins from mammals for use in immunodiagnostics and immunotherapy. Enteropathogenic Escherichia coli (E.coli) F 4 is the main etiological agent associated with swine neonatal diarrhea, and it causes notable economic losses in swine production. The aim of the present study was to evaluate the relationship between humoral immune response and the activation of gut-associated lymphoid tissue (GALT) in laying hens intramuscularly immunized with E. coli F 4 . Adult laying Shaver hens were immunized with a bacterin based on an inactivated lysate E. coli F 4 strain that was originally isolated from neonatal piglet diarrhea, following a recommended schedule. The percentage of B lymphocytes in blood and spleen homogenates was determined by flow cytometry. Villi histomorphometry and the size of germinal centers (GC) activated in GALT and the spleen were measured in histological samples either stained with hematoxylin/eosin or through immunofluorescence. Antibody and isotype-specific antibodies in serum and egg yolk were measured using indirect enzyme-linked immunosorbent assay (ELISA). Secretory and serum immunoglobulin A (IgA) were measured by ELISA tests. Laying hen with intramuscular immunization with E. coli F 4 lysate, activated both mucosal and systemic protection. Mucosal protection was provided through B lymphocytes, and most of them were activated on Peyer's patches and esophageal tonsils, in GALT. Furthermore, increased B lymphocyte number in the lamina propria of the gut, and increased intraepithelial plasmatic cell number, produced high levels of mucosal IgA. Activated B lymphocytes interacted with absorptive cells, immune cells, and microbiota in the gut, producing signals that were translated into a powerful physical defense by producing

Immune system investigations for radiation workers

International Nuclear Information System (INIS)

Obreja, Doina; Tulbure, Rodica; Marinescu, Irina

2001-01-01

During the last decade a great deal of attention has been paid to the research in the field of the immune system. Some important steps forward have been achieved in understanding the mechanisms of action and control of the immunologic responses. At the same time the concern for the possible health effects of exposure to ionizing radiation has considerably increased. On the purpose of the evaluation of the modifications induced by the ionizing radiation for radiation workers, we have applied the method of lymphocytic subpopulations, a method that evinces the proportions for the various subtypes of lymphocytes having different roles within the immune system. A number of 62 persons, employees of the Institute of Physics and Nuclear Engineering at Bucharest - Magurele were involved in this study. All radiation workers from 2 departments characterized by a high exposure to ionizing radiation were included, as follows: Group no. 1, consisting of 20 persons working at RWTS (Radioactive Waste Treating Station), thus presenting both external and internal irradiation; Group no. 2, consisting of 18 persons working at RPC (Radioactive Isotopes Preparing Center), a place where besides the radioactive contamination, the chemical risk was also present. The control group (consisting of 24 persons) was formed of employees from the same institute, with the difference that they were not radiation workers. For the statistical processing of the results the programs EPI INFO 6 and CIA were used. Significantly, when analyzing globally the lymphocytic modifications for TT and/or B lymphocytes (either increments or decrements when compared to the normal values), a noticeable statistical difference among the groups in terms of the frequency of the immune system modifications (Hi square test p=0.001) occurs. The results are in accordance to those in special literature mentioning age as a factor having a role in the appearance of the immune modifications. The obtained results indicate a

Energy efficient security in MANETs: a comparison of cryptographic and artificial immune systems

International Nuclear Information System (INIS)

Mazhar, N.

2010-01-01

MANET is characterized by a set of mobile nodes in an inherently insecure environment, having limited battery capacities. Provisioning of energy efficient security in MANETs is, therefore, an open problem for which a number of solutions have been proposed. In this paper, we present an overview and comparison of the MANET security at routing layer by using the cryptographic and Artificial Immune System (AIS) approaches. The BeeAdHoc protocol, which is a Bio-inspired MANET routing protocol based on the foraging principles of honey bee colony, is taken as case study. We carry out an analysis of the three security frameworks that we have proposed earlier for securing BeeAdHoc protocol; one based on asymmetric key encryption, i.e BeeSec, and the other two using the AIS approach, i.e BeeAIS based on self non-self discrimination from adaptive immune system and BeeAIS-DC based on Dendritic Cell (DC) behavior from innate immune system. We extensively evaluate the performance of the three protocols through network simulations in ns-2 and compare with BeeAdHoc, the base protocol, as well as with state-of-the-art MANET routing protocols DSR and AODV. Our results clearly indicate that AIS based systems provide security at much lower cost to energy as compared with the cryptographic systems. Moreover, the use of dendritic cells and danger signals instead of the classical self non-self discrimination allows to detect the non-self antigens with greater accuracy. Based on the results of this investigation, we also propose a composite AIS model for BeeAdHoc security by combining the concepts from both the adaptive and the innate immune systems by modelling the attributes and behavior of the B-cells and DCs. (author)

Biomedical signals and systems

CERN Document Server

Tranquillo, Joseph V

2013-01-01

Biomedical Signals and Systems is meant to accompany a one-semester undergraduate signals and systems course. It may also serve as a quick-start for graduate students or faculty interested in how signals and systems techniques can be applied to living systems. The biological nature of the examples allows for systems thinking to be applied to electrical, mechanical, fluid, chemical, thermal and even optical systems. Each chapter focuses on a topic from classic signals and systems theory: System block diagrams, mathematical models, transforms, stability, feedback, system response, control, time

Evidence for a common mucosal immune system in the pig.

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Wilson, Heather L; Obradovic, Milan R

2015-07-01

The majority of lymphocytes activated at mucosal sites receive instructions to home back to the local mucosa, but a portion also seed distal mucosa sites. By seeding distal sites with antigen-specific effector or memory lymphocytes, the foundation is laid for the animal's mucosal immune system to respond with a secondary response should to this antigen be encountered at this site in the future. The common mucosal immune system has been studied quite extensively in rodent models but less so in large animal models such as the pig. Reasons for this paucity of reported induction of the common mucosal immune system in this species may be that distal mucosal sites were examined but no induction was observed and therefore it was not reported. However, we suspect that the majority of investigators simply did not sample distal mucosal sites and therefore there is little evidence of immune response induction in the literature. It is our hope that more pig immunologists and infectious disease experts who perform mucosal immunizations or inoculations on pigs will sample distal mucosal sites and report their findings, whether results are positive or negative. In this review, we highlight papers that show that immunization/inoculation using one route triggers mucosal immune system induction locally, systemically, and within at least one distal mucosal site. Only by understanding whether immunizations at one site triggers immunity throughout the common mucosal immune system can we rationally develop vaccines for the pig, and through these works we can gather evidence about the mucosal immune system that may be extrapolated to other livestock species or humans. Copyright © 2014 Elsevier Ltd. All rights reserved.

The immune self: a selectionist theory of recognition, learning, and remembering within the immune system.

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Kradin, R L

1995-01-01

In this paper, I have briefly explored metaphors shared by the immune and nervous systems and shown that this exercise can lead to the elucidation of common principles of organization, as well as to predictions concerning how the immune system functions. Metaphor itself undoubtedly reflects the way in which we categorize and retrieve information 44], so it is not surprising that the deep processes of language tend to sample information from related data categories. Although the nervous and immune systems are obviously not the same and metaphors are indeed just that, my primary goal has been to suggest that by virtue of their having evolved in parallel over millions of years, the nervous and immune systems currently use the same archetypal principles and strategies to address related challenges in information processing and retrieval. Ultimately, nature is conservative. One need only look at a tree, a river, the airways, or the vascular bed in order to see how a fractal pattern of repetitive dichotomous branching has been used by each, in order to optimize the transport of fluids over large distances [45]. While each system has had to adopt different materials in order to solve the problem, the shape of their solutions is remarkably alike. In the immune and nervous systems, the elements used to produce optimal functional responses are also quite different, but again the solutions have been achieved by comparable strategies. I am certain that these two great systems of information processing, each responding with vastly different kinetics, will prove to be far more integrally interdependent than has been previously recognized. For example, should a swift response by the immune system be required in an overwhelming invasion by microbial pathogens, the immune system may be able to cooperate with the rapidly reacting nervous system to rid the host of the invaders. In this regard, we have shown that the beta-adrenergic hormone epinephrine rapidly increases the traffic of

The University Immune System: Overcoming Resistance to Change

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Gilley, Ann; Godek, Marisha; Gilley, Jerry W.

2009-01-01

A university, similar to any other organization, has an immune system that erects a powerful barrier against change. This article discusses the university immune system and what can be done to counteract its negative effects and thereby allow change to occur.

Extracts of Porphyra tenera (Nori Seaweed) Activate the Immune Response in Mouse RAW264.7 Macrophages via NF-κB Signaling.

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Song, Ji-Hye; Kang, Hee-Bum; Park, Seung-Ho; Jeong, Ji-Hoon; Park, Jeongjin; You, Yanghee; Lee, Yoo-Hyun; Lee, Jeongmin; Kim, Eungpil; Choi, Kyung-Chul; Jun, Woojin

2017-12-01

Porphyra tenera, also known as nori, is a red algal species of seaweed. It is cultivated in Asia for culinary purposes. We report that P. tenera extract (PTE) enhances the immune response in mouse macrophages. We found that P. tenera extract regulates the NF-κB IκB kinase (IKK) signaling pathway, and we assessed the expression and translocation of p65, a subunit of NF-κB, in RAW264.7 mouse macrophage cells after treatment with PTE. We also investigated the effects of 10% ethanol PTE (PTE10) in RAW264.7 cells. The production of IL-10, IL-6, TNF-α, and IFN-γ was induced by PTE treatment of the macrophages, and PTE also enhanced p-IκB and p-AKT. PTE10 showed no cytotoxicity at 10-20 μg/mL in RAW264.7 cells. PTE10, in fact, increased cell viability at 24 h, stimulated macrophage cells, and induced the phosphorylation of Akt. Akt stimulates IKK activity through the phosphorylation of IKKα and enhances immune activity through the activation of NF-κB. In this study, NF-κB activation was induced by increasing p-NF-κB and p-IKK. A subunit of NF-κB, p65, was located in the nucleus and increased the expression of various cytokines. PTE thus enhanced the immune response through IκB-α immunostimulation signaling in RAW264.7 cells. PTE10 has potential therefore for development of future treatments requiring immune system stimulation.

Functional aspects of the adaptive immune system in arthritis

NARCIS (Netherlands)

Jansen, D.T.S.L.

2017-01-01

The adaptive immune system is the part of the immune system that is highly specific and generates memory resulting in a fast and specific immune response upon a second infection with the same pathogen. However, when this response is specific for a part of the body itself instead of a pathogen,

Bruton's Tyrosine Kinase: An Emerging Key Player in Innate Immunity.

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Weber, Alexander N R; Bittner, Zsofia; Liu, Xiao; Dang, Truong-Minh; Radsak, Markus Philipp; Brunner, Cornelia

2017-01-01

Bruton's tyrosine kinase (BTK) was initially discovered as a critical mediator of B cell receptor signaling in the development and functioning of adaptive immunity. Growing evidence also suggests multiple roles for BTK in mononuclear cells of the innate immune system, especially in dendritic cells and macrophages. For example, BTK has been shown to function in Toll-like receptor-mediated recognition of infectious agents, cellular maturation and recruitment processes, and Fc receptor signaling. Most recently, BTK was additionally identified as a direct regulator of a key innate inflammatory machinery, the NLRP3 inflammasome. BTK has thus attracted interest not only for gaining a more thorough basic understanding of the human innate immune system but also as a target to therapeutically modulate innate immunity. We here review the latest developments on the role of BTK in mononuclear innate immune cells in mouse versus man, with specific emphasis on the sensing of infectious agents and the induction of inflammation. Therapeutic implications for modulating innate immunity and critical open questions are also discussed.

Autopolyreactivity Confers a Holistic Role in the Immune System.

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Avrameas, S

2016-04-01

In this review, we summarize and discuss some key findings from the study of naturally occurring autoantibodies. The B-cell compartment of the immune system appears to recognize almost all endogenous and environmental antigens. This ability is accomplished principally through autopolyreactive humoral and cellular immune receptors. This extended autopolyreactivity (1) along immunoglobulin gene recombination contributes to the immune system's ability to recognize a very large number of self and non-self constituents; and (2) generates a vast immune network that creates communication channels between the organism's interior and exterior. Thus, the immune system continuously evolves depending on the internal and external stimuli it encounters. Furthermore, this far-reaching network's existence implies activities resembling those of classical biological factors or activities that modulate the function of other classical biological factors. A few such antibodies have already been found. Another important concept is that natural autoantibodies are highly dependent on the presence or absence of commensal microbes in the organism. These results are in line with past and recent findings showing the fundamental influence of the microbiota on proper immune system development, and necessitate the existence of a host-microbe homeostasis. This homeostasis requires that the participating humoral and cellular receptors are able to recognize self-antigens and commensal microbes without damaging them. Autopolyreactive immune receptors expressing low affinity for both types of antigens fulfil this role. The immune system appears to play a holistic role similar to that of the nervous system. © 2016 The Foundation for the Scandinavian Journal of Immunology.

Impact of aging immune system on neurodegeneration and potential immunotherapies.

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Liang, Zhanfeng; Zhao, Yang; Ruan, Linhui; Zhu, Linnan; Jin, Kunlin; Zhuge, Qichuan; Su, Dong-Ming; Zhao, Yong

2017-10-01

The interaction between the nervous and immune systems during aging is an area of avid interest, but many aspects remain unclear. This is due, not only to the complexity of the aging process, but also to a mutual dependency and reciprocal causation of alterations and diseases between both the nervous and immune systems. Aging of the brain drives whole body systemic aging, including aging-related changes of the immune system. In turn, the immune system aging, particularly immunosenescence and T cell aging initiated by thymic involution that are sources of chronic inflammation in the elderly (termed inflammaging), potentially induces brain aging and memory loss in a reciprocal manner. Therefore, immunotherapeutics including modulation of inflammation, vaccination, cellular immune therapies and "protective autoimmunity" provide promising approaches to rejuvenate neuroinflammatory disorders and repair brain injury. In this review, we summarize recent discoveries linking the aging immune system with the development of neurodegeneration. Additionally, we discuss potential rejuvenation strategies, focusing aimed at targeting the aging immune system in an effort to prevent acute brain injury and chronic neurodegeneration during aging. Copyright © 2017 Elsevier Ltd. All rights reserved.

Roles of microRNA in the immature immune system of neonates.

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Yu, Hong-Ren; Huang, Lien-Hung; Li, Sung-Chou

2018-06-13

Neonates have an immature immune system; therefore, their immune activities are different from the activities of adult immune systems. Such differences between neonates and adults are reflected by cell population constitutions, immune responses, cytokine production, and the expression of cellular/humoral molecules, which contribute to the specific neonatal microbial susceptibility and atopic properties. MicroRNAs (miRNAs) have been discovered to modulate many aspects of immune responses. Herein, we summarize the distinct manifestations of the neonatal immune system, including cellular and non-cellular components. We also review the current findings on the modulatory effects of miRNAs on the neonatal immune system. These findings suggest that miRNAs have the potential to be useful therapeutic targets for certain infection or inflammatory conditions by modulating the neonatal immune system. In the future, we need a more comprehensive understanding in regard to miRNAs and how they modulate specific immune cells in neonates. Copyright © 2018. Published by Elsevier B.V.

Effects of ionizing radiation on the immune system

International Nuclear Information System (INIS)

Dubois, J.B.

1986-01-01

After reviewing the different lymphoid organs and the essential phases of the immune response, we studied the morphological and functional effects of ionizing radiation on the immunological system. Histologic changes in the lymph nodes, spleen, thymus, and different lymphocyte subpopulations were studied in relation with the radiation dose and irradiated volume (whole body irradiation, localized irradiation). Functional changes in the immune system induced by ionizing radiation were also investigated by a study of humoral-mediated immunity (antibody formation) and cell-mediated immunity (behavior of macrophages, B-cells, T suppressor cells, T helper cells, T effector cells, and natural killer cells). A study into the mechanisms of action of ionizing radiation and the immune processes it interferes with suggests several likely hypotheses (direct action on the immune cells, on their precursors, on seric mediators or on cell mediators). The effects on cancer patients' immune reactions of low radiation doses delivered to the various lymphoid organs are discussed, as well as the relationships between the host and the evolution of the tumor [fr

The role of the adaptive immune system in regulation of gut microbiota.

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Kato, Lucia M; Kawamoto, Shimpei; Maruya, Mikako; Fagarasan, Sidonia

2014-07-01

The gut nourishes rich bacterial communities that affect profoundly the functions of the immune system. The relationship between gut microbiota and the immune system is one of reciprocity. The microbiota contributes to nutrient processing and the development, maturation, and function of the immune system. Conversely, the immune system, particularly the adaptive immune system, plays a key role in shaping the repertoire of gut microbiota. The fitness of host immune system is reflected in the gut microbiota, and deficiencies in either innate or adaptive immunity impact on diversity and structures of bacterial communities in the gut. Here, we discuss the mechanisms that underlie this reciprocity and emphasize how the adaptive immune system via immunoglobulins (i.e. IgA) contributes to diversification and balance of gut microbiota required for immune homeostasis. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Micromanagement of Immune System: Role of miRNAs in Helminthic Infections.

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Arora, Naina; Tripathi, Shweta; Singh, Aloukick K; Mondal, Prosenjit; Mishra, Amit; Prasad, Amit

2017-01-01

Helminthic infections fall under neglected tropical diseases, although they inflict severe morbidity to human and causes major economic burden on health care system in many developing countries. There is increased effort to understand their immunopathology in recent days due to their immuno-modulatory capabilities. Immune response is primarily controlled at the transcriptional level, however, microRNA-mediated RNA interference is emerging as important regulatory machinery that works at the translation level. In the past decade, microRNA (miRNA/miR) research has advanced with significant momentum. The result is ever increasing list of curated sequences from a broad panel of organisms including helminths. Several miRNAs had been discovered from trematodes, nematodes and cestodes like let-7, miR155, miR-199, miR-134, miR-223, miR-146, and fhe-mir-125a etc., with potential role in immune modulation. These miRs had been associated with TGF-β, MAPK, Toll-like receptor, PI3K/AKT signaling pathways and insulin growth factor regulation. Thus, controlling the immune cells development, survival, proliferation and death. Apart from micromanagement of immune system, they also express certain unique miRNA also like cis- miR-001, cis- miR-2, cis- miR-6, cis- miR-10, cis- miR-18, cis- miR-19, trs-mir-0001, fhe-miR-01, fhe-miR-07, fhe-miR-08, egr-miR-4988, egr-miR-4989 etc. The specific role played by most of these species specific unique miRs are yet to be discovered. However, these newly discovered miRNAs might serve as novel targets for therapeutic intervention or biomarkers for parasitic infections.

Obesity, Fat Mass and Immune System: Role for Leptin

Directory of Open Access Journals (Sweden)

Vera Francisco

2018-06-01

Full Text Available Obesity is an epidemic disease characterized by chronic low-grade inflammation associated with a dysfunctional fat mass. Adipose tissue is now considered an extremely active endocrine organ that secretes cytokine-like hormones, called adipokines, either pro- or anti-inflammatory factors bridging metabolism to the immune system. Leptin is historically one of most relevant adipokines, with important physiological roles in the central control of energy metabolism and in the regulation of metabolism-immune system interplay, being a cornerstone of the emerging field of immunometabolism. Indeed, leptin receptor is expressed throughout the immune system and leptin has been shown to regulate both innate and adaptive immune responses. This review discusses the latest data regarding the role of leptin as a mediator of immune system and metabolism, with particular emphasis on its effects on obesity-associated metabolic disorders and autoimmune and/or inflammatory rheumatic diseases.

Influence of Saccharomyces boulardii CNCM I-745 on the gut-associated immune system

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Stier H

2016-09-01

Full Text Available Heike Stier,1 Stephan C Bischoff2 1analyze & realize GmbH, Berlin, 2Department of Clinical Nutrition, University of Hohenheim, Stuttgart, Germany Background: The probiotic Saccharomyces boulardii CNCM I-745 (also known as Saccharomyces cerevisiae HANSEN CBS 5926; in the following S. boulardii has proven its effectiveness in preventive and therapeutic treatment of many gastrointestinal diseases, especially diseases associated with acute diarrhea. In particular, antibiotic-associated diarrhea, Clostridium difficile-associated diarrhea, traveller’s diarrhea, as well as acute diarrhea due to common viral and bacterial infections in children and adults.Aim: The aim of this review is to summarize the experimental studies elucidating the molecular and immunological mechanisms by which these clinically proven effects are archived, with an emphasis on the gut-associated immune system. The main focus is laid on anti-inflammatory and immune-modulatory action of S. boulardii involved in bacterial or enterotoxin-mediated diarrhea and inflammation. An attempt is made to differentiate between the effects associated with cellular versus soluble factors and between prophylactic and therapeutic effects.Methods: A literature search was performed in PubMed/PubMed Central for the effects of S. boulardii on the gut-associated immune system (focus acute diarrhea. Results and conclusion: S. boulardii exhibits its positive effect by the direct effects on pathogens or their toxins as well as by influencing the host’s infection-induced signaling cascades and its innate and adaptive immune system. The combination of these mechanisms results in a reduction of the pathogens’ ability for adhesion or colonization and an attenuation of the overreacting inflammatory immune response. Thereby, the integrity of the intestinal epithelial cell layer is preserved or restored, and the diarrheic leakage of fluids into the intestinal lumen is attenuated. Keywords: mode of action

Immune system modulation in the central nervous system: A possible role for endocannabinoids

International Nuclear Information System (INIS)

Abd-Allah, Adel R.A.

2007-01-01

The immune system is designed to protect the body from infection and tumor formation. To perform this function, cells of the immune system can be dangerous for the survival and function of the neuronal network in the brain under the influence of infection or immune imbalance. An attack of immune cells inside the brain includes the potential for severe neuronal damage or cell death and therefore impairment of the CNS function. To avoid such undesirable action of the immune system, the CNS performs a cascade of cellular and molecular mechanisms enabling strict control of immune reactions i mmune privilege . Under inflammatory and patholological conditions, uncontrolled immune system results in the activation of neuronal damage that is frequently associated with neurological diseases. On the other hand, processes of neuroprotection and neurorepair after neuronal damage depend on a steady and tightly controlled immunesurvelliance. Many immunoprotectants play a role to imbalance the immune reactions in the CNS and other organs which presents an important therapeutic target. It has been reported recently that endocannabinoids are secreted in abundance in the CNS following neuronal insult, probably for its protection. There are at least two types of cannabinoid receptors, CB1 and CB2. Both are coupled to G proteins. CB1 receptors exist primarily on central and peripheral neurons. CB2 receptors are present mainly on immune cells. Endogenous agonists for cannabinoid receptors (endocannabinoids), have been discovered, the most important being arachidonoyl ethanolamide (anandamide), 2-arachidonoyl glycerol (2AG), and 2-archidonyl glyceryl ether. Following their release, endocannabinoids are removed from the extracellular space and then degraded by intracellular enzymic hydrolysis. Therapeutic uses of cannabinoid receptor agonists/antagonists include the management of many disease conditions. They are also involved in immune system suppression and in cell to cell communication

CMV immune evasion and manipulation of the immune system with aging.

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Jackson, Sarah E; Redeker, Anke; Arens, Ramon; van Baarle, Debbie; van den Berg, Sara P H; Benedict, Chris A; Čičin-Šain, Luka; Hill, Ann B; Wills, Mark R

2017-06-01

Human cytomegalovirus (HCMV) encodes numerous proteins and microRNAs that function to evade the immune response and allow the virus to replicate and disseminate in the face of a competent innate and acquired immune system. The establishment of a latent infection by CMV, which if completely quiescent at the level of viral gene expression would represent an ultimate in immune evasion strategies, is not sufficient for lifelong persistence and dissemination of the virus. CMV needs to reactivate and replicate in a lytic cycle of infection in order to disseminate further, which occurs in the face of a fully primed secondary immune response. Without reactivation, latency itself would be redundant for the virus. It is also becoming clear that latency is not a totally quiescent state, but is characterized by limited viral gene expression. Therefore, the virus also needs immune evasion strategies during latency. An effective immune response to CMV is required or viral replication will cause morbidity and ultimately mortality in the host. There is clearly a complex balance between virus immune evasion and host immune recognition over a lifetime. This poses the important question of whether long-term evasion or manipulation of the immune response driven by CMV is detrimental to health. In this meeting report, three groups used the murine model of CMV (MCMV) to examine if the contribution of the virus to immune senescence is set by the (i) initial viral inoculum, (ii) inflation of T cell responses, (iii) or the balance between functionally distinct effector CD4+ T cells. The work of other groups studying the CMV response in humans is discussed. Their work asks whether the ability to make immune responses to new antigens is compromised by (i) age and HCMV carriage, (ii) long-term exposure to HCMV giving rise to an overall immunosuppressive environment and increased levels of latent virus, or (iii) adapted virus mutants (used as potential vaccines) that have the capacity to

Maintenance of systemic immune functions prevents accelerated presbycusis.

Science.gov (United States)

Iwai, Hiroshi; Baba, Susumu; Omae, Mariko; Lee, Shinryu; Yamashita, Toshio; Ikehara, Susumu

2008-05-07

There is no effective therapy for progressive hearing loss such as presbycusis, the causes of which remain poorly understood because of the difficulty of separating genetic and environmental contributions. In the present study, we show that the age-related dysfunctions of the systemic immune system in an animal model of accelerated presbycusis (SAMP1, senescence-accelerated mouse P1) can be corrected by allogeneic bone marrow transplantation (BMT). We also demonstrate that this presbycusis can be prevented; BMT protects the recipients from age-related hearing impairment and the degeneration of spiral ganglion cells (SGCs) as well as the dysfunctions of T lymphocytes, which have a close relation to immune senescence. No donor cells are infiltrated to the spiral ganglia, confirming that this experimental system using BMT is connected to the systemic immune system and does not contribute to transdifferentiation or fusion by donor hematopoietic stem cells (HSCs), or to the direct maintenance of ganglion cells by locally infiltrated donor immunocompetent cells. Therefore, another procedure which attempts to prevent the age-related dysfunctions of the recipient immune system is the inoculation of syngeneic splenocytes from young donors. These mice show no development of hearing loss, compared with the recipient mice with inoculation of saline or splenocytes from old donors. Our studies on the relationship between age-related systemic immune dysfunctions and neurodegeneration mechanisms open up new avenues of treatment for presbycusis, for which there is no effective therapy.

The Immune System: Basis of so much Health and Disease: 4. Immunocytes.

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Scully, Crispian; Georgakopoulou, Eleni A; Hassona, Yazan

2017-05-01

The immune system is the body’s primary defence mechanism against infections, and disturbances in the system can cause disease if the system fails in defence functions (in immunocompromised people), or if the activity is detrimental to the host (as in auto-immune and auto-inflammatory states). A healthy immune system is also essential to normal health of dental and oral tissues. This series presents the basics for the understanding of the immune system, this article covers cells of the immune system (immunocytes). Clinical relevance: Modern dental clinicians need a basic understanding of the immune system as it underlies health and disease.

The Janus face of death receptor signalling during tumour immunoediting.

Directory of Open Access Journals (Sweden)

Eimear O' Reilly

2016-10-01

Full Text Available Cancer immune-surveillance is essential for the inhibition of carcinogenesis. Malignantly transformed cells can be recognised by both the innate and adaptive immune systems through different mechanisms. Immune effector cells induce extrinsic cell death in the identified tumour cells by expressing death ligand cytokines of the tumour necrosis factor ligand family. However, some tumour cells can escape immune elimination and progress. Acquisition of resistance to the death-ligand induced apoptotic pathway can be obtained through cleavage of effector-cell expressed death-ligands into a poorly active form, mutations or silencing of the death receptors or overexpression of decoy receptors and pro-survival proteins. Although the immune system is highly effective in the elimination of malignantly transformed cells, abnormal/ dysfunctional death-ligand signalling curbs its cytotoxicity. Moreover, death receptors can also transmit pro-survival and pro-migratory signals. Consequently, dysfunctional death receptor-mediated apoptosis/necroptosis signalling does not only give a passive resistance against cell death, but actively drives tumour cell motility, invasion and contributes to consequent metastasis. This dual contribution of the death ligand-death receptor signalling in both the early, elimination phase and then in the late, escape phase of the tumour immunoediting process is discussed in this review. Death receptor agonists still hold potential for cancer therapy since they can execute the tumour-eliminating immune-effector function even in the absence of activation of the immune system against the tumour. The opportunities and challenges of developing death receptor agonists into effective cancer therapeutics are also discussed.

Stress proteins and the immune response.

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Moseley, P

2000-07-25

, 243-282.]. This importance in immune regulation is best addressed using Matzinger's model of the immune response - The Danger Theory of Immunity [Matzinger, P., Fuchs, E.J., 1996. Beyond self and non-self: immunity is a conversation, not a war. J. NIH Res. 8, 35-39.]. Matzinger suggests that an immune system model based on the differentiation between "self and non-self" does not easily account for the changes that occur in the organism with growth and development. Why, for example does an organism not self-destruct when the immune system encounters the myriad of new peptides generated at puberty? Instead, she proposes a model of immune function based on the ability to detect and address dangers. This model states that the basic function of all cells of the organism is appropriately timed death "from natural causes". This type of cell death, or apoptosis, generates no stress signals. If, on the other hand, a cell is "murdered" by an infectious agent or dies an untimely death due to necrosis or ischemia, the cell undergoes a stress response with the liberation of stress protein-peptide complexes into the extracellular environment upon cell lysis. Not only do they serve as a "danger signal" to alert the immune system to the death of a cell under stress, but their role as protein carriers allows the immune effector cells to survey the peptides released by this stressed cell and to activate against new or unrecognized peptides carried by the stress protein. Matzinger bases the Danger Theory of Immunity on three "Laws of Lymphotics". These laws state that: (1) resting T lymphocytes require both antigen stimulation by an antigen-presenting cell (APC) and co-stimulation with a danger signal to become activated; (2) the co-stimulatory signal must be received through the APC; and (3) T cells receiving only antigen stimulation without the co-stimulatory signal undergo apoptosis. The Danger Theory gives a simple model for both tolerance and activation. (ABSTRACT TRUNCATED)

[The role of the innate immune system in atopic dermatitis].

Science.gov (United States)

Volz, T; Kaesler, S; Skabytska, Y; Biedermann, T

2015-02-01

The mechanisms how the innate immune system detects microbes and mounts a rapid immune response have been more and more elucidated in the past years. Subsequently it has been shown that innate immunity also shapes adaptive immune responses and determines their quality that can be either inflammatory or tolerogenic. As atopic dermatitis is characterized by disturbances of innate and adaptive immune responses, colonization with pathogens and defects in skin barrier function, insight into mechanisms of innate immunity has helped to understand the vicious circle of ongoing skin inflammation seen in atopic dermatitis patients. Elucidating general mechanisms of the innate immune system and its functions in atopic dermatitis paves the way for developing new therapies. Especially the novel insights into the human microbiome and potential functional consequences make the innate immune system a very fundamental and promising target. As a result atopic dermatitis manifestations can be attenuated or even resolved. These currently developed strategies will be introduced in the current review.

Dissection of SAP-dependent and SAP-independent SLAM family signaling in NKT cell development and humoral immunity

Science.gov (United States)

Cai, Chenxu; Liu, Guangao; Wang, Yuande; Du, Juan; Lin, Xin; Yang, Meixiang

2017-01-01

Signaling lymphocytic activation molecule (SLAM)–associated protein (SAP) mutations in X-linked lymphoproliferative disease (XLP) lead to defective NKT cell development and impaired humoral immunity. Because of the redundancy of SLAM family receptors (SFRs) and the complexity of SAP actions, how SFRs and SAP mediate these processes remains elusive. Here, we examined NKT cell development and humoral immunity in mice completely deficient in SFR. We found that SFR deficiency severely impaired NKT cell development. In contrast to SAP deficiency, SFR deficiency caused no apparent defect in follicular helper T (TFH) cell differentiation. Intriguingly, the deletion of SFRs completely rescued the severe defect in TFH cell generation caused by SAP deficiency, whereas SFR deletion had a minimal effect on the defective NKT cell development in SAP-deficient mice. These findings suggest that SAP-dependent activating SFR signaling is essential for NKT cell selection; however, SFR signaling is inhibitory in SAP-deficient TFH cells. Thus, our current study revises our understanding of the mechanisms underlying T cell defects in patients with XLP. PMID:28049627

Dissection of SAP-dependent and SAP-independent SLAM family signaling in NKT cell development and humoral immunity.

Science.gov (United States)

Chen, Shasha; Cai, Chenxu; Li, Zehua; Liu, Guangao; Wang, Yuande; Blonska, Marzenna; Li, Dan; Du, Juan; Lin, Xin; Yang, Meixiang; Dong, Zhongjun

2017-02-01

Signaling lymphocytic activation molecule (SLAM)-associated protein (SAP) mutations in X-linked lymphoproliferative disease (XLP) lead to defective NKT cell development and impaired humoral immunity. Because of the redundancy of SLAM family receptors (SFRs) and the complexity of SAP actions, how SFRs and SAP mediate these processes remains elusive. Here, we examined NKT cell development and humoral immunity in mice completely deficient in SFR. We found that SFR deficiency severely impaired NKT cell development. In contrast to SAP deficiency, SFR deficiency caused no apparent defect in follicular helper T (T FH ) cell differentiation. Intriguingly, the deletion of SFRs completely rescued the severe defect in T FH cell generation caused by SAP deficiency, whereas SFR deletion had a minimal effect on the defective NKT cell development in SAP-deficient mice. These findings suggest that SAP-dependent activating SFR signaling is essential for NKT cell selection; however, SFR signaling is inhibitory in SAP-deficient T FH cells. Thus, our current study revises our understanding of the mechanisms underlying T cell defects in patients with XLP. © 2017 Chen et al.

Signal transduction by the major histocompatibility complex class I molecule

DEFF Research Database (Denmark)

Pedersen, A E; Skov, Svend; Bregenholt, S

1999-01-01

Ligation of cell surface major histocompatibility class I (MHC-I) proteins by antibodies, or by their native counter receptor, the CD8 molecule, mediates transduction of signals into the cells. MHC-I-mediated signaling can lead to both increased and decreased activity of the MHC-I-expressing cell...... and functioning, MHC-I molecules might be of importance for the maintenance of cellular homeostasis not only within the immune system, but also in the interplay between the immune system and other organ systems....

The effects of early life adversity on the immune system.

Science.gov (United States)

Elwenspoek, Martha M C; Kuehn, Annette; Muller, Claude P; Turner, Jonathan D

2017-08-01

Early life adversity (ELA) is associated with a higher risk for diseases in adulthood. Although the pathophysiological effects of ELA are varied, there may be a unifying role for the immune system in all of the long-term pathologies such as chronic inflammatory disorders (autoimmune diseases, allergy, and asthma). Recently, significant efforts have been made to elucidate the long-term effects ELA has on immune function, as well as the mechanisms underlying these immune changes. In this review, we focus on data from human studies investigating immune parameters in relation to post-natal adverse experiences. We describe the current understanding of the 'ELA immune phenotype', characterized by inflammation, impairment of the cellular immune system, and immunosenescence. However, at present, data addressing specific immune functions are limited and there is a need for high-quality, well powered, longitudinal studies to unravel cause from effect. Besides the immune system, also the stress system and health behaviors are altered in ELA. We discuss probable underlying mechanisms based on epigenetic programming that could explain the ELA immune phenotype and whether this is a direct effect of immune programming or an indirect consequence of changes in behavior or stress reactivity. Understanding the underlying mechanisms will help define effective strategies to prevent or counteract negative ELA-associated outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Immune System in Hypertension

Science.gov (United States)

Trott, Daniel W.; Harrison, David G.

2014-01-01

While hypertension has predominantly been attributed to perturbations of the vasculature, kidney, and central nervous system, research for almost 50 yr has shown that the immune system also contributes to this disease. Inflammatory cells accumulate in the kidneys and vasculature of humans and experimental animals with hypertension and likely…

The Immune System of HIV-Exposed Uninfected Infants.

Science.gov (United States)

Abu-Raya, Bahaa; Kollmann, Tobias R; Marchant, Arnaud; MacGillivray, Duncan M

2016-01-01

Infants born to human immunodeficiency virus (HIV) infected women are HIV-exposed but the majority remains uninfected [i.e., HIV-exposed uninfected (HEU)]. HEU infants suffer greater morbidity and mortality from infections compared to HIV-unexposed (HU) peers. The reason(s) for these worse outcomes are uncertain, but could be related to an altered immune system state. This review comprehensively summarizes the current literature investigating the adaptive and innate immune system of HEU infants. HEU infants have altered cell-mediated immunity, including impaired T-cell maturation with documented hypo- as well as hyper-responsiveness to T-cell activation. And although prevaccination vaccine-specific antibody levels are often lower in HEU than HU, most HEU infants mount adequate humoral immune response following primary vaccination with diphtheria toxoid, haemophilus influenzae type b, whole cell pertussis, measles, hepatitis B, tetanus toxoid, and pneumococcal conjugate vaccines. However, HEU infants are often found to have lower absolute neutrophil counts as compared to HU infants. On the other hand, an increase of innate immune cytokine production and expression of co-stimulatory markers has been noted in HEU infants, but this increase appears to be restricted to the first few weeks of life. The immune system of HEU children beyond infancy remains largely unexplored.

Signals and systems

CERN Document Server

Rao, K Deergha

2018-01-01

This textbook covers the fundamental theories of signals and systems analysis, while incorporating recent developments from integrated circuits technology into its examples. Starting with basic definitions in signal theory, the text explains the properties of continuous-time and discrete-time systems and their representation by differential equations and state space. From those tools, explanations for the processes of Fourier analysis, the Laplace transform, and the z-Transform provide new ways of experimenting with different kinds of time systems. The text also covers the separate classes of analog filters and their uses in signal processing applications. Intended for undergraduate electrical engineering students, chapter sections include exercise for review and practice for the systems concepts of each chapter. Along with exercises, the text includes MATLAB-based examples to allow readers to experiment with signals and systems code on their own. An online repository of the MATLAB code from this textbook can...

Neuroimmune Interactions: From the Brain to the Immune System and Vice Versa.

Science.gov (United States)

Dantzer, Robert

2018-01-01

Because of the compartmentalization of disciplines that shaped the academic landscape of biology and biomedical sciences in the past, physiological systems have long been studied in isolation from each other. This has particularly been the case for the immune system. As a consequence of its ties with pathology and microbiology, immunology as a discipline has largely grown independently of physiology. Accordingly, it has taken a long time for immunologists to accept the concept that the immune system is not self-regulated but functions in close association with the nervous system. These associations are present at different levels of organization. At the local level, there is clear evidence for the production and use of immune factors by the central nervous system and for the production and use of neuroendocrine mediators by the immune system. Short-range interactions between immune cells and peripheral nerve endings innervating immune organs allow the immune system to recruit local neuronal elements for fine tuning of the immune response. Reciprocally, immune cells and mediators play a regulatory role in the nervous system and participate in the elimination and plasticity of synapses during development as well as in synaptic plasticity at adulthood. At the whole organism level, long-range interactions between immune cells and the central nervous system allow the immune system to engage the rest of the body in the fight against infection from pathogenic microorganisms and permit the nervous system to regulate immune functioning. Alterations in communication pathways between the immune system and the nervous system can account for many pathological conditions that were initially attributed to strict organ dysfunction. This applies in particular to psychiatric disorders and several immune-mediated diseases. This review will show how our understanding of this balance between long-range and short-range interactions between the immune system and the central nervous

The Influence of Maternal Prenatal and Early Childhood Nutrition and Maternal Prenatal Stress on Offspring Immune System Development and Neurodevelopmental Disorders

Directory of Open Access Journals (Sweden)

Andrea Horvath Marques

2013-07-01

Full Text Available The developing immune system and central nervous system in the fetus and child are extremely sensitive to both exogenous and endogenous signals. Early immune system programming, leading to changes that can persist over the life course, has been suggested, and other evidence suggests that immune dysregulation in the early developing brain may play a role in neurodevelopmental disorders such as autism spectrum disorder and schizophrenia. The timing of immune dysregulation with respect to gestational age and neurologic development of the fetus may shape the elicited response. This creates a possible sensitive window of programming or vulnerability. This review will explore the effects of prenatal maternal and infant nutritional status (from conception until early childhood as well as prenatal maternal stress and anxiety on early programming of immune function, and how this might influence neurodevelopment. We will describe fetal immune system development and maternal-fetal immune interactions to provide a better context for understanding the influence of nutrition and stress on the immune system. Finally, we will discuss the implications for prevention of neurodevelopmental disorders, with a focus on nutrition. Although certain micronutrient supplements have shown to both reduce the risk of neurodevelopmental disorders and enhance fetal immune development, we do not know whether their impact on immune development contributes to the preventive effect on neurodevelopmental disorders. Future studies are needed to elucidate this relationship, which may contribute to a better understanding of preventative mechanisms. Integrating studies of neurodevelopmental disorders and prenatal exposures with the simultaneous evaluation of neural and immune systems will shed light on mechanisms that underlie individual vulnerability or resilience to neurodevelopmental disorders and ultimately contribute to the development of primary preventions and early

Brain-gut axis and mucosal immunity: a perspective on mucosal psychoneuroimmunology.

LENUS (Irish Health Repository)

Shanahan, F

2012-02-03

The role of the brain-gut axis has traditionally been investigated in relation to intestinal motility, secretion, and vascularity. More recently, the concept of brain-gut dialogue has extended to the relationship between the nervous system and mucosal immune function. There is compelling evidence for a reciprocal or bi-directional communication between the immune system and the neuroendocrine system. This is mediated, in part, by shared ligands (chemical messengers) and receptors that are common to the immune and nervous systems. Although the concept of psychoneuroimmunology and neuroimmune cross-talk has been studied primarily in the context of the systemic immune system, it is likely to have special significance in the gut. The mucosal immune system is anatomically, functionally, and operationally distinct from the systemic immune system and is subject to independent regulatory signals. Furthermore, the intestinal mucosal immune system operates in a local milieu that depends on a dense innervation for its integrity, with juxtaposition of neuroendocrine cells and mucosal immune cells. An overview of evidence for the biologic plausibility of a brain-gut-immune axis is presented and its potential relevance to mucosal inflammatory disorders is discussed.

Role of the Immune System in Hypertension.

Science.gov (United States)

Rodriguez-Iturbe, Bernardo; Pons, Hector; Johnson, Richard J

2017-07-01

High blood pressure is present in more than one billion adults worldwide and is the most important modifiable risk factor of death resulting from cardiovascular disease. While many factors contribute to the pathogenesis of hypertension, a role of the immune system has been firmly established by a large number of investigations from many laboratories around the world. Immunosuppressive drugs and inhibition of individual cytokines prevent or ameliorate experimental hypertension, and studies in genetically-modified mouse strains have demonstrated that lymphocytes are necessary participants in the development of hypertension and in hypertensive organ injury. Furthermore, immune reactivity may be the driving force of hypertension in autoimmune diseases. Infiltration of immune cells, oxidative stress, and stimulation of the intrarenal angiotensin system are induced by activation of the innate and adaptive immunity. High blood pressure results from the combined effects of inflammation-induced impairment in the pressure natriuresis relationship, dysfunctional vascular relaxation, and overactivity of the sympathetic nervous system. Imbalances between proinflammatory effector responses and anti-inflammatory responses of regulatory T cells to a large extent determine the severity of inflammation. Experimental and human studies have uncovered autoantigens (isoketal-modified proteins and heat shock protein 70) of potential clinical relevance. Further investigations on the immune reactivity in hypertension may result in the identification of new strategies for the treatment of the disease. Copyright © 2017 the American Physiological Society.

Bruton’s Tyrosine Kinase: An Emerging Key Player in Innate Immunity

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Alexander N. R. Weber

2017-11-01

Full Text Available Bruton’s tyrosine kinase (BTK was initially discovered as a critical mediator of B cell receptor signaling in the development and functioning of adaptive immunity. Growing evidence also suggests multiple roles for BTK in mononuclear cells of the innate immune system, especially in dendritic cells and macrophages. For example, BTK has been shown to function in Toll-like receptor-mediated recognition of infectious agents, cellular maturation and recruitment processes, and Fc receptor signaling. Most recently, BTK was additionally identified as a direct regulator of a key innate inflammatory machinery, the NLRP3 inflammasome. BTK has thus attracted interest not only for gaining a more thorough basic understanding of the human innate immune system but also as a target to therapeutically modulate innate immunity. We here review the latest developments on the role of BTK in mononuclear innate immune cells in mouse versus man, with specific emphasis on the sensing of infectious agents and the induction of inflammation. Therapeutic implications for modulating innate immunity and critical open questions are also discussed.

The Immune System in Obesity: Developing Paradigms Amidst Inconvenient Truths.

Science.gov (United States)

Agrawal, Madhur; Kern, Philip A; Nikolajczyk, Barbara S

2017-08-15

Adipose tissue (AT) houses both innate and adaptive immune systems that are crucial for preserving AT function and metabolic homeostasis. In this review, we summarize recent information regarding progression of obesity-associated AT inflammation and insulin resistance. We additionally consider alterations in AT distribution and the immune system in males vs. females and among different racial populations. Innate and adaptive immune cell-derived inflammation drives insulin resistance both locally and systemically. However, new evidence also suggests that the immune system is equally vital for adipocyte differentiation and protection from ectopic lipid deposition. Furthermore, roles of anti-inflammatory immune cells such as regulatory T cells, "M2-like" macrophages, eosinophils, and mast cells are being explored, primarily due to promise of immunotherapeutic applications. Both immune responses and AT distribution are strongly influenced by factors like sex and race, which have been largely underappreciated in the field of metabolically-associated inflammation, or meta-flammation. More studies are required to recognize factors that switch inflammation from controlled to uncontrolled in obesity-associated pathogenesis and to integrate the combined effects of meta-flammation and immunometabolism. It is critical to recognize that the AT-associated immune system can be alternately beneficial and destructive; therefore, simply blocking immune responses early in obesity may not be the best clinical approach. The dearth of information on gender and race-associated disparities in metabolism, AT distribution, and the immune system suggest that a greater understanding of such differences will be critical to develop personalized treatments for obesity and the associated metabolic dysfunction.

Systems biology of neutrophil differentiation and immune response

DEFF Research Database (Denmark)

Theilgaard-Mönch, Kim; Porse, Bo T; Borregaard, Niels

2005-01-01

Systems biology has emerged as a new scientific field, which aims at investigating biological processes at the genomic and proteomic levels. Recent studies have unravelled aspects of neutrophil differentiation and immune responses at the systems level using high-throughput technologies. These stu......Systems biology has emerged as a new scientific field, which aims at investigating biological processes at the genomic and proteomic levels. Recent studies have unravelled aspects of neutrophil differentiation and immune responses at the systems level using high-throughput technologies....... These studies have identified a plethora of novel effector proteins stored in the granules of neutrophils. In addition, these studies provide evidence that neutrophil differentiation and immune response are governed by a highly coordinated transcriptional programme that regulates cellular fate and function...

Immune function of a Rab-related protein by modulating the JAK-STAT signaling pathway in the silkworm, Bombyx mori.

Science.gov (United States)

Chen, Chen; Eldein, Salah; Zhou, Xiaosan; Sun, Yu; Gao, Jin; Sun, Yuxuan; Liu, Chaoliang; Wang, Lei

2018-01-01

The Rab-family GTPases mainly regulate intracellular vesicle transport, and play important roles in the innate immune response in invertebrates. However, the function and signal transduction of Rab proteins in immune reactions remain unclear in silkworms. In this study, we analyzed a Rab-related protein of silkworm Bombyx mori (BmRABRP) by raising antibodies against its bacterially expressed recombinant form. Tissue distribution analysis showed that BmRABRP mRNA and protein were high expressed in the Malpighian tubule and fat body, respectively. However, among the different stages, only the fourth instar larvae and pupae showed significant BmRABRP levels. After challenge with four pathogenic microorganisms (Escherichia coli, BmNPV, Beauveria bassiana, Micrococcus luteus), the expression of BmRABRP mRNA in the fat body was significantly upregulated. In contrast, the BmRABRP protein was significantly upregulated after infection with BmNPV, while it was downregulated by E. coli, B. bassiana, and M. luteus. A specific dsRNA was used to explore the immune function and relationship between BmRABRP and the JAK-STAT signaling pathway. After BmRABRP gene interference, significant reduction in the number of nodules and increased mortality suggested that BmRABRP plays an important role in silkworm's response to bacterial challenge. In addition, four key genes (BmHOP, BmSTAT, BmSOCS2, and BmSOCS6) of the JAK-STAT signaling pathway showed significantly altered expressions after BmRABRP silencing. BmHOP and BmSOCS6 expressions were significantly decreased, while BmSTAT and BmSOCS2 were significantly upregulated. Our results suggested that BmRABRP is involved in the innate immune response against pathogenic microorganisms through the JAK-STAT signaling pathway in silkworm. © 2017 Wiley Periodicals, Inc.

Pathogen-secreted proteases activate a novel plant immune pathway.

Science.gov (United States)

Cheng, Zhenyu; Li, Jian-Feng; Niu, Yajie; Zhang, Xue-Cheng; Woody, Owen Z; Xiong, Yan; Djonović, Slavica; Millet, Yves; Bush, Jenifer; McConkey, Brendan J; Sheen, Jen; Ausubel, Frederick M

2015-05-14

Mitogen-activated protein kinase (MAPK) cascades play central roles in innate immune signalling networks in plants and animals. In plants, however, the molecular mechanisms of how signal perception is transduced to MAPK activation remain elusive. Here we report that pathogen-secreted proteases activate a previously unknown signalling pathway in Arabidopsis thaliana involving the Gα, Gβ, and Gγ subunits of heterotrimeric G-protein complexes, which function upstream of an MAPK cascade. In this pathway, receptor for activated C kinase 1 (RACK1) functions as a novel scaffold that binds to the Gβ subunit as well as to all three tiers of the MAPK cascade, thereby linking upstream G-protein signalling to downstream activation of an MAPK cascade. The protease-G-protein-RACK1-MAPK cascade modules identified in these studies are distinct from previously described plant immune signalling pathways such as that elicited by bacterial flagellin, in which G proteins function downstream of or in parallel to an MAPK cascade without the involvement of the RACK1 scaffolding protein. The discovery of the new protease-mediated immune signalling pathway described here was facilitated by the use of the broad host range, opportunistic bacterial pathogen Pseudomonas aeruginosa. The ability of P. aeruginosa to infect both plants and animals makes it an excellent model to identify novel immunoregulatory strategies that account for its niche adaptation to diverse host tissues and immune systems.

Evolution and integration of innate immune systems from fruit flies to man: lessons and questions.

Science.gov (United States)

Martinelli, Cosimo; Reichhart, Jean-Marc

2005-01-01

Despite broad differences in morphology, ecology and behavior, the fruit fly Drosophila melanogaster and humans show a remarkably high degree of conservation for many molecular, cellular, and developmental aspects of their biology. During the last decade, similarities have also been discovered in some of the mechanisms regulating their innate immune system. These parallels regard mainly the Toll-like receptor family and the intracellular signaling pathways involved in the control of the immune response. However, if the overall similarities are important, the detailed pathogen recognition mechanisms differ significantly between fly and humans, highlighting a complicated evolutionary history of the metazoan innate defenses. In this review, we will discuss the main similarities and differences between the two types of organisms. We hope that this current knowledge will be used as a starting point for a more comprehensive view of innate immunity within the broad variety of metazoan phyla.

Intestinal bacteria and the regulation of immune cell homeostasis.

Science.gov (United States)

Hill, David A; Artis, David

2010-01-01

The human intestine is colonized by an estimated 100 trillion bacteria. Some of these bacteria are essential for normal physiology, whereas others have been implicated in the pathogenesis of multiple inflammatory diseases including IBD and asthma. This review examines the influence of signals from intestinal bacteria on the homeostasis of the mammalian immune system in the context of health and disease. We review the bacterial composition of the mammalian intestine, known bacterial-derived immunoregulatory molecules, and the mammalian innate immune receptors that recognize them. We discuss the influence of bacterial-derived signals on immune cell function and the mechanisms by which these signals modulate the development and progression of inflammatory disease. We conclude with an examination of successes and future challenges in using bacterial communities or their products in the prevention or treatment of human disease.

Targeting the Immune System to Fight Cancer Using Chemical Receptor Homing Vectors Carrying Polyinosine/Cytosine (PolyIC)

International Nuclear Information System (INIS)

Levitzki, Alexander

2012-01-01

Cancer researchers have been looking for ways to harness the immune system and to reinstate immune surveillance, to kill cancer cells without collateral damage. Here we scan current approaches to targeting the immune system against cancer, and emphasize our own approach. We are using chemical vectors attached to a specific ligand, to introduce synthetic dsRNA, polyinosine/cytosine (polyIC), into tumors. The ligand binds to a receptor protein that is overexpressed on the surface of the tumor cells. Upon ligand binding, the receptor complex is internalized, introducing the polyIC into the cell. In this fashion a large amount of synthetic dsRNA can be internalized, leading to the activation of dsRNA-binding proteins, such as dsRNA dependent protein kinase (PKR), Toll-like receptor 3 (TLR3), retinoic acid-inducible gene I (RIG-1), and melanoma differentiation-associated gene 5 (MDA5). The simultaneous activation of these signaling proteins leads to the rapid demise of the targeted cell and to cytokine secretion. The cytokines lead to a strong bystander effect and to the recruitment of immune cells that converge upon the targeted cells. The bystander effects lead to the destruction of neighboring tumor cells not targeted themselves by the vector. Normal cells, being more robust than tumor cells, survive. This strategy has several advantages: (1) recruitment of the immune system is localized to the tumor. (2) The response is rapid, leading to fast tumor eradication. (3) The bystander effects lead to the eradication of tumor cells not harboring the target. (4) The multiplicity of pro-death signaling pathways elicited by PolyIC minimizes the likelihood of the emergence of resistance. In this chapter we focus on EGFR as the targeted receptor, which is overexpressed in many tumors. In principle, the strategy can be extended to other tumors that overexpress a protein that can be internalized by a ligand, which can be a small molecule, a single chain antibody, or an affibody.

Systemic activation of the immune system in HIV infection: The role of the immune complexes (hypothesis).

Science.gov (United States)

Korolevskaya, Larisa B; Shmagel, Konstantin V; Shmagel, Nadezhda G; Saidakova, Evgeniya V

2016-03-01

Currently, immune activation is proven to be the basis for the HIV infection pathogenesis and a strong predictor of the disease progression. Among the causes of systemic immune activation the virus and its products, related infectious agents, pro-inflammatory cytokines, and regulatory CD4+ T cells' decrease are considered. Recently microbial translocation (bacterial products yield into the bloodstream as a result of the gastrointestinal tract mucosal barrier integrity damage) became the most popular hypothesis. Previously, we have found an association between immune complexes present in the bloodstream of HIV infected patients and the T cell activation. On this basis, we propose a significantly modified hypothesis of immune activation in HIV infection. It is based on the immune complexes' participation in the immunocompetent cells' activation. Immune complexes are continuously formed in the chronic phase of the infection. Together with TLR-ligands (viral antigens, bacterial products coming from the damaged gut) present in the bloodstream they interact with macrophages. As a result macrophages are transformed into the type II activated forms. These macrophages block IL-12 production and start synthesizing IL-10. High level of this cytokine slows down the development of the full-scale Th1-response. The anti-viral reactions are shifted towards the serogenesis. Newly synthesized antibodies' binding to viral antigens leads to continuous formation of the immune complexes capable of interacting with antigen-presenting cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

Probiotic Modulation of Innate Cell Pathogen Sensing and Signaling Events

Directory of Open Access Journals (Sweden)

Amy Llewellyn

2017-10-01

Full Text Available There is a growing body of evidence documenting probiotic bacteria to have a beneficial effect to the host through their ability to modulate the mucosal immune system. Many probiotic bacteria can be considered to act as either immune activators or immune suppressors, which have appreciable influence on homeostasis, inflammatory- and suppressive-immunopathology. What is becoming apparent is the ability of these probiotics to modulate innate immune responses via direct or indirect effects on the signaling pathways that drive these activatory or suppressive/tolerogenic mechanisms. This review will focus on the immunomodulatory role of probiotics on signaling pathways in innate immune cells: from positive to negative regulation associated with innate immune cells driving gut mucosal functionality. Research investigations have shown probiotics to modulate innate functionality in many ways including, receptor antagonism, receptor expression, binding to and expression of adaptor proteins, expression of negative regulatory signal molecules, induction of micro-RNAs, endotoxin tolerisation and finally, the secretion of immunomodulatory proteins, lipids and metabolites. The detailed understanding of the immunomodulatory signaling effects of probiotic strains will facilitate strain-specific selective manipulation of innate cell signal mechanisms in the modulation of mucosal adjuvanticity, immune deviation and tolerisation in both healthy subjects and patients with inflammatory and suppressive pathology.

Probiotic Modulation of Innate Cell Pathogen Sensing and Signaling Events

Science.gov (United States)

Llewellyn, Amy; Foey, Andrew

2017-01-01

There is a growing body of evidence documenting probiotic bacteria to have a beneficial effect to the host through their ability to modulate the mucosal immune system. Many probiotic bacteria can be considered to act as either immune activators or immune suppressors, which have appreciable influence on homeostasis, inflammatory- and suppressive-immunopathology. What is becoming apparent is the ability of these probiotics to modulate innate immune responses via direct or indirect effects on the signaling pathways that drive these activatory or suppressive/tolerogenic mechanisms. This review will focus on the immunomodulatory role of probiotics on signaling pathways in innate immune cells: from positive to negative regulation associated with innate immune cells driving gut mucosal functionality. Research investigations have shown probiotics to modulate innate functionality in many ways including, receptor antagonism, receptor expression, binding to and expression of adaptor proteins, expression of negative regulatory signal molecules, induction of micro-RNAs, endotoxin tolerisation and finally, the secretion of immunomodulatory proteins, lipids and metabolites. The detailed understanding of the immunomodulatory signaling effects of probiotic strains will facilitate strain-specific selective manipulation of innate cell signal mechanisms in the modulation of mucosal adjuvanticity, immune deviation and tolerisation in both healthy subjects and patients with inflammatory and suppressive pathology. PMID:29065562

Modulating the immune system through nanotechnology.

Science.gov (United States)

Dacoba, Tamara G; Olivera, Ana; Torres, Dolores; Crecente-Campo, José; Alonso, María José

2017-12-01

Nowadays, nanotechnology-based modulation of the immune system is presented as a cutting-edge strategy, which may lead to significant improvements in the treatment of severe diseases. In particular, efforts have been focused on the development of nanotechnology-based vaccines, which could be used for immunization or generation of tolerance. In this review, we highlight how different immune responses can be elicited by tuning nanosystems properties. In addition, we discuss specific formulation approaches designed for the development of anti-infectious and anti-autoimmune vaccines, as well as those intended to prevent the formation of antibodies against biologicals. Copyright © 2017 Elsevier Ltd. All rights reserved.

Immune mediated liver failure.

Science.gov (United States)

Wang, Xiaojing; Ning, Qin

2014-01-01

Liver failure is a clinical syndrome of various etiologies, manifesting as jaundice, encephalopathy, coagulopathy and circulatory dysfunction, which result in subsequent multiorgan failure. Clinically, liver failure is classified into four categories: acute, subacute, acute-on-chronic and chronic liver failure. Massive hepatocyte death is considered to be the core event in the development of liver failure, which occurs when the extent of hepatocyte death is beyond the liver regenerative capacity. Direct damage and immune-mediated liver injury are two major factors involved in this process. Increasing evidence has suggested the essential role of immune-mediated liver injury in the pathogenesis of liver failure. Here, we review the evolved concepts concerning the mechanisms of immune-mediated liver injury in liver failure from human and animal studies. Both innate and adaptive immunity, especially the interaction of various immune cells and molecules as well as death receptor signaling system are discussed. In addition, we highlight the concept of "immune coagulation", which has been shown to be related to the disease progression and liver injury exacerbation in HBV related acute-on-chronic liver failure.

Molecular and Functional Neuroscience in Immunity.

Science.gov (United States)

Pavlov, Valentin A; Chavan, Sangeeta S; Tracey, Kevin J

2018-04-26

The nervous system regulates immunity and inflammation. The molecular detection of pathogen fragments, cytokines, and other immune molecules by sensory neurons generates immunoregulatory responses through efferent autonomic neuron signaling. The functional organization of this neural control is based on principles of reflex regulation. Reflexes involving the vagus nerve and other nerves have been therapeutically explored in models of inflammatory and autoimmune conditions, and recently in clinical settings. The brain integrates neuro-immune communication, and brain function is altered in diseases characterized by peripheral immune dysregulation and inflammation. Here we review the anatomical and molecular basis of the neural interface with immunity, focusing on peripheral neural control of immune functions and the role of the brain in the model of the immunological homunculus. Clinical advances stemming from this knowledge within the framework of bioelectronic medicine are also briefly outlined.

Regional specialization within the intestinal immune system

DEFF Research Database (Denmark)

Mowat, Allan M.; Agace, William Winston

2014-01-01

The intestine represents the largest compartment of the immune system. It is continually exposed to antigens and immunomodulatory agents from the diet and the commensal microbiota, and it is the port of entry for many clinically important pathogens. Intestinal immune processes are also increasingly...... implicated in controlling disease development elsewhere in the body. In this Review, we detail the anatomical and physiological distinctions that are observed in the small and large intestines, and we suggest how these may account for the diversity in the immune apparatus that is seen throughout...... the intestine. We describe how the distribution of innate, adaptive and innate-like immune cells varies in different segments of the intestine and discuss the environmental factors that may influence this. Finally, we consider the implications of regional immune specialization for inflammatory disease...

Direct and Electronic Health Record Access to the Clinical Decision Support for Immunizations in the Minnesota Immunization Information System.

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Rajamani, Sripriya; Bieringer, Aaron; Wallerius, Stephanie; Jensen, Daniel; Winden, Tamara; Muscoplat, Miriam Halstead

2016-01-01

Immunization information systems (IIS) are population-based and confidential computerized systems maintained by public health agencies containing individual data on immunizations from participating health care providers. IIS hold comprehensive vaccination histories given across providers and over time. An important aspect to IIS is the clinical decision support for immunizations (CDSi), consisting of vaccine forecasting algorithms to determine needed immunizations. The study objective was to analyze the CDSi presentation by IIS in Minnesota (Minnesota Immunization Information Connection [MIIC]) through direct access by IIS interface and by access through electronic health records (EHRs) to outline similarities and differences. The immunization data presented were similar across the three systems examined, but with varying ability to integrate data across MIIC and EHR, which impacts immunization data reconciliation. Study findings will lead to better understanding of immunization data display, clinical decision support, and user functionalities with the ultimate goal of promoting IIS CDSi to improve vaccination rates.

Interleukin-1 and cutaneous inflammation: a crucial link between innate and acquired immunity.

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Murphy, J E; Robert, C; Kupper, T S

2000-03-01

As our primary interface with the environment, the skin is constantly subjected to injury and invasion by pathogens. The fundamental force driving the evolution of the immune system has been the need to protect the host against overwhelming infection. The ability of T and B cells to recombine antigen receptor genes during development provides an efficient, flexible, and powerful immune system with nearly unlimited specificity for antigen. The capacity to expand subsets of antigen-specific lymphocytes that become activated by environmental antigens (memory response) is termed "acquired" immunity. Immunologic memory, although a fundamental aspect of mammalian biology, is a relatively recent evolutionary event that permits organisms to live for years to decades. "Innate" immunity, mediated by genes that remain in germ line conformation and encode for proteins that recognize conserved structural patterns on microorganisms, is a much more ancient system of host defense. Defensins and other antimicrobial peptides, complement and opsonins, and endocytic receptors are all considered components of the innate immune system. None of these, however, are signal-transducing receptors. Most recently, a large family of cell surface receptors that mediate signaling through the NF-kappaB transcription factor has been identified. This family of proteins shares striking homology with plant and Drosophila genes that mediate innate immunity. In mammals, this family includes the type I interleukin-1 receptor, the interleukin-18 receptor, and a growing family of Toll-like receptors, two of which were recently identified as signal-transducing receptors for bacterial endotoxin. In this review, we discuss how interleukin-1 links the innate and acquired immune systems to provide synergistic host defense activities in skin.

Innate and intrinsic antiviral immunity in skin.

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Kawamura, Tatsuyoshi; Ogawa, Youichi; Aoki, Rui; Shimada, Shinji

2014-09-01

As the body's most exposed interface with the environment, the skin is constantly challenged by potentially pathogenic microbes, including viruses. To sense the invading viruses, various types of cells resident in the skin express many different pattern-recognition receptors (PRRs) such as C-type lectin receptors (CLRs), Toll-like receptors (TLRs), nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs), retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs) and cytosolic DNA sensors, that can detect the pathogen-associated molecular patterns (PAMPs) of the viruses. The detection of viral PAMPs initiates two major innate immune signaling cascades: the first involves the activation of the downstream transcription factors, such as interferon regulatory factors (IRFs), nuclear factor kappa B (NF-κB) and activator protein 1 (AP-1), which cooperate to induce the transcription of type I interferons and pro-inflammatory cytokines. The second signaling pathway involves the caspase-1-mediated processing of IL-1β and IL-18 through the formation of an inflammasome complex. Cutaneous innate immunity including the production of the innate cytokines constitutes the first line of host defence that limits the virus dissemination from the skin, and also plays an important role in the activation of adaptive immune response, which represents the second line of defence. More recently, the third immunity "intrinsic immunity" has emerged, that provides an immediate and direct antiviral defense mediated by host intrinsic restriction factors. This review focuses on the recent advances regarding the antiviral immune systems, highlighting the innate and intrinsic immunity against the viral infections in the skin, and describes how viral components are recognized by cutaneous immune systems. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Effects of prebiotics on immune system and cytokine expression.

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Shokryazdan, Parisa; Faseleh Jahromi, Mohammad; Navidshad, Bahman; Liang, Juan Boo

2017-02-01

Nowadays, use of prebiotics as feed and food additives has received increasing interest because of the beneficial effects of prebiotics on the health of animals and humans. One of the beneficial effects of prebiotics is stimulation of immune system, which can be direct or indirect through increasing population of beneficial microbes or probiotics, especially lactic acid bacteria and bifidobacteria, in the gut. An important mechanism of action of probiotics and prebiotics, by which they can affect the immune system, is changing the expression of cytokines. The present review tried to summarize the findings of studies that investigated the effects of prebiotics on immune system with focusing on their effects on cytokine expression. Generally, most of reviewed studies indicated beneficial effects for prebiotics in terms of improving immune system, by increasing the expression of anti-inflammatory cytokines, while reducing the expressions of proinflammatory cytokines. However, most of studies mainly considered the indirect effects of prebiotics on the immune system (through changing the composition and population of gut microbiota), and their direct effects still need to be further studied using prebiotics with different degree of polymerization in different hosts.

Thermodynamics as the driving principle behind the immune system

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Eduardo Finger

2012-09-01

Full Text Available Over the last 120 years, few things contributed more to ourunderstanding of immune system than the study of its behavior inthe host/parasite relationship. Despite the advances though, a fewquestions remain, such as what drives the immune system? Whatare its guiding principles? If we ask these questions randomly, mostwill immediately answer “defend the body from external threats,” butwhat exactly do we defend ourselves from? How do these threatsharm us? What criteria define what constitutes a threat? On theother hand, if the immune system evolved to defend us againstexternal threats, how does its action against “internal” processes,such as neoplasms, qualify? Why do we die from cancer? Or frominfection? Or even, why do we die at all? These apparently obviousquestions are nor simple neither trivial, and the difficulty answeringthem reveals the complex reality that the immune system handles.The objective of this article is to articulate for the reader something that he instinctively already knows: that the decisions of the immune system are thermodynamically driven. Additionally, we will discuss how this apparent change in paradigm alters concepts such as health, disease, and therapeutics.

Artificial immune system applications in computer security

CERN Document Server

Tan, Ying

2016-01-01

This book provides state-of-the-art information on the use, design, and development of the Artificial Immune System (AIS) and AIS-based solutions to computer security issues. Artificial Immune System: Applications in Computer Security focuses on the technologies and applications of AIS in malware detection proposed in recent years by the Computational Intelligence Laboratory of Peking University (CIL@PKU). It offers a theoretical perspective as well as practical solutions for readers interested in AIS, machine learning, pattern recognition and computer security. The book begins by introducing the basic concepts, typical algorithms, important features, and some applications of AIS. The second chapter introduces malware and its detection methods, especially for immune-based malware detection approaches. Successive chapters present a variety of advanced detection approaches for malware, including Virus Detection System, K-Nearest Neighbour (KNN), RBF networ s, and Support Vector Machines (SVM), Danger theory, ...

Single-cell technologies to study the immune system.

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Proserpio, Valentina; Mahata, Bidesh

2016-02-01

The immune system is composed of a variety of cells that act in a coordinated fashion to protect the organism against a multitude of different pathogens. The great variability of existing pathogens corresponds to a similar high heterogeneity of the immune cells. The study of individual immune cells, the fundamental unit of immunity, has recently transformed from a qualitative microscopic imaging to a nearly complete quantitative transcriptomic analysis. This shift has been driven by the rapid development of multiple single-cell technologies. These new advances are expected to boost the detection of less frequent cell types and transient or intermediate cell states. They will highlight the individuality of each single cell and greatly expand the resolution of current available classifications and differentiation trajectories. In this review we discuss the recent advancement and application of single-cell technologies, their limitations and future applications to study the immune system. © 2015 The Authors. Immunology Published by John Wiley & Sons Ltd.

Cannabinoids and Innate Immunity: Taking a Toll on Neuroinflammation

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Eric J. Downer

2011-01-01

Full Text Available The biologically active components of cannabis have therapeutic potential in neuroinflammatory disorders due to their anti-inflammatory propensity. Cannabinoids influence immune function in both the peripheral and the central nervous system (CNS, and the components of the cannabinoid system, the cannabinoid receptors and their endogenous ligands (endocannabinoids, have been detected on immune cells as well as in brain glia. Neuroinflammation is the complex innate immune response of neural tissue to control infection and eliminate pathogens, and Toll-like receptors (TLRs, a major family of pattern recognition receptors (PRRs that mediate innate immunity, have emerged as players in the neuroinflammatory processes underpinning various CNS diseases. This review will highlight evidence that cannabinoids interact with the immune system by impacting TLR-mediated signaling events, which may provide cues for devising novel therapeutic approaches for cannabinoid ligands.

Modulation of immune homeostasis by commensal bacteria

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Ivanov, Ivaylo I.; Littman, Dan R.

2011-01-01

Intestinal bacteria form a resident community that has co-evolved with the mammalian host. In addition to playing important roles in digestion and harvesting energy, commensal bacteria are crucial for the proper functioning of mucosal immune defenses. Most of these functions have been attributed to the presence of large numbers of “innocuous” resident bacteria that dilute or occupy niches for intestinal pathogens or induce innate immune responses that sequester bacteria in the lumen, thus quenching excessive activation of the mucosal immune system. However it has recently become obvious that commensal bacteria are not simply beneficial bystanders, but are important modulators of intestinal immune homeostasis and that the composition of the microbiota is a major factor in pre-determining the type and robustness of mucosal immune responses. Here we review specific examples of individual members of the microbiota that modify innate and adaptive immune responses, and we focus on potential mechanisms by which such species-specific signals are generated and transmitted to the host immune system. PMID:21215684

Mind-Body Medicine and Immune System Outcomes: A Systematic Review

OpenAIRE

Wahbeh, Helané; Haywood, Ashley; Kaufman, Karen; Zwickey, Heather

2009-01-01

This study is a systematic review of mind-body interventions that used immune outcomes in order to: 1) characterize mind-body medicine studies that assessed immune outcomes, 2) evaluate the quality of mind-body medicine studies measuring immune system effects, and 3) systematically evaluate the evidence for mind-body interventions effect on immune system outcomes using existing formal tools. 111 studies with 4,777 subjects were reviewed. The three largest intervention type categories were Rel...

The role of idiotypic interactions in the adaptive immune system: a belief-propagation approach

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Bartolucci, Silvia; Mozeika, Alexander; Annibale, Alessia

2016-08-01

In this work we use belief-propagation techniques to study the equilibrium behaviour of a minimal model for the immune system comprising interacting T and B clones. We investigate the effect of the so-called idiotypic interactions among complementary B clones on the system’s activation. Our results show that B-B interactions increase the system’s resilience to noise, making clonal activation more stable, while increasing the cross-talk between different clones. We derive analytically the noise level at which a B clone gets activated, in the absence of cross-talk, and find that this increases with the strength of idiotypic interactions and with the number of T cells sending signals to the B clones. We also derive, analytically and numerically, via population dynamics, the critical line where clonal cross-talk arises. Our approach allows us to derive the B clone size distribution, which can be experimentally measured and gives important information about the adaptive immune system response to antigens and vaccination.

Behavioural conditioning of immune functions: how the central nervous system controls peripheral immune responses by evoking associative learning processes.

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Riether, Carsten; Doenlen, Raphaël; Pacheco-López, Gustavo; Niemi, Maj-Britt; Engler, Andrea; Engler, Harald; Schedlowski, Manfred

2008-01-01

During the last 30 years of psychoneuroimmunology research the intense bi-directional communication between the central nervous system (CNS) and the immune system has been demonstrated in studies on the interaction between the nervous-endocrine-immune systems. One of the most intriguing examples of such interaction is the capability of the CNS to associate an immune status with specific environmental stimuli. In this review, we systematically summarize experimental evidence demonstrating the behavioural conditioning of peripheral immune functions. In particular, we focus on the mechanisms underlying the behavioural conditioning process and provide a theoretical framework that indicates the potential feasibility of behaviourally conditioned immune changes in clinical situations.

Multiscale modeling of mucosal immune responses

Science.gov (United States)

2015-01-01

Computational modeling techniques are playing increasingly important roles in advancing a systems-level mechanistic understanding of biological processes. Computer simulations guide and underpin experimental and clinical efforts. This study presents ENteric Immune Simulator (ENISI), a multiscale modeling tool for modeling the mucosal immune responses. ENISI's modeling environment can simulate in silico experiments from molecular signaling pathways to tissue level events such as tissue lesion formation. ENISI's architecture integrates multiple modeling technologies including ABM (agent-based modeling), ODE (ordinary differential equations), SDE (stochastic modeling equations), and PDE (partial differential equations). This paper focuses on the implementation and developmental challenges of ENISI. A multiscale model of mucosal immune responses during colonic inflammation, including CD4+ T cell differentiation and tissue level cell-cell interactions was developed to illustrate the capabilities, power and scope of ENISI MSM. Background Computational techniques are becoming increasingly powerful and modeling tools for biological systems are of greater needs. Biological systems are inherently multiscale, from molecules to tissues and from nano-seconds to a lifespan of several years or decades. ENISI MSM integrates multiple modeling technologies to understand immunological processes from signaling pathways within cells to lesion formation at the tissue level. This paper examines and summarizes the technical details of ENISI, from its initial version to its latest cutting-edge implementation. Implementation Object-oriented programming approach is adopted to develop a suite of tools based on ENISI. Multiple modeling technologies are integrated to visualize tissues, cells as well as proteins; furthermore, performance matching between the scales is addressed. Conclusion We used ENISI MSM for developing predictive multiscale models of the mucosal immune system during gut

Multiscale modeling of mucosal immune responses.

Science.gov (United States)

Mei, Yongguo; Abedi, Vida; Carbo, Adria; Zhang, Xiaoying; Lu, Pinyi; Philipson, Casandra; Hontecillas, Raquel; Hoops, Stefan; Liles, Nathan; Bassaganya-Riera, Josep

2015-01-01

Computational techniques are becoming increasingly powerful and modeling tools for biological systems are of greater needs. Biological systems are inherently multiscale, from molecules to tissues and from nano-seconds to a lifespan of several years or decades. ENISI MSM integrates multiple modeling technologies to understand immunological processes from signaling pathways within cells to lesion formation at the tissue level. This paper examines and summarizes the technical details of ENISI, from its initial version to its latest cutting-edge implementation. Object-oriented programming approach is adopted to develop a suite of tools based on ENISI. Multiple modeling technologies are integrated to visualize tissues, cells as well as proteins; furthermore, performance matching between the scales is addressed. We used ENISI MSM for developing predictive multiscale models of the mucosal immune system during gut inflammation. Our modeling predictions dissect the mechanisms by which effector CD4+ T cell responses contribute to tissue damage in the gut mucosa following immune dysregulation.Computational modeling techniques are playing increasingly important roles in advancing a systems-level mechanistic understanding of biological processes. Computer simulations guide and underpin experimental and clinical efforts. This study presents ENteric Immune Simulator (ENISI), a multiscale modeling tool for modeling the mucosal immune responses. ENISI's modeling environment can simulate in silico experiments from molecular signaling pathways to tissue level events such as tissue lesion formation. ENISI's architecture integrates multiple modeling technologies including ABM (agent-based modeling), ODE (ordinary differential equations), SDE (stochastic modeling equations), and PDE (partial differential equations). This paper focuses on the implementation and developmental challenges of ENISI. A multiscale model of mucosal immune responses during colonic inflammation, including CD4+ T

Sphingosine-1-Phosphate Signaling in Immune Cells and Inflammation: Roles and Therapeutic Potential

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Masayo Aoki

2016-01-01

Full Text Available Sphingosine-1-phosphate (S1P is a bioactive sphingolipid metabolite involved in many critical cell processes. It is produced by the phosphorylation of sphingosine by sphingosine kinases (SphKs and exported out of cells via transporters such as spinster homolog 2 (Spns2. S1P regulates diverse physiological processes by binding to specific G protein-binding receptors, S1P receptors (S1PRs 1–5, through a process coined as “inside-out signaling.” The S1P concentration gradient between various tissues promotes S1PR1-dependent migration of T cells from secondary lymphoid organs into the lymphatic and blood circulation. S1P suppresses T cell egress from and promotes retention in inflamed peripheral tissues. S1PR1 in T and B cells as well as Spns2 in endothelial cells contributes to lymphocyte trafficking. FTY720 (Fingolimod is a functional antagonist of S1PRs that induces systemic lymphopenia by suppression of lymphocyte egress from lymphoid organs. In this review, we summarize previous findings and new discoveries about the importance of S1P and S1PR signaling in the recruitment of immune cells and lymphocyte retention in inflamed tissues. We also discuss the role of S1P-S1PR1 axis in inflammatory diseases and wound healing.

Systems biology of host-mycobiota interactions: dissecting Dectin-1 and Dectin-2 signalling in immune cells with DC-ATLAS.

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Rizzetto, Lisa; De Filippo, Carlotta; Rivero, Damariz; Riccadonna, Samantha; Beltrame, Luca; Cavalieri, Duccio

2013-11-01

Modelling the networks sustaining the fruitful coexistence between fungi and their mammalian hosts is becoming increasingly important to control emerging fungal pathogens. The C-type lectins Dectin-1 and Dectin-2 are involved in host defense mechanisms against fungal infection driving inflammatory and adaptive immune responses and complement in containing fungal burdens. Recognizing carbohydrate structures in pathogens, their engagement induces maturation of dendritic cells (DCs) into potent immuno-stimulatory cells endowed with the capacity to efficiently prime T cells. Owing to these properties, Dectin-1 and Dectin-2 agonists are currently under investigation as promising adjuvants in vaccination procedures for the treatment of fungal infection. Thus, a detailed understanding of events' cascade specifically triggered in DCs upon engagement is of great interest in translational research. Here, we summarize the current knowledge on Dectin-1 and Dectin-2 signalling in DCs highlighting similarities and differences. Detailed maps are annotated, using the Biological Connection Markup Language (BCML) data model, and stored in DC-ATLAS, a versatile resource for the interpretation of high-throughput data generated perturbing the signalling network of DCs. Copyright © 2013 Elsevier GmbH. All rights reserved.

Rational modulation of the innate immune system for neuroprotection in ischemic stroke

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Diana eAmantea

2015-04-01

Full Text Available The innate immune system plays a dualistic role in the evolution of ischemic brain damage and has also been implicated in ischemic tolerance produced by different conditioning stimuli. Early after ischemia, perivascular astrocytes release cytokines and activate metalloproteases (MMPs that contribute to blood–brain barrier (BBB disruption and vasogenic oedema; whereas at later stages, they provide extracellular glutamate uptake, BBB regeneration and neurotrophic factors release. Similarly, early activation of microglia contributes to ischemic brain injury via the production of inflammatory cytokines, including tumor necrosis factor (TNF and interleukin (IL-1, reactive oxygen and nitrogen species and proteases. Nevertheless, microglia also contributes to the resolution of inflammation, by releasing IL-10 and tumor growth factor (TGF-beta, and to the late reparative processes by phagocytic activity and growth factors production. Indeed, after ischemia, microglia/macrophages differentiate towards several phenotypes: the M1 pro-inflammatory phenotype is classically activated via toll-like receptors or interferon-γ, whereas M2 phenotypes are alternatively activated by regulatory mediators, such as ILs 4, 10, 13 or TGF-beta. Thus, immune cells exert a dualistic role on the evolution of ischemic brain damage, since the classic phenotypes promote injury, whereas alternatively activated M2 macrophages or N2 neutrophils prompt tissue remodeling and repair.Moreover, a subdued activation of the immune system has been involved in ischemic tolerance, since different preconditioning stimuli act via modulation of inflammatory mediators, including toll-like receptors and cytokine signaling pathways. This further underscores that the immuno-modulatory approach for the treatment of ischemic stroke should be aimed at blocking the detrimental effects, while promoting the beneficial responses of the immune reaction.

The role of immune system exhaustion on cancer cell escape and anti-tumor immune induction after irradiation.

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Mendes, Fernando; Domingues, Cátia; Rodrigues-Santos, Paulo; Abrantes, Ana Margarida; Gonçalves, Ana Cristina; Estrela, Jéssica; Encarnação, João; Pires, Ana Salomé; Laranjo, Mafalda; Alves, Vera; Teixo, Ricardo; Sarmento, Ana Bela; Botelho, Maria Filomena; Rosa, Manuel Santos

2016-04-01

Immune surveillance seems to represent an effective tumor suppressor mechanism. However, some cancer cells survive and become variants, being poorly immunogenic and able to enter a steady-state phase. These cells become functionally dormant or remain hidden clinically throughout. Neoplastic cells seem to be able to instruct immune cells to undergo changes promoting malignancy. Radiotherapy may act as a trigger of the immune response. After radiotherapy a sequence of reactions occurs, starting in the damage of oncogenic cells by multiple mechanisms, leading to the immune system positive feedback against the tumor. The link between radiotherapy and the immune system is evident. T cells, macrophages, Natural Killer cells and other immune cells seem to have a key role in controlling the tumor. T cells may be dysfunctional and remain in a state of T cell exhaustion, nonetheless, they often retain a high potential for successful defense against cancer, being able to be mobilized to become highly functional. The lack of clinical trials on a large scale makes data a little robust, in spite of promising information, there are still many variables in the studies relating to radiation and immune system. The clarification of the mechanisms underlying immune response to radiation exposure may contribute to treatment improvement, gain of life quality and span of patients. Copyright © 2016 Elsevier B.V. All rights reserved.

Breakdown of the innate immune system by bacterial proteases

NARCIS (Netherlands)

Laarman, A.J.

2011-01-01

Bacteria have developed many strategies to circumvent our immune system to survive and colonize human tissues. One of these strategies is by secreting proteases that specifically target the innate immune system. Aureolysin is a metalloprotease from Staphylococcus aureus which target the main

Treatment of autoimmune inflammation by a TLR7 ligand regulating the innate immune system.

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Tomoko Hayashi

Full Text Available The Toll-like receptors (TLR have been advocated as attractive therapeutic targets because TLR signaling plays dual roles in initiating adaptive immune responses and perpetuating inflammation. Paradoxically, repeated stimulation of bone marrow mononuclear cells with a synthetic TLR7 ligand 9-benzyl-8-hydroxy-2-(2-methoxyethoxy adenine (called 1V136 leads to subsequent TLR hyporesponsiveness. Further studies on the mechanism of action of this pharmacologic agent demonstrated that the TLR7 ligand treatment depressed dendritic cell activation, but did not directly affect T cell function. To verify this mechanism, we utilized experimental allergic encephalitis (EAE as an in vivo T cell dependent autoimmune model. Drug treated SJL/J mice immunized with proteolipid protein (PLP(139-151 peptide had attenuated disease severity, reduced accumulation of mononuclear cells in the central nervous system (CNS, and limited demyelination, without any apparent systemic toxicity. Splenic T cells from treated mice produced less cytokines upon antigenic rechallenge. In the spinal cords of 1V136-treated EAE mice, the expression of chemoattractants was also reduced, suggesting innate immune cell hyposensitization in the CNS. Indeed, systemic 1V136 did penetrate the CNS. These experiments indicated that repeated doses of a TLR7 ligand may desensitize dendritic cells in lymphoid organs, leading to diminished T cell responses. This treatment strategy might be a new modality to treat T cell mediated autoimmune diseases.

Critical role of macrophages and their activation via MyD88-NFκB signaling in lung innate immunity to Mycoplasma pneumoniae.

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Jen-Feng Lai

2010-12-01

Full Text Available Mycoplasma pneumoniae (Mp, a common cause of pneumonia, is associated with asthma; however, the mechanisms underlying this association remain unclear. We investigated the cellular immune response to Mp in mice. Intranasal inoculation with Mp elicited infiltration of the lungs with neutrophils, monocytes and macrophages. Systemic depletion of macrophages, but not neutrophils, resulted in impaired clearance of Mp from the lungs. Accumulation and activation of macrophages were decreased in the lungs of MyD88(-/- mice and clearance of Mp was impaired, indicating that MyD88 is a key signaling protein in the anti-Mp response. MyD88-dependent signaling was also required for the Mp-induced activation of NFκB, which was essential for macrophages to eliminate the microbe in vitro. Thus, MyD88-NFκB signaling in macrophages is essential for clearance of Mp from the lungs.

Country Immunization Information System Assessments - Kenya, 2015 and Ghana, 2016.

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Scott, Colleen; Clarke, Kristie E N; Grevendonk, Jan; Dolan, Samantha B; Ahmed, Hussein Osman; Kamau, Peter; Ademba, Peter Aswani; Osadebe, Lynda; Bonsu, George; Opare, Joseph; Diamenu, Stanley; Amenuvegbe, Gregory; Quaye, Pamela; Osei-Sarpong, Fred; Abotsi, Francis; Ankrah, Joseph Dwomor; MacNeil, Adam

2017-11-10

The collection, analysis, and use of data to measure and improve immunization program performance are priorities for the World Health Organization (WHO), global partners, and national immunization programs (NIPs). High quality data are essential for evidence-based decision-making to support successful NIPs. Consistent recording and reporting practices, optimal access to and use of health information systems, and rigorous interpretation and use of data for decision-making are characteristics of high-quality immunization information systems. In 2015 and 2016, immunization information system assessments (IISAs) were conducted in Kenya and Ghana using a new WHO and CDC assessment methodology designed to identify root causes of immunization data quality problems and facilitate development of plans for improvement. Data quality challenges common to both countries included low confidence in facility-level target population data (Kenya = 50%, Ghana = 53%) and poor data concordance between child registers and facility tally sheets (Kenya = 0%, Ghana = 3%). In Kenya, systemic challenges included limited supportive supervision and lack of resources to access electronic reporting systems; in Ghana, challenges included a poorly defined subdistrict administrative level. Data quality improvement plans (DQIPs) based on assessment findings are being implemented in both countries. IISAs can help countries identify and address root causes of poor immunization data to provide a stronger evidence base for future investments in immunization programs.

PKA/KIN-1 mediates innate immune responses to bacterial pathogens in Caenorhabditis elegans.

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Xiao, Yi; Liu, Fang; Zhao, Pei-Ji; Zou, Cheng-Gang; Zhang, Ke-Qin

2017-11-01

The genetically tractable organism Caenorhabditis elegans is a powerful model animal for the study of host innate immunity. Although the intestine and the epidermis of C. elegans that is in contact with pathogens are likely to function as sites for the immune function, recent studies indicate that the nervous system could control innate immunity in C. elegans. In this report, we demonstrated that protein kinase A (PKA)/KIN-1 in the neurons contributes to resistance against Salmonella enterica infection in C. elegans. Microarray analysis revealed that PKA/KIN-1 regulates the expression of a set of antimicrobial effectors in the non-neuron tissues, which are required for innate immune responses to S. enterica. Furthermore, PKA/KIN-1 regulated the expression of lysosomal genes during S. enterica infection. Our results suggest that the lysosomal signaling molecules are involved in autophagy by controlling autophagic flux, rather than formation of autophagosomes. As autophagy is crucial for host defense against S. enterica infection in a metazoan, the lysosomal pathway also acts as a downstream effector of the PKA/KIN-1 signaling for innate immunity. Our data indicate that the PKA pathway contributes to innate immunity in C. elegans by signaling from the nervous system to periphery tissues to protect the host against pathogens.