An immune clock of human pregnancy

PubMed Central

Aghaeepour, Nima; Ganio, Edward A.; Mcilwain, David; Tsai, Amy S.; Tingle, Martha; Van Gassen, Sofie; Gaudilliere, Dyani K.; Baca, Quentin; McNeil, Leslie; Okada, Robin; Ghaemi, Mohammad S.; Furman, David; Wong, Ronald J.; Winn, Virginia D.; Druzin, Maurice L.; El-Sayed, Yaser Y.; Quaintance, Cecele; Gibbs, Ronald; Darmstadt, Gary L.; Shaw, Gary M.; Stevenson, David K.; Tibshirani, Robert; Nolan, Garry P.; Lewis, David B.; Angst, Martin S.; Gaudilliere, Brice

2017-01-01

The maintenance of pregnancy relies on finely tuned immune adaptations. We demonstrate that these adaptations are precisely timed, reflecting an immune clock of pregnancy in women delivering at term. Using mass cytometry, the abundance and functional responses of all major immune cell subsets were quantified in serial blood samples collected throughout pregnancy. Cell signaling–based Elastic Net, a regularized regression method adapted from the elastic net algorithm, was developed to infer and prospectively validate a predictive model of interrelated immune events that accurately captures the chronology of pregnancy. Model components highlighted existing knowledge and revealed previously unreported biology, including a critical role for the interleukin-2–dependent STAT5ab signaling pathway in modulating T cell function during pregnancy. These findings unravel the precise timing of immunological events occurring during a term pregnancy and provide the analytical framework to identify immunological deviations implicated in pregnancy-related pathologies. PMID:28864494

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

PubMed

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.

Adoptive cellular therapy of cancer: exploring innate and adaptive cellular crosstalk to improve anti-tumor efficacy.

PubMed

Payne, Kyle K; Bear, Harry D; Manjili, Masoud H

2014-08-01

The mammalian immune system has evolved to produce multi-tiered responses consisting of both innate and adaptive immune cells collaborating to elicit a functional response to a pathogen or neoplasm. Immune cells possess a shared ancestry, suggestive of a degree of coevolution that has resulted in optimal functionality as an orchestrated and highly collaborative unit. Therefore, the development of therapeutic modalities that harness the immune system should consider the crosstalk between cells of the innate and adaptive immune systems in order to elicit the most effective response. In this review, the authors will discuss the success achieved using adoptive cellular therapy in the treatment of cancer, recent trends that focus on purified T cells, T cells with genetically modified T-cell receptors and T cells modified to express chimeric antigen receptors, as well as the use of unfractionated immune cell reprogramming to achieve optimal cellular crosstalk upon infusion for adoptive cellular therapy.

The role of extracellular vesicles when innate meets adaptive.

PubMed

Groot Kormelink, Tom; Mol, Sanne; de Jong, Esther C; Wauben, Marca H M

2018-04-03

Innate immune cells are recognized for their rapid and critical contribution to the body's first line of defense against invading pathogens and harmful agents. These actions can be further amplified by specific adaptive immune responses adapted to the activating stimulus. Recently, the awareness has grown that virtually all innate immune cells, i.e., mast cells, neutrophils, macrophages, eosinophils, basophils, and NK cells, are able to communicate with dendritic cells (DCs) and/or T and B cells, and thereby significantly contribute to the orchestration of adaptive immune responses. The means of communication that are thus far primarily associated with this function are cell-cell contacts and the release of a broad range of soluble mediators. Moreover, the possible contribution of innate immune cell-derived extracellular vesicles (EVs) to the modulation of adaptive immunity will be outlined in this review. EVs are submicron particles composed of a lipid bilayer, proteins, and nucleic acids released by cells in a regulated fashion. EVs are involved in intercellular communication between multiple cell types, including those of the immune system. A good understanding of the mechanisms by which innate immune cell-derived EVs influence adaptive immune responses, or vice versa, may reveal novel insights in the regulation of the immune system and can open up new possibilities for EVs (or their components) in controlling immune responses, either as a therapy, target, or as an adjuvant in future immune modulating treatments.

Immune and stress responses in oysters with insights on adaptation.

PubMed

Guo, Ximing; He, Yan; Zhang, Linlin; Lelong, Christophe; Jouaux, Aude

2015-09-01

Oysters are representative bivalve molluscs that are widely distributed in world oceans. As successful colonizers of estuaries and intertidal zones, oysters are remarkably resilient against harsh environmental conditions including wide fluctuations in temperature and salinity as well as prolonged air exposure. Oysters have no adaptive immunity but can thrive in microbe-rich estuaries as filter-feeders. These unique adaptations make oysters interesting models to study the evolution of host-defense systems. Recent advances in genomic studies including sequencing of the oyster genome have provided insights into oyster's immune and stress responses underlying their amazing resilience. Studies show that the oyster genomes are highly polymorphic and complex, which may be key to their resilience. The oyster genome has a large gene repertoire that is enriched for immune and stress response genes. Thousands of genes are involved in oyster's immune and stress responses, through complex interactions, with many gene families expanded showing high sequence, structural and functional diversity. The high diversity of immune receptors and effectors may provide oysters with enhanced specificity in immune recognition and response to cope with diverse pathogens in the absence of adaptive immunity. Some members of expanded immune gene families have diverged to function at different temperatures and salinities or assumed new roles in abiotic stress response. Most canonical innate immunity pathways are conserved in oysters and supported by a large number of diverse and often novel genes. The great diversity in immune and stress response genes exhibited by expanded gene families as well as high sequence and structural polymorphisms may be central to oyster's adaptation to highly stressful and widely changing environments. Copyright © 2015 Elsevier Ltd. All rights reserved.

Retinoic Acid as a Modulator of T Cell Immunity

PubMed Central

Bono, Maria Rosa; Tejon, Gabriela; Flores-Santibañez, Felipe; Fernandez, Dominique; Rosemblatt, Mario; Sauma, Daniela

2016-01-01

Vitamin A, a generic designation for an array of organic molecules that includes retinal, retinol and retinoic acid, is an essential nutrient needed in a wide array of aspects including the proper functioning of the visual system, maintenance of cell function and differentiation, epithelial surface integrity, erythrocyte production, reproduction, and normal immune function. Vitamin A deficiency is one of the most common micronutrient deficiencies worldwide and is associated with defects in adaptive immunity. Reports from epidemiological studies, clinical trials and experimental studies have clearly demonstrated that vitamin A plays a central role in immunity and that its deficiency is the cause of broad immune alterations including decreased humoral and cellular responses, inadequate immune regulation, weak response to vaccines and poor lymphoid organ development. In this review, we will examine the role of vitamin A in immunity and focus on several aspects of T cell biology such as T helper cell differentiation, function and homing, as well as lymphoid organ development. Further, we will provide an overview of the effects of vitamin A deficiency in the adaptive immune responses and how retinoic acid, through its effect on T cells can fine-tune the balance between tolerance and immunity. PMID:27304965

Cellular Factors Targeting APCs to Modulate Adaptive T Cell Immunity

PubMed Central

Do, Jeongsu; Min, Booki

2014-01-01

The fate of adaptive T cell immunity is determined by multiple cellular and molecular factors, among which the cytokine milieu plays the most important role in this process. Depending on the cytokines present during the initial T cell activation, T cells become effector cells that produce different effector molecules and execute adaptive immune functions. Studies thus far have primarily focused on defining how these factors control T cell differentiation by targeting T cells themselves. However, other non-T cells, particularly APCs, also express receptors for the factors and are capable of responding to them. In this review, we will discuss how APCs, by responding to those cytokines, influence T cell differentiation and adaptive immunity. PMID:25126585

Development of a human adaptive immune system in cord blood cell-transplanted mice.

PubMed

Traggiai, Elisabetta; Chicha, Laurie; Mazzucchelli, Luca; Bronz, Lucio; Piffaretti, Jean-Claude; Lanzavecchia, Antonio; Manz, Markus G

2004-04-02

Because ethical restrictions limit in vivo studies of the human hemato-lymphoid system, substitute human to small animal xenotransplantation models have been employed. Existing models, however, sustain only limited development and maintenance of human lymphoid cells and rarely produce immune responses. Here we show that intrahepatic injection of CD34+ human cord blood cells into conditioned newborn Rag2-/-gammac-/- mice leads to de novo development of B, T, and dendritic cells; formation of structured primary and secondary lymphoid organs; and production of functional immune responses. This provides a valuable model to study development and function of the human adaptive immune system in vivo.

How and why do T cells and their derived cytokines affect the injured and healthy brain?

PubMed Central

Filiano, Anthony J.; Gadani, Sachin P.; Kipnis, Jonathan

2018-01-01

The evolution of adaptive immunity provides enhanced defence against specific pathogens, as well as homeostatic immune surveillance of all tissues. Despite being ‘immune privileged’, the CNS uses the assistance of the immune system in physiological and pathological states. In this Opinion article, we discuss the influence of adaptive immunity on recovery after CNS injury and on cognitive and social brain function. We further extend a hypothesis that the pro-social effects of interferon-regulated genes were initially exploited by pathogens to increase host–host transmission, and that these genes were later recycled by the host to form part of an immune defence programme. In this way, the evolution of adaptive immunity may reflect a host–pathogen ‘arms race’. PMID:28446786

Poliovirus intrahost evolution is required to overcome tissue-specific innate immune responses.

PubMed

Xiao, Yinghong; Dolan, Patrick Timothy; Goldstein, Elizabeth Faul; Li, Min; Farkov, Mikhail; Brodsky, Leonid; Andino, Raul

2017-08-29

RNA viruses, such as poliovirus, have a great evolutionary capacity, allowing them to quickly adapt and overcome challenges encountered during infection. Here we show that poliovirus infection in immune-competent mice requires adaptation to tissue-specific innate immune microenvironments. The ability of the virus to establish robust infection and virulence correlates with its evolutionary capacity. We further identify a region in the multi-functional poliovirus protein 2B as a hotspot for the accumulation of minor alleles that facilitate a more effective suppression of the interferon response. We propose that population genetic dynamics enables poliovirus spread between tissues through optimization of the genetic composition of low frequency variants, which together cooperate to circumvent tissue-specific challenges. Thus, intrahost virus evolution determines pathogenesis, allowing a dynamic regulation of viral functions required to overcome barriers to infection.RNA viruses, such as polioviruses, have a great evolutionary capacity and can adapt quickly during infection. Here, the authors show that poliovirus infection in mice requires adaptation to innate immune microenvironments encountered in different tissues.

Innate and adaptive immunity in the development of depression: An update on current knowledge and technological advances.

PubMed

Haapakoski, Rita; Ebmeier, Klaus P; Alenius, Harri; Kivimäki, Mika

2016-04-03

The inflammation theory of depression, proposed over 20years ago, was influenced by early studies on T cell responses and since then has been a stimulus for numerous research projects aimed at understanding the relationship between immune function and depression. Observational studies have shown that indicators of immunity, especially C reactive protein and proinflammatory cytokines, such as interleukin 6, are associated with an increased risk of depressive disorders, although the evidence from randomized trials remains limited and only few studies have assessed the interplay between innate and adaptive immunity in depression. In this paper, we review current knowledge on the interactions between central and peripheral innate and adaptive immune molecules and the potential role of immune-related activation of microglia, inflammasomes and indoleamine-2,3-dioxygenase in the development of depressive symptoms. We highlight how combining basic immune methods with more advanced 'omics' technologies would help us to make progress in unravelling the complex associations between altered immune function and depressive disorders, in the identification of depression-specific biomarkers and in developing immunotherapeutic treatment strategies that take individual variability into account. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Innate and adaptive immunity in the development of depression: An update on current knowledge and technological advances

PubMed Central

Haapakoski, Rita; Ebmeier, Klaus P.; Alenius, Harri; Kivimäki, Mika

2016-01-01

The inflammation theory of depression, proposed over 20 years ago, was influenced by early studies on T cell responses and since then has been a stimulus for numerous research projects aimed at understanding the relationship between immune function and depression. Observational studies have shown that indicators of immunity, especially C reactive protein and proinflammatory cytokines, such as interleukin 6, are associated with an increased risk of depressive disorders, although the evidence from randomized trials remains limited and only few studies have assessed the interplay between innate and adaptive immunity in depression. In this paper, we review current knowledge on the interactions between central and peripheral innate and adaptive immune molecules and the potential role of immune-related activation of microglia, inflammasomes and indoleamine-2,3-dioxygenase in the development of depressive symptoms. We highlight how combining basic immune methods with more advanced ‘omics’ technologies would help us to make progress in unravelling the complex associations between altered immune function and depressive disorders, in the identification of depression-specific biomarkers and in developing immunotherapeutic treatment strategies that take individual variability into account. PMID:26631274

Costimulatory Function of Cd58/Cd2 Interaction in Adaptive Humoral Immunity in a Zebrafish Model.

PubMed

Shao, Tong; Shi, Wei; Zheng, Jia-Yu; Xu, Xiao-Xiao; Lin, Ai-Fu; Xiang, Li-Xin; Shao, Jian-Zhong

2018-01-01

CD58 and CD2 have long been known as a pair of reciprocal adhesion molecules involved in the immune modulations of CD8 + T and NK-mediated cellular immunity in humans and several other mammals. However, the functional roles of CD58 and CD2 in CD4 + T-mediated adaptive humoral immunity remain poorly defined. Moreover, the current functional observations of CD58 and CD2 were mainly acquired from in vitro assays, and in vivo investigation is greatly limited due to the absence of a Cd58 homology in murine models. In this study, we identified cd58 and cd2 homologs from the model species zebrafish ( Danio rerio ). These two molecules share conserved structural features to their mammalian counterparts. Functionally, cd58 and cd2 were significantly upregulated on antigen-presenting cells and Cd4 + T cells upon antigen stimulation. Blockade or knockdown of Cd58 and Cd2 dramatically impaired the activation of antigen-specific Cd4 + T and mIgM + B cells, followed by the inhibition of antibody production and host defense against bacterial infections. These results indicate that CD58/CD2 interaction was required for the full activation of CD4 + T-mediated adaptive humoral immunity. The interaction of Cd58 with Cd2 was confirmed by co-immunoprecipitation and functional competitive assays by introducing a soluble Cd2 protein. This study highlights a new costimulatory mechanism underlying the regulatory network of adaptive immunity and makes zebrafish an attractive model organism for the investigation of CD58/CD2-mediated immunology and disorders. It also provides a cross-species understanding of the evolutionary history of costimulatory signals from fish to mammals as a whole.

HIF Transcription Factors, Inflammation, and Immunity

PubMed Central

Palazon, Asis; Goldrath, Ananda; Nizet, Victor

2015-01-01

The hypoxic response in cells and tissues is mediated by the family of hypoxia-inducible factor (HIF) transcription factors that play an integral role in the metabolic changes that drive cellular adaptation to low oxygen availability. HIF expression and stabilization in immune cells can be triggered by hypoxia, but also by other factors associated with pathological stress: e.g., inflammation, infectious microorganisms, and cancer. HIF induces a number of aspects of host immune function, from boosting phagocyte microbicidal capacity to driving T cell differentiation and cytotoxic activity. Cellular metabolism is emerging as a key regulator of immunity, and it constitutes another layer of fine-tuned immune control by HIF that can dictate myeloid cell and lymphocyte development, fate, and function. Here we discuss how oxygen sensing in the immune microenvironment shapes immunological response and examine how HIF and the hypoxia pathway control innate and adaptive immunity. PMID:25367569

HIF transcription factors, inflammation, and immunity.

PubMed

Palazon, Asis; Goldrath, Ananda W; Nizet, Victor; Johnson, Randall S

2014-10-16

The hypoxic response in cells and tissues is mediated by the family of hypoxia-inducible factor (HIF) transcription factors; these play an integral role in the metabolic changes that drive cellular adaptation to low oxygen availability. HIF expression and stabilization in immune cells can be triggered by hypoxia, but also by other factors associated with pathological stress: e.g., inflammation, infectious microorganisms, and cancer. HIF induces a number of aspects of host immune function, from boosting phagocyte microbicidal capacity to driving T cell differentiation and cytotoxic activity. Cellular metabolism is emerging as a key regulator of immunity, and it constitutes another layer of fine-tuned immune control by HIF that can dictate myeloid cell and lymphocyte development, fate, and function. Here we discuss how oxygen sensing in the immune microenvironment shapes immunological response and examine how HIF and the hypoxia pathway control innate and adaptive immunity.

Control of adaptive immunity by the innate immune system.

PubMed

Iwasaki, Akiko; Medzhitov, Ruslan

2015-04-01

Microbial infections are recognized by the innate immune system both to elicit immediate defense and to generate long-lasting adaptive immunity. To detect and respond to vastly different groups of pathogens, the innate immune system uses several recognition systems that rely on sensing common structural and functional features associated with different classes of microorganisms. These recognition systems determine microbial location, viability, replication and pathogenicity. Detection of these features by recognition pathways of the innate immune system is translated into different classes of effector responses though specialized populations of dendritic cells. Multiple mechanisms for the induction of immune responses are variations on a common design principle wherein the cells that sense infections produce one set of cytokines to induce lymphocytes to produce another set of cytokines, which in turn activate effector responses. Here we discuss these emerging principles of innate control of adaptive immunity.

Evolution of complement as an effector system in innate and adaptive immunity.

PubMed

Sunyer, J Oriol; Boshra, Hani; Lorenzo, Gema; Parra, David; Freedman, Bruce; Bosch, Nina

2003-01-01

For a long time, the complement system in mammals has been regarded as a biological system that plays an essential role in innate immunity. More recently, it has been recognized that the complement system contributes heavily to the generation and development of an acquired immune response. In fact, this ancient mechanism of defense has evolved from a primitive mechanism of innate immune recognition in invertebrate species to that of an effector system that bridges the innate with the adaptive immune response in vertebrate species. When and how did complement evolve into a shared effector system between innate and adaptive immunity? To answer this question, our group is interested in understanding the role of complement in innate and adaptive immune responses in an evolutionary relevant species: the teleost fish. The attractiveness of this species as an animal model is based on two important facts. First, teleost fish are one of the oldest animal species to have developed an adaptive immune response. Second, the complement system of teleost fish offers a unique feature, which is the structural and functional diversity of its main effector protein, C3, the third component of the complement system.

Modular Activating Receptors in Innate and Adaptive Immunity.

PubMed

Berry, Richard; Call, Matthew E

2017-03-14

Triggering of cell-mediated immunity is largely dependent on the recognition of foreign or abnormal molecules by a myriad of cell surface-bound receptors. Many activating immune receptors do not possess any intrinsic signaling capacity but instead form noncovalent complexes with one or more dimeric signaling modules that communicate with a common set of kinases to initiate intracellular information-transfer pathways. This modular architecture, where the ligand binding and signaling functions are detached from one another, is a common theme that is widely employed throughout the innate and adaptive arms of immune systems. The evolutionary advantages of this highly adaptable platform for molecular recognition are visible in the variety of ligand-receptor interactions that can be linked to common signaling pathways, the diversification of receptor modules in response to pathogen challenges, and the amplification of cellular responses through incorporation of multiple signaling motifs. Here we provide an overview of the major classes of modular activating immune receptors and outline the current state of knowledge regarding how these receptors assemble, recognize their ligands, and ultimately trigger intracellular signal transduction pathways that activate immune cell effector functions.

A Functional Toll-Interacting Protein Variant Is Associated with Bacillus Calmette-Guérin-Specific Immune Responses and Tuberculosis.

PubMed

Shah, Javeed A; Musvosvi, Munyaradzi; Shey, Muki; Horne, David J; Wells, Richard D; Peterson, Glenna J; Cox, Jeffery S; Daya, Michelle; Hoal, Eileen G; Lin, Lin; Gottardo, Raphael; Hanekom, Willem A; Scriba, Thomas J; Hatherill, Mark; Hawn, Thomas R

2017-08-15

The molecular mechanisms that regulate tuberculosis susceptibility and bacillus Calmette-Guérin (BCG)-induced immunity are mostly unknown. However, induction of the adaptive immune response is a critical step in host control of Mycobacterium tuberculosis. Toll-interacting protein (TOLLIP) is a ubiquitin-binding protein that regulates innate immune responses, including Toll-like receptor signaling, which initiate adaptive immunity. TOLLIP variation is associated with susceptibility to tuberculosis, but the mechanism by which it regulates tuberculosis immunity is poorly understood. To identify functional TOLLIP variants and evaluate the role of TOLLIP variation on innate and adaptive immune responses to mycobacteria and susceptibility to tuberculosis. We used human cellular immunology approaches to characterize the role of a functional TOLLIP variant on monocyte mRNA expression and M. tuberculosis-induced monocyte immune functions. We also examined the association of TOLLIP variation with BCG-induced T-cell responses and susceptibility to latent tuberculosis infection. We identified a functional TOLLIP promoter region single-nucleotide polymorphism, rs5743854, which was associated with decreased TOLLIP mRNA expression in infant monocytes. After M. tuberculosis infection, TOLLIP-deficient monocytes demonstrated increased IL-6, increased nitrite, and decreased bacterial replication. The TOLLIP-deficiency G/G genotype was associated with decreased BCG-specific IL-2 + CD4 + T-cell frequency and proliferation. This genotype was also associated with increased susceptibility to latent tuberculosis infection. TOLLIP deficiency is associated with decreased BCG-specific T-cell responses and increased susceptibility to tuberculosis. We hypothesize that the heightened antibacterial monocyte responses after vaccination of TOLLIP-deficient infants are responsible for decreased BCG-specific T-cell responses. Activating TOLLIP may provide a novel adjuvant strategy for BCG vaccination.

Single cell transcriptomics to explore the immune system in health and disease†

PubMed Central

Regev, Aviv; Teichmann, Sarah A.

2017-01-01

The immune system varies in cell types, states, and locations. The complex networks, interactions and responses of immune cells produce diverse cellular ecosystems composed of multiple cell types, accompanied by genetic diversity in antigen receptors. Within this ecosystem, innate and adaptive immune cells maintain and protect tissue function, integrity and homeostasis upon changes in functional demands and diverse insults. Characterizing this inherent complexity requires studies at single-cell resolution. Recent advances such as, massively-parallel single cell RNA-Seq and sophisticated computational methods are catalysing a revolution in our understanding of immunology. Here, we provide an overview of the state of single cell genomics methods and an outlook on the use of single-cell techniques to decipher the adaptive and innate components of immunity. PMID:28983043

Early adaption to the antarctic environment at dome C: consequences on stress-sensitive innate immune functions.

PubMed

Feuerecker, Matthias; Crucian, Brian; Salam, Alex P; Rybka, Ales; Kaufmann, Ines; Moreels, Marjan; Quintens, Roel; Schelling, Gustav; Thiel, Manfred; Baatout, Sarah; Sams, Clarence; Choukèr, Alexander

2014-09-01

Abstract Feuerecker, Matthias, Brian Crucian, Alex P. Salam, Ales Rybka, Ines Kaufmann, Marjan Moreels, Roel Quintens, Gustav Schelling, Manfred Thiel, Sarah Baatout, Clarence Sams, and Alexander Choukèr. Early adaption in the Antarctic environment at Dome C: Consequences on stress-sensitive innate immune functions. High Alt Med Biol 15:341-348, 2014.-Purpose/Aims: Medical reports of Antarctic expeditions indicate that health is affected under these extreme conditions. The present study at CONCORDIA-Station (Dome C, 3233 m) seeks to investigate the early consequences of confinement and hypobaric hypoxia on the human organism. Nine healthy male participants were included in this study. Data collection occurred before traveling to Antarctica (baseline), and at 1 week and 1 month upon arrival. Investigated parameters included basic physiological variables, psychological stress tests, cell blood count, stress hormones, and markers of innate immune functions in resting and stimulated immune cells. By testing for the hydrogen peroxide (H2O2) production of stimulated polymorphonuclear leukocytes (PMNs), the effects of the hypoxia-adenosine-sensitive immune modulatory pathways were examined. As compared to baseline data, reduced oxygen saturation, hemoconcentration, and an increase of secreted catecholamines was observed, whereas no psychological stress was seen. Upon stimulation, the activity of PMNs and L-selectin shedding was mitigated after 1 week. Endogenous adenosine concentration was elevated during the early phase. In summary, living conditions at high altitude influence the innate immune system's response. After 1 month, some of the early effects on the human organism were restored. As this early adaptation is not related to psychological stress, the changes observed are likely to be induced by environmental stressors, especially hypoxia. As hypoxia is triggering ATP-catabolism, leading to elevated endogenous adenosine concentrations, this and the increased catecholamine concentration might contribute to the early, but reversible downregulation of innate immune functions. This indicates the slope of innate immune adaptation to hypoxia.

Bacterial 'immunity' against bacteriophages.

PubMed

Abedon, Stephen T

2012-01-01

Vertebrate animals possess multiple anti-pathogen defenses. Individual mechanisms usually are differentiated into those that are immunologically adaptive vs. more "primitive" anti-pathogen phenomena described as innate responses. Here I frame defenses used by bacteria against bacteriophages as analogous to these animal immune functions. Included are numerous anti-phage defenses in addition to the adaptive immunity associated with CRISPR/cas systems. As these other anti-pathogen mechanisms are non-adaptive they can be described as making up an innate bacterial immunity. This exercise was undertaken in light of the recent excitement over the discovery that CRISPR/cas systems can serve, as noted, as a form of bacterial adaptive immunity. The broader goal, however, is to gain novel insight into bacterial defenses against phages by fitting these mechanisms into considerations of how multicellular organisms also defend themselves against pathogens. This commentary can be viewed in addition as a bid toward integrating these numerous bacterial anti-phage defenses into a more unified immunology.

Lack of broad functional differences in immunity in fully vaccinated vs. unvaccinated children.

PubMed

Sherrid, Ashley M; Ruck, Candice E; Sutherland, Darren; Cai, Bing; Kollmann, Tobias R

2017-04-01

Concerns have been raised that with an increase in the number of vaccines administered early in life, immune development could be altered, leading to either increased or decreased immune reactivity. We investigated the impact of vaccination on immune status, contrasting the immune response to general, nonantigen-specific stimuli in a cohort of entirely unvaccinated vs. fully vaccinated children at 3-5 y of age. Innate immunity was assessed by quantifying bulk and cell-type-specific cytokine production in response to stimulation with pathogen associated microbial patterns. Adaptive immune status was characterized by assessing lymphocyte proliferation and cytokine production in response to generic T cell stimuli. Our investigations failed to reveal a broadly evident alteration of either innate or adaptive immunity in vaccinated children. Equivalently robust innate and adaptive responses to pathogen associated microbial patterns and generic T cell stimulants were observed in both groups. Although our sample size was small, our data suggest that standard childhood vaccinations do not lead to long-lasting gross alterations of the immune system.

Staphylococcal Immune Evasion Proteins: Structure, Function, and Host Adaptation.

PubMed

Koymans, Kirsten J; Vrieling, Manouk; Gorham, Ronald D; van Strijp, Jos A G

2017-01-01

Staphylococcus aureus is a successful human and animal pathogen. Its pathogenicity is linked to its ability to secrete a large amount of virulence factors. These secreted proteins interfere with many critical components of the immune system, both innate and adaptive, and hamper proper immune functioning. In recent years, numerous studies have been conducted in order to understand the molecular mechanism underlying the interaction of evasion molecules with the host immune system. Structural studies have fundamentally contributed to our understanding of the mechanisms of action of the individual factors. Furthermore, such studies revealed one of the most striking characteristics of the secreted immune evasion molecules: their conserved structure. Despite high-sequence variability, most immune evasion molecules belong to a small number of structural categories. Another remarkable characteristic is that S. aureus carries most of these virulence factors on mobile genetic elements (MGE) or ex-MGE in its accessory genome. Coevolution of pathogen and host has resulted in immune evasion molecules with a highly host-specific function and prevalence. In this review, we explore how these shared structures and genomic locations relate to function and host specificity. This is discussed in the context of therapeutic options for these immune evasion molecules in infectious as well as in inflammatory diseases.

Human adaptive immune system Rag2-/-gamma(c)-/- mice.

PubMed

Chicha, Laurie; Tussiwand, Roxane; Traggiai, Elisabetta; Mazzucchelli, Luca; Bronz, Lucio; Piffaretti, Jean-Claude; Lanzavecchia, Antonio; Manz, Markus G

2005-06-01

Although many biologic principles are conserved in mice and humans, species-specific differences exist, for example, in susceptibility and response to pathogens, that often do not allow direct implementation of findings in experimental mice to humans. Research in humans, however, for ethical and practical reasons, is largely restricted to in vitro assays that lack components and the complexity of a living organism. To nevertheless study the human hematopoietic and immune system in vivo, xenotransplantation assays have been developed that substitute human components to small animals. Here, we summarize our recent findings that transplantation of human cord blood CD34(+) cells to newborn Rag2(-/-)gamma(c)(-/-) mice leads to de novo development of major functional components of the human adaptive immune system. These human adaptive immune system Rag2(-/-)gamma(c)(-/-) (huAIS-RG) mice can now be used as a technically straightforward preclinical model to evaluate in vivo human adaptive immune system development as well as immune responses, for example, to vaccines or live infectious pathogens.

Regulatory dendritic cells: there is more than just immune activation.

PubMed

Schmidt, Susanne V; Nino-Castro, Andrea C; Schultze, Joachim L

2012-01-01

The immune system exists in a delicate equilibrium between inflammatory responses and tolerance. This unique feature allows the immune system to recognize and respond to potential threats in a controlled but normally limited fashion thereby preventing a destructive overreaction against healthy tissues. While the adaptive immune system was the major research focus concerning activation vs. tolerance in the immune system more recent findings suggest that cells of the innate immune system are important players in the decision between effective immunity and induction of tolerance or immune inhibition. Among immune cells of the innate immune system dendritic cells (DCs) have a special function linking innate immune functions with the induction of adaptive immunity. DCs are the primary professional antigen presenting cells (APCs) initiating adaptive immune responses. They belong to the hematopoietic system and arise from CD34(+) stem cells in the bone marrow. Particularly in the murine system two major subgroups of DCs, namely myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) can be distinguished. DCs are important mediators of innate and adaptive immunity mostly due to their remarkable capacity to present processed antigens via major histocompatibility complexes (MHC) to T cells and B cells in secondary lymphoid organs. A large body of literature has been accumulated during the last two decades describing which role DCs play during activation of T cell responses but also during the establishment and maintenance of central tolerance (Steinman et al., 2003). While the concept of peripheral tolerance has been clearly established during the last years, the role of different sets of DCs and their particular molecular mechanisms of immune deviation has not yet fully been appreciated. In this review we summarize accumulating evidence about the role of regulatory DCs in situations where the balance between tolerance and immunogenicity has been altered leading to pathologic conditions such as chronic inflammation or malignancies.

Regulatory dendritic cells: there is more than just immune activation

PubMed Central

Schmidt, Susanne V.; Nino-Castro, Andrea C.; Schultze, Joachim L.

2012-01-01

The immune system exists in a delicate equilibrium between inflammatory responses and tolerance. This unique feature allows the immune system to recognize and respond to potential threats in a controlled but normally limited fashion thereby preventing a destructive overreaction against healthy tissues. While the adaptive immune system was the major research focus concerning activation vs. tolerance in the immune system more recent findings suggest that cells of the innate immune system are important players in the decision between effective immunity and induction of tolerance or immune inhibition. Among immune cells of the innate immune system dendritic cells (DCs) have a special function linking innate immune functions with the induction of adaptive immunity. DCs are the primary professional antigen presenting cells (APCs) initiating adaptive immune responses. They belong to the hematopoietic system and arise from CD34+ stem cells in the bone marrow. Particularly in the murine system two major subgroups of DCs, namely myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) can be distinguished. DCs are important mediators of innate and adaptive immunity mostly due to their remarkable capacity to present processed antigens via major histocompatibility complexes (MHC) to T cells and B cells in secondary lymphoid organs. A large body of literature has been accumulated during the last two decades describing which role DCs play during activation of T cell responses but also during the establishment and maintenance of central tolerance (Steinman et al., 2003). While the concept of peripheral tolerance has been clearly established during the last years, the role of different sets of DCs and their particular molecular mechanisms of immune deviation has not yet fully been appreciated. In this review we summarize accumulating evidence about the role of regulatory DCs in situations where the balance between tolerance and immunogenicity has been altered leading to pathologic conditions such as chronic inflammation or malignancies. PMID:22969767

Pulmonary immunity and extracellular matrix interactions.

PubMed

O'Dwyer, David N; Gurczynski, Stephen J; Moore, Bethany B

2018-04-09

The lung harbors a complex immune system composed of both innate and adaptive immune cells. Recognition of infection and injury by receptors on lung innate immune cells is crucial for generation of antigen-specific responses by adaptive immune cells. The extracellular matrix of the lung, comprising the interstitium and basement membrane, plays a key role in the regulation of these immune systems. The matrix consists of several hundred assembled proteins that interact to form a bioactive scaffold. This template, modified by enzymes, acts to facilitate cell function and differentiation and changes dynamically with age and lung disease. Herein, we explore relationships between innate and adaptive immunity and the lung extracellular matrix. We discuss the interactions between extracellular matrix proteins, including glycosaminoglycans, with prominent effects on innate immune signaling effectors such as toll-like receptors. We describe the relationship of extracellular matrix proteins with adaptive immunity and leukocyte migration to sites of injury within the lung. Further study of these interactions will lead to greater knowledge of the role of matrix biology in lung immunity. The development of novel therapies for acute and chronic lung disease is dependent on a comprehensive understanding of these complex matrix-immunity interactions. Copyright © 2017 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.

Influence of tumors on protective anti-tumor immunity and the effects of irradiation

PubMed Central

Foulds, Gemma A.; Radons, Jürgen; Kreuzer, Mira; Multhoff, Gabriele; Pockley, Alan G.

2012-01-01

Innate and adaptive immunity plays important roles in the development and progression of cancer and it is becoming apparent that tumors can influence the induction of potentially protective responses in a number of ways. The prevalence of immunoregulatory T cell populations in the circulation and tumors of patients with cancer is increased and the presence of these cells appears to present a major barrier to the induction of tumor immunity. One aspect of tumor-mediated immunoregulation which has received comparatively little attention is that which is directed toward natural killer (NK) cells, although evidence that the phenotype and function of NK cell populations are modified in patients with cancer is accumulating. Although the precise mechanisms underlying these localized and systemic immunoregulatory effects remain unclear, tumor-derived factors appear, in part at least, to be involved. The effects could be manifested by an altered function and/or via an influence on the migratory properties of individual cell subsets. A better insight into endogenous immunoregulatory mechanisms and the capacity of tumors to modify the phenotype and function of innate and adaptive immune cells might assist the development of new immunotherapeutic approaches and improve the management of patients with cancer. This article reviews current knowledge relating to the influence of tumors on protective anti-tumor immunity and considers the potential influence that radiation-induced effects might have on the prevalence, phenotype, and function of innate and adaptive immune cells in patients with cancer. PMID:23378947

Immune cell phenotype and function in sepsis

PubMed Central

Rimmelé, Thomas; Payen, Didier; Cantaluppi, Vincenzo; Marshall, John; Gomez, Hernando; Gomez, Alonso; Murray, Patrick; Kellum, John A.

2015-01-01

Cells of the innate and adaptive immune systems play a critical role in the host response to sepsis. Moreover, their accessibility for sampling and their capacity to respond dynamically to an acute threat increases the possibility that leukocytes might serve as a measure of a systemic state of altered responsiveness in sepsis. The working group of the 14th Acute Dialysis Quality Initiative (ADQI) conference sought to obtain consensus on the characteristic functional and phenotypic changes in cells of the innate and adaptive immune system in the setting of sepsis. Techniques for the study of circulating leukocytes were also reviewed and the impact on cellular phenotypes and leukocyte function of non extracorporeal treatments and extracorporeal blood purification therapies proposed for sepsis was analyzed. A large number of alterations in the expression of distinct neutrophil and monocyte surface markers have been reported in septic patients. The most consistent alteration seen in septic neutrophils is their activation of a survival program that resists apoptotic death. Reduced expression of HLA-DR is a characteristic finding on septic monocytes but monocyte antimicrobial function does not appear to be significantly altered in sepsis. Regarding adaptive immunity, sepsis-induced apoptosis leads to lymphopenia in patients with septic shock and it involves all types of T cells (CD4, CD8 and Natural Killer) except T regulatory cells, thus favoring immunosuppression. Finally, numerous promising therapies targeting the host immune response to sepsis are under investigation. These potential treatments can have an effect on the number of immune cells, the proportion of cell subtypes and the cell function. PMID:26529661

IMMUNE CELL PHENOTYPE AND FUNCTION IN SEPSIS.

PubMed

Rimmelé, Thomas; Payen, Didier; Cantaluppi, Vincenzo; Marshall, John; Gomez, Hernando; Gomez, Alonso; Murray, Patrick; Kellum, John A

2016-03-01

Cells of the innate and adaptive immune systems play a critical role in the host response to sepsis. Moreover, their accessibility for sampling and their capacity to respond dynamically to an acute threat increases the possibility that leukocytes might serve as a measure of a systemic state of altered responsiveness in sepsis.The working group of the 14th Acute Dialysis Quality Initiative (ADQI) conference sought to obtain consensus on the characteristic functional and phenotypic changes in cells of the innate and adaptive immune system in the setting of sepsis. Techniques for the study of circulating leukocytes were also reviewed and the impact on cellular phenotypes and leukocyte function of nonextracorporeal treatments and extracorporeal blood purification therapies proposed for sepsis was analyzed.A large number of alterations in the expression of distinct neutrophil and monocyte surface markers have been reported in septic patients. The most consistent alteration seen in septic neutrophils is their activation of a survival program that resists apoptotic death. Reduced expression of HLA-DR is a characteristic finding on septic monocytes, but monocyte antimicrobial function does not appear to be significantly altered in sepsis. Regarding adaptive immunity, sepsis-induced apoptosis leads to lymphopenia in patients with septic shock and it involves all types of T cells (CD4, CD8, and Natural Killer) except T regulatory cells, thus favoring immunosuppression. Finally, numerous promising therapies targeting the host immune response to sepsis are under investigation. These potential treatments can have an effect on the number of immune cells, the proportion of cell subtypes, and the cell function.

Dendritic cell targeted vaccines: Recent progresses and challenges

PubMed Central

Chen, Pengfei; Liu, Xinsheng; Sun, Yuefeng; Zhou, Peng; Wang, Yonglu; Zhang, Yongguang

2016-01-01

ABSTRACT Dendritic cells (DCs) are known to be a set of morphology, structure and function of heterogeneous professional antigen presenting cells (APCs), as well as the strongest functional antigen presenting cells, which can absorb, process and present antigens. As the key regulators of innate and adaptive immune responses, DCs are at the center of the immune system and capable of interacting with both B cells and T cells, thereby manipulating the humoral and cellular immune responses. DCs provide an essential link between the innate and adaptive immunity, and the strong immune activation function of DCs and their properties of natural adjuvants, make them a valuable target for antigen delivery. Targeting antigens to DC-specific endocytic receptors in combination with the relevant antibodies or ligands along with immunostimulatory adjuvants has been recently recognized as a promising strategy for designing an effective vaccine that elicits a strong and durable T cell response against intracellular pathogens and cancer. This opinion article provides a brief summary of the rationales, superiorities and challenges of existing DC-targeting approaches. PMID:26513200

Functional Roles of Syk in Macrophage-Mediated Inflammatory Responses

PubMed Central

Yi, Young-Su; Son, Young-Jin; Ryou, Chongsuk; Sung, Gi-Ho; Kim, Jong-Hoon; Cho, Jae Youl

2014-01-01

Inflammation is a series of complex biological responses to protect the host from pathogen invasion. Chronic inflammation is considered a major cause of diseases, such as various types of inflammatory/autoimmune diseases and cancers. Spleen tyrosine kinase (Syk) was initially found to be highly expressed in hematopoietic cells and has been known to play crucial roles in adaptive immune responses. However, recent studies have reported that Syk is also involved in other biological functions, especially in innate immune responses. Although Syk has been extensively studied in adaptive immune responses, numerous studies have recently presented evidence that Syk has critical functions in macrophage-mediated inflammatory responses and is closely related to innate immune response. This review describes the characteristics of Syk-mediated signaling pathways, summarizes the recent findings supporting the crucial roles of Syk in macrophage-mediated inflammatory responses and diseases, and discusses Syk-targeted drug development for the therapy of inflammatory diseases. PMID:25045209

Ion Channels in Innate and Adaptive Immunity

PubMed Central

Feske, Stefan; Wulff, Heike; Skolnik, Edward Y.

2016-01-01

Ion channels and transporters mediate the transport of charged ions across hydrophobic lipid membranes. In immune cells, divalent cations such as calcium, magnesium, and zinc have important roles as second messengers to regulate intracellular signaling pathways. By contrast, monovalent cations such as sodium and potassium mainly regulate the membrane potential, which indirectly controls the influx of calcium and immune cell signaling. Studies investigating human patients with mutations in ion channels and transporters, analysis of gene-targeted mice, or pharmacological experiments with ion channel inhibitors have revealed important roles of ionic signals in lymphocyte development and in innate and adaptive immune responses. We here review the mechanisms underlying the function of ion channels and transporters in lymphocytes and innate immune cells and discuss their roles in lymphocyte development, adaptive and innate immune responses, and autoimmunity, as well as recent efforts to develop pharmacological inhibitors of ion channels for immunomodulatory therapy. PMID:25861976

The adaptive immune system restrains Alzheimer’s disease pathogenesis by modulating microglial function

PubMed Central

Abud, Edsel M.; Lakatos, Anita; Karimzadeh, Alborz; Yeung, Stephen T.; Davtyan, Hayk; Fote, Gianna M.; Lau, Lydia; Weinger, Jason G.; Lane, Thomas E.; Inlay, Matthew A.; Poon, Wayne W.; Blurton-Jones, Mathew

2016-01-01

The innate immune system is strongly implicated in the pathogenesis of Alzheimer’s disease (AD). In contrast, the role of adaptive immunity in AD remains largely unknown. However, numerous clinical trials are testing vaccination strategies for AD, suggesting that T and B cells play a pivotal role in this disease. To test the hypothesis that adaptive immunity influences AD pathogenesis, we generated an immune-deficient AD mouse model that lacks T, B, and natural killer (NK) cells. The resulting “Rag-5xfAD” mice exhibit a greater than twofold increase in β-amyloid (Aβ) pathology. Gene expression analysis of the brain implicates altered innate and adaptive immune pathways, including changes in cytokine/chemokine signaling and decreased Ig-mediated processes. Neuroinflammation is also greatly exacerbated in Rag-5xfAD mice as indicated by a shift in microglial phenotype, increased cytokine production, and reduced phagocytic capacity. In contrast, immune-intact 5xfAD mice exhibit elevated levels of nonamyloid reactive IgGs in association with microglia, and treatment of Rag-5xfAD mice or microglial cells with preimmune IgG enhances Aβ clearance. Last, we performed bone marrow transplantation studies in Rag-5xfAD mice, revealing that replacement of these missing adaptive immune populations can dramatically reduce AD pathology. Taken together, these data strongly suggest that adaptive immune cell populations play an important role in restraining AD pathology. In contrast, depletion of B cells and their appropriate activation by T cells leads to a loss of adaptive–innate immunity cross talk and accelerated disease progression. PMID:26884167

Innate and adaptive immune responses in male and female reproductive tracts in homeostasis and following HIV infection

PubMed Central

Nguyen, Philip V; Kafka, Jessica K; Ferreira, Victor H; Roth, Kristy; Kaushic, Charu

2014-01-01

The male and female reproductive tracts are complex microenvironments that have diverse functional demands. The immune system in the reproductive tract has the demanding task of providing a protective environment for a fetal allograft while simultaneously conferring protection against potential pathogens. As such, it has evolved a unique set of adaptations, primarily under the influence of sex hormones, which make it distinct from other mucosal sites. Here, we discuss the various components of the immune system that are present in both the male and female reproductive tracts, including innate soluble factors and cells and humoral and cell-mediated adaptive immunity under homeostatic conditions. We review the evidence showing unique phenotypic and functional characteristics of immune cells and responses in the male and female reproductive tracts that exhibit compartmentalization from systemic immunity and discuss how these features are influenced by sex hormones. We also examine the interactions among the reproductive tract, sex hormones and immune responses following HIV-1 infection. An improved understanding of the unique characteristics of the male and female reproductive tracts will provide insights into improving clinical treatments of the immunological causes of infertility and the design of prophylactic interventions for the prevention of sexually transmitted infections. PMID:24976268

B cells as multi-functional players during Mycobacterium tuberculosis infection and disease.

PubMed

du Plessis, Willem J; Walzl, Gerhard; Loxton, André G

2016-03-01

Immunity to tuberculosis is still understood to be driven and maintained by T-cell derived immune responses. With a steady influx of data, it is becoming clear that B cells, the mediators of humoral immunity, have the capacity to function in roles not previously appreciated within the traditional B cell dogma. In this review we aim to discuss B cells, from its generation through to its functioning as effectors in both the innate and adaptive immune response, within the tuberculosis domain. Copyright © 2015 Elsevier Ltd. All rights reserved.

Interleukin (IL)-33 and the IL-1 Family of Cytokines-Regulators of Inflammation and Tissue Homeostasis.

PubMed

Vasanthakumar, Ajithkumar; Kallies, Axel

2017-11-03

Cytokines play an integral role in shaping innate and adaptive immune responses. Members of the interleukin (IL)-1 family regulate a plethora of immune-cell-mediated processes, which include pathogen defense and tissue homeostasis. Notably, the IL-1 family cytokine IL-33 promotes adaptive and innate type 2 immune responses, confers viral protection and facilitates glucose metabolism and tissue repair. At the cellular level, IL-33 stimulates differentiation, maintenance, and function of various immune cell types, including regulatory T cells, effector CD4 + and CD8 + T cells, macrophages, and type 2 innate lymphoid cells (ILC2s). Other IL-1 family members, such as IL-1β and IL-18 promote type 1 responses, while IL-37 limits immune activation. Although IL-1 cytokines play critical roles in immunity and tissue repair, their deregulated expression is often linked to autoimmune and inflammatory diseases. Therefore, IL-1 cytokines are regulated tightly by posttranscriptional mechanisms and decoy receptors. In this review, we discuss the biology and function of IL-1 family cytokines, with a specific focus on regulation and function of IL-33 in immune and tissue homeostasis. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

Genomic Signatures of Selective Pressures and Introgression from Archaic Hominins at Human Innate Immunity Genes

PubMed Central

Deschamps, Matthieu; Laval, Guillaume; Fagny, Maud; Itan, Yuval; Abel, Laurent; Casanova, Jean-Laurent; Patin, Etienne; Quintana-Murci, Lluis

2016-01-01

Human genes governing innate immunity provide a valuable tool for the study of the selective pressure imposed by microorganisms on host genomes. A comprehensive, genome-wide study of how selective constraints and adaptations have driven the evolution of innate immunity genes is missing. Using full-genome sequence variation from the 1000 Genomes Project, we first show that innate immunity genes have globally evolved under stronger purifying selection than the remainder of protein-coding genes. We identify a gene set under the strongest selective constraints, mutations in which are likely to predispose individuals to life-threatening disease, as illustrated by STAT1 and TRAF3. We then evaluate the occurrence of local adaptation and detect 57 high-scoring signals of positive selection at innate immunity genes, variation in which has been associated with susceptibility to common infectious or autoimmune diseases. Furthermore, we show that most adaptations targeting coding variation have occurred in the last 6,000–13,000 years, the period at which populations shifted from hunting and gathering to farming. Finally, we show that innate immunity genes present higher Neandertal introgression than the remainder of the coding genome. Notably, among the genes presenting the highest Neandertal ancestry, we find the TLR6-TLR1-TLR10 cluster, which also contains functional adaptive variation in Europeans. This study identifies highly constrained genes that fulfill essential, non-redundant functions in host survival and reveals others that are more permissive to change—containing variation acquired from archaic hominins or adaptive variants in specific populations—improving our understanding of the relative biological importance of innate immunity pathways in natural conditions. PMID:26748513

E3 ubiquitin ligase Cbl-b in innate and adaptive immunity

PubMed Central

Liu, Qingjun; Zhou, Hong; Langdon, Wallace Y; Zhang, Jian

2014-01-01

Casitas B-lineage lymphoma proto-oncogene-b (Cbl-b), a RING finger E3 ubiquitin-protein ligase, has been demonstrated to play a crucial role in establishing the threshold for T-cell activation and controlling peripheral T-cell tolerance via multiple mechanisms. Accumulating evidence suggests that Cbl-b also regulates innate immune responses and plays an important role in host defense to pathogens. Understanding the signaling pathways regulated by Cbl-b in innate and adaptive immune cells is therefore essential for efficient manipulation of Cbl-b in emerging immunotherapies for human disorders such as autoimmune diseases, allergic inflammation, infections, and cancer. In this article, we review the latest developments in the molecular structural basis of Cbl-b function, the regulation of Cbl-b expression, the signaling mechanisms of Cbl-b in immune cells, as well as the biological function of Cbl-b in physiological and pathological immune responses in animal models and human diseases. PMID:24875217

PBMC transcriptome profiles identifies potential candidate genes and functional networks controlling the innate and the adaptive immune response to PRRSV vaccine in Pietrain pig

PubMed Central

Islam, Md. Aminul; Große-Brinkhaus, Christine; Pröll, Maren Julia; Uddin, Muhammad Jasim; Aqter Rony, Sharmin; Tesfaye, Dawit; Tholen, Ernst; Hoelker, Michael; Schellander, Karl; Neuhoff, Christiane

2017-01-01

The porcine reproductive and respiratory syndrome (PRRS) is a devastating viral disease affecting swine production, health and welfare throughout the world. A synergistic action of the innate and the adaptive immune system of the host is essential for mounting a durable protective immunity through vaccination. Therefore, the current study aimed to investigate the transcriptome profiles of peripheral blood mononuclear cells (PBMCs) to characterize the innate and the adaptive immune response to PRRS Virus (PRRSV) vaccination in Pietrain pigs. The Affymetrix gene chip porcine gene 1.0 ST array was used for the transcriptome profiling of PBMCs collected at immediately before (D0), at one (D1) and 28 days (D28) post PRRSV vaccination with three biological replications. With FDR <0.05 and log2 fold change ±1.5 as cutoff criteria, 295 and 115 transcripts were found to be differentially expressed in PBMCs during the stage of innate and adaptive response, respectively. The microarray expression results were technically validated by qRT-PCR. The gene ontology terms such as viral life cycle, regulation of lymphocyte activation, cytokine activity and inflammatory response were enriched during the innate immunity; cytolysis, T cell mediated cytotoxicity, immunoglobulin production were enriched during adaptive immunity to PRRSV vaccination. Significant enrichment of cytokine-cytokine receptor interaction, signaling by interleukins, signaling by the B cell receptor (BCR), viral mRNA translation, IFN-gamma pathway and AP-1 transcription factor network pathways were indicating the involvement of altered genes in the antiviral defense. Network analysis revealed that four network modules were functionally involved with the transcriptional network of innate immunity, and five modules were linked to adaptive immunity in PBMCs. The innate immune transcriptional network was found to be regulated by LCK, STAT3, ATP5B, UBB and RSP17. While TGFß1, IL7R, RAD21, SP1 and GZMB are likely to be predictive for the adaptive immune transcriptional response to PRRSV vaccine in PBMCs. Results of the current immunogenomics study advances our understanding of PRRS in term of host-vaccine interaction, and thereby contribute to design a rationale for disease control strategy. PMID:28278192

Control of antiviral immunity by pattern recognition and the microbiome

PubMed Central

Pang, Iris K.; Iwasaki, Akiko

2013-01-01

Summary Human skin and mucosal surfaces are in constant contact with resident and invasive microbes. Recognition of microbial products by receptors of the innate immune system triggers rapid innate defense and transduces signals necessary for initiating and maintaining the adaptive immune responses. Microbial sensing by innate pattern recognition receptors is not restricted to pathogens. Rather, proper development, function, and maintenance of innate and adaptive immunity rely on continuous recognition of products derived from the microorganisms indigenous to the internal and external surfaces of mammalian host. Tonic immune activation by the resident microbiota governs host susceptibility to intestinal and extra-intestinal infections including those caused by viruses. This review highlights recent developments in innate viral recognition leading to adaptive immunity, and discusses potential link between viruses, microbiota and the host immune system. Further, we discuss the possible roles of microbiome in chronic viral infection and pathogenesis of autoimmune disease, and speculate on the benefit for probiotic therapies against such diseases. PMID:22168422

[Immunological aspects of a piloted mission to Mars].

PubMed

Morukov, B V; Rykova, M P; Antropova, E N; Berendeeva, T A; Morukov, I B; Ponomarev, S A

2013-01-01

The paper deals with the results of the effects of 520-day isolation and confinement modeling some elements of a mission to Mars on the immune system. Longitudinal analyses revealed that the mechanisms of adaptive response of the human immune system to the conditions of extremely long isolation led to a change of the parameters, characterizing innate and adaptive immunity. Among them the most important are: changes in the signaling PRRs--TLR, manifested in the reduction of the percentage of circulating monocytes and granulocytes expressed on its own surfaces TLR2, TLR4 and TLR6, decreases early NK cell activation potential, increases in the percentage T- and B-lymphocytes, that expressed early activation marker CD69 after adequate stimulation, and in production of cytokines in response to PHA stimulation. The active mobilization of the mechanisms of adaptive immunity, the implementation of the function of the level of immunity to a qualitatively different level, apparently, should be taken as a sign of adaptive adjustment of an organism in response to the complex influence of unfavorable factors, aimed at the preservation of immune homeostasis.

Durable antitumor responses to CD47 blockade require adaptive immune stimulation

PubMed Central

Sockolosky, Jonathan T.; Dougan, Michael; Ingram, Jessica R.; Ho, Chia Chi M.; Kauke, Monique J.; Almo, Steven C.; Ploegh, Hidde L.; Garcia, K. Christopher

2016-01-01

Therapeutic antitumor antibodies treat cancer by mobilizing both innate and adaptive immunity. CD47 is an antiphagocytic ligand exploited by tumor cells to blunt antibody effector functions by transmitting an inhibitory signal through its receptor signal regulatory protein alpha (SIRPα). Interference with the CD47–SIRPα interaction synergizes with tumor-specific monoclonal antibodies to eliminate human tumor xenografts by enhancing macrophage-mediated antibody-dependent cellular phagocytosis (ADCP), but synergy between CD47 blockade and ADCP has yet to be demonstrated in immunocompetent hosts. Here, we show that CD47 blockade alone or in combination with a tumor-specific antibody fails to generate antitumor immunity against syngeneic B16F10 tumors in mice. Durable tumor immunity required programmed death-ligand 1 (PD-L1) blockade in combination with an antitumor antibody, with incorporation of CD47 antagonism substantially improving response rates. Our results highlight an underappreciated contribution of the adaptive immune system to anti-CD47 adjuvant therapy and suggest that targeting both innate and adaptive immune checkpoints can potentiate the vaccinal effect of antitumor antibody therapy. PMID:27091975

Stepwise cytoskeletal polarization as a series of checkpoints in innate but not adaptive cytolytic killing

NASA Astrophysics Data System (ADS)

Wülfing, Christoph; Purtic, Bozidar; Klem, Jennifer; Schatzle, John D.

2003-06-01

Cytolytic killing is a major effector mechanism in the elimination of virally infected and tumor cells. The innate cytolytic effectors, natural killer (NK) cells, and the adaptive effectors, cytotoxic T cells (CTL), despite differential immune recognition, both use the same lytic mechanism, cytolytic granule release. Using live cell video fluorescence microscopy in various primary cell models of NK cell and CTL killing, we show here that on tight target cell contact, a majority of the NK cells established cytoskeletal polarity required for effective lytic function slowly or incompletely. In contrast, CTLs established cytoskeletal polarity rapidly. In addition, NK cell killing was uniquely sensitive to minor interference with cytoskeletal dynamics. We propose that the stepwise NK cell cytoskeletal polarization constitutes a series of checkpoints in NK cell killing. In addition, the use of more deliberate progression to effector function to compensate for inferior immune recognition specificity provides a mechanistic explanation for how the same effector function can be used in the different functional contexts of the innate and adaptive immune response.

Impact of Depleting Therapeutic Monoclonal Antibodies on the Host Adaptive Immunity: A Bonus or a Malus?

PubMed Central

Deligne, Claire; Milcent, Benoît; Josseaume, Nathalie; Teillaud, Jean-Luc; Sibéril, Sophie

2017-01-01

Clinical responses to anti-tumor monoclonal antibody (mAb) treatment have been regarded for many years only as a consequence of the ability of mAbs to destroy tumor cells by innate immune effector mechanisms. More recently, it has also been shown that anti-tumor antibodies can induce a long-lasting anti-tumor adaptive immunity, likely responsible for durable clinical responses, a phenomenon that has been termed the vaccinal effect of antibodies. However, some of these anti-tumor antibodies are directed against molecules expressed both by tumor cells and normal immune cells, in particular lymphocytes, and, hence, can also strongly affect the host adaptive immunity. In addition to a delayed recovery of target cells, lymphocyte depleting-mAb treatments can have dramatic consequences on the adaptive immune cell network, its rebound, and its functional capacities. Thus, in this review, we will not only discuss the mAb-induced vaccinal effect that has emerged from experimental preclinical studies and clinical trials but also the multifaceted impact of lymphocytes-depleting therapeutic antibodies on the host adaptive immunity. We will also discuss some of the molecular and cellular mechanisms of action whereby therapeutic mAbs induce a long-term protective anti-tumor effect and the relationship between the mAb-induced vaccinal effect and the immune response against self-antigens. PMID:28855903

Viruses are a dominant driver of protein adaptation in mammals.

PubMed

Enard, David; Cai, Le; Gwennap, Carina; Petrov, Dmitri A

2016-05-17

Viruses interact with hundreds to thousands of proteins in mammals, yet adaptation against viruses has only been studied in a few proteins specialized in antiviral defense. Whether adaptation to viruses typically involves only specialized antiviral proteins or affects a broad array of virus-interacting proteins is unknown. Here, we analyze adaptation in ~1300 virus-interacting proteins manually curated from a set of 9900 proteins conserved in all sequenced mammalian genomes. We show that viruses (i) use the more evolutionarily constrained proteins within the cellular functions they interact with and that (ii) despite this high constraint, virus-interacting proteins account for a high proportion of all protein adaptation in humans and other mammals. Adaptation is elevated in virus-interacting proteins across all functional categories, including both immune and non-immune functions. We conservatively estimate that viruses have driven close to 30% of all adaptive amino acid changes in the part of the human proteome conserved within mammals. Our results suggest that viruses are one of the most dominant drivers of evolutionary change across mammalian and human proteomes.

Viruses are a dominant driver of protein adaptation in mammals

PubMed Central

Enard, David; Cai, Le; Gwennap, Carina; Petrov, Dmitri A

2016-01-01

Viruses interact with hundreds to thousands of proteins in mammals, yet adaptation against viruses has only been studied in a few proteins specialized in antiviral defense. Whether adaptation to viruses typically involves only specialized antiviral proteins or affects a broad array of virus-interacting proteins is unknown. Here, we analyze adaptation in ~1300 virus-interacting proteins manually curated from a set of 9900 proteins conserved in all sequenced mammalian genomes. We show that viruses (i) use the more evolutionarily constrained proteins within the cellular functions they interact with and that (ii) despite this high constraint, virus-interacting proteins account for a high proportion of all protein adaptation in humans and other mammals. Adaptation is elevated in virus-interacting proteins across all functional categories, including both immune and non-immune functions. We conservatively estimate that viruses have driven close to 30% of all adaptive amino acid changes in the part of the human proteome conserved within mammals. Our results suggest that viruses are one of the most dominant drivers of evolutionary change across mammalian and human proteomes. DOI: http://dx.doi.org/10.7554/eLife.12469.001 PMID:27187613

Immune-Related Functions of the Hivep Gene Family in East African Cichlid Fishes

PubMed Central

Diepeveen, Eveline T.; Roth, Olivia; Salzburger, Walter

2013-01-01

Immune-related genes are often characterized by adaptive protein evolution. Selection on immune genes can be particularly strong when hosts encounter novel parasites, for instance, after the colonization of a new habitat or upon the exploitation of vacant ecological niches in an adaptive radiation. We examined a set of new candidate immune genes in East African cichlid fishes. More specifically, we studied the signatures of selection in five paralogs of the human immunodeficiency virus type I enhancer-binding protein (Hivep) gene family, tested their involvement in the immune defense, and related our results to explosive speciation and adaptive radiation events in cichlids. We found signatures of long-term positive selection in four Hivep paralogs and lineage-specific positive selection in Hivep3b in two radiating cichlid lineages. Exposure of the cichlid Astatotilapia burtoni to a vaccination with Vibrio anguillarum bacteria resulted in a positive correlation between immune response parameters and expression levels of three Hivep loci. This work provides the first evidence for a role of Hivep paralogs in teleost immune defense and links the signatures of positive selection to host–pathogen interactions within an adaptive radiation. PMID:24142922

An evolving new paradigm: endothelial cells – conditional innate immune cells

PubMed Central

2013-01-01

Endothelial cells (ECs) are a heterogeneous population that fulfills many physiological processes. ECs also actively participate in both innate and adaptive immune responses. ECs are one of the first cell types to detect foreign pathogens and endogenous metabolite-related danger signals in the bloodstream, in which ECs function as danger signal sensors. Treatment with lipopolysaccharide activates ECs, causing the production of pro-inflammatory cytokines and chemokines, which amplify the immune response by recruiting immune cells. Thus, ECs function as immune/inflammation effectors and immune cell mobilizers. ECs also induce cytokine production by immune cells, in which ECs function as immune regulators either by activating or suppressing immune cell function. In addition, under certain conditions, ECs can serve as antigen presenting cells (antigen presenters) by expressing both MHC I and II molecules and presenting endothelial antigens to T cells. These facts along with the new concept of endothelial plasticity suggest that ECs are dynamic cells that respond to extracellular environmental changes and play a meaningful role in immune system function. Based on these novel EC functions, we propose a new paradigm that ECs are conditional innate immune cells. This paradigm provides a novel insight into the functions of ECs in inflammatory/immune pathologies. PMID:23965413

An evolving new paradigm: endothelial cells--conditional innate immune cells.

PubMed

Mai, Jietang; Virtue, Anthony; Shen, Jerry; Wang, Hong; Yang, Xiao-Feng

2013-08-22

Endothelial cells (ECs) are a heterogeneous population that fulfills many physiological processes. ECs also actively participate in both innate and adaptive immune responses. ECs are one of the first cell types to detect foreign pathogens and endogenous metabolite-related danger signals in the bloodstream, in which ECs function as danger signal sensors. Treatment with lipopolysaccharide activates ECs, causing the production of pro-inflammatory cytokines and chemokines, which amplify the immune response by recruiting immune cells. Thus, ECs function as immune/inflammation effectors and immune cell mobilizers. ECs also induce cytokine production by immune cells, in which ECs function as immune regulators either by activating or suppressing immune cell function. In addition, under certain conditions, ECs can serve as antigen presenting cells (antigen presenters) by expressing both MHC I and II molecules and presenting endothelial antigens to T cells. These facts along with the new concept of endothelial plasticity suggest that ECs are dynamic cells that respond to extracellular environmental changes and play a meaningful role in immune system function. Based on these novel EC functions, we propose a new paradigm that ECs are conditional innate immune cells. This paradigm provides a novel insight into the functions of ECs in inflammatory/immune pathologies.

Immune cells in term and preterm labor

PubMed Central

Gomez-Lopez, Nardhy; StLouis, Derek; Lehr, Marcus A; Sanchez-Rodriguez, Elly N; Arenas-Hernandez, Marcia

2014-01-01

Labor resembles an inflammatory response that includes secretion of cytokines/chemokines by resident and infiltrating immune cells into reproductive tissues and the maternal/fetal interface. Untimely activation of these inflammatory pathways leads to preterm labor, which can result in preterm birth. Preterm birth is a major determinant of neonatal mortality and morbidity; therefore, the elucidation of the process of labor at a cellular and molecular level is essential for understanding the pathophysiology of preterm labor. Here, we summarize the role of innate and adaptive immune cells in the physiological or pathological activation of labor. We review published literature regarding the role of innate and adaptive immune cells in the cervix, myometrium, fetal membranes, decidua and the fetus in late pregnancy and labor at term and preterm. Accumulating evidence suggests that innate immune cells (neutrophils, macrophages and mast cells) mediate the process of labor by releasing pro-inflammatory factors such as cytokines, chemokines and matrix metalloproteinases. Adaptive immune cells (T-cell subsets and B cells) participate in the maintenance of fetomaternal tolerance during pregnancy, and an alteration in their function or abundance may lead to labor at term or preterm. Also, immune cells that bridge the innate and adaptive immune systems (natural killer T (NKT) cells and dendritic cells (DCs)) seem to participate in the pathophysiology of preterm labor. In conclusion, a balance between innate and adaptive immune cells is required in order to sustain pregnancy; an alteration of this balance will lead to labor at term or preterm. PMID:24954221

A cascade reaction network mimicking the basic functional steps of adaptive immune response

NASA Astrophysics Data System (ADS)

Han, Da; Wu, Cuichen; You, Mingxu; Zhang, Tao; Wan, Shuo; Chen, Tao; Qiu, Liping; Zheng, Zheng; Liang, Hao; Tan, Weihong

2015-10-01

Biological systems use complex ‘information-processing cores’ composed of molecular networks to coordinate their external environment and internal states. An example of this is the acquired, or adaptive, immune system (AIS), which is composed of both humoral and cell-mediated components. Here we report the step-by-step construction of a prototype mimic of the AIS that we call an adaptive immune response simulator (AIRS). DNA and enzymes are used as simple artificial analogues of the components of the AIS to create a system that responds to specific molecular stimuli in vitro. We show that this network of reactions can function in a manner that is superficially similar to the most basic responses of the vertebrate AIS, including reaction sequences that mimic both humoral and cellular responses. As such, AIRS provides guidelines for the design and engineering of artificial reaction networks and molecular devices.

Transcription Factor Networks Directing the Development, Function, and Evolution of Innate Lymphoid Effectors

PubMed Central

Kang, Joonsoo; Malhotra, Nidhi

2015-01-01

Mammalian lymphoid immunity is mediated by fast and slow responders to pathogens. Fast innate lymphocytes are active within hours after infections in mucosal tissues. Slow adaptive lymphocytes are conventional T and B cells with clonal antigen receptors that function days after pathogen exposure. A transcription factor (TF) regulatory network guiding early T cell development is at the core of effector function diversification in all innate lymphocytes, and the kinetics of immune responses is set by developmental programming. Operational units within the innate lymphoid system are not classified by the types of pathogen-sensing machineries but rather by discrete effector functions programmed by regulatory TF networks. Based on the evolutionary history of TFs of the regulatory networks, fast effectors likely arose earlier in the evolution of animals to fortify body barriers, and in mammals they often develop in fetal ontogeny prior to the establishment of fully competent adaptive immunity. PMID:25650177

Impact of Chronic Viral Infection on T-Cell Dependent Humoral Immune Response.

PubMed

Rodriguez, Stéphane; Roussel, Mikaël; Tarte, Karin; Amé-Thomas, Patricia

2017-01-01

During the last decades, considerable efforts have been done to decipher mechanisms supported by microorganisms or viruses involved in the development, differentiation, and function of immune cells. Pathogens and their associated secretome as well as the continuous inflammation observed in chronic infection are shaping both innate and adaptive immunity. Secondary lymphoid organs are functional structures ensuring the mounting of adaptive immune response against microorganisms and viruses. Inside these organs, germinal centers (GCs) are the specialized sites where mature B-cell differentiation occurs leading to the release of high-affinity immunoglobulin (Ig)-secreting cells. Different steps are critical to complete B-cell differentiation process, including proliferation, somatic hypermutations in Ig variable genes, affinity-based selection, and class switch recombination. All these steps require intense interactions with cognate CD4 + helper T cells belonging to follicular helper lineage. Interestingly, pathogens can disturb this subtle machinery affecting the classical adaptive immune response. In this review, we describe how viruses could act directly on GC B cells, either through B-cell infection or by their contribution to B-cell cancer development and maintenance. In addition, we depict the indirect impact of viruses on B-cell response through infection of GC T cells and stromal cells, leading to immune response modulation.

Haematopoietic development and immunological function in the absence of cathepsin D

PubMed Central

Tulone, Calogero; Uchiyama, Yasuo; Novelli, Marco; Grosvenor, Nicholas; Saftig, Paul; Chain, Benjamin M

2007-01-01

Background Cathepsin D is a well-characterized aspartic protease expressed ubiquitously in lysosomes. Cathepsin D deficiency is associated with a spectrum of pathologies leading ultimately to death. Cathepsin D is expressed at high levels in many cells of the immune system, but its role in immune function is not well understood. This study examines the reconstitution and function of the immune system in the absence of cathepsin D, using bone marrow radiation chimaeras in which all haematopoietic cells are derived from cathepsin D deficient mice. Results Cathepsin D deficient bone marrow cells fully reconstitute the major cellular components of both the adaptive and innate immune systems. Spleen cells from cathepsin D deficient chimaeric mice contained an increased number of autofluorescent granules characteristic of lipofuscin positive lysosomal storage diseases. Biochemical and ultrastructural changes in cathepsin D deficient spleen are consistent with increased autolysosomal activity. Chimaeric mice were immunised with either soluble (dinitrophenylated bovine gamma globulin) or particulate (sheep red blood cells) antigens. Both antigens induced equivalent immune responses in wild type or cathepsin D deficient chimaeras. Conclusion All the parameters of haematopoietic reconstitution and adaptive immunity which were measured in this study were found to be normal in the absence of cathepsin D, even though cathepsin D deficiency leads to dysregulation of lysosomal function. PMID:17897442

CRISPR-Cas systems: prokaryotes upgrade to adaptive immunity

PubMed Central

Barrangou, Rodolphe; Marraffini, Luciano A.

2014-01-01

Summary Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), and associated proteins (Cas) comprise the CRISPR-Cas system, which confers adaptive immunity against exogenic elements in many bacteria and most archaea. CRISPR-mediated immunization occurs through the uptake of DNA from invasive genetic elements such as plasmids and viruses, followed by its integration into CRISPR loci. These loci are subsequently transcribed and processed into small interfering RNAs that guide nucleases for specific cleavage of complementary sequences. Conceptually, CRISPR-Cas shares functional features with the mammalian adaptive immune system, while also exhibiting characteristics of Lamarckian evolution. Because immune markers spliced from exogenous agents are integrated iteratively in CRISPR loci, they constitute a genetic record of vaccination events and reflect environmental conditions and changes over time. Cas endonucleases, which can be reprogrammed by small guide RNAs have shown unprecedented potential and flexibility for genome editing, and can be repurposed for numerous DNA targeting applications including transcriptional control. PMID:24766887

In-Vitro Induced Immunosuppression in a Rotary Cell Culture System

NASA Technical Reports Server (NTRS)

Grimm, Elizabeth A.

1998-01-01

The function of the innate immune system is to provide a first-line of defense against infectious organisms, via control of bacterial and viral growth using antigen nonspecific means. These nonspecific immune effectors include macrophages and Natural Killing (NK) cells, and certain cytokines elicited in response to "super antigens" on the infectious agents. This innate system usually keeps most infectious agents from rapidly growing while the adaptive immune system is generating a specific response complete with immunologic memory. Compelling evidence suggests that space flight results in various immunosuppressive effects, including reduced innate and adaptive immune responses. We were particularly concerned with reduced NK activity at landing, and have asked whether the microgravity component of space flight could be responsible for the previously observed NK defect. We have conclusively demonstrated that simulated microgravity as provided by the Synthecon bioreactors does not inhibit the NK function nor the IL-2 activation of lymphokine-activated killing (LAK). Interleukin-2 is the key cytokine responsible for activation of NK cells to express LAK, as well as to support differentiation of lymphocytes during adaptive immune responses. Therefore, we have disproved our original hypothesis based on poor NK in many of the astronauts upon landing.

EVALUATING THE IMPACTS OF COINFECTION ON IMMUNE SYSTEM FUNCTION OF THE DEER MOUSE ( PEROMYSCUS MANICULATUS) USING SIN NOMBRE VIRUS AND BARTONELLA AS MODEL PATHOGEN SYSTEMS.

PubMed

Lehmer, Erin M; Lavengood, Kathryn; Miller, Mason; Rodgers, Jacob; Fenster, Steven D

2018-01-01

:  Simultaneous infections with multiple pathogens can alter the function of the host's immune system, often resulting in additive or synergistic morbidity. We examined how coinfection with the common pathogens Sin Nombre virus (SNV) and Bartonella sp. affected aspects of the adaptive and innate immune responses of wild deer mice ( Peromyscus maniculatus). Adaptive immunity was assessed by measuring SNV antibody production; innate immunity was determined by measuring levels of C-reactive protein (CRP) in blood and the complement activity of plasma. Coinfected mice had reduced plasma complement activity and higher levels of CRP compared to mice infected with either SNV or Bartonella. However, antibody titers of deer mice infected with SNV were more than double those of coinfected mice. Plasma complement activity and CRP levels did not differ between uninfected deer mice and those infected with only Bartonella, suggesting that comorbid SNV and Bartonella infections act synergistically, altering the innate immune response. Collectively, our results indicated that the immune response of deer mice coinfected with both SNV and Bartonella differed substantially from individuals infected with only one of these pathogens. Results of our study provided unique, albeit preliminary, insight into the impacts of coinfection on immune system function in wild animal hosts and underscore the complexity of the immune pathways that exist in coinfected hosts.

Targeting complement-mediated immunoregulation for cancer immunotherapy.

PubMed

Kolev, Martin; Markiewski, Maciej M

2018-06-01

Complement was initially discovered as an assembly of plasma proteins "complementing" the cytolytic activity of antibodies. However, our current knowledge places this complex system of several plasma proteins, receptors, and regulators in the center of innate immunity as a bridge between the initial innate responses and adaptive immune reactions. Consequently, complement appears to be pivotal for elimination of pathogens, not only as an early response defense, but by directing the subsequent adaptive immune response. The discovery of functional intracellular complement and its roles in cellular metabolism opened novel avenues for research and potential therapeutic implications. The recent studies demonstrating immunoregulatory functions of complement in the tumor microenvironment and the premetastatic niche shifted the paradigm on our understanding of functions of the complement system in regulating immunity. Several complement proteins, through their interaction with cells in the tumor microenvironment and in metastasis-targeted organs, contribute to modulating tumor growth, antitumor immunity, angiogenesis, and therefore, the overall progression of malignancy and, perhaps, responsiveness of cancer to different therapies. Here, we focus on recent progress in our understanding of immunostimulatory vs. immunoregulatory functions of complement and potential applications of these findings to the design of novel therapies for cancer patients. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evolutionary Genomics of Defense Systems in Archaea and Bacteria*

PubMed Central

Koonin, Eugene V.; Makarova, Kira S.; Wolf, Yuri I.

2018-01-01

Evolution of bacteria and archaea involves an incessant arms race against an enormous diversity of genetic parasites. Accordingly, a substantial fraction of the genes in most bacteria and archaea are dedicated to antiparasite defense. The functions of these defense systems follow several distinct strategies, including innate immunity; adaptive immunity; and dormancy induction, or programmed cell death. Recent comparative genomic studies taking advantage of the expanding database of microbial genomes and metagenomes, combined with direct experiments, resulted in the discovery of several previously unknown defense systems, including innate immunity centered on Argonaute proteins, bacteriophage exclusion, and new types of CRISPR-Cas systems of adaptive immunity. Some general principles of function and evolution of defense systems are starting to crystallize, in particular, extensive gain and loss of defense genes during the evolution of prokaryotes; formation of genomic defense islands; evolutionary connections between mobile genetic elements and defense, whereby genes of mobile elements are repeatedly recruited for defense functions; the partially selfish and addictive behavior of the defense systems; and coupling between immunity and dormancy induction/programmed cell death. PMID:28657885

Repeat-containing protein effectors of plant-associated organisms

PubMed Central

Mesarich, Carl H.; Bowen, Joanna K.; Hamiaux, Cyril; Templeton, Matthew D.

2015-01-01

Many plant-associated organisms, including microbes, nematodes, and insects, deliver effector proteins into the apoplast, vascular tissue, or cell cytoplasm of their prospective hosts. These effectors function to promote colonization, typically by altering host physiology or by modulating host immune responses. The same effectors however, can also trigger host immunity in the presence of cognate host immune receptor proteins, and thus prevent colonization. To circumvent effector-triggered immunity, or to further enhance host colonization, plant-associated organisms often rely on adaptive effector evolution. In recent years, it has become increasingly apparent that several effectors of plant-associated organisms are repeat-containing proteins (RCPs) that carry tandem or non-tandem arrays of an amino acid sequence or structural motif. In this review, we highlight the diverse roles that these repeat domains play in RCP effector function. We also draw attention to the potential role of these repeat domains in adaptive evolution with regards to RCP effector function and the evasion of effector-triggered immunity. The aim of this review is to increase the profile of RCP effectors from plant-associated organisms. PMID:26557126

Repeat-containing protein effectors of plant-associated organisms.

PubMed

Mesarich, Carl H; Bowen, Joanna K; Hamiaux, Cyril; Templeton, Matthew D

2015-01-01

Many plant-associated organisms, including microbes, nematodes, and insects, deliver effector proteins into the apoplast, vascular tissue, or cell cytoplasm of their prospective hosts. These effectors function to promote colonization, typically by altering host physiology or by modulating host immune responses. The same effectors however, can also trigger host immunity in the presence of cognate host immune receptor proteins, and thus prevent colonization. To circumvent effector-triggered immunity, or to further enhance host colonization, plant-associated organisms often rely on adaptive effector evolution. In recent years, it has become increasingly apparent that several effectors of plant-associated organisms are repeat-containing proteins (RCPs) that carry tandem or non-tandem arrays of an amino acid sequence or structural motif. In this review, we highlight the diverse roles that these repeat domains play in RCP effector function. We also draw attention to the potential role of these repeat domains in adaptive evolution with regards to RCP effector function and the evasion of effector-triggered immunity. The aim of this review is to increase the profile of RCP effectors from plant-associated organisms.

No evidence of local adaptation of immune responses to Gyrodactylus in three-spined stickleback (Gasterosteus aculeatus).

PubMed

Robertson, Shaun; Bradley, Janette E; MacColl, Andrew D C

2017-01-01

Parasitism represents one of the most widespread lifestyles in the animal kingdom, with the potential to drive coevolutionary dynamics with their host population. Where hosts and parasites evolve together, we may find local adaptation. As one of the main host defences against infection, there is the potential for the immune response to be adapted to local parasites. In this study, we used the three-spined stickleback and its Gyrodactylus parasites to examine the extent of local adaptation of parasite infection dynamics and the immune response to infection. We took two geographically isolated host populations infected with two distinct Gyrodactylus species and performed a reciprocal cross-infection experiment in controlled laboratory conditions. Parasite burdens were monitored over the course of the infection, and individuals were sampled at multiple time points for immune gene expression analysis. We found large differences in virulence between parasite species, irrespective of host, and maladaptation of parasites to their sympatric host. The immune system responded to infection, with a decrease in expression of innate and Th1-type adaptive response genes in fish infected with the less virulent parasite, representing a marker of a possible resistance mechanism. There was no evidence of local adaptation in immune gene expression levels. Our results add to the growing understanding of the extent of host-parasite local adaptation, and demonstrate a systemic immune response during infection with a common ectoparasite. Further immunological studies using the stickleback-Gyrodactylus system can continue to contribute to our understanding of the function of the immune response in natural populations. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Chronic grouped social restriction triggers long-lasting immune system adaptations.

PubMed

Tian, Rui; Hou, Gonglin; Song, Liuwei; Zhang, Jianming; Yuan, Ti-Fei

2017-05-16

Chronic stress triggers rigorous psychological and physiological changes, including immunological system adaptations. However, the effects of long-term social restriction on human immune system have not been investigated. The present study is to investigate the effect of chronic stress on immune changes in human blood, with the stress stimuli controlled.10 male volunteers were group isolated from the modern society in a 50-meter-square room for 150 days, with enriched nutrition and good living conditions provided. Serum examination of immune system markers demonstrated numerous changes in different aspects of the immune functions. The changes were observed as early as 30 days and could last for another 150 days after the termination of the restriction period (300 days' time point). The results strongly argued for the adaptation of immunological system under chronic social restriction stress in adult human, preceding a clear change in psychological conditions. The changes of these immune system factors could as well act as the serum biomarkers in clinical early-diagnosis of stress-related disorders.

Effects of stress on immune function: the good, the bad, and the beautiful.

PubMed

Dhabhar, Firdaus S

2014-05-01

Although the concept of stress has earned a bad reputation, it is important to recognize that the adaptive purpose of a physiological stress response is to promote survival during fight or flight. While long-term stress is generally harmful, short-term stress can be protective as it prepares the organism to deal with challenges. This review discusses the immune effects of biological stress responses that can be induced by psychological, physiological, or physical (including exercise) stressors. We have proposed that short-term stress is one of the nature's fundamental but under-appreciated survival mechanisms that could be clinically harnessed to enhance immunoprotection. Short-term (i.e., lasting for minutes to hours) stress experienced during immune activation enhances innate/primary and adaptive/secondary immune responses. Mechanisms of immuno-enhancement include changes in dendritic cell, neutrophil, macrophage, and lymphocyte trafficking, maturation, and function as well as local and systemic production of cytokines. In contrast, long-term stress suppresses or dysregulates innate and adaptive immune responses by altering the Type 1-Type 2 cytokine balance, inducing low-grade chronic inflammation, and suppressing numbers, trafficking, and function of immunoprotective cells. Chronic stress may also increase susceptibility to some types of cancer by suppressing Type 1 cytokines and protective T cells and increasing regulatory/suppressor T cell function. Here, we classify immune responses as being protective, pathological, or regulatory, and discuss "good" versus "bad" effects of stress on health. Thus, short-term stress can enhance the acquisition and/or expression of immunoprotective (wound healing, vaccination, anti-infectious agent, anti-tumor) or immuno-pathological (pro-inflammatory, autoimmune) responses. In contrast, chronic stress can suppress protective immune responses and/or exacerbate pathological immune responses. Studies such as the ones discussed here could provide mechanistic targets and conceptual frameworks for pharmacological and/or biobehavioral interventions designed to enhance the effects of "good" stress, minimize the effects of "bad" stress, and maximally promote health and healing.

Current understanding of HIV-1 and T-cell adaptive immunity: progress to date.

PubMed

Mohan, Teena; Bhatnagar, Santwana; Gupta, Dablu L; Rao, D N

2014-08-01

The cellular immune response to human immunodeficiency virus (HIV) has different components originating from both the adaptive and innate immune systems. HIV cleverly utilizes the host machinery to survive by its intricate nature of interaction with the host immune system. HIV evades the host immune system at innate ad adaptive, allows the pathogen to replicate and transmit from one host to another. Researchers have shown that HIV has multipronged effects especially on the adaptive immunity, with CD4(+) cells being the worst effect T-cell populations. Various analyses have revealed that, the exposure to HIV results in clonal expansion and excessive activation of the immune system. Also, an abnormal process of differentiation has been observed suggestive of an alteration and blocks in the maturation of various T-cell subsets. Additionally, HIV has shown to accelerate immunosenescence and exhaustion of the overtly activated T-cells. Apart from causing phenotypic changes, HIV has adverse effects on the functional aspect of the immune system, with evidences implicating it in the loss of the capacity of T-cells to secrete various antiviral cytokines and chemokines. However, there continues to be many aspects of the immune- pathogenesis of HIV that are still unknown and thus required further research in order to convert the malaise of HIV into a manageable epidemic. Copyright © 2014 Elsevier Ltd. All rights reserved.

Herpes simplex virus-2 in the genital mucosa: insights into the mucosal host response and vaccine development.

PubMed

Lee, Amanda J; Ashkar, Ali A

2012-02-01

Herpes simplex virus (HSV)-2 is the predominant cause of genital herpes and has been implicated in HIV infection and transmission. Thus far, vaccines developed against HSV-2 have been clinically ineffective in preventing infection. This review aims to summarize the innate and adaptive immune responses against HSV-2 and examines the current status of vaccine development. Both innate and adaptive immune responses are essential for an effective primary immune response and the generation of immunity. The innate response involves Toll-like receptors, natural killer cells, plasmacytoid dendritic cells, and type I, II, and III interferons. The adaptive response requires a balance between CD4+ and CD8+ T-cells for optimal viral clearance. T-regulatory cells may be involved, although their exact function has yet to be determined. Current vaccine development involves the use of HSV-2 peptides or attenuated/replication-defective HSV-2 to generate adaptive anti-HSV-2 immune responses, however the generation of innate responses may also be an important consideration. Although vaccine development has primarily focused on the adaptive response, arguments for innate involvement are emerging. A greater understanding of the innate and adaptive processes underlying the response to HSV-2 infection will provide the foundation for the development of an effective vaccine.

Functional Identification of Dendritic Cells in the Teleost Model, Rainbow Trout (Oncorhynchus mykiss)

PubMed Central

Bassity, Elizabeth; Clark, Theodore G.

2012-01-01

Dendritic cells are specialized antigen presenting cells that bridge innate and adaptive immunity in mammals. This link between the ancient innate immune system and the more evolutionarily recent adaptive immune system is of particular interest in fish, the oldest vertebrates to have both innate and adaptive immunity. It is unknown whether dendritic cells co-evolved with the adaptive response, or if the connection between innate and adaptive immunity relied on a fundamentally different cell type early in evolution. We approached this question using the teleost model organism, rainbow trout (Oncorhynchus mykiss), with the aim of identifying dendritic cells based on their ability to stimulate naïve T cells. Adapting mammalian protocols for the generation of dendritic cells, we established a method of culturing highly motile, non-adherent cells from trout hematopoietic tissue that had irregular membrane processes and expressed surface MHCII. When side-by-side mixed leukocyte reactions were performed, these cells stimulated greater proliferation than B cells or macrophages, demonstrating their specialized ability to present antigen and therefore their functional homology to mammalian dendritic cells. Trout dendritic cells were then further analyzed to determine if they exhibited other features of mammalian dendritic cells. Trout dendritic cells were found to have many of the hallmarks of mammalian DCs including tree-like morphology, the expression of dendritic cell markers, the ability to phagocytose small particles, activation by toll-like receptor-ligands, and the ability to migrate in vivo. As in mammals, trout dendritic cells could be isolated directly from the spleen, or larger numbers could be derived from hematopoietic tissue and peripheral blood mononuclear cells in vitro. PMID:22427987

Validating the pivotal role of the immune system in low-dose radiation-induced tumor inhibition in Lewis lung cancer-bearing mice.

PubMed

Zhou, Lei; Zhang, Xiaoying; Li, Hui; Niu, Chao; Yu, Dehai; Yang, Guozi; Liang, Xinyue; Wen, Xue; Li, Min; Cui, Jiuwei

2018-04-01

Although low-dose radiation (LDR) possesses the two distinct functions of inducing hormesis and adaptive responses, which result in immune enhancement and tumor inhibition, its clinical applications have not yet been elucidated. The major obstacle that hinders the application of LDR in the clinical setting is that the mechanisms underlying induction of tumor inhibition are unclear, and the risks associated with LDR are still unknown. Thus, to overcome this obstacle and elucidate the mechanisms mediating the antitumor effects of LDR, in this study, we established an in vivo lung cancer model to investigate the participation of the immune system in LDR-induced tumor inhibition and validated the pivotal role of the immune system by impairing immunity with high-dose radiation (HDR) of 1 Gy. Additionally, the LDR-induced adaptive response of the immune system was also observed by sequential HDR treatment in this mouse model. We found that LDR-activated T cells and natural killer cells and increased the cytotoxicity of splenocytes and the infiltration of T cells in the tumor tissues. In contrast, when immune function was impaired by HDR pretreatment, LDR could not induce tumor inhibition. However, when LDR was administered before HDR, the immunity could be protected from impairment, and tumor growth could be inhibited to some extent, indicating the induction of the immune adaptive response by LDR. Therefore, we demonstrated that immune enhancement played a key role in LDR-induced tumor inhibition. These findings emphasized the importance of the immune response in tumor radiotherapy and may help promote the application of LDR as a novel approach in clinical practice. © 2018 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Amino acid catabolism: a pivotal regulator of innate and adaptive immunity

PubMed Central

McGaha, Tracy L.; Huang, Lei; Lemos, Henrique; Metz, Richard; Mautino, Mario; Prendergast, George C.; Mellor, Andrew L.

2014-01-01

Summary Enhanced amino acid catabolism is a common response to inflammation, but the immunologic significance of altered amino acid consumption remains unclear. The finding that tryptophan catabolism helped maintain fetal tolerance during pregnancy provided novel insights into the significance of amino acid metabolism in controlling immunity. Recent advances in identifying molecular pathways that enhance amino acid catabolism and downstream mechanisms that affect immune cells in response to inflammatory cues support the notion that amino acid catabolism regulates innate and adaptive immune cells in pathologic settings. Cells expressing enzymes that degrade amino acids modulate antigen-presenting cell and lymphocyte functions and reveal critical roles for amino acid- and catabolite-sensing pathways in controlling gene expression, functions, and survival of immune cells. Basal amino acid catabolism may contribute to immune homeostasis that prevents autoimmunity, whereas elevated amino acid catalytic activity may reinforce immune suppression to promote tumorigenesis and persistence of some pathogens that cause chronic infections. For these reasons, there is considerable interest in generating novel drugs that inhibit or induce amino acid consumption and target downstream molecular pathways that control immunity. In this review, we summarize recent developments and highlight novel concepts and key outstanding questions in this active research field. PMID:22889220

The Immune System and Developmental Programming of Brain and Behavior

PubMed Central

Bilbo, Staci D.; Schwarz, Jaclyn M.

2012-01-01

The brain, endocrine, and immune systems are inextricably linked. Immune molecules have a powerful impact on neuroendocrine function, including hormone-behavior interactions, during health as well as sickness. Similarly, alterations in hormones, such as during stress, can powerfully impact immune function or reactivity. These functional shifts are evolved, adaptive responses that organize changes in behavior and mobilize immune resources, but can also lead to pathology or exacerbate disease if prolonged or exaggerated. The developing brain in particular is exquisitely sensitive to both endogenous and exogenous signals, and increasing evidence suggests the immune system has a critical role in brain development and associated behavioral outcomes for the life of the individual. Indeed, there are associations between many neuropsychiatric disorders and immune dysfunction, with a distinct etiology in neurodevelopment. The goal of this review is to describe the important role of the immune system during brain development, and to discuss some of the many ways in which immune activation during early brain development can affect the later-life outcomes of neural function, immune function, mood and cognition. PMID:22982535

Fatal autoimmunity in mice reconstituted with human hematopoietic stem cells encoding defective FOXP3

PubMed Central

Goettel, Jeremy A.; Biswas, Subhabrata; Lexmond, Willem S.; Yeste, Ada; Passerini, Laura; Patel, Bonny; Yang, Siyoung; Sun, Jiusong; Ouahed, Jodie; Shouval, Dror S.; McCann, Katelyn J.; Horwitz, Bruce H.; Mathis, Diane; Milford, Edgar L.; Notarangelo, Luigi D.; Roncarolo, Maria-Grazia; Fiebiger, Edda; Marasco, Wayne A.; Bacchetta, Rosa; Quintana, Francisco J.; Pai, Sung-Yun; Klein, Christoph; Muise, Aleixo M.

2015-01-01

Mice reconstituted with a human immune system provide a tractable in vivo model to assess human immune cell function. To date, reconstitution of murine strains with human hematopoietic stem cells (HSCs) from patients with monogenic immune disorders have not been reported. One obstacle precluding the development of immune-disease specific “humanized” mice is that optimal adaptive immune responses in current strains have required implantation of autologous human thymic tissue. To address this issue, we developed a mouse strain that lacks murine major histocompatibility complex class II (MHC II) and instead expresses human leukocyte antigen DR1 (HLA-DR1). These mice displayed improved adaptive immune responses when reconstituted with human HSCs including enhanced T-cell reconstitution, delayed-type hypersensitivity responses, and class-switch recombination. Following immune reconstitution of this novel strain with HSCs from a patient with immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome, associated with aberrant FOXP3 function, mice developed a lethal inflammatory disorder with multiorgan involvement and autoantibody production mimicking the pathology seen in affected humans. This humanized mouse model permits in vivo evaluation of immune responses associated with genetically altered HSCs, including primary immunodeficiencies, and should facilitate the study of human immune pathobiology and the development of targeted therapeutics. PMID:25833964

SIRT1 and HIF1α signaling in metabolism and immune responses.

PubMed

Yu, Qing; Dong, Lin; Li, Yan; Liu, Gaungwei

2018-04-01

SIRT1 and HIF1α are regarded as two key metabolic sensors in cellular metabolism pathways and play vital roles in influencing immune responses. SIRT1 and HIF1α regulate immune responses in metabolism-dependent and -independent ways. Here, we summarized the recent knowledge of SIRT1 and HIF1α signaling in metabolism and immune responses. HIF1α is a direct target of SIRT1. Sometimes, SIRT1 and HIF1α cooperate or act separately to mediate immune responses. In innate immune responses, SIRT1 can regulate the glycolytic activity of myeloid-derived suppressor cells (MDSCs) and influence MDSC functional differentiation. SIRT1 can regulate monocyte function through NF-κB and PGC-1, accompanying an increased NAD + level. The SIRT1-HIF1α axis bridges the innate immune signal to an adaptive immune response by directing cytokine production of dendritic cells in a metabolism-independent manner, promoting the differentiation of CD4 + T cells. For adaptive immune cells, SIRT1 can mediate the differentiation of inflammatory T cell subsets in a NAD + -dependent manner. HIF1α can stimulate some glycolysis-associated genes and regulate the ATP and ROS generations. In addition, SIRT1-and HIF1α-associated metabolism inhibits the activity of mTOR, thus negatively regulating the differentiation and function of Th9 cells. As immune cells are crucial in controlling immune-associated diseases, SIRT1-and HIF1α associated-metabolism is closely linked to immune-associated diseases, including infection, tumors, allergic airway inflammation, and autoimmune diseases. Copyright © 2018 Elsevier B.V. All rights reserved.

Intrinsic functional defects of type 2 innate lymphoid cells impair innate allergic inflammation in promyelocytic leukemia zinc finger (PLZF)-deficient mice.

PubMed

Verhoef, Philip A; Constantinides, Michael G; McDonald, Benjamin D; Urban, Joseph F; Sperling, Anne I; Bendelac, Albert

2016-02-01

The transcription factor promyelocytic leukemia zinc finger (PLZF) is transiently expressed during development of type 2 innate lymphoid cells (ILC2s) but is not present at the mature stage. We hypothesized that PLZF-deficient ILC2s have functional defects in the innate allergic response and represent a tool for studying innate immunity in a mouse with a functional adaptive immune response. We determined the consequences of PLZF deficiency on ILC2 function in response to innate and adaptive immune stimuli by using PLZF(-/-) mice and mixed wild-type:PLZF(-/-) bone marrow chimeras. PLZF(-/-) mice, wild-type littermates, or mixed bone marrow chimeras were treated with the protease allergen papain or the cytokines IL-25 and IL-33 or infected with the helminth Nippostrongylus brasiliensis to induce innate type 2 allergic responses. Mice were sensitized with intraperitoneal ovalbumin-alum, followed by intranasal challenge with ovalbumin alone, to induce adaptive TH2 responses. Lungs were analyzed for immune cell subsets, and alveolar lavage fluid was analyzed for ILC2-derived cytokines. In addition, ILC2s were stimulated ex vivo for their capacity to release type 2 cytokines. PLZF-deficient lung ILC2s exhibit a cell-intrinsic defect in the secretion of IL-5 and IL-13 in response to innate stimuli, resulting in defective recruitment of eosinophils and goblet cell hyperplasia. In contrast, the adaptive allergic inflammatory response to ovalbumin and alum was unimpaired. PLZF expression at the innate lymphoid cell precursor stage has a long-range effect on the functional properties of mature ILC2s and highlights the importance of these cells for innate allergic responses in otherwise immunocompetent mice. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. All rights reserved.

TAM receptor tyrosine kinases as emerging targets of innate immune checkpoint blockade for cancer therapy.

PubMed

Akalu, Yemsratch T; Rothlin, Carla V; Ghosh, Sourav

2017-03-01

Cancer immunotherapy utilizing T-cell checkpoint inhibitors has shown tremendous clinical success. Yet, this mode of treatment is effective in only a subset of patients. Unresponsive patients tend to have non-T-cell-inflamed tumors that lack markers associated with the activation of adaptive anti-tumor immune responses. Notably, elimination of cancer cells by T cells is critically dependent on the optimal activity of innate immune cells. Therefore, identifying new targets that regulate innate immune cell function and promote the engagement of adaptive tumoricidal responses is likely to lead to the development of improved therapies against cancer. Here, we review the TAM receptor tyrosine kinases-TYRO3, AXL, and MERTK-as an emerging class of innate immune checkpoints that participate in key steps of anti-tumoral immunity. Namely, TAM-mediated efferocytosis, negative regulation of dendritic cell activity, and dysregulated production of chemokines collectively favor the escape of malignant cells. Hence, disabling TAM signaling may promote engagement of adaptive immunity and complement T-cell checkpoint blockade. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The circadian clock controls toll-like receptor 9-mediated innate and adaptive immunity

PubMed Central

Silver, Adam C.; Arjona, Alvaro; Walker, Wendy E.; Fikrig, Erol

2012-01-01

Circadian rhythms refer to biologic processes that oscillate with a period of approximately 24 hours. These rhythms are sustained by a molecular clock and provide a temporal matrix that ensures the coordination of homeostatic processes with the periodicity of environmental challenges. We demonstrate the circadian molecular clock controls the expression and function of toll like receptor 9 (TLR9). In a vaccination model using TLR9 ligand as adjuvant, mice immunized at the time of enhanced TLR9 responsiveness presented weeks later with an improved adaptive immune response. In a TLR9-dependent mouse model of sepsis, we found that disease severity was dependent on the timing of sepsis induction, coinciding with the daily changes in TLR9 expression and function. These findings unveil a direct molecular link between the circadian and innate immune systems with important implications for immunoprophylaxis and immunotherapy. PMID:22342842

Psychological Stress and the Human Immune System: A Meta-Analytic Study of 30 Years of Inquiry

ERIC Educational Resources Information Center

Segerstrom, Suzanne C.; Miller, Gregory E.

2004-01-01

The present report meta-analyzes more than 300 empirical articles describing a relationship between psychological stress and parameters of the immune system in human participants. Acute stressors (lasting minutes) were associated with potentially adaptive upregulation of some parameters of natural immunity and downregulation of some functions of…

Exploring a regulatory role for mast cells: 'MCregs'?

PubMed

Frossi, Barbara; Gri, Giorgia; Tripodo, Claudio; Pucillo, Carlo

2010-03-01

Regulatory cells can mould the fate of the immune response by direct suppression of specific subsets of effector cells, or by redirecting effectors against invading pathogens and infected or neoplastic cells. These functions have been classically, although not exclusively, ascribed to different subsets of T cells. Recently, mast cells have been shown to regulate physiological and pathological immune responses, and thus to act at the interface between innate and adaptive immunity assuming different functions and behaviors at discrete stages of the immune response. Here, we focus on these poorly defined, and sometimes apparently conflicting, functions of mast cells. Copyright 2010 Elsevier Ltd. All rights reserved.

Essential Neuroscience in Immunology

PubMed Central

Chavan, Sangeeta S.; Tracey, Kevin J.

2017-01-01

The field of immunology is principally focused on the molecular mechanisms by which hematopoetic cells initiate and maintain innate and adaptive immunity. That cornerstone of attention has been expanded by recent discoveries that neuronal signals occupy a critical regulatory niche in immunity. The discovery is that neuronal circuits operating reflexively regulate innate and adaptive immunity. One particularly well-characterized circuit regulating innate immunity, the inflammatory reflex, is dependent upon action potentials transmitted to the reticuloendothelial system via the vagus and splenic nerves. This field has grown significantly with identification of several other reflexes regulating discrete immune functions. As reviewed here, the delineation of these mechanisms revealed a new understanding of immunity, enabled a first in class clinical trial using bioelectronic devices to inhibit cytokines and inflammation in rheumatoid arthritis patients, and provided a mosaic view of immunity as the integration of hematopoetic and neural responses to infection and injury. PMID:28416717

Essential Neuroscience in Immunology.

PubMed

Chavan, Sangeeta S; Tracey, Kevin J

2017-05-01

The field of immunology is principally focused on the molecular mechanisms by which hematopoietic cells initiate and maintain innate and adaptive immunity. That cornerstone of attention has been expanded by recent discoveries that neuronal signals occupy a critical regulatory niche in immunity. The discovery is that neuronal circuits operating reflexively regulate innate and adaptive immunity. One particularly well-characterized circuit regulating innate immunity, the inflammatory reflex, is dependent upon action potentials transmitted to the reticuloendothelial system via the vagus and splenic nerves. This field has grown significantly with the identification of several other reflexes regulating discrete immune functions. As outlined in this review, the delineation of these mechanisms revealed a new understanding of immunity, enabled a first-in-class clinical trial using bioelectronic devices to inhibit cytokines and inflammation in rheumatoid arthritis patients, and provided a mosaic view of immunity as the integration of hematopoietic and neural responses to infection and injury. Copyright © 2017 by The American Association of Immunologists, Inc.

Activation of colo-rectal high-threshold afferent nerves by Interleukin-2 is tetrodotoxin-sensitive and upregulated in a mouse model of chronic visceral hypersensitivity.

PubMed

Campaniello, M A; Harrington, A M; Martin, C M; Ashley Blackshaw, L; Brierley, S M; Hughes, P A

2016-01-01

Chronic visceral pain is a defining feature of irritable bowel syndrome (IBS). IBS patients often show alterations in innate and adaptive immune function which may contribute to symptoms. Immune mediators are known to modulate the activity of viscero-sensory afferent nerves, but the focus has been on the innate immune system. Interleukin-2 (IL-2) is primarily associated with adaptive immune responses but its effects on colo-rectal afferent function in health or disease are unknown. Myeloperoxidase (MPO) activity determined the extent of inflammation in health, acute trinitrobenzene-sulfonic acid (TNBS) colitis, and in our post-TNBS colitis model of chronic visceral hypersensitivity (CVH). The functional effects of IL-2 on high-threshold colo-rectal afferents and the expression of IL-2R and NaV 1.7 mRNA in colo-rectal dorsal root ganglia (DRG) neurons were compared between healthy and CVH mice. MPO activity was increased during acute colitis, but subsided to levels comparable to health in CVH mice. IL-2 caused direct excitation of colo-rectal afferents that was blocked by tetrodotoxin. IL-2 did not affect afferent mechanosensitivity in health or CVH. However, an increased proportion of afferents responded directly to IL-2 in CVH mice compared with controls (73% vs 33%; p < 0.05), and the abundance of IL-2R and NaV 1.7 mRNA was increased 3.5- and 2-fold (p < 0.001 for both) in colo-rectal DRG neurons. IL-2, an immune mediator from the adaptive arm of the immune response, affects colo-rectal afferent function, indicating these effects are not restricted to innate immune mediators. Colo-rectal afferent sensitivity to IL-2 is increased long after healing from inflammation. © 2015 John Wiley & Sons Ltd.

The interplay between Angiotensin II, TLR4 and hypertension.

PubMed

Biancardi, Vinicia Campana; Bomfim, Gisele Facholi; Reis, Wagner Luis; Al-Gassimi, Sarah; Nunes, Kenia Pedrosa

2017-06-01

Hypertension is a multifactorial disease. Although a number of different underlying mechanisms have been learned from the various experimental models of the disease, hypertension still poses challenges for treatment. Angiotensin II plays an unquestionable role in blood pressure regulation acting through central and peripheral mechanisms. During hypertension, dysregulation of the Renin-Angiotensin System is associated with increased expression of pro-inflammatory cytokines and reactive oxygen species causing kidney damage, endothelial dysfunction, and increase in sympathetic activity, among other damages, eventually leading to decline in organ function. Recent studies have shown that these effects involve both the innate and the adaptive immune response. The contribution of adaptive immune responses involving different lymphocyte populations in various models of hypertension has been extensively studied. However, the involvement of the innate immunity mediating inflammation in hypertension is still not well understood. The innate and adaptive immune systems intimately interact with one another and are essential to an effectively functioning of the immune response; hence, the importance of a better understanding of the underlying mechanisms mediating innate immune system during hypertension. In this review, we aim to discuss mechanisms linking Angiotensin II and the innate immune system, in the pathogenesis of hypertension. The newest research investigating Angiotensin II triggering toll like receptor 4 activation in the kidney, vasculature and central nervous system contributing to hypertension will be discussed. Understanding the role of the innate immune system in the development of hypertension may bring to light new insights necessary to improve hypertension management. Copyright © 2017 Elsevier Ltd. All rights reserved.

Heat and immunity: an experimental heat wave alters immune functions in three-spined sticklebacks (Gasterosteus aculeatus).

PubMed

Dittmar, Janine; Janssen, Hannah; Kuske, Andra; Kurtz, Joachim; Scharsack, Jörn P

2014-07-01

Global climate change is predicted to lead to increased temperatures and more extreme climatic events. This may influence host-parasite interactions, immunity and therefore the impact of infectious diseases on ecosystems. However, little is known about the effects of rising temperatures on immune defence, in particular in ectothermic animals, where the immune system is directly exposed to external temperature change. Fish are ideal models for studying the effect of temperature on immunity, because they are poikilothermic, but possess a complete vertebrate immune system with both innate and adaptive immunity. We used three-spined sticklebacks ( Gasterosteus aculeatus) originating from a stream and a pond, whereby the latter supposedly were adapted to higher temperature variation. We studied the effect of increasing and decreasing temperatures and a simulated heat wave with subsequent recovery on body condition and immune parameters. We hypothesized that the immune system might be less active at low temperatures, but will be even more suppressed at temperatures towards the upper tolerable temperature range. Contrary to our expectation, we found innate and adaptive immune activity to be highest at a temperature as low as 13 °C. Exposure to a simulated heat wave induced long-lasting immune disorders, in particular in a stickleback population that might be less adapted to temperature variation in its natural environment. The results show that the activity of the immune system of an ectothermic animal species is temperature dependent and suggest that heat waves associated with global warming may immunocompromise host species, thereby potentially facilitating the spread of infectious diseases. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

Ly49 Receptors: Innate and Adaptive Immune Paradigms

PubMed Central

Rahim, Mir Munir A.; Tu, Megan M.; Mahmoud, Ahmad Bakur; Wight, Andrew; Abou-Samra, Elias; Lima, Patricia D. A.; Makrigiannis, Andrew P.

2014-01-01

The Ly49 receptors are type II C-type lectin-like membrane glycoproteins encoded by a family of highly polymorphic and polygenic genes within the mouse natural killer (NK) gene complex. This gene family is designated Klra, and includes genes that encode both inhibitory and activating Ly49 receptors in mice. Ly49 receptors recognize class I major histocompatibility complex-I (MHC-I) and MHC-I-like proteins on normal as well as altered cells. Their functional homologs in humans are the killer cell immunoglobulin-like receptors, which recognize HLA class I molecules as ligands. Classically, Ly49 receptors are described as being expressed on both the developing and mature NK cells. The inhibitory Ly49 receptors are involved in NK cell education, a process in which NK cells acquire function and tolerance toward cells that express “self-MHC-I.” On the other hand, the activating Ly49 receptors recognize altered cells expressing activating ligands. New evidence shows a broader Ly49 expression pattern on both innate and adaptive immune cells. Ly49 receptors have been described on multiple NK cell subsets, such as uterine NK and memory NK cells, as well as NKT cells, dendritic cells, plasmacytoid dendritic cells, macrophages, neutrophils, and cells of the adaptive immune system, such as activated T cells and regulatory CD8+ T cells. In this review, we discuss the expression pattern and proposed functions of Ly49 receptors on various immune cells and their contribution to immunity. PMID:24765094

CRISPR-Cas systems: Prokaryotes upgrade to adaptive immunity.

PubMed

Barrangou, Rodolphe; Marraffini, Luciano A

2014-04-24

Clustered regularly interspaced short palindromic repeats (CRISPR), and associated proteins (Cas) comprise the CRISPR-Cas system, which confers adaptive immunity against exogenic elements in many bacteria and most archaea. CRISPR-mediated immunization occurs through the uptake of DNA from invasive genetic elements such as plasmids and viruses, followed by its integration into CRISPR loci. These loci are subsequently transcribed and processed into small interfering RNAs that guide nucleases for specific cleavage of complementary sequences. Conceptually, CRISPR-Cas shares functional features with the mammalian adaptive immune system, while also exhibiting characteristics of Lamarckian evolution. Because immune markers spliced from exogenous agents are integrated iteratively in CRISPR loci, they constitute a genetic record of vaccination events and reflect environmental conditions and changes over time. Cas endonucleases, which can be reprogrammed by small guide RNAs have shown unprecedented potential and flexibility for genome editing and can be repurposed for numerous DNA targeting applications including transcriptional control. Copyright © 2014 Elsevier Inc. All rights reserved.

GATA-3 function in innate and adaptive immunity.

PubMed

Tindemans, Irma; Serafini, Nicolas; Di Santo, James P; Hendriks, Rudi W

2014-08-21

The zinc-finger transcription factor GATA-3 has received much attention as a master regulator of T helper 2 (Th2) cell differentiation, during which it controls interleukin-4 (IL-4), IL-5, and IL-13 expression. More recently, GATA-3 was shown to contribute to type 2 immunity through regulation of group 2 innate lymphoid cell (ILC2) development and function. Furthermore, during thymopoiesis, GATA-3 represses B cell potential in early T cell precursors, activates TCR signaling in pre-T cells, and promotes the CD4(+) T cell lineage after positive selection. GATA-3 also functions outside the thymus in hematopoietic stem cells, regulatory T cells, CD8(+) T cells, thymic natural killer cells, and ILC precursors. Here we discuss the varied functions of GATA-3 in innate and adaptive immune cells, with emphasis on its activity in T cells and ILCs, and examine the mechanistic basis for the dose-dependent, developmental-stage- and cell-lineage-specific activity of this transcription factor. Copyright © 2014 Elsevier Inc. All rights reserved.

Regulation of Adaptive Immunity in Health and Disease by Cholesterol Metabolism

PubMed Central

Fessler, Michael B.

2015-01-01

Four decades ago, it was observed that stimulation of T cells induces rapid changes in cellular cholesterol that are required before proliferation can commence. Investigators returning to this phenomenon have finally revealed its molecular underpinnings. Cholesterol trafficking and its dysregulation are now also recognized to strongly influence dendritic cell function, T cell polarization, and antibody responses. In this review, the state of the literature is reviewed on how cholesterol and its trafficking regulate the cells of the adaptive immune response and in vivo disease phenotypes of dysregulated adaptive immunity, including allergy, asthma, and autoimmune disease. Emerging evidence supporting a potential role for statins and other lipid-targeted therapies in the treatment of these diseases is presented. Just as vascular biologists have embraced immunity in the pathogenesis and treatment of atherosclerosis, so should basic and clinical immunologists in allergy, pulmonology, and other disciplines seek to encompass a basic understanding of lipid science. PMID:26149587

Obligate brood parasites show more functionally effective innate immune responses: an eco-immunological hypothesis

USGS Publications Warehouse

Hahn, D. Caldwell; Summers, Scott G.; Genovese, Kenneth J.; He, Haiqi; Kogut, Michael H.

2013-01-01

Immune adaptations of obligate brood parasites attracted interest when three New World cowbird species (Passeriformes, Icteridae, genus Molothrus) proved unusually resistant to West Nile virus. We have used cowbirds as models to investigate the eco-immunological hypothesis that species in parasite-rich environments characteristically have enhanced immunity as a life history adaptation. As part of an ongoing program to understand the cowbird immune system, in this study we measured degranulation and oxidative burst, two fundamental responses of the innate immune system. Innate immunity provides non-specific, fast-acting defenses against a variety of invading pathogens, and we hypothesized that innate immunity experiences particularly strong selection in cowbirds, because their life history strategy exposes them to diverse novel and unpredictable parasites. We compared the relative effectiveness of degranulation and oxidative burst responses in two cowbird species and one related, non-parasitic species. Both innate immune defenses were significantly more functionally efficient in the two parasitic cowbird species than in the non-parasitic red-winged blackbird (Icteridae, Agelaius phoeniceus). Additionally, both immune defenses were more functionally efficient in the brown-headed cowbird (M. ater), an extreme host-generalist brood parasite, than in the bronzed cowbird (M. aeneus), a moderate host-specialist with lower exposure to other species and their parasites. Thus the relative effectiveness of these two innate immune responses corresponds to the diversity of parasites in the niche of each species and to their relative resistance to WNV. This study is the first use of these two specialized assays in a comparative immunology study of wild avian species.

Unique Features of Fish Immune Repertoires: Particularities of Adaptive Immunity Within the Largest Group of Vertebrates

PubMed Central

Sunyer, Oriol J.

2016-01-01

Fishes (i.e., teleost fishes) are the largest group of vertebrates. Although their immune system is based on the fundamental receptors, pathways, and cell types found in all groups of vertebrates, fishes show a diversity of particular features that challenge some classical concepts of immunology. In this chapter, we discuss the particularities of fish immune repertoires from a comparative perspective. We examine how allelic exclusion can be achieved when multiple Ig loci are present, how isotypic diversity and functional specificity impact clonal complexity, how loss of the MHC class II molecules affects the cooperation between T and B cells, and how deep sequencing technologies bring new insights about somatic hypermutation in the absence of germinal centers. The unique coexistence of two distinct B-cell lineages respectively specialized in systemic and mucosal responses is also discussed. Finally, we try to show that the diverse adaptations of immune repertoires in teleosts can help in understanding how somatic adaptive mechanisms of immunity evolved in parallel in different lineages across vertebrates. PMID:26537384

Protective and pathological immunity during CNS infections

PubMed Central

Klein, Robyn S.; Hunter, Christopher A.

2017-01-01

The concept of immune privilege of the central nervous system (CNS) has dominated the study of inflammatory processes in the brain. However, clinically relevant models have highlighted the innate pathways that limit pathogen invasion of the CNS and that adaptive immunity mediates control of many neural infections. Because protective responses can result in bystander damage there are regulatory mechanisms that balance protective and pathological inflammation but which may also allow microbial persistence. The focus of this review is to consider the host-pathogen interactions that influence neurotropic infections and to highlight advances in understanding of innate and adaptive mechanisms of resistance as key determinants of the outcome of CNS infection. Advances in these areas have broadened our comprehension of how the immune system functions in the brain and can readily overcome immune privilege. PMID:28636958

Integration of Immunity with Physical and Cognitive Function in Definitions of Successful Aging

PubMed Central

Griffin, Patricia; Michel, Joshua J.; Huysman, Kristy; Logar, Alison J.; Vallejo, Abbe N.

2012-01-01

Studies comparing chronologically “young” versus “old” humans document age-related decline of classical immunological functions. However, older adults aged ≥65 years have very heterogeneous health phenotypes. A significant number of them are functionally independent and are surviving well into their 8th–11th decade life, observations indicating that aging or old age is not synonymous with immune incompetence. While there are dramatic age-related changes in the immune system, not all of these changes may be considered detrimental. Here, we review evidences for novel immunologic processes that become elaborated with advancing age that complement preserved classical immune functions and promote immune homeostasis later in life. We propose that elaboration such of late life immunologic properties is indicative of beneficial immune remodeling that is an integral component of successful aging, an emerging physiologic construct associated with similar age-related physiologic adaptations underlying maintenance of physical and cognitive function. We suggest that a systems approach integrating immune, physical, and cognitive functions, rather than a strict immunodeficiency-minded approach, will be key towards innovations in clinical interventions to better promote protective immunity and functional independence among the elderly. PMID:22500270

Novel Target for Ameliorating Pain and Other Problems after SCI: Spontaneous Activity in Nociceptors

DTIC Science & Technology

2014-10-01

disruption of the BSCB will permit blood-borne mye- loid and lymphoid immune cells to enter the spinal cord parenchyma and exert direct inflammatory actions...recently evolved adaptive immune system, the innate immune system does not em- ploy antigen-specific humoral and cell -mediated immunity mecha- nisms. Two... innate immune functions have been emphasized traditionally: 1) the recruitment of cells and proteins to destroy pathogens and toxins, and 2) increases

Use of the local lymph node assay in assessment of immune function.

PubMed

van den Berg, Femke A; Baken, Kirsten A; Vermeulen, Jolanda P; Gremmer, Eric R; van Steeg, Harry; van Loveren, Henk

2005-07-01

The murine local lymph node assay (LLNA) was originally developed as a predictive test method for the identification of chemicals with sensitizing potential. In this study we demonstrated that an adapted LLNA can also be used as an immune function assay by studying the effects of orally administered immunomodulating compounds on the T-cell-dependent immune response induced by the contact sensitizer 2,4-dinitrochlorobenzene (DNCB). C57Bl/6 mice were treated with the immunotoxic compounds cyclosporin A (CsA), bis(tri-n-butyltin)oxide (TBTO) or benzo[a]pyrene, (B[a]P). Subsequently, cell proliferation and interferon-gamma (IFN-gamma) and interleukin (IL)-4 release were determined in the auricular lymph nodes (LNs) after DNCB application on both ears. Immunosuppression induced by CsA, TBTO and B[a]P was clearly detectable in this application of the LLNA. Cytokine release measurements proved valuable to confirm the results of the cell proliferation assay and to obtain an indication of the effect on Th1/Th2 balance. We believe to have demonstrated the applicability of an adapted LLNA as an immune function assay in the mouse.

PARylation of the forkhead-associated domain protein DAWDLE regulates plant immunity.

PubMed

Feng, Baomin; Ma, Shisong; Chen, Sixue; Zhu, Ning; Zhang, Shuxin; Yu, Bin; Yu, Yu; Le, Brandon; Chen, Xuemei; Dinesh-Kumar, Savithramma P; Shan, Libo; He, Ping

2016-12-01

Protein poly(ADP-ribosyl)ation (PARylation) primarily catalyzed by poly(ADP-ribose) polymerases (PARPs) plays a crucial role in controlling various cellular responses. However, PARylation targets and their functions remain largely elusive. Here, we deployed an Arabidopsis protein microarray coupled with in vitro PARylation assays to globally identify PARylation targets in plants. Consistent with the essential role of PARylation in plant immunity, the forkhead-associated (FHA) domain protein DAWDLE (DDL), one of PARP2 targets, positively regulates plant defense to both adapted and non-adapted pathogens. Arabidopsis PARP2 interacts with and PARylates DDL, which was enhanced upon treatment of bacterial flagellin. Mass spectrometry and mutagenesis analysis identified multiple PARylation sites of DDL by PARP2. Genetic complementation assays indicate that DDL PARylation is required for its function in plant immunity. In contrast, DDL PARylation appears to be dispensable for its previously reported function in plant development partially mediated by the regulation of microRNA biogenesis. Our study uncovers many previously unknown PARylation targets and points to the distinct functions of DDL in plant immunity and development mediated by protein PARylation and small RNA biogenesis, respectively. © 2016 The Authors.

Opinion: Interactions of innate and adaptive lymphocytes

PubMed Central

Gasteiger, Georg; Rudensky, Alexander Y.

2015-01-01

Innate lymphocytes, including natural killer (NK) cells and the recently discovered innate lymphoid cells (ILCs) have crucial roles during infection, tissue injury and inflammation. Innate signals regulate the activation and homeostasis of innate lymphocytes. Less well understood is the contribution of the adaptive immune system to the orchestration of innate lymphocyte responses. We review our current understanding of the interactions between adaptive and innate lymphocytes, and propose a model in which adaptive T cells function as antigen-specific sensors for the activation of innate lymphocytes to amplify and instruct local immune responses. We highlight the potential role of regulatory and helper T cells in these processes and discuss major questions in the emerging area of crosstalk between adaptive and innate lymphocytes. PMID:25132095

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

PubMed

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.

Cheetahs have a stronger constitutive innate immunity than leopards

PubMed Central

Heinrich, Sonja K.; Hofer, Heribert; Courtiol, Alexandre; Melzheimer, Jörg; Dehnhard, Martin; Czirják, Gábor Á.; Wachter, Bettina

2017-01-01

As a textbook case for the importance of genetics in conservation, absence of genetic variability at the major histocompatibility complex (MHC) is thought to endanger species viability, since it is considered crucial for pathogen resistance. An alternative view of the immune system inspired by life history theory posits that a strong response should evolve in other components of the immune system if there is little variation in the MHC. In contrast to the leopard (Panthera pardus), the cheetah (Acinonyx jubatus) has a relatively low genetic variability at the MHC, yet free-ranging cheetahs are healthy. By comparing the functional competence of the humoral immune system of both species in sympatric populations in Namibia, we demonstrate that cheetahs have a higher constitutive innate but lower induced innate and adaptive immunity than leopards. We conclude (1) immunocompetence of cheetahs is higher than previously thought; (2) studying both innate and adaptive components of immune systems will enrich conservation science. PMID:28333126

Cheetahs have a stronger constitutive innate immunity than leopards.

PubMed

Heinrich, Sonja K; Hofer, Heribert; Courtiol, Alexandre; Melzheimer, Jörg; Dehnhard, Martin; Czirják, Gábor Á; Wachter, Bettina

2017-03-23

As a textbook case for the importance of genetics in conservation, absence of genetic variability at the major histocompatibility complex (MHC) is thought to endanger species viability, since it is considered crucial for pathogen resistance. An alternative view of the immune system inspired by life history theory posits that a strong response should evolve in other components of the immune system if there is little variation in the MHC. In contrast to the leopard (Panthera pardus), the cheetah (Acinonyx jubatus) has a relatively low genetic variability at the MHC, yet free-ranging cheetahs are healthy. By comparing the functional competence of the humoral immune system of both species in sympatric populations in Namibia, we demonstrate that cheetahs have a higher constitutive innate but lower induced innate and adaptive immunity than leopards. We conclude (1) immunocompetence of cheetahs is higher than previously thought; (2) studying both innate and adaptive components of immune systems will enrich conservation science.

Innate scavenger receptor-A regulates adaptive T helper cell responses to pathogen infection

PubMed Central

Xu, Zhipeng; Xu, Lei; Li, Wei; Jin, Xin; Song, Xian; Chen, Xiaojun; Zhu, Jifeng; Zhou, Sha; Li, Yong; Zhang, Weiwei; Dong, Xiaoxiao; Yang, Xiaowei; Liu, Feng; Bai, Hui; Chen, Qi; Su, Chuan

2017-01-01

The pattern recognition receptor (PRR) scavenger receptor class A (SR-A) has an important function in the pathogenesis of non-infectious diseases and in innate immune responses to pathogen infections. However, little is known about the role of SR-A in the host adaptive immune responses to pathogen infection. Here we show with mouse models of helminth Schistosoma japonicum infection and heat-inactivated Mycobacterium tuberculosis stimulation that SR-A is regulated by pathogens and suppresses IRF5 nuclear translocation by direct interaction. Reduced abundance of nuclear IRF5 shifts macrophage polarization from M1 towards M2, which subsequently switches T-helper responses from type 1 to type 2. Our study identifies a role for SR-A as an innate PRR in regulating adaptive immune responses. PMID:28695899

Immune Dysregulation and Chronic Stress Among Older Adults: A Review

PubMed Central

Gouin, Jean-Philippe; Hantsoo, Liisa; Kiecolt-Glaser, Janice K.

2009-01-01

Aging is associated with a natural dysregulation in immune functioning which may be amplified when it occurs in the context of chronic stress. Family dementia caregiving provides an excellent model to study the impact of chronic stress on immune functioning among older individuals. Empirical data suggest that the stress of caregiving dysregulate multiple components of innate and adaptive immunity. Elderly caregivers have poorer responses to vaccines, impaired control of latent viruses, exaggerated production of inflammatory mediators, and accelerated cellular aging, compared to noncaregiving older adults. The chronic stress-induced immune dysregulation observed among older caregivers appear to be of sufficient magnitude to impact health. Furthermore, evidence suggests that chronic stress lead to premature aging of the immune system. PMID:19047802

Innate Lymphoid Cells: a new paradigm in immunology

PubMed Central

Eberl, Gérard; Colonna, Marco; Di Santo, James P.; McKenzie, Andrew N.J.

2016-01-01

Summary Innate lymphoid cells (ILCs) are a growing family of immune cells that mirror the phenotypes and functions of T cells. However, in contrast to T cells, ILCs do not express acquired antigen receptors or undergo clonal selection and expansion when stimulated. Instead, ILCs react promptly to signals from infected or injured tissues and produce an array of secreted proteins termed cytokines that direct the developing immune response into one that is adapted to the original insult. The complex crosstalk between microenvironment, ILCs and adaptive immunity remains to be fully deciphered. Only by understanding these complex regulatory networks can the power of ILCs be controlled or unleashed to regulate or enhance immune responses in disease prevention and therapy. PMID:25999512

The two sides of complement C3d: evolution of electrostatics in a link between innate and adaptive immunity.

PubMed

Kieslich, Chris A; Morikis, Dimitrios

2012-01-01

The interaction between complement fragment C3d and complement receptor 2 (CR2) is a key aspect of complement immune system activation, and is a component in a link between innate and adaptive immunities. The complement immune system is an ancient mechanism for defense, and can be found in species that have been on Earth for the last 600 million years. However, the link between the complement system and adaptive immunity, which is formed through the association of the B-cell co-receptor complex, including the C3d-CR2 interaction, is a much more recent adaptation. Human C3d and CR2 have net charges of -1 and +7 respectively, and are believed to have evolved favoring the role of electrostatics in their functions. To investigate the role of electrostatics in the function and evolution of human C3d and CR2, we have applied electrostatic similarity methods to identify regions of evolutionarily conserved electrostatic potential based on 24 homologues of complement C3d and 4 homologues of CR2. We also examine the effects of structural perturbation, as introduced through molecular dynamics and mutations, on spatial distributions of electrostatic potential to identify perturbation resistant regions, generated by so-called electrostatic "hot-spots". Distributions of electrostatic similarity based on families of perturbed structures illustrate the presence of electrostatic "hot-spots" at the two functional sites of C3d, while the surface of CR2 lacks electrostatic "hot-spots" despite its excessively positive nature. We propose that the electrostatic "hot-spots" of C3d have evolved to optimize its dual-functionality (covalently attaching to pathogen surfaces and interaction with CR2), which are both necessary for the formation B-cell co-receptor complexes. Comparison of the perturbation resistance of the electrostatic character of the homologues of C3d suggests that there was an emergence of a new role of electrostatics, and a transition in the function of C3d, after the divergence of jawless fish.

The Two Sides of Complement C3d: Evolution of Electrostatics in a Link between Innate and Adaptive Immunity

PubMed Central

Kieslich, Chris A.; Morikis, Dimitrios

2012-01-01

The interaction between complement fragment C3d and complement receptor 2 (CR2) is a key aspect of complement immune system activation, and is a component in a link between innate and adaptive immunities. The complement immune system is an ancient mechanism for defense, and can be found in species that have been on Earth for the last 600 million years. However, the link between the complement system and adaptive immunity, which is formed through the association of the B-cell co-receptor complex, including the C3d-CR2 interaction, is a much more recent adaptation. Human C3d and CR2 have net charges of −1 and +7 respectively, and are believed to have evolved favoring the role of electrostatics in their functions. To investigate the role of electrostatics in the function and evolution of human C3d and CR2, we have applied electrostatic similarity methods to identify regions of evolutionarily conserved electrostatic potential based on 24 homologues of complement C3d and 4 homologues of CR2. We also examine the effects of structural perturbation, as introduced through molecular dynamics and mutations, on spatial distributions of electrostatic potential to identify perturbation resistant regions, generated by so-called electrostatic “hot-spots”. Distributions of electrostatic similarity based on families of perturbed structures illustrate the presence of electrostatic “hot-spots” at the two functional sites of C3d, while the surface of CR2 lacks electrostatic “hot-spots” despite its excessively positive nature. We propose that the electrostatic “hot-spots” of C3d have evolved to optimize its dual-functionality (covalently attaching to pathogen surfaces and interaction with CR2), which are both necessary for the formation B-cell co-receptor complexes. Comparison of the perturbation resistance of the electrostatic character of the homologues of C3d suggests that there was an emergence of a new role of electrostatics, and a transition in the function of C3d, after the divergence of jawless fish. PMID:23300422

Identification of pancreatic glycoprotein 2 as an endogenous immunomodulator of innate and adaptive immune responses.

PubMed

Werner, Lael; Paclik, Daniela; Fritz, Christina; Reinhold, Dirk; Roggenbuck, Dirk; Sturm, Andreas

2012-09-15

Pancreatic autoantibodies are Crohn disease-specific serologic markers. The function and immunological role of their recently identified autoantigen, glycoprotein 2 (GP2), are unknown. We therefore investigated the impact of GP2 on modulation of innate and adaptive immune responses to evaluate its potential therapeutic use in mucosal inflammation. Our data indicate a previously unknown function for GP2 as an immunomodulator. GP2 was ubiquitously expressed on cells vital to mucosal immune responses. The expression of GP2 was upregulated on activated human T cells, and it was further influenced by pharmaceutical TNF-α inhibitors. Recombinant GP2 significantly decreased human intestinal epithelial cells, mucosal and peripheral T cell proliferation, apoptosis, and activation, and it distinctly modulated cytokine secretion. Furthermore, intestinal epithelial cells stimulated with GP2 potently attracted T cells. In conclusion, we demonstrate a novel role for GP2 in immune regulation that could provide a platform for new therapeutic interventions in the treatment of Crohn disease.

Eosinophils in mucosal immune responses

PubMed Central

Travers, J; Rothenberg, M E

2015-01-01

Eosinophils, multifunctional cells that contribute to both innate and adaptive immunity, are involved in the initiation, propagation and resolution of immune responses, including tissue repair. They achieve this multifunctionality by expression of a diverse set of activation receptors, including those that directly recognize pathogens and opsonized targets, and by their ability to store and release preformed cytotoxic mediators that participate in host defense, to produce a variety of de novo pleotropic mediators and cytokines and to interact directly and indirectly with diverse cell types, including adaptive and innate immunocytes and structural cells. Herein, we review the basic biology of eosinophils and then focus on new emerging concepts about their role in mucosal immune homeostasis, particularly maintenance of intestinal IgA. We review emerging data about their development and regulation and describe new concepts concerning mucosal eosinophilic diseases. We describe recently developed therapeutic strategies to modify eosinophil levels and function and provide collective insight about the beneficial and detrimental functions of these enigmatic cells. PMID:25807184

Protective and Pathological Immunity during Central Nervous System Infections.

PubMed

Klein, Robyn S; Hunter, Christopher A

2017-06-20

The concept of immune privilege of the central nervous system (CNS) has dominated the study of inflammatory processes in the brain. However, clinically relevant models have highlighted that innate pathways limit pathogen invasion of the CNS and adaptive immunity mediates control of many neural infections. As protective responses can result in bystander damage, there are regulatory mechanisms that balance protective and pathological inflammation, but these mechanisms might also allow microbial persistence. The focus of this review is to consider the host-pathogen interactions that influence neurotropic infections and to highlight advances in our understanding of innate and adaptive mechanisms of resistance as key determinants of the outcome of CNS infection. Advances in these areas have broadened our comprehension of how the immune system functions in the brain and can readily overcome immune privilege. Copyright © 2017. Published by Elsevier Inc.

Cytokines and the immune-neuroendocrine network: What did we learn from infection and autoimmunity?

PubMed

Correa, Silvia G; Maccioni, Mariana; Rivero, Virginia E; Iribarren, Pablo; Sotomayor, Claudia E; Riera, Clelia M

2007-01-01

The initial view of the neuroendocrine-immune communication as the brake of immune activation is changing. Recent evidence suggests that the optimization of the body's overall response to infection could be actually the role of the immune-endocrine network. In gradually more complex organisms, the multiplicity of host-pathogen interfaces forced the development of efficient and protective responses. Molecules such as cytokines and Toll-like receptors (TLRs) are distributed both in the periphery and in the brain to participate in a coordinated adaptive function. When sustained release of inflammatory mediators occurs, as in autoimmune diseases, undesirable pathological consequences become evident with different manifestations and outcomes. Clearly, organisms are not well adapted to that disregulated condition yet, suggesting that additional partners within neuroendocrine-immune interactions might emerge from the evolutionary road.

Asymmetric T lymphocyte division in the initiation of adaptive immune responses.

PubMed

Chang, John T; Palanivel, Vikram R; Kinjyo, Ichiko; Schambach, Felix; Intlekofer, Andrew M; Banerjee, Arnob; Longworth, Sarah A; Vinup, Kristine E; Mrass, Paul; Oliaro, Jane; Killeen, Nigel; Orange, Jordan S; Russell, Sarah M; Weninger, Wolfgang; Reiner, Steven L

2007-03-23

A hallmark of mammalian immunity is the heterogeneity of cell fate that exists among pathogen-experienced lymphocytes. We show that a dividing T lymphocyte initially responding to a microbe exhibits unequal partitioning of proteins that mediate signaling, cell fate specification, and asymmetric cell division. Asymmetric segregation of determinants appears to be coordinated by prolonged interaction between the T cell and its antigen-presenting cell before division. Additionally, the first two daughter T cells displayed phenotypic and functional indicators of being differentially fated toward effector and memory lineages. These results suggest a mechanism by which a single lymphocyte can apportion diverse cell fates necessary for adaptive immunity.

The Interaction between Regulatory T Cells and NKT Cells in the Liver: A CD1d Bridge Links Innate and Adaptive Immunity

PubMed Central

Webb, Tonya J.; Potter, James P.; Li, Zhiping

2011-01-01

Background/Aims Regulatory T cells (Tregs) and natural killer T (NKT) cells are two distinct lymphocyte subsets that independently regulate hepatic adaptive and innate immunity, respectively. In the current study, we examine the interaction between Tregs and NKT cells to understand the mechanisms of cross immune regulation by these cells. Methods The frequency and function of Tregs were evaluated in wild type and NKT cell deficient (CD1dko) mice. In vitro lymphocyte proliferation and apoptosis assays were performed with NKT cells co-cultured with Tregs. The ability of Tregs to inhibit NKT cells in vivo was examined by adoptive transfer of Tregs in a model of NKT cell mediated hepatitis. Results CD1dko mice have a significant reduction in hepatic Tregs. Although, the Tregs from CD1dko mice remain functional and can suppress conventional T cells, their ability to suppress activation induced NKT cell proliferation and to promote NKT cell apoptosis is greatly diminished. These effects are CD1d dependent and require cell to cell contact. Adoptive transfer of Tregs inhibits NKT cell-mediated liver injury. Conclusions NKT cells promote Tregs, and Tregs inhibit NKT cells in a CD1d dependent manner requiring cell to cell contact. These cross-talk immune regulations provide a linkage between innate and adaptive immunity. PMID:22073248

Gel-Trapped Lymphorganogenic Chemokines Trigger Artificial Tertiary Lymphoid Organs and Mount Adaptive Immune Responses In Vivo.

PubMed

Kobayashi, Yuka; Watanabe, Takeshi

2016-01-01

We previously generated artificial lymph node-like tertiary lymphoid organs (artTLOs) in mice using lymphotoxin α-expressing stromal cells. Here, we show the construction of transplantable and functional artTLOs by applying soluble factors trapped in slow-releasing gels in the absence of lymphoid tissue organizer stromal cells. The resultant artTLOs were easily removable, transplantable, and were capable of attracting memory B and T cells. Importantly, artTLOs induced a powerful antigen-specific secondary immune response, which was particularly pronounced in immune-compromised hosts. Synthesis of functionally stable immune tissues/organs like those described here may be a first step to eventually develop immune system-based therapeutics. Although much needs to be learned from the precise mechanisms of action, they may offer ways in the future to reestablish immune functions to overcome hitherto untreatable diseases, including severe infection, cancer, autoimmune diseases, and various forms of immune deficiencies, including immune-senescence during aging.

Neurokinin-1 receptor agonists bias therapeutic dendritic cells to induce type 1 immunity by licensing host dendritic cells to produce IL-12

PubMed Central

Janelsins, Brian M.; Sumpter, Tina L.; Tkacheva, Olga A.; Rojas-Canales, Darling M.; Erdos, Geza; Mathers, Alicia R.; Shufesky, William J.; Storkus, Walter J.; Falo, Louis D.; Morelli, Adrian E.; Larregina, Adriana T.

2013-01-01

Substance-P and hemokinin-1 are proinflammatory neuropeptides with potential to promote type 1 immunity through agonistic binding to neurokinin-1 receptor (NK1R). Dendritic cells (DCs) are professional antigen-presenting cells that initiate and regulate the outcome of innate and adaptive immune responses. Immunostimulatory DCs are highly desired for the development of positive immunization techniques. DCs express functional NK1R; however, regardless of their potential DC-stimulatory function, the ability of NK1R agonists to promote immunostimulatory DCs remains unexplored. Here, we demonstrate that NK1R signaling activates therapeutic DCs capable of biasing type 1 immunity by inhibition of interleukin-10 (IL-10) synthesis and secretion, without affecting their low levels of IL-12 production. The potent type 1 effector immune response observed following cutaneous administration of NK1R-signaled DCs required their homing in skin-draining lymph nodes (sDLNs) where they induced inflammation and licensed endogenous-conventional sDLN-resident and -recruited inflammatory DCs to secrete IL-12. Our data demonstrate that NK1R signaling promotes immunostimulatory DCs, and provide relevant insight into the mechanisms used by neuromediators to regulate innate and adaptive immune responses. PMID:23365459

Innate and adaptive immune responses in migrating spring-run adult chinook salmon, Oncorhynchus tshawytscha

USGS Publications Warehouse

Dolan, Brian P.; Fisher, Kathleen M.; Colvin, Michael E.; Benda, Susan E.; Peterson, James T.; Kent, Michael L.; Schreck, Carl B.

2016-01-01

Adult Chinook salmon (Oncorhynchus tshawytscha) migrate from salt water to freshwater streams to spawn. Immune responses in migrating adult salmon are thought to diminish in the run up to spawning, though the exact mechanisms for diminished immune responses remain unknown. Here we examine both adaptive and innate immune responses as well as pathogen burdens in migrating adult Chinook salmon in the Upper Willamette River basin. Messenger RNA transcripts encoding antibody heavy chain molecules slightly diminish as a function of time, but are still present even after fish have successfully spawned. In contrast, the innate anti-bacterial effector proteins present in fish plasma rapidly decrease as spawning approaches. Fish also were examined for the presence and severity of eight different pathogens in different organs. While pathogen burden tended to increase during the migration, no specific pathogen signature was associated with diminished immune responses. Transcript levels of the immunosuppressive cytokines IL-10 and TGF beta were measured and did not change during the migration. These results suggest that loss of immune functions in adult migrating salmon are not due to pathogen infection or cytokine-mediated immune suppression, but is rather part of the life history of Chinook salmon likely induced by diminished energy reserves or hormonal changes which accompany spawning.

A human tissue-based functional assay platform to evaluate the immune function impact of small molecule inhibitors that target the immune system.

PubMed

St Pierre, Cristina; Guo, Jane; Shin, John D; Engstrom, Laura W; Lee, Hyun-Hee; Herbert, Alan; Surdi, Laura; Baker, James; Salmon, Michael; Shah, Sanjiv; Ellis, J Michael; Houshyar, Hani; Crackower, Michael A; Kleinschek, Melanie A; Jones, Dallas C; Hicks, Alexandra; Zaller, Dennis M; Alves, Stephen E; Ramadas, Ravisankar A

2017-01-01

While the immune system is essential for the maintenance of the homeostasis, health and survival of humans, aberrant immune responses can lead to chronic inflammatory and autoimmune disorders. Pharmacological modulation of drug targets in the immune system to ameliorate disease also carry a risk of immunosuppression that could lead to adverse outcomes. Therefore, it is important to understand the 'immune fingerprint' of novel therapeutics as they relate to current and, clinically used immunological therapies to better understand their potential therapeutic benefit as well as immunosuppressive ability that might lead to adverse events such as infection risks and cancer. Since the mechanistic investigation of pharmacological modulators in a drug discovery setting is largely compound- and mechanism-centric but not comprehensive in terms of immune system impact, we developed a human tissue based functional assay platform to evaluate the impact of pharmacological modulators on a range of innate and adaptive immune functions. Here, we demonstrate that it is possible to generate a qualitative and quantitative immune system impact of pharmacological modulators, which might help better understand and predict the benefit-risk profiles of these compounds in the treatment of immune disorders.

Autophagy genes in immunity

PubMed Central

Virgin, Herbert W; Levine, Beth

2009-01-01

In its classical form, autophagy is a pathway by which cytoplasmic constituents, including intracellular pathogens, are sequestered in a double-membrane–bound autophagosome and delivered to the lysosome for degradation. This pathway has been linked to diverse aspects of innate and adaptive immunity, including pathogen resistance, production of type I interferon, antigen presentation, tolerance and lymphocyte development, as well as the negative regulation of cytokine signaling and inflammation. Most of these links have emerged from studies in which genes encoding molecules involved in autophagy are inactivated in immune effector cells. However, it is not yet known whether all of the critical functions of such genes in immunity represent ‘classical autophagy’ or possible as-yet-undefined autophagolysosome-independent functions of these genes. This review summarizes phenotypes that result from the inactivation of autophagy genes in the immune system and discusses the pleiotropic functions of autophagy genes in immunity. PMID:19381141

Harnessing the Prokaryotic Adaptive Immune System as a Eukaryotic Antiviral Defense

PubMed Central

Price, Aryn A.; Grakoui, Arash; Weiss, David S.

2016-01-01

Clustered, regularly interspaced, short palindromic repeats - CRISPR associated (CRISPR-Cas) systems are sequence specific RNA-directed endonuclease complexes that bind and cleave nucleic acids. These systems evolved within prokaryotes as adaptive immune defenses to target and degrade nucleic acids derived from bacteriophages and other foreign genetic elements. The antiviral function of these systems has now been exploited to combat eukaryotic viruses throughout the viral life cycle. Here we discuss current advances in CRISPR-Cas9 technology as a eukaryotic antiviral defense. PMID:26852268

The cAMP Pathway as Therapeutic Target in Autoimmune and Inflammatory Diseases

PubMed Central

Raker, Verena Katharina; Becker, Christian; Steinbrink, Kerstin

2016-01-01

Nucleotide signaling molecules contribute to the regulation of cellular pathways. In the immune system, cyclic adenosine monophosphate (cAMP) is well established as a potent regulator of innate and adaptive immune cell functions. Therapeutic strategies to interrupt or enhance cAMP generation or effects have immunoregulatory potential in autoimmune and inflammatory disorders. Here, we provide an overview of the cyclic AMP axis and its role as a regulator of immune functions and discuss the clinical and translational relevance of interventions with these processes. PMID:27065076

Linking innate to adaptive immunity through dendritic cells.

PubMed

Steinman, Ralph M

2006-01-01

The function of dendritic cells (DCs) in linking innate to adaptive immunity is often summarized with two terms. DCs are sentinels, able to capture, process and present antigens and to migrate to lymphoid tissues to select rare, antigen-reactive T cell clones. DCs are also sensors, responding to a spectrum of environmental cues by extensive differentiation or maturation. The type of DC and the type of maturation induced by different stimuli influences the immunological outcome, such as the differentiation of Thl vs. Th2 T cells. Here we summarize the contributions of DCs to innate defences, particularly the production of immune enhancing cytokines and the activation of innate lymphocytes. Then we outline three innate features of DCs that influence peripheral tolerance and lead to adaptive immunity: a specialized endocytic system for antigen capture and processing, location and movements in vivo, and maturation in response to an array of stimuli. A new approach to the analysis of DC biology is to target antigens selectively to maturing DCs in vivo. This leads to stronger, more prolonged and broader (many immunogenic peptides) immunity by both T cells and B cells.

Mucosal Herpes Immunity and Immunopathology to Ocular and Genital Herpes Simplex Virus Infections

PubMed Central

Chentoufi, Aziz Alami; BenMohamed, Lbachir

2012-01-01

Herpes simplex viruses type 1 and type 2 (HSV-1 and HSV-2) are amongst the most common human infectious viral pathogens capable of causing serious clinical diseases at every stage of life, from fatal disseminated disease in newborns to cold sores genital ulcerations and blinding eye disease. Primary mucocutaneous infection with HSV-1 & HSV-2 is followed by a lifelong viral latency in the sensory ganglia. In the majority of cases, herpes infections are clinically asymptomatic. However, in symptomatic individuals, the latent HSV can spontaneously and frequently reactivate, reinfecting the muco-cutaneous surfaces and causing painful recurrent diseases. The innate and adaptive mucosal immunities to herpes infections and disease remain to be fully characterized. The understanding of innate and adaptive immune mechanisms operating at muco-cutaneous surfaces is fundamental to the design of next-generation herpes vaccines. In this paper, the phenotypic and functional properties of innate and adaptive mucosal immune cells, their role in antiherpes immunity, and immunopathology are reviewed. The progress and limitations in developing a safe and efficient mucosal herpes vaccine are discussed. PMID:23320014

Gold kiwifruit ( Actinidia chinensis 'Hort16A') for immune support.

PubMed

Skinner, Margot A; Loh, Jacelyn M S; Hunter, Denise C; Zhang, Jingli

2011-05-01

Kiwifruit is a good source of several vitamins and minerals and dietary fibre, and contains a number of phytochemicals; so kiwifruit potentially provides health benefits beyond basic nutrition. Consumption of green kiwifruit can have positive effects on cardiovascular health through antioxidant activity, inhibition of platelet aggregation and lowered TAG levels, and gut health through improving laxation, aiding digestion and promoting a healthy gut microflora. The importance of nutrition on immune function is well recognised, with deficiencies in vitamins A, C, E, B6 and B12, folic acid, Zn, Cu, Fe and Se being associated with impaired immune function and increased susceptibility to diseases. Evidence is growing that kiwifruit enhances immunity, with several small murine studies showing enhancement of innate and adaptive immune function. Few studies have examined the effect of kiwifruit on immune function in human subjects, but a recent study has revealed that kiwifruit up-regulates several 'immune' and 'DNA and repair'-related gene sets, and down-regulates one gene set related to Ig secretion. Taken together, the evidence from the literature provides supporting data for designing a human intervention trial to validate the ability of kiwifruit to support immune function in healthy and immunocompromised populations.

Gene expression profiling of dendritic cells by microarray.

PubMed

Foti, Maria; Ricciardi-Castagnoli, Paola; Granucci, Francesca

2007-01-01

The immune system of vertebrate animals has evolved to respond to different types of perturbations (invading pathogens, stress signals), limiting self-tissue damage. The decision to activate an immune response is made by antigen-presenting cells (APCs) that are quiescent until they encounter a foreign microorganism or inflammatory stimuli. Early activated APCs trigger innate immune responses that represent the first line of reaction against invading pathogens to limit the infections. At later times, activated APCs acquire the ability to prime antigen-specific immune responses that clear the infections and give rise to memory. During the immune response self-tissue damage is limited and tolerance to self is maintained through life. Among the cells that constitute the immune system, dendritic cells (DC) play a central role. They are extremely versatile APCs involved in the initiation of both innate and adaptive immunity and also in the differentiation of regulatory T cells required for the maintenance of self-tolerance. How DC can mediate these diverse and almost contradictory functions has recently been investigated. The plasticity of these cells allows them to undergo a complete genetic reprogramming in response to external microbial stimuli with the sequential acquisition of different regulatory functions in innate and adaptive immunity. The specific genetic reprogramming DC undergo upon activation can be easily investigated by using microarrays to perform global gene expression analysis in different conditions.

Bovine maternal, fetal and neonatal responses to bovine viral diarrhea virus infections.

PubMed

Kelling, Clayton L; Topliff, Christina L

2013-01-01

Due to the affinity of BVDV for the fetus and for cells of lymphatic organs of infected cattle, reproductive failure or immunosuppression, respectively, are likely consequences of BVDV infections of susceptible cattle. Infection of susceptible pregnant cattle with noncytopathic (ncp) BVDV results in transplacental infection with induction of maternal and fetal innate and adaptive immune responses. Differences in maternal innate and adaptive immune responses are evident in late gestation between cows carrying fetuses persistently-infected (PI) with BVDV and cows with fetuses transiently-infected with BVDV. Fetal innate and adaptive immune responses to ncp BVDV infection are defined by fetal age and developmental stage of the fetal immune system. Since a functional fetal adaptive immune response does not occur in the early fetus, immunotolerance to ncp BVDV is established, virus replicates unrestricted in fetal tissues and calves are born immunotolerant and PI with the virus. In the last trimester of gestation, the fetal immune system is adequately developed to respond in an efficacious manner, most commonly resulting in the birth of a clinically normal calf with pre-colostral antibodies. Immunosuppression due to postnatal acute ncp BVDV infections of susceptible calves may contribute to the occurrence and severity of multi-factorial respiratory tract and enteric diseases. Copyright © 2012 The International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

Instructed subsets or agile swarms: how T-helper cells may adaptively counter uncertainty with variability and plasticity.

PubMed

Schrom, Edward C; Graham, Andrea L

2017-12-01

Over recent years, extensive phenotypic variability and plasticity have been revealed among the T-helper cells of the mammalian adaptive immune system, even within clonal lineages of identical antigen specificity. This challenges the conventional view that T-helper cells assort into functionally distinct subsets following differential instruction by the innate immune system. We argue that the adaptive value of coping with uncertainty can reconcile the 'instructed subset' framework with T-helper variability and plasticity. However, we also suggest that T-helper cells might better be understood as agile swarms engaged in collective decision-making to promote host fitness. With rigorous testing, the 'agile swarms' framework may illuminate how variable and plastic individual T-helper cells interact to create coherent immunity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of HIV infection and ART on phenotype and function of circulating monocytes, natural killer, and innate lymphoid cells.

PubMed

Nabatanzi, Rose; Cose, Stephen; Joloba, Moses; Jones, Sarah Rowland; Nakanjako, Damalie

2018-03-15

HIV infection causes upregulation of markers of inflammation, immune activation and apoptosis of host adaptive, and innate immune cells particularly monocytes, natural killer (NK) and innate lymphoid cells (ILCs). Although antiretroviral therapy (ART) restores CD4 T-cell counts, the persistent aberrant activation of monocytes, NK and ILCs observed likely contributes to the incomplete recovery of T-cell effector functions. A better understanding of the effects of HIV infection and ART on the phenotype and function of circulating monocytes, NK, and ILCs is required to guide development of novel therapeutic interventions to optimize immune recovery.

TLR10 is a B-cell Intrinsic Suppressor of Adaptive Immune Responses

PubMed Central

Hess, Nicholas J.; Jiang, Song; Li, Xinyan; Guan, Yue; Tapping, Richard I.

2016-01-01

Toll-like receptors (TLRs) play a central role in the initiation of adaptive immune responses with several TLR agonists acting as known B-cell mitogens. Despite thousands of publications on TLRs, the function of TLR10 remains unknown. We have found that antibody mediated engagement of TLR10 on primary human B-cells suppresses B-cell proliferation, cytokine production and signal transduction. When challenged with either a T-independent or T-dependent antigen, TLR10 transgenic mice exhibit diminished antibody responses. Adoptive transfer of splenic B-cells into B-cell deficient mice revealed that the suppressive effects on antigen-specific humoral immune responses are entirely B-cell intrinsic. Our results demonstrate that TLR10 has a functional role within the B-cell lineage that is distinct from that of other TLR family members and may provide a potential therapeutic target for diseases characterized by dysregulated B-cell activity. PMID:27956526

Immune heterogeneity in neuroinflammation: dendritic cells in the brain.

PubMed

Colton, Carol A

2013-03-01

Dendritic cells (DC) are critical to an integrated immune response and serve as the key link between the innate and adaptive arms of the immune system. Under steady state conditions, brain DC's act as sentinels, continually sampling their local environment. They share this function with macrophages derived from the same basic hemopoietic (bone marrow-derived) precursor and with parenchymal microglia that arise from a unique non-hemopoietic origin. While multiple cells may serve as antigen presenting cells (APCs), dendritic cells present both foreign and self-proteins to naïve T cells that, in turn, carry out effector functions that serve to protect or destroy. The resulting activation of the adaptive response is a critical step to resolution of injury or infection and is key to survival. In this review we will explore the critical roles that DCs play in the brain's response to neuroinflammatory disease with emphasis on how the brain's microenvironment impacts these actions.

Redox sensitivity of the MyD88 immune signaling adapter.

PubMed

Stottmeier, Benjamin; Dick, Tobias P

2016-12-01

The transcription factor nuclear factor-κB (NF-κB) mediates expression of key genes involved in innate immunity and inflammation. NF-κB activation has been repeatedly reported to be modulated by hydrogen peroxide (H 2 O 2 ). Here, we show that the NF-κB-activating signaling adapter myeloid differentiation primary response gene 88 (MyD88) is highly sensitive to oxidation by H 2 O 2 and may be redox-regulated in its function, thus facilitating an influence of H 2 O 2 on the NF-κB signaling pathway. Upon oxidation, MyD88 forms distinct disulfide-linked conjugates which are reduced by the MyD88-interacting oxidoreductase nucleoredoxin (Nrx). MyD88 cysteine residues functionally modulate MyD88-dependent NF-κB activation, suggesting a link between MyD88 thiol oxidation state and immune signaling. Copyright © 2016 Elsevier Inc. All rights reserved.

Innate Immune Cytokines, Fibroblast Phenotypes, and Regulation of Extracellular Matrix in Lung.

PubMed

Richards, Carl D

2017-02-01

Chronic inflammation can be caused by adaptive immune responses in autoimmune and allergic conditions, driven by a T lymphocyte subset balance (TH1, TH2, Th17, Th22, and/or Treg) and skewed cellular profiles in an antigen-specific manner. However, several chronic inflammatory diseases have no clearly defined adaptive immune mechanisms that drive chronicity. These conditions include those that affect the lung such as nonatopic asthma or idiopathic pulmonary fibrosis comprising significant health problems. The remodeling of extracellular matrix (ECM) causes organ dysfunction, and it is largely generated by fibroblasts as the major cell controlling net ECM. As such, these are potential targets of treatment approaches in the context of ECM pathology. Fibroblast phenotypes contribute to ECM and inflammatory cell accumulation, and they are integrated into chronic disease mechanisms including cancer. Evidence suggests that innate cytokine responses may be critical in nonallergic/nonautoimmune disease, and they enable environmental agent exposure mechanisms that are independent of adaptive immunity. Innate immune cytokines derived from macrophage subsets (M1/M2) and innate lymphoid cell (ILC) subsets can directly regulate fibroblast function. We also suggest that STAT3-activating gp130 cytokines can sensitize fibroblasts to the innate cytokine milieu to drive phenotypes and exacerbate existing adaptive responses. Here, we review evidence exploring innate cytokine regulation of fibroblast behavior.

Molecular control of steady-state dendritic cell maturation and immune homeostasis.

PubMed

Hammer, Gianna Elena; Ma, Averil

2013-01-01

Dendritic cells (DCs) are specialized sentinels responsible for coordinating adaptive immunity. This function is dependent upon coupled sensitivity to environmental signs of inflammation and infection to cellular maturation-the programmed alteration of DC phenotype and function to enhance immune cell activation. Although DCs are thus well equipped to respond to pathogens, maturation triggers are not unique to infection. Given that immune cells are exquisitely sensitive to the biological functions of DCs, we now appreciate that multiple layers of suppression are required to restrict the environmental sensitivity, cellular maturation, and even life span of DCs to prevent aberrant immune activation during the steady state. At the same time, steady-state DCs are not quiescent but rather perform key functions that support homeostasis of numerous cell types. Here we review these functions and molecular mechanisms of suppression that control steady-state DC maturation. Corruption of these steady-state operatives has diverse immunological consequences and pinpoints DCs as potent drivers of autoimmune and inflammatory disease.

Immune Reconstitution after Allogeneic Hematopoietic Stem Cell Transplantation

PubMed Central

Ogonek, Justyna; Kralj Juric, Mateja; Ghimire, Sakhila; Varanasi, Pavankumar Reddy; Holler, Ernst; Greinix, Hildegard; Weissinger, Eva

2016-01-01

The timely reconstitution and regain of function of a donor-derived immune system is of utmost importance for the recovery and long-term survival of patients after allogeneic hematopoietic stem cell transplantation (HSCT). Of note, new developments such as umbilical cord blood or haploidentical grafts were associated with prolonged immunodeficiency due to delayed immune reconstitution, raising the need for better understanding and enhancing the process of immune reconstitution and finding strategies to further optimize these transplant procedures. Immune reconstitution post-HSCT occurs in several phases, innate immunity being the first to regain function. The slow T cell reconstitution is regarded as primarily responsible for deleterious infections with latent viruses or fungi, occurrence of graft-versus-host disease, and relapse. Here we aim to summarize the major steps of the adaptive immune reconstitution and will discuss the importance of immune balance in patients after HSCT. PMID:27909435

Cutting edge: impairment of dendritic cells and adaptive immunity by Ebola and Lassa viruses.

PubMed

Mahanty, Siddhartha; Hutchinson, Karen; Agarwal, Sudhanshu; McRae, Michael; Rollin, Pierre E; Pulendran, Bali

2003-03-15

Acute infection of humans with Ebola and Lassa viruses, two principal etiologic agents of hemorrhagic fevers, often results in a paradoxical pattern of immune responses: early infection, characterized by an outpouring of inflammatory mediators such as TNF-alpha, IL-1 beta, and IL-6, vs late stage infections, which are associated with poor immune responses. The mechanisms underlying these diverse outcomes are poorly understood. In particular, the role played by cells of the innate immune system, such as dendritic cells (DC), is not known. In this study, we show that Ebola and Lassa viruses infect human monocyte-derived DC and impair their function. Monocyte-derived DC exposed to either virus fail to secrete proinflammatory cytokines, do not up-regulate costimulatory molecules, and are poor stimulators of T cells. These data represent the first evidence for a mechanism by which Ebola and Lassa viruses target DC to impair adaptive immunity.

Synthetic mast-cell granules as adjuvants to promote and polarize immunity in lymph nodes

NASA Astrophysics Data System (ADS)

St. John, Ashley L.; Chan, Cheryl Y.; Staats, Herman F.; Leong, Kam W.; Abraham, Soman N.

2012-03-01

Granules of mast cells (MCs) enhance adaptive immunity when, on activation, they are released as stable particles. Here we show that submicrometre particles modelled after MC granules augment immunity when used as adjuvants in vaccines. The synthetic particles, which consist of a carbohydrate backbone with encapsulated inflammatory mediators such as tumour necrosis factor, replicate attributes of MCs in vivo including the targeting of draining lymph nodes and the timed release of the encapsulated mediators. When used as an adjuvant during vaccination of mice with haemagglutinin from the influenza virus, the particles enhanced adaptive immune responses and increased survival of mice on lethal challenge. Furthermore, differential loading of the particles with the cytokine IL-12 directed the character of the response towards Th1 lymphocytes. The synthetic MC adjuvants replicate and enhance the functions of MCs during vaccination, and can be extended to polarize the resulting immunity.

Unbiased transcriptomic analyses reveal distinct effects of immune deficiency in CNS function with and without injury.

PubMed

Luo, Dandan; Ge, Weihong; Hu, Xiao; Li, Chen; Lee, Chia-Ming; Zhou, Liqiang; Wu, Zhourui; Yu, Juehua; Lin, Sheng; Yu, Jing; Xu, Wei; Chen, Lei; Zhang, Chong; Jiang, Kun; Zhu, Xingfei; Li, Haotian; Gao, Xinpei; Geng, Yanan; Jing, Bo; Wang, Zhen; Zheng, Changhong; Zhu, Rongrong; Yan, Qiao; Lin, Quan; Ye, Keqiang; Sun, Yi E; Cheng, Liming

2018-06-28

The mammalian central nervous system (CNS) is considered an immune privileged system as it is separated from the periphery by the blood brain barrier (BBB). Yet, immune functions have been postulated to heavily influence the functional state of the CNS, especially after injury or during neurodegeneration. There is controversy regarding whether adaptive immune responses are beneficial or detrimental to CNS injury repair. In this study, we utilized immunocompromised SCID mice and subjected them to spinal cord injury (SCI). We analyzed motor function, electrophysiology, histochemistry, and performed unbiased RNA-sequencing. SCID mice displayed improved CNS functional recovery compared to WT mice after SCI. Weighted gene-coexpression network analysis (WGCNA) of spinal cord transcriptomes revealed that SCID mice had reduced expression of immune function-related genes and heightened expression of neural transmission-related genes after SCI, which was confirmed by immunohistochemical analysis and was consistent with better functional recovery. Transcriptomic analyses also indicated heightened expression of neurotransmission-related genes before injury in SCID mice, suggesting that a steady state of immune-deficiency potentially led to CNS hyper-connectivity. Consequently, SCID mice without injury demonstrated worse performance in Morris water maze test. Taken together, not only reduced inflammation after injury but also dampened steady-state immune function without injury heightened the neurotransmission program, resulting in better or worse behavioral outcomes respectively. This study revealed the intricate relationship between immune and nervous systems, raising the possibility for therapeutic manipulation of neural function via immune modulation.

CRISPR-Cas: evolution of an RNA-based adaptive immunity system in prokaryotes.

PubMed

Koonin, Eugene V; Makarova, Kira S

2013-05-01

The CRISPR-Cas (clustered regularly interspaced short palindromic repeats, CRISPR-associated genes) is an adaptive immunity system in bacteria and archaea that functions via a distinct self-non-self recognition mechanism that is partially analogous to the mechanism of eukaryotic RNA interference (RNAi). The CRISPR-Cas system incorporates fragments of virus or plasmid DNA into the CRISPR repeat cassettes and employs the processed transcripts of these spacers as guide RNAs to cleave the cognate foreign DNA or RNA. The Cas proteins, however, are not homologous to the proteins involved in RNAi and comprise numerous, highly diverged families. The majority of the Cas proteins contain diverse variants of the RNA recognition motif (RRM), a widespread RNA-binding domain. Despite the fast evolution that is typical of the cas genes, the presence of diverse versions of the RRM in most Cas proteins provides for a simple scenario for the evolution of the three distinct types of CRISPR-cas systems. In addition to several proteins that are directly implicated in the immune response, the cas genes encode a variety of proteins that are homologous to prokaryotic toxins that typically possess nuclease activity. The predicted toxins associated with CRISPR-Cas systems include the essential Cas2 protein, proteins of COG1517 that, in addition to a ligand-binding domain and a helix-turn-helix domain, typically contain different nuclease domains and several other predicted nucleases. The tight association of the CRISPR-Cas immunity systems with predicted toxins that, upon activation, would induce dormancy or cell death suggests that adaptive immunity and dormancy/suicide response are functionally coupled. Such coupling could manifest in the persistence state being induced and potentially providing conditions for more effective action of the immune system or in cell death being triggered when immunity fails.

Platelets: versatile effector cells in hemostasis, inflammation, and the immune continuum

PubMed Central

Vieira-de-Abreu, Adriana; Campbell, Robert A.; Weyrich, Andrew S.

2015-01-01

Platelets are chief effector cells in hemostasis. In addition, however, their specializations include activities and intercellular interactions that make them key effectors in inflammation and in the continuum of innate and adaptive immunity. This review focuses on the immune features of human platelets and platelets from experimental animals and on interactions between inflammatory, immune, and hemostatic activities of these anucleate but complex and versatile cells. The experimental findings and evidence for physiologic immune functions include previously unrecognized biologic characteristics of platelets and are paralleled by new evidence for unique roles of platelets in inflammatory, immune, and thrombotic diseases. PMID:21818701

Protein tyrosine phosphatase non-receptor type 2 and inflammatory bowel disease.

PubMed

Spalinger, Marianne R; McCole, Declan F; Rogler, Gerhard; Scharl, Michael

2016-01-21

Genome wide association studies have associated single nucleotide polymorphisms within the gene locus encoding protein tyrosine phosphatase non-receptor type 2 (PTPN2) with the onset of inflammatory bowel disease (IBD) and other inflammatory disorders. Expression of PTPN2 is enhanced in actively inflamed intestinal tissue featuring a marked up-regulation in intestinal epithelial cells. PTPN2 deficient mice suffer from severe intestinal and systemic inflammation and display aberrant innate and adaptive immune responses. In particular, PTPN2 is involved in the regulation of inflammatory signalling cascades, and critical for protecting intestinal epithelial barrier function, regulating innate and adaptive immune responses, and finally for maintaining intestinal homeostasis. On one hand, dysfunction of PTPN2 has drastic effects on innate host defence mechanisms, including increased secretion of pro-inflammatory cytokines, limited autophagosome formation in response to invading pathogens, and disruption of the intestinal epithelial barrier. On the other hand, PTPN2 function is crucial for controlling adaptive immune functions, by regulating T cell proliferation and differentiation as well as maintaining T cell tolerance. In this way, dysfunction of PTPN2 contributes to the manifestation of IBD. The aim of this review is to present an overview of recent findings on the role of PTPN2 in intestinal homeostasis and the impact of dysfunctional PTPN2 on intestinal inflammation.

Platelets as Cellular Effectors of Inflammation in Vascular Diseases

PubMed Central

Rondina, Matthew T.; Weyrich, Andrew S.; Zimmerman, Guy A.

2013-01-01

Platelets are chief effector cells in hemostasis. In addition, they are multifaceted inflammatory cells with functions that span the continuum from innate immune responses to adaptive immunity. Activated platelets have key “thromboinflammatory” activities in a variety of vascular disorders and vasculopathies. Recently-identified inflammatory and immune activities provide insights into the biology of these versatile blood cells that are directly relevant to human vascular diseases. PMID:23704217

No evidence for the immunocompetence handicap hypothesis in male humans.

PubMed

Nowak, Judyta; Pawłowski, Bogusław; Borkowska, Barbara; Augustyniak, Daria; Drulis-Kawa, Zuzanna

2018-05-09

The observations that testosterone might be immunosuppressive, form the basis for the immunocompetence handicap hypothesis (ICHH). According to ICHH only high-quality individuals can maintain high levels of testosterone and afford the physiological cost of hormone-derived immunosuppression. The animal and human studies that attempted to support the ICHH by precisely defined impairment of immunity associated with high testosterone levels are inconclusive. Furthermore, human studies have used only selected immune functions and varying testosterone fractions. This is the first study examining the relationship between multiple innate and adaptive immunity and serum levels of free testosterone, total testosterone, DHT and DHEA in ninety-seven healthy men. Free testosterone and marginally DHT levels were positively correlated with the strength of the influenza post-vaccination response. Total testosterone and DHEA showed no immunomodulatory properties. Our findings did not support ICHH assumptions about immunosuppressive function of androgens. In the affluent society studied here, men with higher levels of free testosterone could afford to invest more in adaptive immunity. Since the hormone-immune relationship is complex and may depend on multiple factors, including access to food resources, androgens should be treated as immunomodulators rather than implicit immunosuppressants.

[IMMUNE SYSTEM INTERNSHIP WITH SYMBIOTIC MICROORGANISMS IN GNOTOBIOTIC ANIMAL'S INTESTINUM ILEUM].

PubMed

Kochlamasashvili, B; Gogiashvili, L; Jandieri, K

2017-11-01

Structures, responsible for acceptive (comensaling relation) and protective (pathogenic defense) immunity, were studied and compared in small intestine - to ileum mucosa. Data shown, that main application of the both domains of immune system is to support the correlation between body and foreign microbes, but they response is different. Most significant differences are as follows: in acceptive reactions presented only in aseptic animals - gnotobionts, inflammatory changes absent, so immune reaction complex develops into physiological condition. Symbiotic reactions release in mucosa epithelial cells, also in cells, responsible for adaptive and congenital immune reactivity. Thus, acceptive immune reactions contribute symbiotic biocenosis versus elimination; which is function of protective immunity.

Cellular energy metabolism in T-lymphocytes.

PubMed

Gaber, Timo; Strehl, Cindy; Sawitzki, Birgit; Hoff, Paula; Buttgereit, Frank

2015-01-01

Energy homeostasis is a hallmark of cell survival and maintenance of cell function. Here we focus on the impact of cellular energy metabolism on T-lymphocyte differentiation, activation, and function in health and disease. We describe the role of transcriptional and posttranscriptional regulation of lymphocyte metabolism on immune functions of T cells. We also summarize the current knowledge about T-lymphocyte adaptations to inflammation and hypoxia, and the impact on T-cell behavior of pathophysiological hypoxia (as found in tumor tissue, chronically inflamed joints in rheumatoid arthritis and during bone regeneration). A better understanding of the underlying mechanisms that control immune cell metabolism and immune response may provide therapeutic opportunities to alter the immune response under conditions of either immunosuppression or inflammation, potentially targeting infections, vaccine response, tumor surveillance, autoimmunity, and inflammatory disorders.

The p36 isoform of murine cytomegalovirus m152 protein suffices for mediating innate and adaptive immune evasion.

PubMed

Fink, Annette; Renzaho, Angeliqué; Reddehase, Matthias J; Lemmermann, Niels A W

2013-12-16

The MHC-class I (MHC-I)-like viral (MHC-Iv) m152 gene product of murine cytomegalovirus (mCMV) was the first immune evasion molecule described for a member of the β-subfamily of herpesviruses as a paradigm for analogous functions of human cytomegalovirus proteins. Notably, by interacting with classical MHC-I molecules and with MHC-I-like RAE1 family ligands of the activatory natural killer (NK) cell receptor NKG2D, it inhibits presentation of antigenic peptides to CD8 T cells and the NKG2D-dependent activation of NK cells, respectively, thus simultaneously interfering with adaptive and innate immune recognition of infected cells. Although the m152 gene product exists in differentially glycosylated isoforms whose individual contributions to immune evasion are unknown, it has entered the scientific literature as m152/gp40, based on the quantitatively most prominent isoform but with no functional justification. By construction of a recombinant mCMV in which all three N-glycosylation sites are mutated (N61Q, N208Q, and N241Q), we show here that N-linked glycosylation is not essential for functional interaction of the m152 immune evasion protein with either MHC-I or RAE1. These data add an important functional detail to recent structural analysis of the m152/RAE1g complex that has revealed N-glycosylations at positions Asn61 and Asn208 of m152 distant from the m152/RAE1g interface.

A method for high purity intestinal epithelial cell culture from adult human and murine tissues for the investigation of innate immune function.

PubMed

Graves, Christina L; Harden, Scott W; LaPato, Melissa; Nelson, Michael; Amador, Byron; Sorenson, Heather; Frazier, Charles J; Wallet, Shannon M

2014-12-01

Intestinal epithelial cells (IECs) serve as an important physiologic barrier between environmental antigens and the host intestinal immune system. Thus, IECs serve as a first line of defense and may act as sentinel cells during inflammatory insults. Despite recent renewed interest in IEC contributions to host immune function, the study of primary IEC has been hindered by lack of a robust culture technique, particularly for small intestinal and adult tissues. Here, a novel adaptation for culture of primary IEC is described for human duodenal organ donor tissue as well as duodenum and colon of adult mice. These epithelial cell cultures display characteristic phenotypes and are of high purity. In addition, the innate immune function of human primary IEC, specifically with regard to Toll-like receptor (TLR) expression and microbial ligand responsiveness, is contrasted with a commonly used intestinal epithelial cell line (HT-29). Specifically, TLR expression at the mRNA level and production of cytokine (IFNγ and TNFα) in response to TLR agonist stimulation is assessed. Differential expression of TLRs as well as innate immune responses to ligand stimulation is observed in human-derived cultures compared to that of HT-29. Thus, use of this adapted method to culture primary epithelial cells from adult human donors and from adult mice will allow for more appropriate studies of IECs as innate immune effectors. Published by Elsevier B.V.

Alterations in adaptive immunity persist during long-duration spaceflight.

PubMed

Crucian, Brian; Stowe, Raymond P; Mehta, Satish; Quiriarte, Heather; Pierson, Duane; Sams, Clarence

2015-01-01

It is currently unknown whether immune system alterations persist during long-duration spaceflight. In this study various adaptive immune parameters were assessed in astronauts at three intervals during 6-month spaceflight on board the International Space Station (ISS). To assess phenotypic and functional immune system alterations in astronauts participating in 6-month orbital spaceflight. Blood was collected before, during, and after flight from 23 astronauts participating in 6-month ISS expeditions. In-flight samples were returned to Earth within 48 h of collection for immediate analysis. Assays included peripheral leukocyte distribution, T-cell function, virus-specific immunity, and mitogen-stimulated cytokine production profiles. Redistribution of leukocyte subsets occurred during flight, including an elevated white blood cell (WBC) count and alterations in CD8 + T-cell maturation. A reduction in general T-cell function (both CD4 + and CD8 + ) persisted for the duration of the 6-month spaceflights, with differential responses between mitogens suggesting an activation threshold shift. The percentage of CD4 + T cells capable of producing IL-2 was depressed after landing. Significant reductions in mitogen-stimulated production of IFNγ, IL-10, IL-5, TNFα, and IL-6 persisted during spaceflight. Following lipopolysaccharide (LPS) stimulation, production of IL-10 was reduced, whereas IL-8 production was increased during flight. The data indicated that immune alterations persist during long-duration spaceflight. This phenomenon, in the absence of appropriate countermeasures, has the potential to increase specific clinical risks for crewmembers during exploration-class deep space missions.

Alterations in adaptive immunity persist during long-duration spaceflight

PubMed Central

Crucian, Brian; Stowe, Raymond P; Mehta, Satish; Quiriarte, Heather; Pierson, Duane; Sams, Clarence

2015-01-01

Background: It is currently unknown whether immune system alterations persist during long-duration spaceflight. In this study various adaptive immune parameters were assessed in astronauts at three intervals during 6-month spaceflight on board the International Space Station (ISS). AIMS: To assess phenotypic and functional immune system alterations in astronauts participating in 6-month orbital spaceflight. Methods: Blood was collected before, during, and after flight from 23 astronauts participating in 6-month ISS expeditions. In-flight samples were returned to Earth within 48 h of collection for immediate analysis. Assays included peripheral leukocyte distribution, T-cell function, virus-specific immunity, and mitogen-stimulated cytokine production profiles. Results: Redistribution of leukocyte subsets occurred during flight, including an elevated white blood cell (WBC) count and alterations in CD8+ T-cell maturation. A reduction in general T-cell function (both CD4+ and CD8+) persisted for the duration of the 6-month spaceflights, with differential responses between mitogens suggesting an activation threshold shift. The percentage of CD4+ T cells capable of producing IL-2 was depressed after landing. Significant reductions in mitogen-stimulated production of IFNγ, IL-10, IL-5, TNFα, and IL-6 persisted during spaceflight. Following lipopolysaccharide (LPS) stimulation, production of IL-10 was reduced, whereas IL-8 production was increased during flight. Conclusions: The data indicated that immune alterations persist during long-duration spaceflight. This phenomenon, in the absence of appropriate countermeasures, has the potential to increase specific clinical risks for crewmembers during exploration-class deep space missions. PMID:28725716

A Simulated Heat Wave Has Diverse Effects on Immune Function and Oxidative Physiology in the Corn Snake (Pantherophis guttatus).

PubMed

Stahlschmidt, Z R; French, S S; Ahn, A; Webb, A; Butler, M W

Animals will continue to encounter increasingly warm environments, including more frequent and intense heat waves. Yet the physiological consequences of heat waves remain equivocal, potentially because of variation in adaptive plasticity (reversible acclimation) and/or aspects of experimental design. Thus, we measured a suite of physiological variables in the corn snake (Pantherophis guttatus) after exposure to field-parameterized, fluctuating temperature regimes (moderate temperature and heat wave treatments) to address two hypotheses: (1) a heat wave causes physiological stress, and (2) thermal performance of immune function exhibits adaptive plasticity in response to a heat wave. We found little support for our first hypothesis because a simulated heat wave had a negative effect on body mass, but it also reduced oxidative damage and did not affect peak performance of three immune metrics. Likewise, we found only partial support for our second hypothesis. After exposure to a simulated heat wave, P. guttatus exhibited greater performance breadth and reduced temperature specialization (the standardized difference between peak performance and performance breadth) for only one of three immune metrics and did so in a sex-dependent manner. Further, a simulated heat wave did not elicit greater performance of any immune metric at higher temperatures. Yet a heat wave likely reduced innate immune function in P. guttatus because each metric of innate immune performance in this species (as in most vertebrates) was lower at elevated temperatures. Together with previous research, our study indicates that a heat wave may have complex, modest, and even positive physiological effects in some taxa.

TAM receptor tyrosine kinase function and the immunopathology of liver disease.

PubMed

Mukherjee, S K; Wilhelm, A; Antoniades, C G

2016-06-01

Tyro3, Axl, MERTK (TAM) receptor tyrosine kinases are implicated in the regulation of the innate immune response through clearance of apoptotic cellular debris and control of cytokine signaling cascades. As a result they are pivotal in regulating the inflammatory response to tissue injury. Within the liver, immune regulatory signaling is employed to prevent the overactivation of innate immunity in response to continual antigenic challenge from the gastrointestinal tract. In this review we appraise current understanding of the role of TAM receptor function in the regulation of both innate and adaptive immunity, with a focus on its impact upon hepatic inflammatory pathology. Copyright © 2016 the American Physiological Society.

Steroid Sulfates from Ophiuroids (Brittle Stars): Action on Some Factors of Innate and Adaptive Immunity.

PubMed

Gazha, Anna K; Ivanushko, Lyudmila A; Levina, Eleonora V; Fedorov, Sergey N; Zaporozets, Tatyana S; Stonik, Valentin A; Besednova, Nataliya N

2016-06-01

The action of seven polyhydroxylated sterol mono- and disulfates (1-7), isolated from ophiuroids, on innate and adaptive immunity was examined in in vitro and in vivo experiments. At least, three of them (1, 2 and 4) increased the functional activities of neutrophils, including levels of oxygen-dependent metabolism, adhesive and phagocytic properties, and induced the expression of pro-inflammatory cytokines TNF-α and IL-8. Compound 4 was the most active for enhancing the production of antibody forming cells in the mouse spleen.

Ageing and the immune system: focus on macrophages.

PubMed

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.

Cryotherapy with concurrent CpG oligonucleotide treatment controls local tumor recurrence and modulates HER2/neu immunity.

PubMed

Veenstra, Jesse J; Gibson, Heather M; Littrup, Peter J; Reyes, Joyce D; Cher, Michael L; Takashima, Akira; Wei, Wei-Zen

2014-10-01

Percutaneous cryoablation is a minimally invasive procedure for tumor destruction, which can potentially initiate or amplify antitumor immunity through the release of tumor-associated antigens. However, clinically efficacious immunity is lacking and regional recurrences are a limiting factor relative to surgical excision. To understand the mechanism of immune activation by cryoablation, comprehensive analyses of innate immunity and HER2/neu humoral and cellular immunity following cryoablation with or without peritumoral CpG injection were conducted using two HER2/neu(+) tumor systems in wild-type (WT), neu-tolerant, and SCID mice. Cryoablation of neu(+) TUBO tumor in BALB/c mice resulted in systemic immune priming, but not in neu-tolerant BALB NeuT mice. Cryoablation of human HER2(+) D2F2/E2 tumor enabled the functionality of tumor-induced immunity, but secondary tumors were refractory to antitumor immunity if rechallenge occurred during the resolution phase of the cryoablated tumor. A step-wise increase in local recurrence was observed in WT, neu-tolerant, and SCID mice, indicating a role of adaptive immunity in controlling residual tumor foci. Importantly, local recurrences were eliminated or greatly reduced in WT, neu tolerant, and SCID mice when CpG was incorporated in the cryoablation regimen, showing significant local control by innate immunity. For long-term protection, however, adaptive immunity was required because most SCID mice eventually succumbed to local tumor recurrence even with combined cryoablation and CpG treatment. This improved understanding of the mechanisms by which cryoablation affects innate and adaptive immunity will help guide appropriate combination of therapeutic interventions to improve treatment outcomes. ©2014 American Association for Cancer Research.

Impaired functioning of immune defenses to infection in premature and term infants and their implications for vaccination.

PubMed

Baxter, David

2010-06-01

Newborn infants, particularly those born prematurely are at increased risk of infections, including vaccine preventable ones, resulting in an increased morbidity and mortality risk. Defects associated with higher mortality may involve external barriers and the innate and adaptive systems. The available evidence suggests a complex situation that ranges from pathogen/immunogen non-responsiveness to fully mature adult-equivalent functionality depending on both host and vaccine characteristics. This review considers potential qualitative and quantitative differences with respect to immune defences between premature/term infants and adults and evaluates implications of such differences for immunization outcomes.

The TAM family receptor tyrosine kinase TYRO3 is a negative regulator of type 2 immunity

PubMed Central

Chan, Pamela Y.; Carrera Silva, Eugenio A.; De Kouchkovsky, Dimitri; Joannas, Leonel D.; Hao, Liming; Hu, Donglei; Huntsman, Scott; Eng, Celeste; Licona-Limón, Paula; Weinstein, Jason S.; Herbert, De’Broski R.; Craft, Joseph E.; Flavell, Richard A.; Repetto, Silvia; Correale, Jorge; Burchard, Esteban G.; Torgerson, Dara G.; Ghosh, Sourav; Rothlin, Carla V.

2016-01-01

Host responses against metazoan parasites or an array of environmental substances elicit type 2 immunity. Despite its protective function, type 2 immunity also drives allergic diseases. The mechanisms that regulate the magnitude of the type 2 response remain largely unknown. Here, we show that genetic ablation of a receptor tyrosine kinase encoded by Tyro3 in mice or the functional neutralization of its ortholog in human dendritic cells resulted in enhanced type 2 immunity. Furthermore, the TYRO3 agonist PROS1 was induced in T cells by the quintessential type 2 cytokine, interleukin-4. T cell–specific Pros1 knockouts phenocopied the loss of Tyro3. Thus, a PROS1-mediated feedback from adaptive immunity engages a rheostat, TYRO3, on innate immune cells to limit the intensity of type 2 responses. PMID:27034374

Origins of adaptive immunity.

PubMed

Liongue, Clifford; John, Liza B; Ward, Alister

2011-01-01

Adaptive immunity, involving distinctive antibody- and cell-mediated responses to specific antigens based on "memory" of previous exposure, is a hallmark of higher vertebrates. It has been argued that adaptive immunity arose rapidly, as articulated in the "big bang theory" surrounding its origins, which stresses the importance of coincident whole-genome duplications. Through a close examination of the key molecules and molecular processes underpinning adaptive immunity, this review suggests a less-extreme model, in which adaptive immunity emerged as part of longer evolutionary journey. Clearly, whole-genome duplications provided additional raw genetic materials that were vital to the emergence of adaptive immunity, but a variety of other genetic events were also required to generate some of the key molecules, whereas others were preexisting and simply co-opted into adaptive immunity.

ZFP36 RNA-binding proteins restrain T-cell activation and anti-viral immunity.

PubMed

Moore, Michael J; Blachere, Nathalie E; Fak, John J; Park, Christopher Y; Sawicka, Kirsty; Parveen, Salina; Zucker-Scharff, Ilana; Moltedo, Bruno; Rudensky, Alexander Y; Darnell, Robert B

2018-05-31

Dynamic post-transcriptional control of RNA expression by RNA-binding proteins (RBPs) is critical during immune response. ZFP36 RBPs are prominent inflammatory regulators linked to autoimmunity and cancer, but functions in adaptive immunity are less clear. We used HITS-CLIP to define ZFP36 targets in mouse T cells, revealing unanticipated actions in regulating T cell activation, proliferation, and effector functions. Transcriptome and ribosome profiling showed that ZFP36 represses mRNA target abundance and translation, notably through novel AU-rich sites in coding sequence. Functional studies revealed that ZFP36 regulates early T cell activation kinetics cell autonomously, by attenuating activation marker expression, limiting T cell expansion, and promoting apoptosis. Strikingly, loss of ZFP36 in vivo accelerated T cell responses to acute viral infection and enhanced anti-viral immunity. These findings uncover a critical role for ZFP36 RBPs in restraining T cell expansion and effector functions, and suggest ZFP36 inhibition as a strategy to enhance immune-based therapies. © 2018, Moore et al.

The adaptive immune system promotes initiation of prostate carcinogenesis in a human c-Myc transgenic mouse model.

PubMed

Melis, Monique H M; Nevedomskaya, Ekaterina; van Burgsteden, Johan; Cioni, Bianca; van Zeeburg, Hester J T; Song, Ji-Ying; Zevenhoven, John; Hawinkels, Lukas J A C; de Visser, Karin E; Bergman, Andries M

2017-11-07

Increasing evidence from epidemiological and pathological studies suggests a role of the immune system in the initiation and progression of multiple cancers, including prostate cancer. Reports on the contribution of the adaptive immune system are contradictive, since both suppression and acceleration of disease development have been reported. This study addresses the functional role of lymphocytes in prostate cancer development using a genetically engineered mouse model (GEMM) of human c-Myc driven prostate cancer (Hi-Myc mice) combined with B and T cell deficiency (RAG1 -/- mice). From a pre-cancerous stage on, Hi-Myc mice showed higher accumulation of immune cells in their prostates then wild-type mice, of which macrophages were the most abundant. The onset of invasive adenocarcinoma was delayed in Hi-MycRAG1 -/- compared to Hi-Myc mice and associated with decreased infiltration of leukocytes into the prostate. In addition, lower levels of the cytokines CXCL2, CCL5 and TGF-β1 were detected in Hi-MycRAG1 -/- compared to Hi-Myc mouse prostates. These results from a GEMM of prostate cancer provide new insights into the promoting role of the adaptive immune system in prostate cancer development. Our findings indicate that the endogenous adaptive immune system does not protect against de novo prostate carcinogenesis in Hi-Myc transgenic mice, but rather accelerates the formation of invasive adenocarcinomas. This may have implications for the development of novel treatment strategies.

Impaired B cell immunity in acute myeloid leukemia patients after chemotherapy.

PubMed

Goswami, Meghali; Prince, Gabrielle; Biancotto, Angelique; Moir, Susan; Kardava, Lela; Santich, Brian H; Cheung, Foo; Kotliarov, Yuri; Chen, Jinguo; Shi, Rongye; Zhou, Huizhi; Golding, Hana; Manischewitz, Jody; King, Lisa; Kunz, Lauren M; Noonan, Kimberly; Borrello, Ivan M; Smith, B Douglas; Hourigan, Christopher S

2017-07-10

Changes in adaptive immune cells after chemotherapy in adult acute myeloid leukemia (AML) may have implications for the success of immunotherapy. This study was designed to determine the functional capacity of the immune system in adult patients with AML who have completed chemotherapy and are potential candidates for immunotherapy. We used the response to seasonal influenza vaccination as a surrogate for the robustness of the immune system in 10 AML patients in a complete remission post-chemotherapy and performed genetic, phenotypic, and functional characterization of adaptive immune cell subsets. Only 2 patients generated protective titers in response to vaccination, and a majority of patients had abnormal frequencies of transitional and memory B-cells. B-cell receptor sequencing showed a B-cell repertoire with little evidence of somatic hypermutation in most patients. Conversely, frequencies of T-cell populations were similar to those seen in healthy controls, and cytotoxic T-cells demonstrated antigen-specific activity after vaccination. Effector T-cells had increased PD-1 expression in AML patients least removed from chemotherapy. Our results suggest that while some aspects of cellular immunity recover quickly, humoral immunity is incompletely reconstituted in the year following intensive cytotoxic chemotherapy for AML. The observed B-cell abnormalities may explain the poor response to vaccination often seen in AML patients after chemotherapy. Furthermore, the uncoupled recovery of B-cell and T-cell immunity and increased PD-1 expression shortly after chemotherapy might have implications for the success of several modalities of immunotherapy.

Distinct Effects of Monophosphoryl Lipid A, Oligodeoxynucleotide CpG, and Combination Adjuvants on Modulating Innate and Adaptive Immune Responses to Influenza Vaccination.

PubMed

Ko, Eun-Ju; Lee, Young-Tae; Lee, Youri; Kim, Ki-Hye; Kang, Sang-Moo

2017-10-01

Monophosphoryl lipid A (MPL) and oligodeoxynucleotide CpG are toll-like receptor (TLR) 4 and 9 agonist, respectively. Here, we investigated the effects of MPL, CpG, and combination adjuvants on stimulating in vitro dendritic cells (DCs), in vivo innate and adaptive immune responses, and protective efficacy of influenza vaccination. Combination of MPL and CpG was found to exhibit distinct effects on stimulating DCs in vitro to secrete IL-12p70 and tumor necrosis factor (TNF)-α and proliferate allogeneic CD8 T cells. Prime immunization of mice with inactivated split influenza vaccine in the presence of low dose MPL+CpG adjuvants increased the induction of virus-specific IgG and IgG2a isotype antibodies. MPL and CpG adjuvants contribute to improving the efficacy of prime influenza vaccination against lethal influenza challenge as determined by body weight monitoring, lung function, viral titers, and histology. A combination of MPL and CpG adjuvants was effective in improving vaccine efficacy as well as in reducing inflammatory immune responses locally and in inducing cellular immune responses upon lethal influenza virus challenge. This study demonstrates unique adjuvant effects of MPL, CpG, and combination adjuvants on modulating innate and adaptive immune responses to influenza prime vaccination.

Intermediates of Metabolism: From Bystanders to Signalling Molecules.

PubMed

Haas, Robert; Cucchi, Danilo; Smith, Joanne; Pucino, Valentina; Macdougall, Claire Elizabeth; Mauro, Claudio

2016-05-01

The integration of biochemistry into immune cell biology has contributed immensely to our understanding of immune cell function and the associated pathologies. So far, most studies have focused on the regulation of metabolic pathways during an immune response and their contribution to its success. More recently, novel signalling functions of metabolic intermediates are being discovered that might play important roles in the regulation of immunity. Here we describe the three long-known small metabolites lactate, acetyl-CoA, and succinate in the context of immunometabolic signalling. Functions of these ubiquitous molecules are largely dependent on their intra- and extracellular concentrations as well as their subcompartmental localisation. Importantly, the signalling functions of these metabolic intermediates extend beyond self-regulatory roles and include cell-to-cell communication and sensing of microenvironmental conditions to elicit stress responses and cellular adaptation. Copyright © 2016 Elsevier Ltd. All rights reserved.

The NLRP3 Inflammasome Suppresses Protective Immunity to Gastrointestinal Helminth Infection.

PubMed

Alhallaf, Rafid; Agha, Zainab; Miller, Catherine M; Robertson, Avril A B; Sotillo, Javier; Croese, John; Cooper, Matthew A; Masters, Seth L; Kupz, Andreas; Smith, Nicholas C; Loukas, Alex; Giacomin, Paul R

2018-04-24

Inflammasomes promote immunity to microbial pathogens by regulating the function of IL-1-family cytokines such as IL-18 and IL-1β. However, the roles for inflammasomes during parasitic helminth infections remain unclear. We demonstrate that mice and humans infected with gastrointestinal nematodes display increased IL-18 secretion, which in Trichuris-infected or worm antigen-treated mice and in macrophages co-cultured with Trichuris antigens or exosome-like vesicles was dependent on the NLRP3 inflammasome. NLRP3-deficient mice displayed reduced pro-inflammatory type 1 cytokine responses and augmented protective type 2 immunity, which was reversed by IL-18 administration. NLRP3-dependent suppression of immunity partially required CD4 + cells but was apparent even in Rag1 -/- mice that lack adaptive immune cells, suggesting that NLRP3 influences both innate and adaptive immunity. These data highlight a role for NLRP3 in limiting protective immunity to helminths, suggesting that targeting the NLRP3 inflammasome may be an approach for limiting the disease burden associated with helminth infections. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Novel "Elements" of Immune Suppression within the Tumor Microenvironment.

PubMed

Gurusamy, Devikala; Clever, David; Eil, Robert; Restifo, Nicholas P

2017-06-01

Adaptive evolution has prompted immune cells to use a wide variety of inhibitory signals, many of which are usurped by tumor cells to evade immune surveillance. Although tumor immunologists often focus on genes and proteins as mediators of immune function, here we highlight two elements from the periodic table-oxygen and potassium-that suppress the immune system in previously unappreciated ways. While both are key to the maintenance of T-cell function and tissue homeostasis, they are exploited by tumors to suppress immuno-surveillance and promote metastatic spread. We discuss the temporal and spatial roles of these elements within the tumor microenvironment and explore possible therapeutic interventions for effective and promising anticancer therapies. Cancer Immunol Res; 5(6); 426-33. ©2017 AACR . ©2017 American Association for Cancer Research.

Immune Evasion by Epstein-Barr Virus.

PubMed

Ressing, Maaike E; van Gent, Michiel; Gram, Anna M; Hooykaas, Marjolein J G; Piersma, Sytse J; Wiertz, Emmanuel J H J

2015-01-01

Epstein-Bar virus (EBV) is widespread within the human population with over 90% of adults being infected. In response to primary EBV infection, the host mounts an antiviral immune response comprising both innate and adaptive effector functions. Although the immune system can control EBV infection to a large extent, the virus is not cleared. Instead, EBV establishes a latent infection in B lymphocytes characterized by limited viral gene expression. For the production of new viral progeny, EBV reactivates from these latently infected cells. During the productive phase of infection, a repertoire of over 80 EBV gene products is expressed, presenting a vast number of viral antigens to the primed immune system. In particular the EBV-specific CD4+ and CD8+ memory T lymphocytes can respond within hours, potentially destroying the virus-producing cells before viral replication is completed and viral particles have been released. Preceding the adaptive immune response, potent innate immune mechanisms provide a first line of defense during primary and recurrent infections. In spite of this broad range of antiviral immune effector mechanisms, EBV persists for life and continues to replicate. Studies performed over the past decades have revealed a wide array of viral gene products interfering with both innate and adaptive immunity. These include EBV-encoded proteins as well as small noncoding RNAs with immune-evasive properties. The current review presents an overview of the evasion strategies that are employed by EBV to facilitate immune escape during latency and productive infection. These evasion mechanisms may also compromise the elimination of EBV-transformed cells, and thus contribute to malignancies associated with EBV infection.

The Multifaceted Role of T-Helper Responses in Host Defense against Aspergillus fumigatus.

PubMed

Dewi, Intan M W; van de Veerdonk, Frank L; Gresnigt, Mark S

2017-10-04

The ubiquitous opportunistic fungal pathogen Aspergillus fumigatus rarely causes infections in immunocompetent individuals. A healthy functional innate immune system plays a crucial role in preventing Aspergillus -infection. This pivotal role for the innate immune system makes it a main research focus in studying the pathogenesis of aspergillosis. Although sometimes overshadowed by the innate immune response, the adaptive immune response, and in particular T-helper responses, also represents a key player in host defense against Aspergillus . Virtually all T-helper subsets have been described to play a role during aspergillosis, with the Th1 response being crucial for fungal clearance. However; morbidity and mortality of aspergillosis can also be partly attributed to detrimental immune responses resulting from adaptive immune activation. Th2 responses benefit fungal persistence; and are the foundation of allergic forms of aspergillosis. The Th17 response has two sides; although crucial for granulocyte recruitment, it can be involved in detrimental immunopathology. Regulatory T-cells, the endogenous regulators of inflammatory responses, play a key role in controlling detrimental inflammatory responses during aspergillosis. The current knowledge of the adaptive immune response against A. fumigatus is summarized in this review. A better understanding on how T-helper responses facilitate clearance of Aspergillus -infection and control inflammation can be the fundamental basis for understanding the pathogenesis of aspergillosis and for the development of novel host-directed therapies.

Identification of immune-related genes in gill cells of Japanese eels (Anguilla japonica) in adaptation to water salinity changes.

PubMed

Gu, Jie; Dai, Shuya; Liu, Haitao; Cao, Quanquan; Yin, Shaowu; Lai, Keng Po; Tse, William Ka Fai; Wong, Chris Kong Chu; Shi, Haifeng

2018-02-01

The changes in ambient salinity influence ion and water homeostasis, hormones secretion, and immune response in fish gills. The physiological functions of hormones and ion transporters in the regulation of gill-osmoregulation have been widely studied, however the modulation of immune response under salinity changes is not determined. Using transcriptome sequencing, we obtained a comprehensive profile of osmo-responsive genes in gill cells of Japanese eel (Anguilla japonica). Herein, we applied bioinformatics analysis to identify the immune-related genes that were significantly higher expressed in gill pavement cells (PVCs) and mitochondrial-rich cells (MRCs) in freshwater (FW) than seawater (SW) adapted fish. We validated the data using the real-time qPCR, which showed a high correlation between the RNA-seq and real-time qPCR data. In addition, the immunohistochemistry results confirmed the changes of the expression of selected immune-related genes, including C-reactive protein (CRP) in PVCs, toll-like receptor 2 (TLR2) in MRCs and interleukin-1 receptor type 2 (IL-1R2) in both PVCs and MRCs. Collectively our results demonstrated that those immune-related genes respond to salinity changes, and might trigger related special signaling pathways and network. This study provides new insights into the impacts of ambient salinity changes on adaptive immune response in fish gill cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

Innate control of adaptive immunity: Beyond the three-signal paradigm

PubMed Central

Jain, Aakanksha; Pasare, Chandrashekhar

2017-01-01

Activation of cells in the adaptive immune system is a highly orchestrated process dictated by multiples cues from the innate immune system. Although the fundamental principles of innate control of adaptive immunity are well established, it is not fully understood how innate cells integrate qualitative pathogenic information in order to generate tailored protective adaptive immune responses. In this review, we discuss complexities involved in the innate control of adaptive immunity that extend beyond T cell receptor engagement, co-stimulation and priming cytokine production but are critical for generation of protective T cell immunity. PMID:28483987

CD8+ T Cells Orchestrate pDC-XCR1+ Dendritic Cell Spatial and Functional Cooperativity to Optimize Priming.

PubMed

Brewitz, Anna; Eickhoff, Sarah; Dähling, Sabrina; Quast, Thomas; Bedoui, Sammy; Kroczek, Richard A; Kurts, Christian; Garbi, Natalio; Barchet, Winfried; Iannacone, Matteo; Klauschen, Frederick; Kolanus, Waldemar; Kaisho, Tsuneyasu; Colonna, Marco; Germain, Ronald N; Kastenmüller, Wolfgang

2017-02-21

Adaptive cellular immunity is initiated by antigen-specific interactions between T lymphocytes and dendritic cells (DCs). Plasmacytoid DCs (pDCs) support antiviral immunity by linking innate and adaptive immune responses. Here we examined pDC spatiotemporal dynamics during viral infection to uncover when, where, and how they exert their functions. We found that pDCs accumulated at sites of CD8 + T cell antigen-driven activation in a CCR5-dependent fashion. Furthermore, activated CD8 + T cells orchestrated the local recruitment of lymph node-resident XCR1 chemokine receptor-expressing DCs via secretion of the XCL1 chemokine. Functionally, this CD8 + T cell-mediated reorganization of the local DC network allowed for the interaction and cooperation of pDCs and XCR1 + DCs, thereby optimizing XCR1 + DC maturation and cross-presentation. These data support a model in which CD8 + T cells upon activation create their own optimal priming microenvironment by recruiting additional DC subsets to the site of initial antigen recognition. Published by Elsevier Inc.

Specialized Proresolving Mediators in Innate and Adaptive Immune Responses in Airway Diseases.

PubMed

Krishnamoorthy, Nandini; Abdulnour, Raja-Elie E; Walker, Katherine H; Engstrom, Braden D; Levy, Bruce D

2018-07-01

Airborne pathogens and environmental stimuli evoke immune responses in the lung. It is critical to health that these responses be controlled to prevent tissue damage and the compromise of organ function. Resolution of inflammation is a dynamic process that is coordinated by biochemical and cellular mechanisms. Recently, specialized proresolving mediators (SPMs) have been identified in resolution exudates. These molecules orchestrate anti-inflammatory and proresolving actions that are cell type specific. In this review, we highlight SPM biosynthesis, the influence of SPMs on the innate and adaptive immune responses in the lung, as well as recent insights from SPMs on inflammatory disease pathophysiology. Uncovering these mediators and cellular mechanisms for resolution is providing new windows into physiology and disease pathogenesis.

Rapamycin has suppressive and stimulatory effects on human plasmacytoid dendritic cell functions

PubMed Central

Boor, P P C; Metselaar, H J; Mancham, S; van der Laan, L J W; Kwekkeboom, J

2013-01-01

Plasmacytoid dendritic cells (PDC) are involved in innate immunity by interferon (IFN)-α production, and in adaptive immunity by stimulating T cells and inducing generation of regulatory T cells (Treg). In this study we studied the effects of mammalian target of rapamycin (mTOR) inhibition by rapamycin, a commonly used immunosuppressive and anti-cancer drug, on innate and adaptive immune functions of human PDC. A clinically relevant concentration of rapamycin inhibited Toll-like receptor (TLR)-7-induced IFN-α secretion potently (−64%) but TLR-9-induced IFN-α secretion only slightly (−20%), while the same concentration suppressed proinflammatory cytokine production by TLR-7-activated and TLR-9-activated PDC with similar efficacy. Rapamycin inhibited the ability of both TLR-7-activated and TLR-9-activated PDC to stimulate production of IFN-γ and interleukin (IL)-10 by allogeneic T cells. Surprisingly, mTOR-inhibition enhanced the capacity of TLR-7-activated PDC to stimulate naive and memory T helper cell proliferation, which was caused by rapamycin-induced up-regulation of CD80 expression on PDC. Finally, rapamycin treatment of TLR-7-activated PDC enhanced their capacity to induce CD4+forkhead box protein 3 (FoxP3)+ regulatory T cells, but did not affect the generation of suppressive CD8+CD38+lymphocyte activation gene (LAG)-3+ Treg. In general, rapamycin inhibits innate and adaptive immune functions of TLR-stimulated human PDC, but enhances the ability of TLR-7-stimulated PDC to stimulate CD4+ T cell proliferation and induce CD4+FoxP3+ regulatory T cell generation. PMID:23968562

Innate immune reconstitution with suppression of HIV-1.

PubMed

Scully, Eileen P; Lockhart, Ainsley; Garcia-Beltran, Wilfredo; Palmer, Christine D; Musante, Chelsey; Rosenberg, Eric; Allen, Todd M; Chang, J Judy; Bosch, Ronald J; Altfeld, Marcus

2016-03-17

Progressive HIV-1 infection leads to both profound immune suppression and pathologic inflammation in the majority of infected individuals. While adaptive immune dysfunction, as evidenced by CD4 + T cell depletion and exhaustion, has been extensively studied, less is known about the functional capacity of innate immune cell populations in the context of HIV-1 infection. Given the broad susceptibility to opportunistic infections and the dysregulated inflammation observed in progressive disease, we hypothesized that there would be significant changes in the innate cellular responses. Using a cohort of patients with multiple samplings before and after antiretroviral therapy (ART) initiation, we demonstrated increased responses to innate immune stimuli following viral suppression, as measured by the production of inflammatory cytokines. Plasma viral load itself had the strongest association with this change in innate functional capacity. We further identified epigenetic modifications in the TNFA promoter locus in monocytes that are associated with viremia, suggesting a molecular mechanism for the observed changes in innate immune function following initiation of ART. These data indicate that suppression of HIV-1 viremia is associated with changes in innate cellular function that may in part determine the restoration of protective immune responses.

Innate immune reconstitution with suppression of HIV-1

PubMed Central

Scully, Eileen P.; Garcia-Beltran, Wilfredo; Palmer, Christine D.; Musante, Chelsey; Rosenberg, Eric; Allen, Todd M.; Bosch, Ronald J.

2016-01-01

Progressive HIV-1 infection leads to both profound immune suppression and pathologic inflammation in the majority of infected individuals. While adaptive immune dysfunction, as evidenced by CD4+ T cell depletion and exhaustion, has been extensively studied, less is known about the functional capacity of innate immune cell populations in the context of HIV-1 infection. Given the broad susceptibility to opportunistic infections and the dysregulated inflammation observed in progressive disease, we hypothesized that there would be significant changes in the innate cellular responses. Using a cohort of patients with multiple samplings before and after antiretroviral therapy (ART) initiation, we demonstrated increased responses to innate immune stimuli following viral suppression, as measured by the production of inflammatory cytokines. Plasma viral load itself had the strongest association with this change in innate functional capacity. We further identified epigenetic modifications in the TNFA promoter locus in monocytes that are associated with viremia, suggesting a molecular mechanism for the observed changes in innate immune function following initiation of ART. These data indicate that suppression of HIV-1 viremia is associated with changes in innate cellular function that may in part determine the restoration of protective immune responses. PMID:27158667

MiR-155-regulated molecular network orchestrates cell fate in the innate and adaptive immune response to Mycobacterium tuberculosis.

PubMed

Rothchild, Alissa C; Sissons, James R; Shafiani, Shahin; Plaisier, Christopher; Min, Deborah; Mai, Dat; Gilchrist, Mark; Peschon, Jacques; Larson, Ryan P; Bergthaler, Andreas; Baliga, Nitin S; Urdahl, Kevin B; Aderem, Alan

2016-10-11

The regulation of host-pathogen interactions during Mycobacterium tuberculosis (Mtb) infection remains unresolved. MicroRNAs (miRNAs) are important regulators of the immune system, and so we used a systems biology approach to construct an miRNA regulatory network activated in macrophages during Mtb infection. Our network comprises 77 putative miRNAs that are associated with temporal gene expression signatures in macrophages early after Mtb infection. In this study, we demonstrate a dual role for one of these regulators, miR-155. On the one hand, miR-155 maintains the survival of Mtb-infected macrophages, thereby providing a niche favoring bacterial replication; on the other hand, miR-155 promotes the survival and function of Mtb-specific T cells, enabling an effective adaptive immune response. MiR-155-induced cell survival is mediated through the SH2 domain-containing inositol 5-phosphatase 1 (SHIP1)/protein kinase B (Akt) pathway. Thus, dual regulation of the same cell survival pathway in innate and adaptive immune cells leads to vastly different outcomes with respect to bacterial containment.

Modulation of Dendritic Cell Innate and Adaptive Immune Functions by Oral and Sublingual Immunotherapy

PubMed Central

Frischmeyer-Guerrerio, Pamela A.; Keet, Corinne A.; Guerrerio, Anthony L.; Chichester, Kristin L.; Bieneman, Anja P.; Hamilton, Robert G.; Wood, Robert A.; Schroeder, John T.

2014-01-01

Sublingual (SLIT) and oral immunotherapy (OIT) are promising treatments for food allergy, but underlying mechanisms are poorly understood. Dendritic cells (DC) induce and maintain Th2-type allergen-specific T cells, and also regulate innate immunity through their expression of Toll-like receptors (TLRs). We examined how SLIT and OIT influenced DC innate and adaptive immune responses in children with IgE-mediated cow's milk (CM) allergy. SLIT, but not OIT, decreased TLR-induced IL-6 secretion by myeloid DCs (mDCs). SLIT and OIT altered mDC IL-10 secretion, a potent inhibitor of FcεRI-dependent pro-inflammatory responses. OIT uniquely augmented IFN-α and decreased IL-6 secretion by plasmacytoid DCs (pDCs), which was associated with reduced TLR-induced IL-13 release in pDC-T cell co-cultures. Both SLIT and OIT decreased Th2 cytokine secretion to CM in pDC-T, but not mDC-T, co-cultures. Therefore, SLIT and OIT exert unique effects on DC-driven innate and adaptive immune responses, which may inhibit allergic inflammation and promote tolerance. PMID:25173802

Viewing Siglecs through the lens of tumor immunology.

PubMed

Fraschilla, Isabella; Pillai, Shiv

2017-03-01

Many Siglecs function as inhibitory receptors on innate and adaptive immune cells and may contribute to the attenuation of immune responses to tumors. Siglec 9 on neutrophils and Siglec 7 on NK cells are prominent examples of inhibitory Siglecs that can potentially dampen anti-tumor immunity. CD169 is a Siglec that may function as an adhesion molecule and a facilitator of the recognition and internalization of sialic acid decorated apoptotic bodies and exosomes derived from tumors. It can potentially contribute to both the attenuation as well as the facilitation of anti-tumor immunity. Siglecs have been best studied in the tumor context in animal models of cancer. Modulators of Siglec function are likely to be developed and investigated clinically in a cancer context over the next few years. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Pseudomonas aeruginosa Airway Infection Recruits and Modulates Neutrophilic Myeloid-Derived Suppressor Cells

PubMed Central

Öz, Hasan H.; Zhou, Benyuan; Voss, Pina; Carevic, Melanie; Schroth, Carolin; Frey, Nina; Rieber, Nikolaus; Hector, Andreas; Hartl, Dominik

2016-01-01

Pseudomonas aeruginosa is an opportunistic pathogen that causes infections mainly in patients with cystic fibrosis (CF) lung disease. Despite innate and adaptive immune responses upon infection, P. aeruginosa is capable of efficiently escaping host defenses, but the underlying immune mechanisms remain poorly understood. Myeloid-derived suppressor cells (MDSCs) are innate immune cells that are functionally characterized by their potential to suppress T- and natural killer (NK)-cell responses. Here we demonstrate, using an airway in vivo infection model, that P. aeruginosa recruits and activates neutrophilic MDSCs, which functionally suppress T-cell responses. We further show that the CF gene defect (CF transmembrane conductance regulator, CFTR) modulates the functionality, but not the recruitment or generation of neutrophilic MDSCs. Collectively, we define a mechanism by which P. aeruginosa airway infection undermines host immunity by modulating neutrophilic MDSCs in vivo. PMID:27965936

Activation of caspase-1 by the NLRP3 inflammasome regulates the NADPH oxidase NOX2 to control phagosome function

PubMed Central

Sokolovska, Anna; Becker, Christine E.; Eddie Ip, WK; Rathinam, Vijay A.K.; Brudner, Matthew; Paquette, Nicholas; Tanne, Antoine; Vanaja, Sivapriya K.; Moore, Kathryn J.; Fitzgerald, Katherine A.; Lacy-Hulbert, Adam; Stuart, Lynda M.

2013-01-01

Phagocytosis is a fundamental cellular process that is pivotal for immunity as it coordinates microbial killing, innate immune activation and antigen presentation. An essential step in this process is phagosome acidification, which regulates a number of functions of these organelles that allow them to participate in processes essential to both innate and adaptive immunity. Here we report that acidification of phagosomes containing Gram-positive bacteria is regulated by the NLRP3-inflammasome and caspase-1. Active caspase-1 accumulates on phagosomes and acts locally to control the pH by modulating buffering by the NADPH oxidase NOX2. These data provide insight into a mechanism by which innate immune signals can modify cellular defenses and establish a new function for the NLRP3-inflammasome and caspase-1 in host defense. PMID:23644505

Immune and genetic gardening of the intestinal microbiome

PubMed Central

Jacobs, Jonathan P.; Braun, Jonathan

2014-01-01

The mucosal immune system – consisting of adaptive and innate immune cells as well as the epithelium – is profoundly influenced by its microbial environment. There is now growing evidence that the converse is also true, that the immune system shapes the composition of the intestinal microbiome. During conditions of health, this bidirectional interaction achieves a homeostasis in which inappropriate immune responses to nonpathogenic microbes are averted and immune activity suppresses blooms of potentially pathogenic microbes (pathobionts). Genetic alteration in immune/epithelial function can affect host gardening of the intestinal microbiome, contributing to the diversity of intestinal microbiota within a population and in some cases allowing for unfavorable microbial ecologies (dysbiosis) that confer disease susceptibility. PMID:24613921

MiRNAs: dynamic regulators of immune cell functions in inflammation and cancer.

PubMed

Hirschberger, Simon; Hinske, Ludwig Christian; Kreth, Simone

2018-09-01

MicroRNAs (miRNAs), small noncoding RNA molecules, have emerged as important regulators of almost all cellular processes. By binding to specific sequence motifs within the 3'- untranslated region of their target mRNAs, they induce either mRNA degradation or translational repression. In the human immune system, potent miRNAs and miRNA-clusters have been discovered, that exert pivotal roles in the regulation of gene expression. By targeting cellular signaling hubs, these so-called immuno-miRs have fundamental regulative impact on both innate and adaptive immune cells in health and disease. Importantly, they also act as mediators of tumor immune escape. Secreted by cancer cells and consecutively taken up by immune cells, immuno-miRs are capable to influence immune functions towards a blunted anti-tumor response, thus shaping a permissive tumor environment. This review provides an overview of immuno-miRs and their functional impact on individual immune cell entities. Further, implications of immuno-miRs in the amelioration of tumor surveillance are discussed. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Comparative transcriptomics of elasmobranchs and teleosts highlight important processes in adaptive immunity and regional endothermy.

PubMed

Marra, Nicholas J; Richards, Vincent P; Early, Angela; Bogdanowicz, Steve M; Pavinski Bitar, Paulina D; Stanhope, Michael J; Shivji, Mahmood S

2017-01-30

Comparative genomic and/or transcriptomic analyses involving elasmobranchs remain limited, with genome level comparisons of the elasmobranch immune system to that of higher vertebrates, non-existent. This paper reports a comparative RNA-seq analysis of heart tissue from seven species, including four elasmobranchs and three teleosts, focusing on immunity, but concomitantly seeking to identify genetic similarities shared by the two lamnid sharks and the single billfish in our study, which could be linked to convergent evolution of regional endothermy. Across seven species, we identified an average of 10,877 Swiss-Prot annotated genes from an average of 32,474 open reading frames within each species' heart transcriptome. About half of these genes were shared between all species while the remainder included functional differences between our groups of interest (elasmobranch vs. teleost and endotherms vs. ectotherms) as revealed by Gene Ontology (GO) and selection analyses. A repeatedly represented functional category, in both the uniquely expressed elasmobranch genes (total of 259) and the elasmobranch GO enrichment results, involved antibody-mediated immunity, either in the recruitment of immune cells (Fc receptors) or in antigen presentation, including such terms as "antigen processing and presentation of exogenous peptide antigen via MHC class II", and such genes as MHC class II, HLA-DPB1. Molecular adaptation analyses identified three genes in elasmobranchs with a history of positive selection, including legumain (LGMN), a gene with roles in both innate and adaptive immunity including producing antigens for presentation by MHC class II. Comparisons between the endothermic and ectothermic species revealed an enrichment of GO terms associated with cardiac muscle contraction in endotherms, with 19 genes expressed solely in endotherms, several of which have significant roles in lipid and fat metabolism. This collective comparative evidence provides the first multi-taxa transcriptomic-based perspective on differences between elasmobranchs and teleosts, and suggests various unique features associated with the adaptive immune system of elasmobranchs, pointing in particular to the potential importance of MHC Class II. This in turn suggests that expanded comparative work involving additional tissues, as well as genome sequencing of multiple elasmobranch species would be productive in elucidating the regulatory and genome architectural hallmarks of elasmobranchs.

Microglia, the missing link in maternal immune activation and fetal neurodevelopment; and a possible link in preeclampsia and disturbed neurodevelopment?

PubMed

Prins, Jelmer R; Eskandar, Sharon; Eggen, Bart J L; Scherjon, Sicco A

2018-04-01

Disturbances in fetal neurodevelopment have extensively been related to neurodevelopmental disorders in early and later life. Fetal neurodevelopment is dependent on adequate functioning of the fetal immune system. During pregnancy, the maternal immune system is challenged to both tolerate the semi-allogenic fetus and to protect the mother and fetus from microbes. The fetal immune system is influenced by maternal immune disturbances; therefore, perturbations in maternal immunity likely do not only alter pregnancy outcome but also alter fetal neurodevelopment. A possible common pathway could be modulating the functioning of tissue macrophages in the placenta and brain. Maternal immune tolerance towards the fetus involves several complex adaptations. In this active maternal immune state, the fetus develops its own immunity. As cytokines and other players of the immune system -which can pass the placenta- are involved in neurodevelopment, disruptions in immune balance influence fetal neurodevelopment. Several studies reported an association between maternal immune activation, complications of pregnancy as preeclampsia, and altered neonatal neurodevelopment. A possible pathway involves dysfunctioning of microglia cells, the immune cells of the brain. Functionality of microglia cells during normal pregnancy is, however, poorly understood. The recent outbreak of ZIKA virus (ZKV), but also the literature on virus infections in general and its consequences on microglial cell function and fetal neurodevelopment show the devastating effects a virus infection during pregnancy can have. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Rationale for combination of therapeutic antibodies targeting tumor cells and immune checkpoint receptors: Harnessing innate and adaptive immunity through IgG1 isotype immune effector stimulation.

PubMed

Ferris, Robert L; Lenz, Heinz-Josef; Trotta, Anna Maria; García-Foncillas, Jesús; Schulten, Jeltje; Audhuy, François; Merlano, Marco; Milano, Gerard

2018-02-01

Immunoglobulin (Ig) G1 antibodies stimulate antibody-dependent cell-mediated cytotoxicity (ADCC). Cetuximab, an IgG1 isotype monoclonal antibody, is a standard-of-care treatment for locally advanced and recurrent and/or metastatic squamous cell carcinoma of the head and neck (SCCHN) and metastatic colorectal cancer (CRC). Here we review evidence regarding the clinical relevance of cetuximab-mediated ADCC and other immune functions and provide a biological rationale concerning why this property positions cetuximab as an ideal partner for immune checkpoint inhibitors (ICIs) and other emerging immunotherapies. We performed a nonsystematic review of available preclinical and clinical data involving cetuximab-mediated immune activity and combination approaches of cetuximab with other immunotherapies, including ICIs, in SCCHN and CRC. Indeed, cetuximab mediates ADCC activity in the intratumoral space and primes adaptive and innate cellular immunity. However, counterregulatory mechanisms may lead to immunosuppressive feedback loops. Accordingly, there is a strong rationale for combining ICIs with cetuximab for the treatment of advanced tumors, as targeting CTLA-4, PD-1, and PD-L1 can ostensibly overcome these immunosuppressive counter-mechanisms in the tumor microenvironment. Moreover, combining ICIs (or other immunotherapies) with cetuximab is a promising strategy for boosting immune response and enhancing response rates and durability of response. Cetuximab immune activity-including, but not limited to, ADCC-provides a strong rationale for its combination with ICIs or other immunotherapies to synergistically and fully mobilize the adaptive and innate immunity against tumor cells. Ongoing prospective studies will evaluate the clinical effect of these combination regimens and their immune effect in CRC and SCCHN and in other indications. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Role of Hippo signaling in regulating immunity.

PubMed

Hong, Lixin; Li, Xun; Zhou, Dawang; Geng, Jing; Chen, Lanfen

2018-03-22

The Hippo signaling pathway has been established as a key regulator of organ size control, tumor suppression, and tissue regeneration in multiple organisms. Recently, emerging evidence has indicated that Hippo signaling might play an important role in regulating the immune system in both Drosophila and mammals. In particular, patients bearing a loss-of-function mutation of MST1 are reported to have an autosomal recessive primary immunodeficiency syndrome. MST1/2 kinases, the mammalian orthologs of Drosophila Hippo, may activate the non-canonical Hippo signaling pathway via MOB1A/B and/or NDR1/2 or cross-talk with other essential signaling pathways to regulate both innate and adaptive immunity. In this review, we present and discuss recent findings of cellular mechanisms/functions of Hippo signaling in the innate immunity in Drosophila and in mammals, T cell immunity, as well as the implications of Hippo signaling for tumor immunity.

Emerging Mechanisms of Innate Immunity and Their Translational Potential in Inflammatory Bowel Disease

PubMed Central

Corridoni, Daniele; Chapman, Thomas; Ambrose, Tim; Simmons, Alison

2018-01-01

Activation of the innate immune system through pattern-recognition receptor (PRR) signaling plays a pivotal role in the early induction of host defense following exposure to pathogens. Loss of intestinal innate immune regulation leading aberrant immune responses has been implicated in the pathogenesis of inflammatory bowel disease (IBD). The precise role of PRRs in gut inflammation is not well understood, but considering their role as bacterial sensors and their genetic association with IBD, they likely contribute to dysregulated immune responses to the commensal microbiota. The purpose of this review is to evaluate the emerging functions of PRRs including their functional cross-talk, how they respond to mitochondrial damage, induce mitophagy or autophagy, and influence adaptive immune responses by interacting with the antigen presentation machinery. The review also summarizes some of the recent attempts to harness these pathways for therapeutic approaches in intestinal inflammation. PMID:29515999

Role of the immune system in cardiac tissue damage and repair following myocardial infarction.

PubMed

Saparov, Arman; Ogay, Vyacheslav; Nurgozhin, Talgat; Chen, William C W; Mansurov, Nurlan; Issabekova, Assel; Zhakupova, Jamilya

2017-09-01

The immune system plays a crucial role in the initiation, development, and resolution of inflammation following myocardial infarction (MI). The lack of oxygen and nutrients causes the death of cardiomyocytes and leads to the exposure of danger-associated molecular patterns that are recognized by the immune system to initiate inflammation. At the initial stage of post-MI inflammation, the immune system further damages cardiac tissue to clear cell debris. The excessive production of reactive oxygen species (ROS) by immune cells and the inability of the anti-oxidant system to neutralize ROS cause oxidative stress that further aggravates inflammation. On the other hand, the cells of both innate and adaptive immune system and their secreted factors are critically instrumental in the very dynamic and complex processes of regulating inflammation and mediating cardiac repair. It is important to decipher the balance between detrimental and beneficial effects of the immune system in MI. This enables us to identify better therapeutic targets for reducing the infarct size, sustaining the cardiac function, and minimizing the likelihood of heart failure. This review discusses the role of both innate and adaptive immune systems in cardiac tissue damage and repair in experimental models of MI.

Innate immunity is sufficient for the clearance of Chlamydia trachomatis from the female mouse genital tract.

PubMed

Sturdevant, Gail L; Caldwell, Harlan D

2014-10-01

Chlamydia muridarum and Chlamydia trachomatis, mouse and human strains, respectively, have been used to study immunity in a murine model of female genital tract infection. Despite evidence that unique genes of these otherwise genomically similar strains could play a role in innate immune evasion in their respective mouse and human hosts, there have been no animal model findings to directly support this conclusion. Here, we infected C57BL/6 and adaptive immune-deficient Rag1(-/-) female mice with these strains and evaluated their ability to spontaneously resolve genital infection. Predictably, C57BL/6 mice spontaneously cleared infection caused by both chlamydial strains. In contrast, Rag1(-/-) mice which lack mature T and B cell immunity but maintain functional innate immune effectors were incapable of resolving C. muridarum infection but spontaneously cleared C. trachomatis infection. This distinct dichotomy in adaptive and innate immune-mediated clearance between mouse and human strains has important cautionary implications for the study of natural immunity and vaccine development in the mouse model. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

High rate of adaptation of mammalian proteins that interact with Plasmodium and related parasites

PubMed Central

Telis, Natalie; Petrov, Dmitri A.

2017-01-01

Plasmodium parasites, along with their Piroplasm relatives, have caused malaria-like illnesses in terrestrial mammals for millions of years. Several Plasmodium-protective alleles have recently evolved in human populations, but little is known about host adaptation to blood parasites over deeper evolutionary timescales. In this work, we analyze mammalian adaptation in ~500 Plasmodium- or Piroplasm- interacting proteins (PPIPs) manually curated from the scientific literature. We show that (i) PPIPs are enriched for both immune functions and pleiotropy with other pathogens, and (ii) the rate of adaptation across mammals is significantly elevated in PPIPs, compared to carefully matched control proteins. PPIPs with high pathogen pleiotropy show the strongest signatures of adaptation, but this pattern is fully explained by their immune enrichment. Several pieces of evidence suggest that blood parasites specifically have imposed selection on PPIPs. First, even non-immune PPIPs that lack interactions with other pathogens have adapted at twice the rate of matched controls. Second, PPIP adaptation is linked to high expression in the liver, a critical organ in the parasite life cycle. Finally, our detailed investigation of alpha-spectrin, a major red blood cell membrane protein, shows that domains with particularly high rates of adaptation are those known to interact specifically with P. falciparum. Overall, we show that host proteins that interact with Plasmodium and Piroplasm parasites have experienced elevated rates of adaptation across mammals, and provide evidence that some of this adaptation has likely been driven by blood parasites. PMID:28957326

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

PubMed

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.

Immunity to intestinal pathogens: lessons learned from Salmonella

PubMed Central

McSorley, Stephen J.

2014-01-01

Summary Salmonella are a common source of food or water-borne infection and cause a wide range of clinical disease in human and animal hosts. Salmonella are relatively easy to culture and manipulate in a laboratory setting, and the infection of laboratory animals induces robust innate and adaptive immune responses. Thus, immunologists have frequently turned to Salmonella infection models to expand understanding of immunity to intestinal pathogens. In this review, I summarize current knowledge of innate and adaptive immunity to Salmonella and highlight features of this response that have emerged from recent studies. These include the heterogeneity of the antigen-specific T-cell response to intestinal infection, the prominence of microbial mechanisms to impede T and B-cell responses, and the contribution of non-cognate pathways for elicitation of T-cell effector functions. Together, these different issues challenge an overly simplistic view of host-pathogen interaction during mucosal infection but also allow deeper insight into the real-world dynamic of protective immunity to intestinal pathogens. PMID:24942689

The p36 Isoform of Murine Cytomegalovirus m152 Protein Suffices for Mediating Innate and Adaptive Immune Evasion

PubMed Central

Fink, Annette; Renzaho, Angeliqué; Reddehase, Matthias J.; Lemmermann, Niels A. W.

2013-01-01

The MHC-class I (MHC-I)-like viral (MHC-Iv) m152 gene product of murine cytomegalovirus (mCMV) was the first immune evasion molecule described for a member of the β-subfamily of herpesviruses as a paradigm for analogous functions of human cytomegalovirus proteins. Notably, by interacting with classical MHC-I molecules and with MHC-I-like RAE1 family ligands of the activatory natural killer (NK) cell receptor NKG2D, it inhibits presentation of antigenic peptides to CD8 T cells and the NKG2D-dependent activation of NK cells, respectively, thus simultaneously interfering with adaptive and innate immune recognition of infected cells. Although the m152 gene product exists in differentially glycosylated isoforms whose individual contributions to immune evasion are unknown, it has entered the scientific literature as m152/gp40, based on the quantitatively most prominent isoform but with no functional justification. By construction of a recombinant mCMV in which all three N-glycosylation sites are mutated (N61Q, N208Q, and N241Q), we show here that N-linked glycosylation is not essential for functional interaction of the m152 immune evasion protein with either MHC-I or RAE1. These data add an important functional detail to recent structural analysis of the m152/RAE1γ complex that has revealed N-glycosylations at positions Asn61 and Asn208 of m152 distant from the m152/RAE1γ interface. PMID:24351798

Memory-like Responses of Natural Killer Cells

PubMed Central

Cooper, Megan A.; Yokoyama, Wayne M.

2010-01-01

Summary Natural killer (NK) cells are lymphocytes with the capacity to produce cytokines and kill target cells upon activation. NK cells have long been categorized as members of the innate immune system and as such have been thought to follow the ‘rules’ of innate immunity, including the principle that they have no immunologic memory, a property thought to be strictly limited to adaptive immunity. However, recent studies have suggested that NK cells have the capacity to alter their behavior based on prior activation. This property is analogous to adaptive immune memory; however, some NK cell memory-like functions are not strictly antigen-dependent and can be demonstrated following cytokine stimulation. Here we discuss the recent evidence that NK cells can exhibit properties of immunologic memory, focusing on the ability of cytokines to non-specifically induce memory-like NK cells with enhanced responses to restimulation. PMID:20536571

Activation of VIP signaling enhances immunosuppressive effect of MDSCs on CMV-induced adaptive immunity.

PubMed

Forghani, Parvin; Petersen, Christopher T; Waller, Edmund K

2017-10-10

Vasoactive intestinal peptide (VIP) is recognized as a potent anti-inflammatory factor which affects both the innate and adaptive arms of the immune system. These effects include, but are not limited to, inhibition of T cell proliferation and disruption of immune homeostasis. Myeloid-derived suppressor cells (MDSC) are an immune regulatory cell type that has been described in settings of cancer and infectious disease._Here we demonstrate a reduced circulating monocytic MDSCs in the VIP -/- vs. wild type MCMV. VIP-/- MDSCs secretes less NO upon stimulation with LPS and interferon that relatively lose the ability to suppress T cells activation in vitro compared to wild type MDSCs._Considering the importance of VIP in immunomodulation, the possible effect of VIP in the suppressive function of MDSC populations following CMV infection remains unknown. We describe the possible role of VIP in the regulation of anti-CMV activity of T cells through the activation of MDSCs.

NK cells interactions with dendritic cells shape innate and adaptive immunity.

PubMed

Brilot, Fabienne; Strowig, Till; Munz, Christian

2008-05-01

While natural killer (NK) cells received their name from their ability to mediate spontaneous cytotoxicity, it has recently become clear that they require activation to target most transformed and infected cells. Dendritic cells (DCs) have been shown to mediate NK cell activation during innate immune responses. Surprisingly, this interaction was recently reported to be required to restrict infections by NK cells, and to take place in secondary lymphoid organs. Here we review these recent studies on NK cell interactions with DCs, discuss the molecular mechanisms underlying the cross-talk between these two innate lymphocyte populations, and out-line how DCs and NK cells synergize to enhance innate immunity against microbes and tumors as well as shape the adaptive immune system. Based on this better understanding, we propose that NK cells should be targeted for their protective functions and as an adjuvant during immunotherapy development.

The T Cell Response to Staphylococcus aureus

PubMed Central

Bröker, Barbara M.; Mrochen, Daniel; Péton, Vincent

2016-01-01

Staphylococcus aureus (S. aureus) is a dangerous pathogen and a leading cause of both nosocomial and community acquired bacterial infection worldwide. However, on the other hand, we are all exposed to this bacterium, often within the first hours of life, and usually manage to establish equilibrium and coexist with it. What does the adaptive immune system contribute toward lifelong control of S. aureus? Will it become possible to raise or enhance protective immune memory by vaccination? While in the past the S. aureus-specific antibody response has dominated this discussion, the research community is now coming to appreciate the role that the cellular arm of adaptive immunity, the T cells, plays. There are numerous T cell subsets, each with differing functions, which together have the ability to orchestrate the immune response to S. aureus and hence to tip the balance between protection and pathology. This review summarizes the state of the art in this dynamic field of research. PMID:26999219

The MHC-II transactivator CIITA, a restriction factor against oncogenic HTLV-1 and HTLV-2 retroviruses: similarities and differences in the inhibition of Tax-1 and Tax-2 viral transactivators

PubMed Central

Forlani, Greta; Abdallah, Rawan; Accolla, Roberto S.; Tosi, Giovanna

2013-01-01

The activation of CD4+ T helper cells is strictly dependent on the presentation of antigenic peptides by MHC class II (MHC-II) molecules. MHC-II expression is primarily regulated at the transcriptional level by the AIR-1 gene product CIITA (class II transactivator). Thus, CIITA plays a pivotal role in the triggering of the adaptive immune response against pathogens. Besides this well known function, we recently found that CIITA acts as an endogenous restriction factor against HTLV-1 (human T cell lymphotropic virus type 1) and HTLV-2 oncogenic retroviruses by targeting their viral transactivators Tax-1 and Tax-2, respectively. Here we review our findings on CIITA-mediated inhibition of viral replication and discuss similarities and differences in the molecular mechanisms by which CIITA specifically counteracts the function of Tax-1 and Tax-2 molecules. The dual function of CIITA as a key regulator of adaptive and intrinsic immunity represents a rather unique example of adaptation of host-derived factors against pathogen infections during evolution. PMID:23986750

Pressure Induced Changes in Adaptive Immune Function in Belugas (Delphinapterus leucas); Implications for Dive Physiology and Health

PubMed Central

Thompson, Laura A.; Romano, Tracy A.

2016-01-01

Increased pressure, associated with diving, can alter cell function through several mechanisms and has been shown to impact immune functions performed by peripheral blood mononuclear cells (PBMC) in humans. While marine mammals possess specific adaptations which protect them from dive related injury, it is unknown how their immune system is adapted to the challenges associated with diving. The purpose of this study was to measure PBMC activation (IL2R expression) and Concanavalin A induced lymphocyte proliferation (BrdU incorporation) in belugas following in vitro pressure exposures during baseline, Out of Water Examination (OWE) and capture/release conditions. Beluga blood samples (n = 4) were obtained from animals at the Mystic Aquarium and from free ranging animals in Alaska (n = 9). Human blood samples (n = 4) (Biological Specialty Corporation) were run for comparison. In vivo catecholamines and cortisol were measured in belugas to characterize the neuroendocrine response. Comparison of cellular responses between controls and pressure exposed cells, between conditions in belugas, between belugas and humans as well as between dive profiles, were run using mixed generalized linear models (α = 0.05). Cortisol was significantly higher in Bristol Bay belugas and OWE samples as compared with baseline for aquarium animals. Both IL2R expression and proliferation displayed significant pressure induced changes, and these responses varied between conditions in belugas. Both belugas and humans displayed increased IL2R expression, while lymphocyte proliferation decreased for aquarium animals and increased for humans and Bristol Bay belugas. Results suggest beluga PBMC function is altered during diving and changes may represent dive adaptation as the response differs from humans, a non-dive adapted mammal. In addition, characteristics of a dive (i.e., duration, depth) as well as neuroendocrine activity can alter the response of beluga cells, potentially impacting the ability of animals to fight infection or avoid dive related pathologies. PMID:27746745

Pressure Induced Changes in Adaptive Immune Function in Belugas (Delphinapterus leucas); Implications for Dive Physiology and Health.

PubMed

Thompson, Laura A; Romano, Tracy A

2016-01-01

Increased pressure, associated with diving, can alter cell function through several mechanisms and has been shown to impact immune functions performed by peripheral blood mononuclear cells (PBMC) in humans. While marine mammals possess specific adaptations which protect them from dive related injury, it is unknown how their immune system is adapted to the challenges associated with diving. The purpose of this study was to measure PBMC activation (IL2R expression) and Concanavalin A induced lymphocyte proliferation (BrdU incorporation) in belugas following in vitro pressure exposures during baseline, Out of Water Examination (OWE) and capture/release conditions. Beluga blood samples ( n = 4) were obtained from animals at the Mystic Aquarium and from free ranging animals in Alaska ( n = 9). Human blood samples ( n = 4) (Biological Specialty Corporation) were run for comparison. In vivo catecholamines and cortisol were measured in belugas to characterize the neuroendocrine response. Comparison of cellular responses between controls and pressure exposed cells, between conditions in belugas, between belugas and humans as well as between dive profiles, were run using mixed generalized linear models (α = 0.05). Cortisol was significantly higher in Bristol Bay belugas and OWE samples as compared with baseline for aquarium animals. Both IL2R expression and proliferation displayed significant pressure induced changes, and these responses varied between conditions in belugas. Both belugas and humans displayed increased IL2R expression, while lymphocyte proliferation decreased for aquarium animals and increased for humans and Bristol Bay belugas. Results suggest beluga PBMC function is altered during diving and changes may represent dive adaptation as the response differs from humans, a non-dive adapted mammal. In addition, characteristics of a dive (i.e., duration, depth) as well as neuroendocrine activity can alter the response of beluga cells, potentially impacting the ability of animals to fight infection or avoid dive related pathologies.

Adaptive and Innate Transforming Growth Factor β Signaling Impact Herpes Simplex Virus 1 Latency and Reactivation▿

PubMed Central

Allen, Sariah J.; Mott, Kevin R.; Wechsler, Steven L.; Flavell, Richard A.; Town, Terrence; Ghiasi, Homayon

2011-01-01

Innate and adaptive immunity play important protective roles by combating herpes simplex virus 1 (HSV-1) infection. Transforming growth factor β (TGF-β) is a key negative cytokine regulator of both innate and adaptive immune responses. Yet, it is unknown whether TGF-β signaling in either immune compartment impacts HSV-1 replication and latency. We undertook genetic approaches to address these issues by infecting two different dominant negative TGF-β receptor type II transgenic mouse lines. These mice have specific TGF-β signaling blockades in either T cells or innate cells. Mice were ocularly infected with HSV-1 to evaluate the effects of restricted innate or adaptive TGF-β signaling during acute and latent infections. Limiting innate cell but not T cell TGF-β signaling reduced virus replication in the eyes of infected mice. On the other hand, blocking TGF-β signaling in either innate cells or T cells resulted in decreased latency in the trigeminal ganglia of infected mice. Furthermore, inhibiting TGF-β signaling in T cells reduced cell lysis and leukocyte infiltration in corneas and trigeminal ganglia during primary HSV-1 infection of mice. These findings strongly suggest that TGF-β signaling, which generally functions to dampen immune responses, results in increased HSV-1 latency. PMID:21880769

[Clustered regularly interspaced short palindromic repeats: structure, function and application--a review].

PubMed

Cui, Yujun; Li, Yanjun; Yan, Yanfeng; Yang, Ruifu

2008-11-01

CRISPRs (Clustered Regularly Interspaced Short Palindromic Repeats), the basis of spoligotyping technology, can provide prokaryotes with heritable adaptive immunity against phages' invasion. Studies on CRISPR loci and their associated elements, including various CAS (CRISPR-associated) proteins and leader sequences, are still in its infant period. We introduce the brief history', structure, function, bioinformatics research and application of this amazing immunity system in prokaryotic organism for inspiring more scientists to find their interest in this developing topic.

The immunomodulatory role of the hypothalamus-pituitary-gonad axis: Proximate mechanism for reproduction-immune trade offs?

PubMed

Segner, Helmut; Verburg-van Kemenade, B M Lidy; Chadzinska, Magdalena

2017-01-01

The present review discusses the communication between the hypothalamic-pituitary-gonad (HPG) axis and the immune system of vertebrates, attempting to situate the HPG-immune interaction into the context of life history trade-offs between reproductive and immune functions. More specifically, (i) we review molecular and cellular interactions between hormones of the HPG axis, and, as far as known, the involved mechanisms on immune functions, (ii) we evaluate whether the HPG-immune crosstalk serves as proximate mechanism mediating reproductive-immune trade-offs, and (iii) we ask whether the nature of the HPG-immune interaction is conserved throughout vertebrate evolution, despite the changes in immune functions, reproductive modes, and life histories. In all vertebrate classes studied so far, HPG hormones have immunomodulatory functions, and indications exist that they contribute to reproduction-immunity resource trade-offs, although the very limited information available for most non-mammalian vertebrates makes it difficult to judge how comparable or different the interactions are. There is good evidence that the HPG-immune crosstalk is part of the proximate mechanisms underlying the reproductive-immune trade-offs of vertebrates, but it is only one factor in a complex network of factors and processes. The fact that the HPG-immune interaction is flexible and can adapt to the functional and physiological requirements of specific life histories. Moreover, the assumption of a relatively fixed pattern of HPG influence on immune functions, with, for example, androgens always leading to immunosuppression and estrogens always being immunoprotective, is probably oversimplified, but the HPG-immune interaction can vary depending on the physiological and envoironmental context. Finally, the HPG-immune interaction is not only driven by resource trade-offs, but additional factors such as, for instance, the evolution of viviparity shape this neuroendocrine-immune relationship. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enhancing artificial bee colony algorithm with self-adaptive searching strategy and artificial immune network operators for global optimization.

PubMed

Chen, Tinggui; Xiao, Renbin

2014-01-01

Artificial bee colony (ABC) algorithm, inspired by the intelligent foraging behavior of honey bees, was proposed by Karaboga. It has been shown to be superior to some conventional intelligent algorithms such as genetic algorithm (GA), artificial colony optimization (ACO), and particle swarm optimization (PSO). However, the ABC still has some limitations. For example, ABC can easily get trapped in the local optimum when handing in functions that have a narrow curving valley, a high eccentric ellipse, or complex multimodal functions. As a result, we proposed an enhanced ABC algorithm called EABC by introducing self-adaptive searching strategy and artificial immune network operators to improve the exploitation and exploration. The simulation results tested on a suite of unimodal or multimodal benchmark functions illustrate that the EABC algorithm outperforms ACO, PSO, and the basic ABC in most of the experiments.

Enhancing Artificial Bee Colony Algorithm with Self-Adaptive Searching Strategy and Artificial Immune Network Operators for Global Optimization

PubMed Central

Chen, Tinggui; Xiao, Renbin

2014-01-01

Artificial bee colony (ABC) algorithm, inspired by the intelligent foraging behavior of honey bees, was proposed by Karaboga. It has been shown to be superior to some conventional intelligent algorithms such as genetic algorithm (GA), artificial colony optimization (ACO), and particle swarm optimization (PSO). However, the ABC still has some limitations. For example, ABC can easily get trapped in the local optimum when handing in functions that have a narrow curving valley, a high eccentric ellipse, or complex multimodal functions. As a result, we proposed an enhanced ABC algorithm called EABC by introducing self-adaptive searching strategy and artificial immune network operators to improve the exploitation and exploration. The simulation results tested on a suite of unimodal or multimodal benchmark functions illustrate that the EABC algorithm outperforms ACO, PSO, and the basic ABC in most of the experiments. PMID:24772023

Independent and interactive effects of immune activation and larval diet on adult immune function, growth and development in the greater wax moth (Galleria mellonella).

PubMed

Kangassalo, Katariina; Valtonen, Terhi M; Sorvari, Jouni; Kecko, Sanita; Pölkki, Mari; Krams, Indrikis; Krama, Tatjana; Rantala, Markus J

2018-06-29

Organisms in the wild are likely to face multiple immune challenges as well as additional ecological stressors, yet their interactive effects on immune function are poorly understood. Insects are found to respond to cues of increased infection risk by enhancing their immune capacity. However, such adaptive plasticity in immune function may be limited by physiological and environmental constraints. Here, we investigated the effects of two environmental stressors - poor larval diet and an artificial parasite-like immune challenge at the pupal stage - on adult immune function, growth and development in the greater wax moth (Galleria mellonella). Males whose immune system was activated with an artificial parasite-like immune challenge had weaker immune response - measured as strength of encapsulation response - as adults compared to the control groups, but only when raised in high-nutrition larval diet. Immune activation did not negatively affect adult immune response in males reared in low-nutrition larval diet, indicating that poor larval diet improved the capacity of the insects to respond to repeated immune challenges. Low-nutrition larval diet also had a positive independent effect on immune capacity in females, yet it negatively affected development time and adult body mass in both sexes. As in the nature immune challenges are rarely isolated, and adverse nutritional environment may indicate an elevated risk of infection, resilience to repeated immune challenges as a response to poor nutritional environment could provide a significant fitness advantage. The present study highlights the importance of considering environmental context when investigating effects of immune activation in insects. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Innate immune signalling at intestinal mucosal surfaces: a fine line between host protection and destruction.

PubMed

Cario, Elke

2008-11-01

Emerging evidence underscores that inappropriate innate immune responses driven by commensals contribute to the pathogenesis of chronic inflammatory bowel diseases in genetically susceptible hosts. The present review focuses on defining the recently described mechanistic functions through which the innate immune signalling apparatus shapes mucosal homeostasis of the intestine in health and disease. Commensal-induced innate immune signalling actively drives at least six major interdependent functions to control homeostasis in the healthy intestinal mucosa: 1) barrier preservation, 2) inhibition of apoptosis and inflammation, 3) acceleration of wound repair and tissue regeneration, 4) exclusion of harmful pathogens through autophagy and other antimicrobial defenses, while 5) maintaining immune tolerance towards harmless commensals, and 6) linkage to adaptive immunity. Any disturbance of this peaceful and mutually beneficial host-commensal relationship may imbalance innate immune signalling, which predisposes to chronic intestinal inflammation and associated tumourigenesis in inflammatory bowel diseases. Recent advances have highlighted the complex mechanistics and functional diversity of innate immunity that paradoxically mediate both protective and destructive responses in the intestinal mucosa. Related signalling targets may offer novel therapeutic approaches in the treatment of inflammatory bowel diseases and inflammation-related cancer.

Distinct Effects of Monophosphoryl Lipid A, Oligodeoxynucleotide CpG, and Combination Adjuvants on Modulating Innate and Adaptive Immune Responses to Influenza Vaccination

PubMed Central

Ko, Eun-Ju; Lee, Young-Tae; Lee, Youri; Kim, Ki-Hye

2017-01-01

Monophosphoryl lipid A (MPL) and oligodeoxynucleotide CpG are toll-like receptor (TLR) 4 and 9 agonist, respectively. Here, we investigated the effects of MPL, CpG, and combination adjuvants on stimulating in vitro dendritic cells (DCs), in vivo innate and adaptive immune responses, and protective efficacy of influenza vaccination. Combination of MPL and CpG was found to exhibit distinct effects on stimulating DCs in vitro to secrete IL-12p70 and tumor necrosis factor (TNF)-α and proliferate allogeneic CD8 T cells. Prime immunization of mice with inactivated split influenza vaccine in the presence of low dose MPL+CpG adjuvants increased the induction of virus-specific IgG and IgG2a isotype antibodies. MPL and CpG adjuvants contribute to improving the efficacy of prime influenza vaccination against lethal influenza challenge as determined by body weight monitoring, lung function, viral titers, and histology. A combination of MPL and CpG adjuvants was effective in improving vaccine efficacy as well as in reducing inflammatory immune responses locally and in inducing cellular immune responses upon lethal influenza virus challenge. This study demonstrates unique adjuvant effects of MPL, CpG, and combination adjuvants on modulating innate and adaptive immune responses to influenza prime vaccination. PMID:29093654

The soluble pattern recognition receptor PTX3 links humoral innate and adaptive immune responses by helping marginal zone B cells

PubMed Central

Sintes, Jordi; Polentarutti, Nadia; Walland, A. Cooper; Yeiser, John R.; Cunha, Cristina; Lacerda, João F.; Salvatori, Giovanni; Blander, J. Magarian

2016-01-01

Pentraxin 3 (PTX3) is a fluid-phase pattern recognition receptor of the humoral innate immune system with ancestral antibody-like properties but unknown antibody-inducing function. In this study, we found binding of PTX3 to splenic marginal zone (MZ) B cells, an innate-like subset of antibody-producing lymphocytes strategically positioned at the interface between the circulation and the adaptive immune system. PTX3 was released by a subset of neutrophils that surrounded the splenic MZ and expressed an immune activation–related gene signature distinct from that of circulating neutrophils. Binding of PTX3 promoted homeostatic production of IgM and class-switched IgG antibodies to microbial capsular polysaccharides, which decreased in PTX3-deficient mice and humans. In addition, PTX3 increased IgM and IgG production after infection with blood-borne encapsulated bacteria or immunization with bacterial carbohydrates. This immunogenic effect stemmed from the activation of MZ B cells through a neutrophil-regulated pathway that elicited class switching and plasmablast expansion via a combination of T cell–independent and T cell–dependent signals. Thus, PTX3 may bridge the humoral arms of the innate and adaptive immune systems by serving as an endogenous adjuvant for MZ B cells. This property could be harnessed to develop more effective vaccines against encapsulated pathogens. PMID:27621420

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

PubMed

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.

Zebra Fish Lacking Adaptive Immunity Acquire an Antiviral Alert State Characterized by Upregulated Gene Expression of Apoptosis, Multigene Families, and Interferon-Related Genes

PubMed Central

García-Valtanen, Pablo; Martínez-López, Alicia; López-Muñoz, Azucena; Bello-Perez, Melissa; Medina-Gali, Regla M.; Ortega-Villaizán, María del Mar; Varela, Monica; Figueras, Antonio; Mulero, Víctoriano; Novoa, Beatriz; Estepa, Amparo; Coll, Julio

2017-01-01

To investigate fish innate immunity, we have conducted organ and cell immune-related transcriptomic as well as immunohistologic analysis in mutant zebra fish (Danio rerio) lacking adaptive immunity (rag1−/−) at different developmental stages (egg, larvae, and adult), before and after infection with spring viremia carp virus (SVCV). The results revealed that, compared to immunocompetent zebra fish (rag1+/+), rag1−/− acquired increased resistance to SVCV with age, correlating with elevated transcript levels of immune genes in skin/fins and lymphoid organs (head kidney and spleen). Gene sets corresponding to apoptotic functions, immune-related multigene families, and interferon-related genes were constitutively upregulated in uninfected adult rag1−/− zebra fish. Overexpression of activated CASPASE-3 in different tissues before and after infection with SVCV further confirmed increased apoptotic function in rag1−/− zebra fish. Concurrently, staining of different tissue samples with a pan-leukocyte antibody marker showed abundant leukocyte infiltrations in SVCV-infected rag1−/− fish, coinciding with increased transcript expression of genes related to NK-cells and macrophages, suggesting that these genes played a key role in the enhanced immune response of rag1−/− zebra fish to SVCV lethal infection. Overall, we present evidence that indicates that rag1−/− zebra fish acquire an antiviral alert state while they reach adulthood in the absence of adaptive immunity. This antiviral state was characterized by (i) a more rapid response to viral infection, which resulted in increased survival, (ii) the involvement of NK-cell- and macrophage-mediated transcript responses rather than B- and/or T-cell dependent cells, and (iii) enhanced apoptosis, described here for the first time, as well as the similar modulation of multigene family/interferon-related genes previously associated to fish that survived lethal viral infections. From this and other studies, it might be concluded that some of the characteristics of mammalian trained immunity are present in lower vertebrates. PMID:28243233

The Regulatory Function of Eosinophils

PubMed Central

Wen, Ting; Rothenberg, Marc E.

2016-01-01

Eosinophils are a minority circulating granulocyte classically viewed as being involved in host defense against parasites and promoting allergic reactions. However, a series of new regulatory functions for these cells have been identified in the past decade. During homeostasis, eosinophils develop in the bone marrow and migrate from the blood into target tissues following an eotaxin gradient, with IL-5 being a key cytokine for eosinophil proliferation, survival and priming. In multiple target tissues, eosinophils actively regulate a variety of immune functions through their vast arsenal of granule products and cytokines, as well as direct cellular interaction with cells in proximity. The immunologic regulation of eosinophils extends from innate immunity to adaptive immunity and also involves non-immune cells. Herein, we summarize recent findings regarding novel roles of murine and human eosinophils focused on interactions with other hematopoietic cells. We also review new experimental tools available and remaining questions to uncover a greater understanding of this enigmatic cell. PMID:27780017

The Regulatory Function of Eosinophils.

PubMed

Wen, Ting; Rothenberg, Marc E

2016-10-01

Eosinophils are a minority circulating granulocyte classically viewed as being involved in host defense against parasites and promoting allergic reactions. However, a series of new regulatory functions for these cells have been identified in the past decade. During homeostasis, eosinophils develop in the bone marrow and migrate from the blood into target tissues following an eotaxin gradient, with interleukin-5 being a key cytokine for eosinophil proliferation, survival, and priming. In multiple target tissues, eosinophils actively regulate a variety of immune functions through their vast arsenal of granule products and cytokines, as well as direct cellular interaction with cells in proximity. The immunologic regulation of eosinophils extends from innate immunity to adaptive immunity and also involves non-immune cells. Herein, we summarize recent findings regarding novel roles of murine and human eosinophils, focusing on interactions with other hematopoietic cells. We also review new experimental tools available and remaining questions to uncover a greater understanding of this enigmatic cell.

Inactivated Influenza Vaccine That Provides Rapid, Innate-Immune-System-Mediated Protection and Subsequent Long-Term Adaptive Immunity.

PubMed

Chua, Brendon Y; Wong, Chinn Yi; Mifsud, Edin J; Edenborough, Kathryn M; Sekiya, Toshiki; Tan, Amabel C L; Mercuri, Francesca; Rockman, Steve; Chen, Weisan; Turner, Stephen J; Doherty, Peter C; Kelso, Anne; Brown, Lorena E; Jackson, David C

2015-10-27

The continual threat to global health posed by influenza has led to increased efforts to improve the effectiveness of influenza vaccines for use in epidemics and pandemics. We show in this study that formulation of a low dose of inactivated detergent-split influenza vaccine with a Toll-like receptor 2 (TLR2) agonist-based lipopeptide adjuvant (R4Pam2Cys) provides (i) immediate, antigen-independent immunity mediated by the innate immune system and (ii) significant enhancement of antigen-dependent immunity which exhibits an increased breadth of effector function. Intranasal administration of mice with vaccine formulated with R4Pam2Cys but not vaccine alone provides protection against both homologous and serologically distinct (heterologous) viral strains within a day of administration. Vaccination in the presence of R4Pam2Cys subsequently also induces high levels of systemic IgM, IgG1, and IgG2b antibodies and pulmonary IgA antibodies that inhibit hemagglutination (HA) and neuraminidase (NA) activities of homologous but not heterologous virus. Improved primary virus nucleoprotein (NP)-specific CD8(+) T cell responses are also induced by the use of R4Pam2Cys and are associated with robust recall responses to provide heterologous protection. These protective effects are demonstrated in wild-type and antibody-deficient animals but not in those depleted of CD8(+) T cells. Using a contact-dependent virus transmission model, we also found that heterologous virus transmission from vaccinated mice to naive mice is significantly reduced. These results demonstrate the potential of adding a TLR2 agonist to an existing seasonal influenza vaccine to improve its utility by inducing immediate short-term nonspecific antiviral protection and also antigen-specific responses to provide homologous and heterologous immunity. The innate and adaptive immune systems differ in mechanisms, specificities, and times at which they take effect. The innate immune system responds within hours of exposure to infectious agents, while adaptive immunity takes several days to become effective. Here we show, by using a simple lipopeptide-based TLR2 agonist, that an influenza detergent-split vaccine can be made to simultaneously stimulate and amplify both systems to provide immediate antiviral protection while giving the adaptive immune system time to implement long-term immunity. Both types of immunity induced by this approach protect against vaccine-matched as well as unrelated virus strains and potentially even against strains yet to be encountered. Conferring dual functionality to influenza vaccines is beneficial for improving community protection, particularly during periods between the onset of an outbreak and the time when a vaccine becomes available or in scenarios in which mass vaccination with a strain to which the population is immunologically naive is imperative. Copyright © 2015 Chua et al.

Established T-cell inflamed tumors rejected after adaptive resistance was reversed by combination STING activation and PD-1–pathway blockade

PubMed Central

Moore, Ellen; Clavijo, Paul E.; Davis, Ruth; Cash, Harrison; Van Waes, Carter; Kim, Young; Allen, Clint

2016-01-01

Patients with head and neck squamous cell carcinoma harbor T-cell inflamed and non-T-cell inflamed tumors. Despite this, only 20% of patients respond to checkpoint inhibitor immunotherapy. Lack of induction of innate immunity through pattern-recognition receptors such as the stimulator of interferon (IFN) genes (STING) receptor may represent a significant barrier to the development of effective antitumor immunity. Here, we demonstrate robust control of a T-cell inflamed (MOC1), but not non-T-cell inflamed (MOC2), model of head and neck cancer by activation of the STING pathway with the synthetic cyclic dinucleotide RP,RP dithio-c-di-GMP. Rejection or durable tumor control of MOC1 tumors was dependent upon a functional STING receptor and CD8 T lymphocytes. STING activation resulted in increased tumor microenvironment type 1 and type 2 IFN and greater expression of PD-1–pathway components in vivo. Established MOC1 tumors were rejected and distant tumors abscopally controlled, after adaptive immune resistance had been reversed by the addition of PD-L1 mAb. These findings suggest that PD-1-pathway blockade may reverse adaptive immune resistance following cyclic dinucleotide treatment, enhancing both local and systemic antitumor immunity. PMID:27821498

Anti-Immune Strategies of Pathogenic Fungi

PubMed Central

Marcos, Caroline M.; de Oliveira, Haroldo C.; de Melo, Wanessa de Cássia M. Antunes; da Silva, Julhiany de Fátima; Assato, Patrícia A.; Scorzoni, Liliana; Rossi, Suélen A.; de Paula e Silva, Ana C. A.; Mendes-Giannini, Maria J. S.; Fusco-Almeida, Ana M.

2016-01-01

Pathogenic fungi have developed many strategies to evade the host immune system. Multiple escape mechanisms appear to function together to inhibit attack by the various stages of both the adaptive and the innate immune response. Thus, after entering the host, such pathogens fight to overcome the immune system to allow their survival, colonization and spread to different sites of infection. Consequently, the establishment of a successful infectious process is closely related to the ability of the pathogen to modulate attack by the immune system. Most strategies employed to subvert or exploit the immune system are shared among different species of fungi. In this review, we summarize the main strategies employed for immune evasion by some of the major pathogenic fungi. PMID:27896220

The lymphoid cell network in the skin.

PubMed

Tikoo, Shweta; Jain, Rohit; Kurz, Angela Rm; Weninger, Wolfgang

2018-05-01

Cutaneous immunity represents a crucial component of the mammalian immune response. The presence of a large array of commensal microorganisms along with a myriad of environmental stresses necessitates constant immuno-surveillance of the tissue. To achieve a perfect balance between immune-tolerance and immune-activation, the skin harbors strategically localized immune cell populations that modulate these responses. To maintain homeostasis, innate and adaptive immune cells assimilate microenvironmental cues and coordinate cellular and molecular functions in a spatiotemporal manner. The role of lymphoid cells in cutaneous immunity is gaining much appreciation due to their important roles in regulating skin health and pathology. In this review, we aim to highlight the recent advances in the field of cutaneous lymphoid biology. © 2018 Australasian Society for Immunology Inc.

Amplifying IFN-γ Signaling in Dendritic Cells by CD11c-Specific Loss of SOCS1 Increases Innate Immunity to Infection while Decreasing Adaptive Immunity.

PubMed

Alice, Alejandro F; Kramer, Gwen; Bambina, Shelly; Baird, Jason R; Bahjat, Keith S; Gough, Michael J; Crittenden, Marka R

2018-01-01

Although prophylactic vaccines provide protective humoral immunity against infectious agents, vaccines that elicit potent CD8 T cell responses are valuable tools to shape and drive cellular immunity against cancer and intracellular infection. In particular, IFN-γ-polarized cytotoxic CD8 T cell immunity is considered optimal for protective immunity against intracellular Ags. Suppressor of cytokine signaling (SOCS)1 is a cross-functional negative regulator of TLR and cytokine receptor signaling via degradation of the receptor-signaling complex. We hypothesized that loss of SOCS1 in dendritic cells (DCs) would improve T cell responses by accentuating IFN-γ-directed immune responses. We tested this hypothesis using a recombinant Listeria monocytogenes vaccine platform that targets CD11c + DCs in mice in which SOCS1 is selectively deleted in all CD11c + cells. Unexpectedly, in mice lacking SOCS1 expression in CD11c + cells, we observed a decrease in CD8 + T cell response to the L. monocytogenes vaccine. NK cell responses were also decreased in mice lacking SOCS1 expression in CD11c + cells but did not explain the defect in CD8 + T cell immunity. We found that DCs lacking SOCS1 expression were functional in driving Ag-specific CD8 + T cell expansion in vitro but that this process was defective following infection in vivo. Instead, monocyte-derived innate TNF-α and inducible NO synthase-producing DCs dominated the antibacterial response. Thus, loss of SOCS1 in CD11c + cells skewed the balance of immune response to infection by increasing innate responses while decreasing Ag-specific adaptive responses to infectious Ags. Copyright © 2017 by The American Association of Immunologists, Inc.

A Stromal Cell Niche for Human and Mouse Type 3 Innate Lymphoid Cells.

PubMed

Hoorweg, Kerim; Narang, Priyanka; Li, Zhi; Thuery, Anne; Papazian, Natalie; Withers, David R; Coles, Mark C; Cupedo, Tom

2015-11-01

Adaptive immunity critically depends on the functional compartmentalization of secondary lymphoid organs. Mesenchymal stromal cells create and maintain specialized niches that support survival, activation, and expansion of T and B cells, and integrated analysis of lymphocytes and their niche has been instrumental in understanding adaptive immunity. Lymphoid organs are also home to type 3 innate lymphoid cells (ILC3), innate effector cells essential for barrier immunity. However, a specialized stromal niche for ILC3 has not been identified. A novel lineage-tracing approach now identifies a subset of murine fetal lymphoid tissue organizer cells that gives rise exclusively to adult marginal reticular cells. Moreover, both cell types are conserved from mice to humans and colocalize with ILC3 in secondary lymphoid tissues throughout life. In sum, we provide evidence that fetal stromal organizers give rise to adult marginal reticular cells and form a dedicated stromal niche for innate ILC3 in adaptive lymphoid organs. Copyright © 2015 by The American Association of Immunologists, Inc.

Advances on molecular mechanism of the adaptive evolution of Chiroptera (bats).

PubMed

Yunpeng, Liang; Li, Yu

2015-01-01

As the second biggest animal group in mammals, Chiroptera (bats) demonstrates many unique adaptive features in terms of flight, echolocation, auditory acuity, feeding habit, hibernation and immune defense, providing an excellent system for understanding the molecular basis of how organisms adapt to the living environments encountered. In this review, we summarize the researches on the molecular mechanism of the adaptive evolution of Chiroptera, especially the recent researches at the genome levels, suggesting a far more complex evolutionary pattern and functional diversity than previously thought. In the future, along with the increasing numbers of Chiroptera species genomes available, new evolutionary patterns and functional divergence will be revealed, which can promote the further understanding of this animal group and the molecular mechanism of adaptive evolution.

PPAR-γ in innate and adaptive lung immunity.

PubMed

Nobs, Samuel Philip; Kopf, Manfred

2018-05-16

The transcription factor PPAR-γ (peroxisome proliferator-activated receptor-γ) is a key regulator of lung immunity exhibiting multiple cell type specific roles in controlling development and function of the lung immune system. It is strictly required for the generation of alveolar macrophages by controlling differentiation of fetal lung monocyte precursors. Furthermore, it plays an important role in lung allergic inflammation by licensing lung dendritic cell t helper 2 (Th2) priming capacity as well as acting as a master transcription factor for pathogenic Th2 cells. Due to this plethora of functions and its involvement in multiple pulmonary diseases including asthma and pulmonary alveolar proteinosis, understanding the role of PPAR-γ in lung immunity is an important subject of ongoing research. ©2018 Society for Leukocyte Biology.

Immune remodeling: lessons from repertoire alterations during chronological aging and in immune-mediated disease.

PubMed

Vallejo, Abbe N

2007-03-01

Immunological studies of aging and of patients with chronic immune-mediated diseases document overlap of immune phenotypes. Here, the term "immune remodeling" refers to these phenotypes that are indicative of biological processes of deterioration and repair. This concept is explored through lessons from studies about the changes in the T-cell repertoire and the functional diversity of otherwise oligoclonal, senescent T cells. Immune remodeling suggests a gradual process that occurs throughout life. However, similar but more drastic remodeling occurs disproportionately among young patients with chronic disease. In this article, I propose that immune remodeling is a beneficial adaptation of aging to promote healthy survival beyond reproductive performance, but acute remodeling poses risk of premature exhaustion of the immune repertoire and, thus, is detrimental in young individuals.

Ginseng (Panax ginseng Meyer) oligopeptides regulate innate and adaptive immune responses in mice via increased macrophage phagocytosis capacity, NK cell activity and Th cells secretion.

PubMed

He, Li-Xia; Ren, Jin-Wei; Liu, Rui; Chen, Qi-He; Zhao, Jian; Wu, Xin; Zhang, Zhao-Feng; Wang, Jun-Bo; Pettinato, Giuseppe; Li, Yong

2017-10-01

Traditionally used as a restorative medicine, ginseng (Panax ginseng Meyer) has been the most widely used and acclaimed herb in Chinese communities for thousands of years. To investigate the immune-modulating activity of ginseng oligopeptides (GOP), 420 healthy female BALB/c mice were intragastrically administered distilled water (control), whey protein (0.15 g per kg body weight (BW)), and GOP 0.0375, 0.075, 0.15, 0.3 and 0.6 g per kg BW for 30 days. Blood samples from mice were collected from the ophthalmic venous plexus and then sacrificed by cervical dislocation. Seven assays were conducted to determine the immunomodulatory effects of GOP on innate and adaptive immune responses, followed by flow cytometry to investigate spleen T lymphocyte sub-populations, multiplex sandwich immunoassays to investigate serum cytokine and immunoglobulin levels, and ELISA to investigate intestinally secreted immunoglobulin to study the mechanism of GOP affecting the immune system. Our results showed that GOP was able to enhance innate and adaptive immune responses in mice by improving cell-mediated and humoral immunity, macrophage phagocytosis capacity and NK cell activity. Notably, the use of GOP revealed a better immune-modulating activity compared to whey protein. We conclude that the immune-modulating activity might be due to the increased macrophage phagocytosis capacity and NK cell activity, and the enhancement of T and Th cells, as well as IL-2, IL-6 and IL-12 secretion and IgA, IgG1 and IgG2b production. These results indicate that GOP could be considered a good candidate that may improve immune functions if used as a dietary supplement, with a dosage that ranges from 0.3 to 0.6 g per kg BW.

Emerging Concepts of Adaptive Immunity in Leprosy

PubMed Central

Sadhu, Soumi; Mitra, Dipendra Kumar

2018-01-01

Leprosy is a chronic intracellular infection caused by the acid-fast bacillus, Mycobacterium leprae. The disease chiefly affects the skin, peripheral nerves, mucosa of the upper respiratory tract, and the eyes. The damage to peripheral nerves results in sensory and motor impairment with characteristic deformities and disability. Presently, the disease remains concentrated in resource-poor countries in tropical and warm temperate regions with the largest number of cases reported from India. Even though innate immunity influences the clinical manifestation of the disease, it is the components of adaptive immune system which seem to tightly correlate with the characteristic spectrum of leprosy. M. leprae-specific T cell anergy with bacillary dissemination is the defining feature of lepromatous leprosy (LL) patients in contrast to tuberculoid leprosy (TT) patients, which is characterized by strong Th1-type cell response with localized lesions. Generation of Th1/Th2-like effector cells, however, cannot wholly explain the polarized state of immunity in leprosy. A comprehensive understanding of the role of various regulatory T cells, such as Treg and natural killer T cells, in deciding the polarized state of T cell immunity is crucial. Interaction of these T cell subsets with effector T cells like Th1 (IFN-γ dominant), Th2 (interluekin-4 dominant), and Th17 (IL-17+) cells through various regulatory cytokines and molecules (programmed death-1/programmed death ligand-1) may constitute key events in dictating the state of immune polarization, thus controlling the clinical manifestation. Studying these important components of the adaptive immune system in leprosy patients is essential for better understanding of immune function, correlate(s) the immunity and mechanism(s) of its containment. PMID:29686668

IFN-α and CD46 stimulation are associated with active lupus and skew natural T regulatory cell differentiation to type 1 regulatory T (Tr1) cells

PubMed Central

Le Buanec, Hélène; Gougeon, Marie-Lise; Mathian, Alexis; Lebon, Pierre; Dupont, Jean-Michel; Peltre, Gabriel; Hemon, Patrice; Schmid, Michel; Bizzini, Bernard; Künding, Thomas; Burny, Arsène; Bensussan, Armand; Amoura, Zahir; Gallo, Robert C.; Zagury, Daniel

2011-01-01

Immune suppressive activities exerted by regulatory T-cell subsets have several specific functions, including self-tolerance and regulation of adaptive immune reactions, and their dysfunction can lead to autoimmune diseases and contribute to AIDS and cancer. Two functionally distinct regulatory T-cell subsets are currently identified in peripheral tissues: thymus-developed natural T regulatory cells (nTregs) controlling self-tolerance and antiinflammatory IL-10–secreting type 1 regulatory T cells (Tr1) derived from Ag-stimulated T cells, which regulate inflammation-dependent adaptive immunity and minimize immunopathology. We establish herein that cell contact-mediated nTreg regulatory function is inhibited by inflammation, especially in the presence of the complement C3b receptor (CD46). Instead, as with other T-cell subsets, the latter inflammatory conditions of stimulation skew nTreg differentiation to Tr1 cells secreting IL-10, an effect potentiated by IFN-α. The clinical relevance of these findings was verified in a study of 152 lupus patients, in which we showed that lupus nTreg dysfunction is not due to intrinsic defects but is rather induced by C3b stimulation of CD46 and IFN-α and that these immune components of inflammation are directly associated with active lupus. These results provide a rationale for using anti–IFN-α Ab immunotherapy in lupus patients. PMID:22065791

Tissue homeostasis and immunity--more on models.

PubMed

Cunliffe, J

2006-09-01

This article continues the ongoing debate around models of the immune system. Earlier contributors have paid much attention to the various processes that lead to adaptive immune system aggression or tolerance. They have often based their discussions around facts that have been established by experimental investigation. However, both the observation and interpretation of these facts have been influenced by the function--or system goal--that is believed to have generated them. The perception of this function (of all or part of the immune system) is influenced by long established theories in immunology (e.g. horror autotoxicus, clonal deletion in utero, pathogen elimination, clonal selection, auto-immunity and so on) which, for many, have become enshrined as facts. One function that has had less consideration and has not been extensively investigated is the maintenance of tissue homeostasis. When the immune system is viewed from this perspective, the facts invite alternative interpretations. Whilst this perspective may not necessarily be the only valid one, let alone a correct one, viewing things this way--at least briefly--might help to expose hidden assumptions. It also emphasizes that the immune system is a system and, as such, it can by analysed through the principles of general systems theory.

The varieties of immunological experience: of pathogens, stress, and dendritic cells.

PubMed

Pulendran, Bali

2015-01-01

In the 40 years since their discovery, dendritic cells (DCs) have been recognized as central players in immune regulation. DCs sense microbial stimuli through pathogen-recognition receptors (PRRs) and decode, integrate, and present information derived from such stimuli to T cells, thus stimulating immune responses. DCs can also regulate the quality of immune responses. Several functionally specialized subsets of DCs exist, but DCs also display functional plasticity in response to diverse stimuli. In addition to sensing pathogens via PRRs, emerging evidence suggests that DCs can also sense stress signals, such as amino acid starvation, through ancient stress and nutrient sensing pathways, to stimulate adaptive immunity. Here, I discuss these exciting advances in the context of a historic perspective on the discovery of DCs and their role in immune regulation. I conclude with a discussion of emerging areas in DC biology in the systems immunology era and suggest that the impact of DCs on immunity can be usefully contextualized in a hierarchy-of-organization model in which DCs, their receptors and signaling networks, cell-cell interactions, tissue microenvironment, and the host macroenvironment represent different levels of the hierarchy. Immunity or tolerance can then be represented as a complex function of each of these hierarchies.

[Researches in immunological responses after burn injury in China].

PubMed

Peng, Dai-zhi

2008-10-01

For five decades it has been recognized that severe burn injury may precipitate in marked alterations in immune function, resulting in life-threatening systemic infections, sepsis, multiple organ failure, and even death. Extensive and deep burns exert widespread and profound impacts on various cells and molecules of the immune system. The general characteristics of abnormal immune responses following major burns are hyperinflammatory response and hypoimmune response of innate and adaptive immunity. These are recognized as postburn immune dysfunction (PID). The stress reaction, massive necrotic tissue, shock, infection, malnutrition and various therapeutic procedures after burns alter the microenvironment of the immune cells and molecules in which they reside, and consequently result in the changes in immune cells and their secretions in quantity and/or activity, and also aberrant signal transduction in different immune cells. These events constitute the cellular and molecular bases in the pathogenesis of PID. The main clinical consequences of PID include tissue damages and increased susceptibility to opportunistic pathogens caused by refractory inflammation and suppressed adaptive immunity. In order to decrease the morbidity of these lethal complications, efforts to improve the immune dysfunction after burn injury have been made not only at the integral level of etiological factors, but also at the cellular and molecular levels of its mechanisms. In this review, all these above-mentioned aspects of PID are comprehensively discussed.

The stress response and immune system share, borrow, and reconfigure their physiological network elements: Evidence from the insects.

PubMed

Adamo, Shelley A

2017-02-01

The classic biomedical view is that stress hormone effects on the immune system are largely pathological, especially if the stress is chronic. However, more recent interpretations have focused on the potential adaptive function of these effects. This paper examines stress response-immune system interactions from a physiological network perspective, using insects because of their simpler physiology. For example, stress hormones can reduce disease resistance, yet activating an immune response results in the release of stress hormones in both vertebrates and invertebrates. From a network perspective, this phenomenon is consistent with the 'sharing' of the energy-releasing ability of stress hormones by both the stress response and the immune system. Stress-induced immunosuppression is consistent with the stress response 'borrowing' molecular components from the immune system to increase the capacity of stress-relevant physiological processes (i.e. a trade off). The insect stress hormones octopamine and adipokinetic hormone can also 'reconfigure' the immune system to help compensate for the loss of some of the immune system's molecular resources (e.g. apolipophorin III). This view helps explain seemingly maladaptive interactions between the stress response and immune system. The adaptiveness of stress hormone effects on individual immune components may be apparent only from the perspective of the whole organism. These broad principles will apply to both vertebrates and invertebrates. Copyright © 2016 Elsevier Inc. All rights reserved.

Chronic infection and the origin of adaptive immune system.

PubMed

Usharauli, David

2010-08-01

It has been speculated that the rise of the adaptive immune system in jawed vertebrates some 400 million years ago gave them a superior protection to detect and defend against pathogens that became more elusive and/or virulent to the host that had only innate immune system. First, this line of thought implies that adaptive immune system was a new, more sophisticated layer of host defense that operated independently of the innate immune system. Second, the natural consequence of this scenario would be that pathogens would have exercised so strong an evolutionary pressure that eventually no host could have afforded not to have an adaptive immune system. Neither of these arguments is supported by the facts. First, new experimental evidence has firmly established that operation of adaptive immune system is critically dependent on the ability of the innate immune system to detect invader-pathogens and second, the absolute majority of animal kingdom survives just fine with only an innate immune system. Thus, these data raise the dilemma: If innate immune system was sufficient to detect and protect against pathogens, why then did adaptive immune system develop in the first place? In contrast to the innate immune system, the adaptive immune system has one important advantage, precision. By precision I mean the ability of the defense system to detect and remove the target, for example, infected cells, without causing unwanted bystander damage of surrounding tissue. While the target precision per se is not important for short-term immune response, it becomes a critical factor when the immune response is long-lasting, as during chronic infection. In this paper I would like to propose new, "toxic index" hypothesis where I argue that the need to reduce the collateral damage to the tissue during chronic infection(s) was the evolutionary pressure that led to the development of the adaptive immune system. Copyright 2010 Elsevier Ltd. All rights reserved.

[Immune granulomatous inflammation as the body's adaptive response].

PubMed

Paukov, V S; Kogan, E A

2014-01-01

Based on their studies and literature analysis, the authors offer a hypothesis for the adaptive pattern of chronic immune granulomatous inflammation occurring in infectious diseases that are characterized by the development of non-sterile immunity. The authors' proposed hypothesis holds that not every chronic inflammation is a manifestation of failing defenses of the body exposed to a damaging factor. By using tuberculosis and leprosy as an example, the authors show the insolvency of a number of existing notions of the pathogenesis and morphogenesis of epithelioid-cell and leprous granulomas. Thus, the authors consider that resident macrophages in tuberculosis maintain their function to kill mycobacteria; thereby the immune system obtains information on the antigenic determinants of the causative agents. At the same time, by consuming all hydrolases to kill mycobacteria, the macrophage fails to elaborate new lysosomes for the capacity of the pathogens to prevent them from forming. As a result, the lysosome-depleted macrophage transforms into an epithelioid cell that, maintaining phagocytic functions, loses its ability to kill the causative agents. It is this epithelioid cell where endocytobiosis takes place. These microorganisms destroy the epithelioid cell and fall out in the area of caseating granuloma necrosis at regular intervals. Some of them phagocytize epithelioid cells to maintain non-sterile immunity; the others are killed by inflammatory macrophages. The pathogenesis and morphogenesis of leprous granuloma, its tuberculous type in particular, proceed in a fundamentally similar way. Thus, non-sterile immunity required for tuberculosis, leprosy, and, possibly, other mycobacterioses is maintained.

Nuclear processes associated with plant immunity and pathogen susceptibility

PubMed Central

Motion, Graham B.; Amaro, Tiago M.M.M.; Kulagina, Natalja

2015-01-01

Plants are sessile organisms that have evolved exquisite and sophisticated mechanisms to adapt to their biotic and abiotic environment. Plants deploy receptors and vast signalling networks to detect, transmit and respond to a given biotic threat by inducing properly dosed defence responses. Genetic analyses and, more recently, next-generation -omics approaches have allowed unprecedented insights into the mechanisms that drive immunity. Similarly, functional genomics and the emergence of pathogen genomes have allowed reciprocal studies on the mechanisms governing pathogen virulence and host susceptibility, collectively allowing more comprehensive views on the processes that govern disease and resistance. Among others, the identification of secreted pathogen molecules (effectors) that modify immunity-associated processes has changed the plant–microbe interactions conceptual landscape. Effectors are now considered both important factors facilitating disease and novel probes, suited to study immunity in plants. In this review, we will describe the various mechanisms and processes that take place in the nucleus and help regulate immune responses in plants. Based on the premise that any process required for immunity could be targeted by pathogen effectors, we highlight and describe a number of functional assays that should help determine effector functions and their impact on immune-related processes. The identification of new effector functions that modify nuclear processes will help dissect nuclear signalling further and assist us in our bid to bolster immunity in crop plants. PMID:25846755

Nuclear processes associated with plant immunity and pathogen susceptibility.

PubMed

Motion, Graham B; Amaro, Tiago M M M; Kulagina, Natalja; Huitema, Edgar

2015-07-01

Plants are sessile organisms that have evolved exquisite and sophisticated mechanisms to adapt to their biotic and abiotic environment. Plants deploy receptors and vast signalling networks to detect, transmit and respond to a given biotic threat by inducing properly dosed defence responses. Genetic analyses and, more recently, next-generation -omics approaches have allowed unprecedented insights into the mechanisms that drive immunity. Similarly, functional genomics and the emergence of pathogen genomes have allowed reciprocal studies on the mechanisms governing pathogen virulence and host susceptibility, collectively allowing more comprehensive views on the processes that govern disease and resistance. Among others, the identification of secreted pathogen molecules (effectors) that modify immunity-associated processes has changed the plant-microbe interactions conceptual landscape. Effectors are now considered both important factors facilitating disease and novel probes, suited to study immunity in plants. In this review, we will describe the various mechanisms and processes that take place in the nucleus and help regulate immune responses in plants. Based on the premise that any process required for immunity could be targeted by pathogen effectors, we highlight and describe a number of functional assays that should help determine effector functions and their impact on immune-related processes. The identification of new effector functions that modify nuclear processes will help dissect nuclear signalling further and assist us in our bid to bolster immunity in crop plants. © The Author 2015. Published by Oxford University Press.

Overwintering Is Associated with Reduced Expression of Immune Genes and Higher Susceptibility to Virus Infection in Honey Bees

PubMed Central

Steinmann, Nadja; Corona, Miguel; Neumann, Peter; Dainat, Benjamin

2015-01-01

The eusocial honey bee, Apis mellifera, has evolved remarkable abilities to survive extreme seasonal differences in temperature and availability of resources by dividing the worker caste into two groups that differ in physiology and lifespan: summer and winter bees. Most of the recent major losses of managed honey bee colonies occur during the winter, suggesting that winter bees may have compromised immune function and higher susceptibility to diseases. We tested this hypothesis by comparing the expression of eight immune genes and naturally occurring infection levels of deformed wing virus (DWV), one of the most widespread viruses in A. mellifera populations, between summer and winter bees. Possible interactions between immune response and physiological activity were tested by measuring the expression of vitellogenin and methyl farnesoate epoxidase, a gene coding for the last enzyme involved in juvenile hormone biosynthesis. Our data show that high DWV loads in winter bees correlate with reduced expression of genes involved in the cellular immune response and physiological activity and high expression of humoral immune genes involved in antibacterial defense compared with summer bees. This expression pattern could reflect evolutionary adaptations to resist bacterial pathogens and economize energy during the winter under a pathogen landscape with reduced risk of pathogenic viral infections. The outbreak of Varroa destructor infestation could have overcome these adaptations by promoting the transmission of viruses. Our results suggest that reduced cellular immune function during the winter may have increased honey bee’s susceptibility to DWV. These results contribute to our understanding of honey bee colony losses in temperate regions. PMID:26121358

Plasma Cytokine Levels During Long-Duration Spaceflight

NASA Technical Reports Server (NTRS)

Crucian, Brian E.; Zwart, Sara R.; Quiriarte, Heather A.; Smith, Scott M.; Sams, Clarence F.

2011-01-01

Reduced T cell, granulocyte, NK and monocyte function have all been reported following both long and short duration spaceflight, however these data indicate crews are generally not experiencing inflammatory or adaptive immune activation during spaceflight. There appear to be varied individual crew responses, and specific relationships between cytokines and markers of iron status and muscle turnover that warrant further evaluation. Increases in growth factors and chemokines may indicate other types of adaptation occurring during spaceflight, such as attempts to overcome diminished immunocyte function.

Th17 cell cytokine secretion profile in host defense and autoimmunity.

PubMed

Graeber, Kristen E; Olsen, Nancy J

2012-02-01

The goal of this review is to examine the effector functions of Th17 cells in host defense and autoimmunity. Published literature on Th17 cells was reviewed with a focus on the secreted products that mediate effector activities of these cells. Th17 cells secrete an array of cytokines that contribute to host defense and that bridge the innate and adaptive arms of the immune response. When this subset of T cells is dysregulated, autoimmune phenomena develop that contribute to the manifestations of many autoimmune diseases. Th17 cells are positioned at a crossroads between innate and adaptive immunity and provide mediators that are essential for host defense. Current interest in harnessing this system for treatment of autoimmune disease will be challenged by the need to avoid abrogating these many protective functions.

Psychoneuroimmunology - psyche and autoimmunity.

PubMed

Ziemssen, Tjalf

2012-01-01

Psychoneuroimmunology is a relatively young field of research that investigates interactions between central nervous and immune system. The brain modulates the immune system by the endocrine and autonomic nervous system. Vice versa, the immune system modulates brain activity including sleep and body temperature. Based on a close functional and anatomical link, the immune and nervous systems act in a highly reciprocal manner. From fever to stress, the influence of one system on the other has evolved in an intricate manner to help sense danger and to mount an appropriate adaptive response. Over recent decades, reasonable evidence has emerged that these brain-to-immune interactions are highly modulated by psychological factors which influence immunity and autoimmune disease. For several diseases, the relevance of psychoneuroimmunological findings has already been demonstrated.

Functional characterization of the turkey macrophage migration inhibitory factor

USDA-ARS?s Scientific Manuscript database

Macrophage migration inhibitory factor (MIF) is a soluble protein that inhibits the random migration of macrophages and plays a pivotal immunoregulatory function in innate and adaptive immunity. The aim of this study was to clone the turkey MIF (TkMIF) gene, express the active protein, and characte...

Both host and parasite MIF molecules bind to chicken macrophages via CD74 surface receptor

USDA-ARS?s Scientific Manuscript database

Macrophage migration inhibitory factor (MIF) is recognized as a soluble factor that inhibits the random migration of macrophages and plays a pivotal immunoregulatory function in innate and adaptive immunity. Our group has identified both chicken and Eimeria MIFs, and characterized their function in...

STING-Dependent Cytosolic DNA Sensing Promotes Radiation-Induced Type I Interferon-Dependent Antitumor Immunity in Immunogenic Tumors.

PubMed

Deng, Liufu; Liang, Hua; Xu, Meng; Yang, Xuanming; Burnette, Byron; Arina, Ainhoa; Li, Xiao-Dong; Mauceri, Helena; Beckett, Michael; Darga, Thomas; Huang, Xiaona; Gajewski, Thomas F; Chen, Zhijian J; Fu, Yang-Xin; Weichselbaum, Ralph R

2014-11-20

Ionizing radiation-mediated tumor regression depends on type I interferon (IFN) and the adaptive immune response, but several pathways control I IFN induction. Here, we demonstrate that adaptor protein STING, but not MyD88, is required for type I IFN-dependent antitumor effects of radiation. In dendritic cells (DCs), STING was required for IFN-? induction in response to irradiated-tumor cells. The cytosolic DNA sensor cyclic GMP-AMP (cGAMP) synthase (cGAS) mediated sensing of irradiated-tumor cells in DCs. Moreover, STING was essential for radiation-induced adaptive immune responses, which relied on type I IFN signaling on DCs. Exogenous IFN-? treatment rescued the cross-priming by cGAS or STING-deficient DCs. Accordingly, activation of STING by a second messenger cGAMP administration enhanced antitumor immunity induced by radiation. Thus radiation-mediated antitumor immunity in immunogenic tumors requires a functional cytosolic DNA-sensing pathway and suggests that cGAMP treatment might provide a new strategy to improve radiotherapy. Copyright © 2014 Elsevier Inc. All rights reserved.

Mast cell: an emerging partner in immune interaction.

PubMed

Gri, Giorgia; Frossi, Barbara; D'Inca, Federica; Danelli, Luca; Betto, Elena; Mion, Francesca; Sibilano, Riccardo; Pucillo, Carlo

2012-01-01

Mast cells (MCs) are currently recognized as effector cells in many settings of the immune response, including host defense, immune regulation, allergy, chronic inflammation, and autoimmune diseases. MC pleiotropic functions reflect their ability to secrete a wide spectrum of preformed or newly synthesized biologically active products with pro-inflammatory, anti-inflammatory and/or immunosuppressive properties, in response to multiple signals. Moreover, the modulation of MC effector phenotypes relies on the interaction of a wide variety of membrane molecules involved in cell-cell or cell-extracellular-matrix interaction. The delivery of co-stimulatory signals allows MC to specifically communicate with immune cells belonging to both innate and acquired immunity, as well as with non-immune tissue-specific cell types. This article reviews and discusses the evidence that MC membrane-expressed molecules play a central role in regulating MC priming and activation and in the modulation of innate and adaptive immune response not only against host injury, but also in peripheral tolerance and tumor-surveillance or -escape. The complex expression of MC surface molecules may be regarded as a measure of connectivity, with altered patterns of cell-cell interaction representing functionally distinct MC states. We will focalize our attention on roles and functions of recently discovered molecules involved in the cross-talk of MCs with other immune partners.

Mast Cell: An Emerging Partner in Immune Interaction

PubMed Central

Gri, Giorgia; Frossi, Barbara; D’Inca, Federica; Danelli, Luca; Betto, Elena; Mion, Francesca; Sibilano, Riccardo; Pucillo, Carlo

2012-01-01

Mast cells (MCs) are currently recognized as effector cells in many settings of the immune response, including host defense, immune regulation, allergy, chronic inflammation, and autoimmune diseases. MC pleiotropic functions reflect their ability to secrete a wide spectrum of preformed or newly synthesized biologically active products with pro-inflammatory, anti-inflammatory and/or immunosuppressive properties, in response to multiple signals. Moreover, the modulation of MC effector phenotypes relies on the interaction of a wide variety of membrane molecules involved in cell–cell or cell-extracellular-matrix interaction. The delivery of co-stimulatory signals allows MC to specifically communicate with immune cells belonging to both innate and acquired immunity, as well as with non-immune tissue-specific cell types. This article reviews and discusses the evidence that MC membrane-expressed molecules play a central role in regulating MC priming and activation and in the modulation of innate and adaptive immune response not only against host injury, but also in peripheral tolerance and tumor-surveillance or -escape. The complex expression of MC surface molecules may be regarded as a measure of connectivity, with altered patterns of cell–cell interaction representing functionally distinct MC states. We will focalize our attention on roles and functions of recently discovered molecules involved in the cross-talk of MCs with other immune partners. PMID:22654879

Neuron-directed autoimmunity in the central nervous system: entities, mechanisms, diagnostic clues, and therapeutic options.

PubMed

Melzer, Nico; Meuth, Sven G; Wiendl, Heinz

2012-06-01

The human central nervous system (CNS) can mistakenly be the target of adaptive cellular and humoral immune responses causing both functional and structural impairment. We here provide an overview of neuron-directed autoimmunity as a novel class of inflammatory CNS disorders, their differential diagnoses, clinical hallmarks, imaging features, characteristic laboratory, electrophysiological, cerebrospinal fluid and neuropathological findings, cellular and molecular disease mechanisms, as well as therapeutic options. A growing number of immune-mediated CNS disorders of both autoimmune and paraneoplastic origin have emerged, in which neurons seem to be the target of the immune response. Antibodies binding to a variety of synaptic and extrasynaptic antigens located on the neuronal surface membrane can define distinct entities. Clinically, these disorders are characterized by subacute CNS-related [and sometimes peripheral nervous system (PNS)-related] symptoms involving a variety of cortical and subcortical gray matter areas, which often reflect the expression pattern and function of the respective target antigen. Antibodies seem to be pathogenic and cause (reversible) disturbance of synaptic transmission and neuronal excitability by selective functional inhibition or crosslinking and internalization of their antigen in the absence of overt cytotoxicity, at least at early disease stages. Whether at later disease stages antibody-mediated cytotoxicity, cytotoxic CD8+ T cells, or other detrimental immune mechanisms contribute to neuronal impairment is unclear at present. Adaptive humoral autoimmunity directed to neuronal cell-surface antigens offers first and unique insights and provokes further investigation into the systemic, cellular, and molecular consequences of immune-mediated disruption of distinct neuronal signaling pathways within the living human CNS.

B and T lymphocyte attenuator restricts the protective immune response against experimental malaria.

PubMed

Adler, Guido; Steeg, Christiane; Pfeffer, Klaus; Murphy, Theresa L; Murphy, Kenneth M; Langhorne, Jean; Jacobs, Thomas

2011-11-15

The immune response against the blood stage of malaria has to be tightly regulated to allow for vigorous antiplasmodial activity while restraining potentially lethal immunopathologic damage to the host like cerebral malaria. Coinhibitory cell surface receptors are important modulators of immune activation. B and T lymphocyte attenuator (BTLA) (CD272) is a coinhibitory receptor expressed by most leukocytes, with the highest expression levels on T and B cells, and is involved in the maintenance of peripheral tolerance by dampening the activation of lymphocytes. The function of BTLA is described in several models of inflammatory disorders and autoimmunity, but its function in infectious diseases is less well characterized. Also, little is known about the influence of BTLA on non-T cells. In this study, we analyzed the function of BTLA during blood-stage malaria infection with the nonlethal Plasmodium yoelii strain 17NL. We show that BTLA knockout mice exhibit strongly reduced parasitemia and clear the infection earlier compared with wild-type mice. This increased resistance was seen before the onset of adaptive immune mechanisms and even in the absence of T and B cells but was more pronounced at later time points when activation of T and B cells was observed. We demonstrate that BTLA regulates production of proinflammatory cytokines in a T cell-intrinsic way and B cell intrinsically regulates the production of P. yoelii 17NL-specific Abs. These results indicate that the coinhibitory receptor BTLA plays a critical role during experimental malaria and attenuates the innate as well as the subsequent adaptive immune response.

The immunoregulatory role of type I and type II NKT cells in cancer and other diseases

PubMed Central

Terabe, Masaki; Berzofsky, Jay A.

2014-01-01

NKT cells are CD1d-restricted T cells that recognize lipid antigens. They also have been shown to play critical roles in the regulation of immune responses. In the immune responses against tumors, two subsets of NKT cells, type I and type II, play opposing roles and cross-regulate each other. As members of both the innate and adaptive immune systems, which form a network of multiple components, they also interact with other immune components. Here we discuss the function of NKT cells in tumor immunity and their interaction with other regulatory cells, especially CD4+CD25+Foxp3+ regulatory T cells. PMID:24384834

Trained immunity: a program of innate immune memory in health and disease

PubMed Central

Netea, Mihai G.; Joosten, Leo A.B.; Latz, Eicke; Mills, Kingston H.G.; Natoli, Gioacchino; Stunnenberg, Hendrik G.; O’Neill, Luke A.J.; Xavier, Ramnik J.

2016-01-01

The general view that only adaptive immunity can build immunological memory has recently been challenged. In organisms lacking adaptive immunity as well as in mammals, the innate immune system can mount resistance to reinfection, a phenomenon termed trained immunity or innate immune memory. Trained immunity is orchestrated by epigenetic reprogramming, broadly defined as sustained changes in gene expression and cell physiology that do not involve permanent genetic changes such as mutations and recombination, which are essential for adaptive immunity. The discovery of trained immunity may open the door for novel vaccine approaches, for new therapeutic strategies for the treatment of immune deficiency states, and for modulation of exaggerated inflammation in autoinflammatory diseases. PMID:27102489

Two distinct RNase activities of CRISPR-C2c2 enable guide-RNA processing and RNA detection.

PubMed

East-Seletsky, Alexandra; O'Connell, Mitchell R; Knight, Spencer C; Burstein, David; Cate, Jamie H D; Tjian, Robert; Doudna, Jennifer A

2016-10-13

Bacterial adaptive immune systems use CRISPRs (clustered regularly interspaced short palindromic repeats) and CRISPR-associated (Cas) proteins for RNA-guided nucleic acid cleavage. Although most prokaryotic adaptive immune systems generally target DNA substrates, type III and VI CRISPR systems direct interference complexes against single-stranded RNA substrates. In type VI systems, the single-subunit C2c2 protein functions as an RNA-guided RNA endonuclease (RNase). How this enzyme acquires mature CRISPR RNAs (crRNAs) that are essential for immune surveillance and how it carries out crRNA-mediated RNA cleavage remain unclear. Here we show that bacterial C2c2 possesses a unique RNase activity responsible for CRISPR RNA maturation that is distinct from its RNA-activated single-stranded RNA degradation activity. These dual RNase functions are chemically and mechanistically different from each other and from the crRNA-processing behaviour of the evolutionarily unrelated CRISPR enzyme Cpf1 (ref. 11). The two RNase activities of C2c2 enable multiplexed processing and loading of guide RNAs that in turn allow sensitive detection of cellular transcripts.

Host protective roles of type 2 immunity: Parasite killing and tissue repair, flip sides of the same coin

PubMed Central

Allen, Judith E.; Sutherland, Tara E.

2014-01-01

Metazoan parasites typically induce a type 2 immune response, characterized by T helper 2 (Th2) cells that produce the cytokines IL-4, IL-5 and IL-13 among others. The type 2 response is host protective, reducing the number of parasites either through direct killing in the tissues, or expulsion from the intestine. Type 2 immunity also protects the host against damage mediated by these large extracellular parasites as they migrate through the body. At the center of both the innate and adaptive type 2 immune response, is the IL-4Rα that mediates many of the key effector functions. Here we highlight the striking overlap between the molecules, cells and pathways that mediate both parasite control and tissue repair. We have proposed that adaptive Th2 immunity evolved out of our innate repair pathways to mediate both accelerated repair and parasite control in the face of continual assault from multicellular pathogens. Type 2 cytokines are involved in many aspects of mammalian physiology independent of helminth infection. Therefore understanding the evolutionary relationship between helminth killing and tissue repair should provide new insight into immune mechanisms of tissue protection in the face of physical injury. PMID:25028340

IL-33: biological properties, functions, and roles in airway disease.

PubMed

Drake, Li Yin; Kita, Hirohito

2017-07-01

Interleukin (IL)-33 is a key cytokine involved in type 2 immunity and allergic airway diseases. Abundantly expressed in lung epithelial cells, IL-33 plays critical roles in both innate and adaptive immune responses in mucosal organs. In innate immunity, IL-33 and group 2 innate lymphoid cells (ILC2s) provide an essential axis for rapid immune responses and tissue homeostasis. In adaptive immunity, IL-33 interacts with dendritic cells, Th2 cells, follicular T cells, and regulatory T cells, where IL-33 influences the development of chronic airway inflammation and tissue remodeling. The clinical findings that both the IL-33 and ILC2 levels are elevated in patients with allergic airway diseases suggest that IL-33 plays an important role in the pathogenesis of these diseases. IL-33 and ILC2 may also serve as biomarkers for disease classification and to monitor the progression of diseases. In this article, we reviewed the current knowledge of the biology of IL-33 and discussed the roles of the IL-33 in regulating airway immune responses and allergic airway diseases. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The role of TGF-β signaling and apoptosis in innate and adaptive immunity in zebrafish: a systems biology approach.

PubMed

Lin, Che; Lin, Chin-Nan; Wang, Yu-Chao; Liu, Fang-Yu; Chuang, Yung-Jen; Lan, Chung-Yu; Hsieh, Wen-Ping; Chen, Bor-Sen

2014-10-24

The immune system is a key biological system present in vertebrates. Exposure to pathogens elicits various defensive immune mechanisms that protect the host from potential threats and harmful substances derived from pathogens such as parasites, bacteria, and viruses. The complex immune system of humans and many other vertebrates can be divided into two major categories: the innate and the adaptive immune systems. At present, analysis of the complex interactions between the two subsystems that regulate host defense and inflammatory responses remains challenging. Based on time-course microarray data following primary and secondary infection of zebrafish by Candida albicans, we constructed two intracellular protein-protein interaction (PPI) networks for primary and secondary responses of the host. 57 proteins and 341 PPIs were identified for primary infection while 90 proteins and 385 PPIs were identified for secondary infection. There were 20 proteins in common while 37 and 70 proteins specific to primary and secondary infection. By inspecting the hub proteins of each network and comparing significant changes in the number of linkages between the two PPI networks, we identified TGF-β signaling and apoptosis as two of the main functional modules involved in primary and secondary infection. Our initial in silico analyses pave the way for further investigation into the interesting roles played by the TGF-β signaling pathway and apoptosis in innate and adaptive immunity in zebrafish. Such insights could lead to therapeutic advances and improved drug design in the continual battle against infectious diseases.

Fever-like thermal conditions regulate the activation of maturing dendritic cells.

PubMed

Tournier, Jean-Nicolas; Hellmann, Anne Quesnel; Lesca, Gaëtan; Jouan, Alain; Drouet, Emmanuel; Mathieu, Jacques

2003-04-01

Fever is one of the most frequent clinical signs encountered in pathology, especially with respect to infectious diseases. It is currently thought that the role of fever on immunity is limited to activation of innate immunity; however, its relevance to activation of adaptive immunity remains unclear. Dendritic cells (DCs) that behave as sentinels of the immune system provide an important bridge between innate and adaptive immunity. To highlight the role of fever on adaptive immunity, we exposed murine bone marrow-derived lipopolysaccharide (LPS)- or live bacteria-maturing DCs over a 3-h period to 37 degrees C or to fever-like thermal conditions (39 degrees C or 40 degrees C). At these three temperatures, we measured the kinetics of cytokine production and the ability of DCs to induce an allogeneic mixed lymphocyte reaction. Our results show that short exposure of DCs to temperatures of 39 degrees C or 40 degrees C differentially increased the secretion of interleukin (IL)-12p70 and decreased the secretion of IL-10 and tumor necrosis factor alpha by maturing DCs. These fever-like conditions induced a regulation of cytokine production at the single-cell level. In addition, short-term exposed LPS-maturing DCs to 39 degrees C induced a stronger reaction with allogeneic CD4(+) T cells than maturing DCs incubated at 37 degrees C. These results provide evidence that temperature regulates cytokine secretion and DC functions, both of which are of particular importance in bacterial diseases.

An Evolution-Based Screen for Genetic Differentiation between Anopheles Sister Taxa Enriches for Detection of Functional Immune Factors

PubMed Central

Takashima, Eizo; Williams, Marni; Eiglmeier, Karin; Pain, Adrien; Guelbeogo, Wamdaogo M.; Gneme, Awa; Brito-Fravallo, Emma; Holm, Inge; Lavazec, Catherine; Sagnon, N’Fale; Baxter, Richard H.; Riehle, Michelle M.; Vernick, Kenneth D.

2015-01-01

Nucleotide variation patterns across species are shaped by the processes of natural selection, including exposure to environmental pathogens. We examined patterns of genetic variation in two sister species, Anopheles gambiae and Anopheles coluzzii, both efficient natural vectors of human malaria in West Africa. We used the differentiation signature displayed by a known coordinate selective sweep of immune genes APL1 and TEP1 in A. coluzzii to design a population genetic screen trained on the sweep, classified a panel of 26 potential immune genes for concordance with the signature, and functionally tested their immune phenotypes. The screen results were strongly predictive for genes with protective immune phenotypes: genes meeting the screen criteria were significantly more likely to display a functional phenotype against malaria infection than genes not meeting the criteria (p = 0.0005). Thus, an evolution-based screen can efficiently prioritize candidate genes for labor-intensive downstream functional testing, and safely allow the elimination of genes not meeting the screen criteria. The suite of immune genes with characteristics similar to the APL1-TEP1 selective sweep appears to be more widespread in the A. coluzzii genome than previously recognized. The immune gene differentiation may be a consequence of adaptation of A. coluzzii to new pathogens encountered in its niche expansion during the separation from A. gambiae, although the role, if any of natural selection by Plasmodium is unknown. Application of the screen allowed identification of new functional immune factors, and assignment of new functions to known factors. We describe biochemical binding interactions between immune proteins that underlie functional activity for malaria infection, which highlights the interplay between pathogen specificity and the structure of immune complexes. We also find that most malaria-protective immune factors display phenotypes for either human or rodent malaria, with broad specificity a rarity. PMID:26633695

Psychoneuroimmunology in Pregnancy: Immune Pathways Linking Stress with Maternal Health, Adverse Birth Outcomes, and Fetal Development

PubMed Central

Christian, Lisa M.

2011-01-01

It is well-established that psychological stress promotes immune dysregulation in nonpregnant humans and animals. Stress promotes inflammation, impairs antibody responses to vaccination, slows wound healing, and suppresses cell-mediated immune function. Importantly, the immune system changes substantially to support healthy pregnancy, with attenuation of inflammatory responses and impairment of cell-mediated immunity. This adaptation is postulated to protect the fetus from rejection by the maternal immune system. Thus, stress-induced immune dysregulation during pregnancy has unique implications for both maternal and fetal health, particularly preterm birth. However, very limited research has examined stress-immune relationships in pregnancy. The application of psychoneuroimmunology research models to the perinatal period holds great promise for elucidating biological pathways by which stress may affect adverse pregnancy outcomes, maternal health, and fetal development. PMID:21787802

Cancer immunoediting by the innate immune system in the absence of adaptive immunity

PubMed Central

O’Sullivan, Timothy; Saddawi-Konefka, Robert; Vermi, William; Koebel, Catherine M.; Arthur, Cora; White, J. Michael; Uppaluri, Ravi; Andrews, Daniel M.; Ngiow, Shin Foong; Teng, Michele W.L.; Smyth, Mark J.; Schreiber, Robert D.

2012-01-01

Cancer immunoediting is the process whereby immune cells protect against cancer formation by sculpting the immunogenicity of developing tumors. Although the full process depends on innate and adaptive immunity, it remains unclear whether innate immunity alone is capable of immunoediting. To determine whether the innate immune system can edit tumor cells in the absence of adaptive immunity, we compared the incidence and immunogenicity of 3′methylcholanthrene-induced sarcomas in syngeneic wild-type, RAG2−/−, and RAG2−/−x γc−/− mice. We found that innate immune cells could manifest cancer immunoediting activity in the absence of adaptive immunity. This activity required natural killer (NK) cells and interferon γ (IFN-γ), which mediated the induction of M1 macrophages. M1 macrophages could be elicited by administration of CD40 agonists, thereby restoring editing activity in RAG2−/−x γc−/− mice. Our results suggest that in the absence of adaptive immunity, NK cell production of IFN-γ induces M1 macrophages, which act as important effectors during cancer immunoediting. PMID:22927549

Leptin as regulator of pulmonary immune responses: Involvement in respiratory diseases

PubMed Central

Vernooy, Juanita H.J.; Ubags, Niki D.J.; Brusselle, Guy G.; Tavernier, Jan; Suratt, Benjamin T.; Joos, Guy F.; Wouters, Emiel F.M.; Bracke, Ken R.

2014-01-01

Leptin is an adipocyte-derived hormone, recognized as a critical mediator of the balance between food intake and energy expenditure by signalling through its functional receptor (Ob-Rb) in the hypothalamus. Structurally, leptin belongs to the long-chain helical cytokine family, and is now known to have pleiotropic functions in both innate and adaptive immunity. The presence of the functional leptin receptor in the lung together with evidence of increased airspace leptin levels arising during pulmonary inflammation, suggests an important role for leptin in lung development, respiratory immune responses and eventually pathogenesis of inflammatory respiratory diseases. The purpose of this article is to review our current understanding of leptin and its functional role on the different resident cell types of the lung in health as well as in the context of three major respiratory conditions being chronic obstructive pulmonary disease (COPD), asthma, and pneumonia. PMID:23542720

Genome complexity in the coelacanth is reflected in its adaptive immune system

USGS Publications Warehouse

Saha, Nil Ratan; Ota, Tatsuya; Litman, Gary W.; Hansen, John; Parra, Zuly; Hsu, Ellen; Buonocore, Francesco; Canapa, Adriana; Cheng, Jan-Fang; Amemiya, Chris T.

2014-01-01

We have analyzed the available genome and transcriptome resources from the coelacanth in order to characterize genes involved in adaptive immunity. Two highly distinctive IgW-encoding loci have been identified that exhibit a unique genomic organization, including a multiplicity of tandemly repeated constant region exons. The overall organization of the IgW loci precludes typical heavy chain class switching. A locus encoding IgM could not be identified either computationally or by using several different experimental strategies. Four distinct sets of genes encoding Ig light chains were identified. This includes a variant sigma-type Ig light chain previously identified only in cartilaginous fishes and which is now provisionally denoted sigma-2. Genes encoding α/β and γ/δ T-cell receptors, and CD3, CD4, and CD8 co-receptors also were characterized. Ig heavy chain variable region genes and TCR components are interspersed within the TCR α/δ locus; this organization previously was reported only in tetrapods and raises questions regarding evolution and functional cooption of genes encoding variable regions. The composition, organization and syntenic conservation of the major histocompatibility complex locus have been characterized. We also identified large numbers of genes encoding cytokines and their receptors, and other genes associated with adaptive immunity. In terms of sequence identity and organization, the adaptive immune genes of the coelacanth more closely resemble orthologous genes in tetrapods than those in teleost fishes, consistent with current phylogenomic interpretations. Overall, the work reported described herein highlights the complexity inherent in the coelacanth genome and provides a rich catalog of immune genes for future investigations.

A perception theory in mind-body medicine: guided imagery and mindful meditation as cross-modal adaptation.

PubMed

Bedford, Felice L

2012-02-01

A new theory of mind-body interaction in healing is proposed based on considerations from the field of perception. It is suggested that the combined effect of visual imagery and mindful meditation on physical healing is simply another example of cross-modal adaptation in perception, much like adaptation to prism-displaced vision. It is argued that psychological interventions produce a conflict between the perceptual modalities of the immune system and vision (or touch), which leads to change in the immune system in order to realign the modalities. It is argued that mind-body interactions do not exist because of higher-order cognitive thoughts or beliefs influencing the body, but instead result from ordinary interactions between lower-level perceptual modalities that function to detect when sensory systems have made an error. The theory helps explain why certain illnesses may be more amenable to mind-body interaction, such as autoimmune conditions in which a sensory system (the immune system) has made an error. It also renders sensible erroneous changes, such as those brought about by "faith healers," as conflicts between modalities that are resolved in favor of the wrong modality. The present view provides one of very few psychological theories of how guided imagery and mindfulness meditation bring about positive physical change. Also discussed are issues of self versus non-self, pain, cancer, body schema, attention, consciousness, and, importantly, developing the concept that the immune system is a rightful perceptual modality. Recognizing mind-body healing as perceptual cross-modal adaptation implies that a century of cross-modal perception research is applicable to the immune system.

Retinoic Acid-Related Orphan Receptors (RORs): Regulatory Functions in Immunity, Development, Circadian Rhythm, and Metabolism

PubMed Central

Cook, Donald N.; Kang, Hong Soon; Jetten, Anton M.

2015-01-01

In this overview, we provide an update on recent progress made in understanding the mechanisms of action, physiological functions, and roles in disease of retinoic acid related orphan receptors (RORs). We are particularly focusing on their roles in the regulation of adaptive and innate immunity, brain function, retinal development, cancer, glucose and lipid metabolism, circadian rhythm, metabolic and inflammatory diseases and neuropsychiatric disorders. We also summarize the current status of ROR agonists and inverse agonists, including their regulation of ROR activity and their therapeutic potential for management of various diseases in which RORs have been implicated. PMID:26878025

Immune Checkpoint Blockade for Breast Cancer.

PubMed

Swoboda, April; Nanda, Rita

An effective antitumor immune response requires interaction between cells of the adaptive and innate immune system. Three key elements are required: generation of activated tumor-directed T cells, infiltration of activated T cells into the tumor microenvironment, and killing of tumor cells by activated T cells. Tumor immune evasion can occur as a result of the disruption of each of these three key T cell activities, resulting in three distinct cancer-immune phenotypes. The immune inflamed phenotype, characterized by the presence of a robust tumor immune infiltrate, suggests impaired activated T cell killing of tumor cells related to the presence of inhibitory factors. Programmed death receptor-1 (PD-1) is an inhibitory transmembrane protein expressed on T cells, B cells, and NK cells. The interaction between PD-1 and its ligands (PD-L1/L2) functions as an immune checkpoint against unrestrained cytotoxic T effector cell activity-it promotes peripheral T effector cell exhaustion and conversion of T effector cells to immunosuppressive T regulatory (Treg) cells. Immune checkpoint inhibitors, which block the PD-1/PD-L1 axis and reactivate cytotoxic T effector cell function, are actively being investigated for the treatment of breast cancer.

Cutaneous immunology: basics and new concepts.

PubMed

Yazdi, Amir S; Röcken, Martin; Ghoreschi, Kamran

2016-01-01

As one of the largest organs, the skin forms a mechanical and immunological barrier to the environment. The skin immune system harbors cells of the innate immune system and cells of the adaptive immune system. Signals of the innate immune system typically initiate skin immune responses, while cells and cytokines of the adaptive immune system perpetuate the inflammation. Skin immune responses ensure effective host defense against pathogens but can also cause inflammatory skin diseases. An extensive crosstalk between the different cell types of the immune system, tissue cells, and pathogens is responsible for the complexity of skin immune reactions. Here we summarize the major cellular and molecular components of the innate and adaptive skin immune system.

Liver immunology and herbal treatment

PubMed Central

Balaban, Yasemin H; Aka, Ceylan; Koca-Caliskan, Ufuk

2017-01-01

Beyond the metabolic functions, the liver recently has been defined as an organ of immune system (IS), which have central regulatory role for innate and adaptive immunity. The liver keeps a delicate balance between hepatic screening of pathogenic antigens and immune tolerance to self-antigens. Herbal treatments with immunological effects have potential to alter this hepatic immune balance towards either therapeutic side or diseases side by inducing liver injury via hepatotoxicity or initiation of autoimmune diseases. Most commonly known herbal treatments, which have therapeutic effect on liver and IS, have proven via in vitro, in vivo, and/or clinical studies were summarized in this review. PMID:28660010

Developing a pro-regenerative biomaterial scaffold microenvironment requires T helper 2 cells.

PubMed

Sadtler, Kaitlyn; Estrellas, Kenneth; Allen, Brian W; Wolf, Matthew T; Fan, Hongni; Tam, Ada J; Patel, Chirag H; Luber, Brandon S; Wang, Hao; Wagner, Kathryn R; Powell, Jonathan D; Housseau, Franck; Pardoll, Drew M; Elisseeff, Jennifer H

2016-04-15

Immune-mediated tissue regeneration driven by a biomaterial scaffold is emerging as an innovative regenerative strategy to repair damaged tissues. We investigated how biomaterial scaffolds shape the immune microenvironment in traumatic muscle wounds to improve tissue regeneration. The scaffolds induced a pro-regenerative response, characterized by an mTOR/Rictor-dependent T helper 2 pathway that guides interleukin-4-dependent macrophage polarization, which is critical for functional muscle recovery. Manipulating the adaptive immune system using biomaterials engineering may support the development of therapies that promote both systemic and local pro-regenerative immune responses, ultimately stimulating tissue repair. Copyright © 2016, American Association for the Advancement of Science.

Developing a pro-regenerative biomaterial scaffold microenvironment requires T helper 2 cells

PubMed Central

Sadtler, Kaitlyn; Estrellas, Kenneth; Allen, Brian W.; Wolf, Matthew T.; Fan, Hongni; Tam, Ada J.; Patel, Chirag H.; Luber, Brandon S.; Wang, Hao; Wagner, Kathryn R.; Powell, Jonathan D.; Housseau, Franck; Pardoll, Drew M.

2016-01-01

Immune-mediated tissue regeneration driven by a biomaterial scaffold is emerging as an innovative regenerative strategy to repair damaged tissues. We investigated how biomaterial scaffolds shape the immune microenvironment in traumatic muscle wounds to improve tissue regeneration. The scaffolds induced a pro-regenerative response, characterized by an mTOR/Rictor-dependent T helper 2 pathway that guides interleukin-4–dependent macrophage polarization, which is critical for functional muscle recovery. Manipulating the adaptive immune system using biomaterials engineering may support the development of therapies that promote both systemic and local pro-regenerative immune responses, ultimately stimulating tissue repair. PMID:27081073

Role of adaptive and innate immune cells in chronic fatigue syndrome/myalgic encephalomyelitis.

PubMed

Brenu, Ekua Weba; Huth, Teilah K; Hardcastle, Sharni L; Fuller, Kirsty; Kaur, Manprit; Johnston, Samantha; Ramos, Sandra B; Staines, Don R; Marshall-Gradisnik, Sonya M

2014-04-01

Perturbations in immune processes are a hallmark of a number of autoimmune and inflammatory disorders. Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is an inflammatory disorder with possible autoimmune correlates, characterized by reduced NK cell activity, elevations in regulatory T cells (Tregs) and dysregulation in cytokine levels. The purpose of this article is to examine innate and adaptive immune cell phenotypes and functional characteristics that have not been previously examined in CFS/ME patients. Thirty patients with CFS/ME and 25 non-fatigued controls were recruited for this study. Whole blood samples were collected from all participants for the assessment of cell phenotypes, functional properties, receptors, adhesion molecules, antigens and intracellular proteins using flow cytometric protocols. The cells investigated included NK cells, dendritic cells, neutrophils, B cells, T cells, γδT cells and Tregs. Significant changes were observed in B-cell subsets, Tregs, CD4(+)CD73(+)CD39(+) T cells, cytotoxic activity, granzyme B, neutrophil antigens, TNF-α and IFN-γ in the CFS/ME patients in comparison with the non-fatigued controls. Alterations in B cells, Tregs, NK cells and neutrophils suggest significant impairments in immune regulation in CFS/ME and these may have similarities to a number of autoimmune disorders.

Mechanical regulation of T-cell functions

PubMed Central

Chen, Wei; Zhu, Cheng

2013-01-01

Summary T cells are key players of the mammalian adaptive immune system. They experience different mechanical microenvironments during their life cycles, from the thymus, secondary lymph organs, and peripheral tissues that are free of externally applied force but display variable substrate rigidities, to the blood and lymphatic circulation systems where complicated hydrodynamic forces are present. Regardless of whether T cells are subject to external forces or generate their own internal forces, they response and adapt to different biomechanical cues to modulate their adhesion, migration, trafficking, and triggering of immune functions through mechanical regulation of various molecules that bear force. These include adhesive receptors, immunoreceptors, motor proteins, cytoskeletal proteins, and their associated molecules. Here we discuss the forces acting on various surface and cytoplasmic proteins of a T cell in different mechanical milieus. We review existing data on how force regulates protein conformational changes and interactions with counter molecules, including integrins, actin, and the T-cell receptor, and how each relates to T-cell functions. PMID:24117820

Autoselection of cytoplasmic yeast virus like elements encoding toxin/antitoxin systems involves a nuclear barrier for immunity gene expression.

PubMed

Kast, Alene; Voges, Raphael; Schroth, Michael; Schaffrath, Raffael; Klassen, Roland; Meinhardt, Friedhelm

2015-05-01

Cytoplasmic virus like elements (VLEs) from Kluyveromyces lactis (Kl), Pichia acaciae (Pa) and Debaryomyces robertsiae (Dr) are extremely A/T-rich (>75%) and encode toxic anticodon nucleases (ACNases) along with specific immunity proteins. Here we show that nuclear, not cytoplasmic expression of either immunity gene (PaORF4, KlORF3 or DrORF5) results in transcript fragmentation and is insufficient to establish immunity to the cognate ACNase. Since rapid amplification of 3' ends (RACE) as well as linker ligation of immunity transcripts expressed in the nucleus revealed polyadenylation to occur along with fragmentation, ORF-internal poly(A) site cleavage due to the high A/T content is likely to prevent functional expression of the immunity genes. Consistently, lowering the A/T content of PaORF4 to 55% and KlORF3 to 46% by gene synthesis entirely prevented transcript cleavage and permitted functional nuclear expression leading to full immunity against the respective ACNase toxin. Consistent with a specific adaptation of the immunity proteins to the cognate ACNases, cross-immunity to non-cognate ACNases is neither conferred by PaOrf4 nor KlOrf3. Thus, the high A/T content of cytoplasmic VLEs minimizes the potential of functional nuclear recruitment of VLE encoded genes, in particular those involved in autoselection of the VLEs via a toxin/antitoxin principle.

Immunotoxic effects of environmental pollutants in marine mammals.

PubMed

Desforges, Jean-Pierre W; Sonne, Christian; Levin, Milton; Siebert, Ursula; De Guise, Sylvain; Dietz, Rune

2016-01-01

Due to their marine ecology and life-history, marine mammals accumulate some of the highest levels of environmental contaminants of all wildlife. Given the increasing prevalence and severity of diseases in marine wildlife, it is imperative to understand how pollutants affect the immune system and consequently disease susceptibility. Advancements and adaptations of analytical techniques have facilitated marine mammal immunotoxicology research. Field studies, captive-feeding experiments and in vitro laboratory studies with marine mammals have associated exposure to environmental pollutants, most notable polychlorinated biphenyls (PCBs), organochlorine pesticides and heavy metals, to alterations of both the innate and adaptive arms of immune systems, which include aspects of cellular and humoral immunity. For marine mammals, reported immunotoxicology endpoints fell into several major categories: immune tissue histopathology, haematology/circulating immune cell populations, functional immune assays (lymphocyte proliferation, phagocytosis, respiratory burst, and natural killer cell activity), immunoglobulin production, and cytokine gene expression. Lymphocyte proliferation is by far the most commonly used immune assay, with studies using different organic pollutants and metals predominantly reporting immunosuppressive effects despite the many differences in study design and animal life history. Using combined field and laboratory data, we determined effect threshold levels for suppression of lymphocyte proliferation to be between b0.001-10 ppm for PCBs, 0.002-1.3 ppm for Hg, 0.009-0.06 for MeHg, and 0.1-2.4 for cadmium in polar bears and several pinniped and cetacean species. Similarly, thresholds for suppression of phagocytosis were 0.6-1.4 and 0.08-1.9 ppm for PCBs and mercury, respectively. Although data are lacking for many important immune endpoints and mechanisms of specific immune alterations are not well understood, this review revealed a systemic suppression of immune function in marine mammals exposed to environmental contaminants. Exposure to immunotoxic contaminants may have significant population level consequences as a contributing factor to increasing anthropogenic stress in wildlife and infectious disease outbreaks.

Lack of genetic diversity across diverse immune genes in an endangered mammal, the Tasmanian devil (Sarcophilus harrisii).

PubMed

Morris, Katrina M; Wright, Belinda; Grueber, Catherine E; Hogg, Carolyn; Belov, Katherine

2015-08-01

The Tasmanian devil (Sarcophilus harrisii) is threatened with extinction due to the spread of devil facial tumour disease. Polymorphisms in immune genes can provide adaptive potential to resist diseases. Previous studies in diversity at immune loci in wild species have almost exclusively focused on genes of the major histocompatibility complex (MHC); however, these genes only account for a fraction of immune gene diversity. Devils lack diversity at functionally important immunity loci, including MHC and Toll-like receptor genes. Whether there are polymorphisms at devil immune genes outside these two families is unknown. Here, we identify polymorphisms in a wide range of key immune genes, and develop assays to type single nucleotide polymorphisms (SNPs) within a subset of these genes. A total of 167 immune genes were examined, including cytokines, chemokines and natural killer cell receptors. Using genome-level data from ten devils, SNPs within coding regions, introns and 10 kb flanking genes of interest were identified. We found low polymorphism across 167 immune genes examined bioinformatically using whole-genome data. From this data, we developed long amplicon assays to target nine genes. These amplicons were sequenced in 29-220 devils and found to contain 78 SNPs, including eight SNPS within exons. Despite the extreme paucity of genetic diversity within these genes, signatures of balancing selection were exhibited by one chemokine gene, suggesting that remaining diversity may hold adaptive potential. The low functional diversity may leave devils highly vulnerable to infectious disease, and therefore, monitoring and preserving remaining diversity will be critical for the long-term management of this species. Examining genetic variation in diverse immune genes should be a priority for threatened wildlife species. This study can act as a model for broad-scale immunogenetic diversity analysis in threatened species. © 2015 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

Toxic effects of dietary methylmercury on immune system development in nestling American kestrels (Falco sparverius)

USGS Publications Warehouse

Fallacara, Dawn M.; Halbrook, Richard S.; French, John B.

2011-01-01

This study evaluated the effects of dietary methylmercury (MeHg) on immune system development in captive-reared nestling American kestrels (Falco sparverius) to determine whether T cell–mediated and antibody-mediated adaptive immunity are targets for MeHg toxicity at environmentally relevant concentrations. Nestlings received various diets, including 0 (control), 0.6, and 3.9 μg/g (dry wt) MeHg for up to 18 d posthatch. Immunotoxicity endpoints included cell-mediated immunity (CMI) using the phytohemagglutinin (PHA) skin-swelling assay and antibody-mediated immune response via the sheep red blood cell (SRBC) hemagglutination assay. T cell– and B cell–dependent histological parameters in the spleen, thymus, and bursa of Fabricius were correlated with the functional assays. For nestlings in the 0.6 and 3.9 μg/g MeHg groups, CMI was suppressed by 73 and 62%, respectively, at 11 d of age. Results of this functional assay were correlated with T cell–dependent components of the spleen and thymus. Dose-dependent lymphoid depletion in spleen tissue directly affected the proliferation of T-lymphocyte populations, insofar as lower stimulation indexes from the PHA assay occurred in nestlings with lower proportions of splenic white pulp and higher THg concentrations. Nestlings in the 3.9 μg/g group also exhibited lymphoid depletion and a lack of macrophage activity in the thymus. Methylmercury did not have a noticeable effect on antibody-mediated immune function or B cell–dependent histological correlates. We conclude that T cell–mediated immunosuppression is the primary target of MeHg toward adaptive immunity in developing kestrels. This study provides evidence that environmentally relevant concentrations of MeHg may compromise immunocompetence in a developing terrestrial predator and raises concern regarding the long-term health effects of kestrels that were exposed to dietary MeHg during early avian development.

TET1 and TET3 are essential in induction of Th2-type immunity partly through regulation of IL-4/13A expression in zebrafish model.

PubMed

Yang, Chao; Li, Zhuo; Kang, Wei; Tian, Yu; Yan, Yuzhu; Chen, Wei

2016-10-10

It has been considered that epigenetic modulation can affect a diverse array of cellular activities, in which ten eleven translocation (TET) methylcytosine dioxygenase family members refer to a group of fundamental components involved in catalyzation of 5-hydroxymethylcytosine and modification of gene expression. Even though the function of TET proteins has been gradually revealed, their roles in immune regulation are still largely unknown. Recent studies provided clues that TET2 could regulate several innate immune-related inflammatory mediators in mammals. This study sought to explore the function of TET family members in potential T-helper (Th) cell differentiation involved in adaptive immunity by utilizing a zebrafish model. As shown by results, soluble antigens could induce expression of zebrafish IL-4/13A (i.e. a pivotal Th2-type cytokine essential in Th2 cell differentiation and functions), and further trigger the expression of Th1- and Th2-related genes. It is noteworthy that this response was accompanied by the up-regulation of two TET family members (TET1 and TET3) both in immune organs (spleen and kidney) and cells (peripheral lymphocytes). Knocking-down of TET1 and TET3 will give rise to the decreased responses of IL-4/13A induction against exogenous soluble antigen stimulation, and further restrain the expression of Th2-related genes, which indicates a restrained Th2 cell differentiation. Nonetheless, TET2 did not exhibit effect on the modification of Th1/Th2 related gene expression. Hence, these data showed that TET1 and TET3 might be two significant epigenetic regulators involved in Th2 differentiation through regulation of IL-4/13A expression. This is the first report to show that TET family members play indispensable roles in Th2-type immunity, indicating an epigenetic modulation manner involved in adaptive immune regulations and responses. Copyright © 2016 Elsevier B.V. All rights reserved.

Mutations in a Highly Conserved Motif of nsp1β Protein Attenuate the Innate Immune Suppression Function of Porcine Reproductive and Respiratory Syndrome Virus

PubMed Central

Li, Yanhua; Shyu, Duan-Liang; Shang, Pengcheng; Bai, Jianfa; Ouyang, Kang; Dhakal, Santosh; Hiremath, Jagadish; Binjawadagi, Basavaraj

2016-01-01

ABSTRACT Porcine reproductive and respiratory syndrome virus (PRRSV) nonstructural protein 1β (nsp1β) is a multifunctional viral protein, which is involved in suppressing the host innate immune response and activating a unique −2/−1 programmed ribosomal frameshifting (PRF) signal for the expression of frameshifting products. In this study, site-directed mutagenesis analysis showed that the R128A or R129A mutation introduced into a highly conserved motif (123GKYLQRRLQ131) reduced the ability of nsp1β to suppress interferon beta (IFN-β) activation and also impaired nsp1β's function as a PRF transactivator. Three recombinant viruses, vR128A, vR129A, and vRR129AA, carrying single or double mutations in the GKYLQRRLQ motif were characterized. In comparison to the wild-type (WT) virus, vR128A and vR129A showed slightly reduced growth abilities, while the vRR129AA mutant had a significantly reduced growth ability in infected cells. Consistent with the attenuated growth phenotype in vitro, pigs infected with nsp1β mutants had lower levels of viremia than did WT virus-infected pigs. Compared to the WT virus in infected cells, all three mutated viruses stimulated high levels of IFN-α expression and exhibited a reduced ability to suppress the mRNA expression of selected interferon-stimulated genes (ISGs). In pigs infected with nsp1β mutants, IFN-α production was increased in the lungs at early time points postinfection, which was correlated with increased innate NK cell function. Furthermore, the augmented innate response was consistent with the increased production of IFN-γ in pigs infected with mutated viruses. These data demonstrate that residues R128 and R129 are critical for nsp1β function and that modifying these key residues in the GKYLQRRLQ motif attenuates virus growth ability and improves the innate and adaptive immune responses in infected animals. IMPORTANCE PRRSV infection induces poor antiviral innate IFN and cytokine responses, which results in weak adaptive immunity. One of the strategies in next-generation vaccine construction is to manipulate viral proteins/genetic elements involved in antagonizing the host immune response. PRRSV nsp1β was identified to be a strong innate immune antagonist. In this study, two basic amino acids, R128 and R129, in a highly conserved GKYLQRRLQ motif were determined to be critical for nsp1β function. Mutations introduced into these two residues attenuated virus growth and improved the innate and adaptive immune responses of infected animals. Technologies developed in this study could be broadly applied to current commercial PRRSV modified live-virus (MLV) vaccines and other candidate vaccines. PMID:26792733

Functional diversity of human vaginal APC subsets in directing T cell responses

PubMed Central

Duluc, Dorothée; Gannevat, Julien; Anguiano, Esperanza; Zurawski, Sandra; Carley, Michael; Boreham, Muriel; Stecher, Jack; Dullaers, Melissa; Banchereau, Jacques; Oh, SangKon

2012-01-01

Human vaginal mucosa is the major entry site of sexually transmitted pathogens and thus has long been attractive as a site for mounting mucosal immunity. It is also known as a tolerogenic microenvironment. Here, we demonstrate that immune responses in the vagina are orchestrated by the functional diversity of four major antigen-presenting cell (APC) subsets. Langerhans cells (LCs) and CD14− lamina propria (LP)-DCs polarize CD4+ and CD8+ T cells toward Th2, whereas CD14+ LP-DCs and macrophages polarize CD4+ T cells toward Th1. Both LCs and CD14− LP-DCs are potent inducers of Th22. Due to their functional specialties and the different expression levels of pattern-recognition receptors on the APC subsets, microbial products do not bias them to elicit common types of immune responses (Th1 or Th2). To evoke desired types of adaptive immune responses in the human vagina, antigens may need to be targeted to proper APC subsets with right adjuvants. PMID:23131784

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

PubMed

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.

[Advances in molecular mechanisms of adaptive immunity mediated by type I-E CRISPR/Cas system--A review].

PubMed

Sun, Dongchang; Qiu, Juanping

2016-01-04

To better adapt to the environment, prokaryocyte can take up exogenous genes (from bacteriophages, plasmids or genomes of other species) through horizontal gene transfer. Accompanied by the acquisition of exogenous genes, prokaryocyte is challenged by the invasion of 'selfish genes'. Therefore, to protect against the risk of gene transfer, prokaryocyte needs to establish mechanisms for selectively taking up or degrading exogenous DNA. In recent years, researchers discovered an adaptive immunity, which is mediated by the small RNA guided DNA degradation, prevents the invasion of exogenous genes in prokaryocyte. During the immune process, partial DNA fragments are firstly integrated.to the clustered regularly interspaced short palindromic repeats (CRISPR) located within the genome DNA, and then the mature CRISPR RNA transcript and the CRISPR associated proteins (Cas) form a complex CRISPR/Cas for degrading exogenous DNA. In this review, we will first briefly describe the CRISPR/Cas systems and then mainly focus on the recent advances of the function mechanism and the regulation mechanism of the type I-E CRISPR/Cas system in Escherichia coli.

Beluga (Delphinapterus leucas) granulocytes and monocytes display variable responses to in vitro pressure exposures

PubMed Central

Thompson, Laura A.; Romano, Tracy A.

2015-01-01

While it is widely known that marine mammals possess adaptations which allow them to make repetitive and extended dives to great depths without suffering ill effects seen in humans, the response of marine mammal immune cells to diving is unknown. Renewed interest in marine mammal dive physiology has arisen due to reports of decompression sickness-like symptoms and embolic damage in stranded and by-caught animals, and there is concern over whether anthropogenic activities can impact marine mammal health by disrupting adaptive dive responses and behavior. This work addresses the need for information concerning marine mammal immune function during diving by evaluating granulocyte and monocyte phagocytosis, and granulocyte activation in belugas (n = 4) in comparison with humans (n = 4), with and without in vitro pressure exposures. In addition, the potential for additional stressors to impact immune function was investigated by comparing the response of beluga cells to pressure between baseline and stressor conditions. Granulocyte and monocyte phagocytosis, as well as granulocyte activation, were compared between pressure exposed and non-exposed cells for each condition, between different pressure profiles and between conditions using mixed generalized linear models (α = 0.05). The effects of pressure varied between species as well by depth, compression/decompression rates, and length of exposures, and condition for belugas. Pressure induced changes in granulocyte and monocyte function in belugas could serve a protective function against dive-related pathologies and differences in the response between humans and belugas could reflect degrees of dive adaptation. The alteration of these responses during physiologically challenging conditions may increase the potential for dive-related in jury and disease in marine mammals. PMID:25999860

Beluga (Delphinapterus leucas) granulocytes and monocytes display variable responses to in vitro pressure exposures.

PubMed

Thompson, Laura A; Romano, Tracy A

2015-01-01

While it is widely known that marine mammals possess adaptations which allow them to make repetitive and extended dives to great depths without suffering ill effects seen in humans, the response of marine mammal immune cells to diving is unknown. Renewed interest in marine mammal dive physiology has arisen due to reports of decompression sickness-like symptoms and embolic damage in stranded and by-caught animals, and there is concern over whether anthropogenic activities can impact marine mammal health by disrupting adaptive dive responses and behavior. This work addresses the need for information concerning marine mammal immune function during diving by evaluating granulocyte and monocyte phagocytosis, and granulocyte activation in belugas (n = 4) in comparison with humans (n = 4), with and without in vitro pressure exposures. In addition, the potential for additional stressors to impact immune function was investigated by comparing the response of beluga cells to pressure between baseline and stressor conditions. Granulocyte and monocyte phagocytosis, as well as granulocyte activation, were compared between pressure exposed and non-exposed cells for each condition, between different pressure profiles and between conditions using mixed generalized linear models (α = 0.05). The effects of pressure varied between species as well by depth, compression/decompression rates, and length of exposures, and condition for belugas. Pressure induced changes in granulocyte and monocyte function in belugas could serve a protective function against dive-related pathologies and differences in the response between humans and belugas could reflect degrees of dive adaptation. The alteration of these responses during physiologically challenging conditions may increase the potential for dive-related in jury and disease in marine mammals.

[Connective tissue and inflammation].

PubMed

Jakab, Lajos

2014-03-23

The author summarizes the structure of the connective tissues, the increasing motion of the constituents, which determine the role in establishing the structure and function of that. The structure and function of the connective tissue are related to each other in the resting as well as inflammatory states. It is emphasized that cellular events in the connective tissue are part of the defence of the organism, the localisation of the damage and, if possible, the maintenance of restitutio ad integrum. The organism responds to damage with inflammation, the non specific immune response, as well as specific, adaptive immunity. These processes are located in the connective tissue. Sterile and pathogenic inflammation are relatively similar processes, but inevitable differences are present, too. Sialic acids and glycoproteins containing sialic acids have important roles, and the role of Siglecs is also highlighted. Also, similarities and differences in damages caused by pathogens and sterile agents are briefly summarized. In addition, the roles of adhesion molecules linked to each other, and the whole event of inflammatory processes are presented. When considering practical consequences it is stressed that the structure (building up) of the organism and the defending function of inflammation both have fundamental importance. Inflammation has a crucial role in maintaining the integrity and the unimpaired somato-psychological state of the organism. Thus, inflammation serves as a tool of organism identical with the natural immune response, inseparably connected with the specific, adaptive immune response. The main events of the inflammatory processes take place in the connective tissue.

Immune pathogenesis of pediatric HIV-1 infection

PubMed Central

TIEMESSEN, CAROLINE T.; KUHN, LOUISE

2008-01-01

Vertical exposure to HIV occurs at a time when functional capacity of the infant’s immune system is attenuated through immaturity. Immune response capability is rooted in host genetic makeup, and the broad and fine specificity of innate and adaptive immune responses, respectively, shape the outcomes of HIV encounter in some instances and imprint viral changes through selective immune pressure in others. Findings from recent studies have profound implications for understanding immune pathogenesis of pediatric HIV infection, and in particular highlight the importance of host genetics of both mother and child in determining whether an exposed child acquires HIV infection or not, and if infected, the rate of disease progression. This review focuses on the key host molecules, the CC chemokine CCL3 and HLA, which have taken center stage in these new developments. PMID:16522254

Functional changes in neutrophils and psychoneuroendocrine responses during 105 days of confinement.

PubMed

Strewe, C; Muckenthaler, F; Feuerecker, M; Yi, B; Rykova, M; Kaufmann, I; Nichiporuk, I; Vassilieva, G; Hörl, M; Matzel, S; Schelling, G; Thiel, M; Morukov, B; Choukèr, A

2015-05-01

The innate immune system as one key element of immunity and a prerequisite for an adequate host defense is of emerging interest in space research to ensure crew health and thus mission success. In ground-based studies, spaceflight-associated specifics such as confinement caused altered immune functions paralleled by changes in stress hormone levels. In this study, six men were confined for 105 days to a space module of ~500 m(3) mimicking conditions of a long-term space mission. Psychic stress was surveyed by different questionnaires. Blood, saliva, and urine samples were taken before, during, and after confinement to determine quantitative and qualitative immune responses by analyzing enumerative assays and quantifying microbicide and phagocytic functions. Additionally, expression and shedding of L-selectin (CD62L) on granulocytes and different plasma cytokine levels were measured. Cortisol and catecholamine levels were analyzed in saliva and urine. Psychic stress or an activation of the psychoneuroendocrine system could not be testified. White blood cell counts were not significantly altered, but innate immune functions showed increased cytotoxic and reduced microbicide capabilities. Furthermore, a significantly enhanced shedding of CD62L might be a hint at increased migratory capabilities. However, this was observed in the absence of any acute inflammatory state, and no rise in plasma cytokine levels was detected. In summary, confinement for 105 days caused changes in innate immune functions. Whether these changes result from an alert immune state in preparation for further immune challenges or from a normal adaptive process during confinement remains to be clarified in future research. Copyright © 2015 the American Physiological Society.

Leptin in pediatrics: A hormone from adipocyte that wheels several functions in children

PubMed Central

Soliman, Ashraf T.; Yasin, Mohamed; Kassem, Ahmed

2012-01-01

The protein leptin, a pleiotropic hormone regulates appetite and energy balance of the body and plays important roles in controlling linear growth, pubertal development, cardiovascular function, and immunity. Recent findings in the understanding of the structure, functional roles, and clinical significance of conditions with increased and decreased leptin secretion are summarized. Balance between leptin and other hormones is significantly regulated by nutritional status. This balance influences many organ systems, including the brain, liver, and skeletal muscle, to mediate the essential adaptation process. The aim of this review is to summarize the possible physiological functions of leptin and its signaling pathways during childhood and adolescence including control of food intake, energy regulation, growth and puberty, and immunity. Moreover, its secretion and possible roles in the adaptation process during different disease states (obesity, malnutrition, eating disorders, delayed puberty, congenital heart diseases and hepatic disorders) are discussed. The clinical manifestations and the successful management of patients with genetic leptin deficiency and the application of leptin therapy in other diseases including lipodystrophy, states with severe insulin resistance, and diabetes mellitus are discussed. PMID:23565493

Neurotrophin Receptor p75NTR Regulates Immune Function of Plasmacytoid Dendritic Cells.

PubMed

Bandoła, Joanna; Richter, Cornelia; Ryser, Martin; Jamal, Arshad; Ashton, Michelle P; von Bonin, Malte; Kuhn, Matthias; Dorschner, Benjamin; Alexopoulou, Dimitra; Navratiel, Katrin; Roeder, Ingo; Dahl, Andreas; Hedrich, Christian M; Bonifacio, Ezio; Brenner, Sebastian; Thieme, Sebastian

2017-01-01

Plasmacytoid dendritic cells (pDCs) regulate innate and adaptive immunity. Neurotrophins and their receptors control the function of neuronal tissue. In addition, they have been demonstrated to be part of the immune response but little is known about the effector immune cells involved. We report, for the first time, the expression and immune-regulatory function of the low affinity neurotrophin receptor p75 neurotrophin receptor (p75NTR) by the antigen-presenting pDCs, mediated by toll-like receptor (TLR) 9 activation and differential phosphorylation of interferon regulatory factor 3 and 7. The modulation of p75NTR on pDCs significantly influences disease progression of asthma in an ovalbumin-induced mouse model mediated by the TLR9 signaling pathway. p75NTR activation of pDCs from patients with asthma increased allergen-specific T cell proliferation and cytokine secretion in nerve growth factor concentration-dependent manner. Further, p75NTR activation of pDCs delayed the onset of autoimmune diabetes in RIP-CD80GP mice and aggravated graft-versus-host disease in a xenotransplantation model. Thus, p75NTR signaling on pDCs constitutes a new and critical mechanism connecting neurotrophin signaling and immune response regulation with great therapeutic potential for a variety of immune disorders.

Neurotrophin Receptor p75NTR Regulates Immune Function of Plasmacytoid Dendritic Cells

PubMed Central

Bandoła, Joanna; Richter, Cornelia; Ryser, Martin; Jamal, Arshad; Ashton, Michelle P.; von Bonin, Malte; Kuhn, Matthias; Dorschner, Benjamin; Alexopoulou, Dimitra; Navratiel, Katrin; Roeder, Ingo; Dahl, Andreas; Hedrich, Christian M.; Bonifacio, Ezio; Brenner, Sebastian; Thieme, Sebastian

2017-01-01

Plasmacytoid dendritic cells (pDCs) regulate innate and adaptive immunity. Neurotrophins and their receptors control the function of neuronal tissue. In addition, they have been demonstrated to be part of the immune response but little is known about the effector immune cells involved. We report, for the first time, the expression and immune-regulatory function of the low affinity neurotrophin receptor p75 neurotrophin receptor (p75NTR) by the antigen-presenting pDCs, mediated by toll-like receptor (TLR) 9 activation and differential phosphorylation of interferon regulatory factor 3 and 7. The modulation of p75NTR on pDCs significantly influences disease progression of asthma in an ovalbumin-induced mouse model mediated by the TLR9 signaling pathway. p75NTR activation of pDCs from patients with asthma increased allergen-specific T cell proliferation and cytokine secretion in nerve growth factor concentration-dependent manner. Further, p75NTR activation of pDCs delayed the onset of autoimmune diabetes in RIP-CD80GP mice and aggravated graft-versus-host disease in a xenotransplantation model. Thus, p75NTR signaling on pDCs constitutes a new and critical mechanism connecting neurotrophin signaling and immune response regulation with great therapeutic potential for a variety of immune disorders. PMID:28861085

Parental Exposure to Dim Light at Night Prior to Mating Alters Offspring Adaptive Immunity.

PubMed

Cissé, Yasmine M; Russart, Kathryn L G; Nelson, Randy J

2017-03-31

Exposure to dim light at night (dLAN) disrupts natural light/dark cycles and impairs endogenous circadian rhythms necessary to maintain optimal biological function, including the endocrine and immune systems. We have previously demonstrated that white dLAN compromises innate and cell mediated immune responses in adult Siberian hamsters (Phodopus sungorus). We hypothesized that dLAN has transgenerational influences on immune function. Adult male and female Siberian hamsters were exposed to either dark nights (DARK) or dLAN (~5 lux) for 9 weeks, then paired in full factorial design, mated, and thereafter housed under dark nights. Offspring were gestated and reared in dark nights, then tested as adults for cell-mediated and humoral immunity. Maternal exposure to dLAN dampened delayed type hypersensitivity (DTH) responses in male offspring. Maternal and paternal exposure to dLAN reduced DTH responses in female offspring. IgG antibodies to a novel antigen were elevated in offspring of dams exposed to dLAN. Paternal exposure to dLAN decreased splenic endocrine receptor expression and global methylation in a parental sex-specific manner. Together, these data suggest that exposure to dLAN has transgenerational effects on endocrine-immune function that may be mediated by global alterations in the epigenetic landscape of immune tissues.

Parental Exposure to Dim Light at Night Prior to Mating Alters Offspring Adaptive Immunity

PubMed Central

Cissé, Yasmine M.; Russart, Kathryn L.G.; Nelson, Randy J.

2017-01-01

Exposure to dim light at night (dLAN) disrupts natural light/dark cycles and impairs endogenous circadian rhythms necessary to maintain optimal biological function, including the endocrine and immune systems. We have previously demonstrated that white dLAN compromises innate and cell mediated immune responses in adult Siberian hamsters (Phodopus sungorus). We hypothesized that dLAN has transgenerational influences on immune function. Adult male and female Siberian hamsters were exposed to either dark nights (DARK) or dLAN (~5 lux) for 9 weeks, then paired in full factorial design, mated, and thereafter housed under dark nights. Offspring were gestated and reared in dark nights, then tested as adults for cell-mediated and humoral immunity. Maternal exposure to dLAN dampened delayed type hypersensitivity (DTH) responses in male offspring. Maternal and paternal exposure to dLAN reduced DTH responses in female offspring. IgG antibodies to a novel antigen were elevated in offspring of dams exposed to dLAN. Paternal exposure to dLAN decreased splenic endocrine receptor expression and global methylation in a parental sex-specific manner. Together, these data suggest that exposure to dLAN has transgenerational effects on endocrine-immune function that may be mediated by global alterations in the epigenetic landscape of immune tissues. PMID:28361901

Neuroimmune Axes of the Blood–Brain Barriers and Blood–Brain Interfaces: Bases for Physiological Regulation, Disease States, and Pharmacological Interventions

PubMed Central

Erickson, Michelle A.

2018-01-01

Central nervous system (CNS) barriers predominantly mediate the immune-privileged status of the brain, and are also important regulators of neuroimmune communication. It is increasingly appreciated that communication between the brain and immune system contributes to physiologic processes, adaptive responses, and disease states. In this review, we discuss the highly specialized features of brain barriers that regulate neuroimmune communication in health and disease. In section I, we discuss the concept of immune privilege, provide working definitions of brain barriers, and outline the historical work that contributed to the understanding of CNS barrier functions. In section II, we discuss the unique anatomic, cellular, and molecular characteristics of the vascular blood–brain barrier (BBB), blood–cerebrospinal fluid barrier, and tanycytic barriers that confer their functions as neuroimmune interfaces. In section III, we consider BBB-mediated neuroimmune functions and interactions categorized as five neuroimmune axes: disruption, responses to immune stimuli, uptake and transport of immunoactive substances, immune cell trafficking, and secretions of immunoactive substances. In section IV, we discuss neuroimmune functions of CNS barriers in physiologic and disease states, as well as pharmacological interventions for CNS diseases. Throughout this review, we highlight many recent advances that have contributed to the modern understanding of CNS barriers and their interface functions. PMID:29496890

Innate immunity and effector and regulatory mechanisms involved in allergic contact dermatitis.

PubMed

Silvestre, Marilene Chaves; Sato, Maria Notomi; Reis, Vitor Manoel Silva Dos

2018-03-01

Skin's innate immunity is the initial activator of immune response mechanisms, influencing the development of adaptive immunity. Some contact allergens are detected by Toll-like receptors (TLRs) and inflammasome NLR3. Keratinocytes participate in innate immunity and, in addition to functioning as an anatomical barrier, secrete cytokines, such as TNF, IL-1β, and IL-18, contributing to the development of Allergic Contact Dermatitis. Dendritic cells recognize and process antigenic peptides into T cells. Neutrophils cause pro-inflammatory reactions, mast cells induce migration/maturation of skin DCs, the natural killer cells have natural cytotoxic capacity, the γδ T cells favor contact with hapten during the sensitization phase, and the innate lymphoid cells act in the early stages by secreting cytokines, as well as act in inflammation and tissue homeostasis. The antigen-specific inflammation is mediated by T cells, and each subtype of T cells (Th1/Tc1, Th2/Tc2, and Th17/Tc17) activates resident skin cells, thus contributing to inflammation. Skin's regulatory T cells have a strong ability to inhibit the proliferation of hapten-specific T cells, acting at the end of the Allergic Contact Dermatitis response and in the control of systemic immune responses. In this review, we report how cutaneous innate immunity is the first line of defense and focus its role in the activation of the adaptive immune response, with effector response induction and its regulation.

Tetanus toxoid-pulsed monocyte vaccination for augmentation of collateral vessel growth.

PubMed

Herold, Joerg; Francke, Alexander; Weinert, Soenke; Schmeisser, Alexander; Hebel, Katrin; Schraven, Burkhart; Roehl, Friedich-Wilhelm; Strasser, Ruth H; Braun-Dullaeus, Ruediger C

2014-04-14

The pathogenesis of collateral growth (arteriogenesis) has been linked to both the innate and adaptive immune systems. While therapeutic approaches for the augmentation of arteriogenesis have focused on innate immunity, exploiting both innate and adaptive immune responses has not been examined. We hypothesized that tetanus toxoid (tt) immunization of mice followed by transplantation of monocytes (Mo) exposed ex vivo to tt augments arteriogenesis after ligation of the hind limb. Mo were generated from nonimmunized BALB/c mice, exposed ex vivo to tt for 24 hours and intravenously injected (ttMo, 2.5×10(6)) into the tail veins of tt-immunized syngeneic mice whose hind limbs had been ligated 24 hours prior to transplantation. Laser Doppler perfusion imaging was applied, and a perfusion index (PI) was calculated (ratio ligated/unligated). Twenty-one days after ligation, the arteriogenesis of untreated BALB/c mice was limited (PI=0.49±0.09). Hind limb function was impaired in 80% of animals. Injection of non-engineered Mo insignificantly increased the PI to 0.56±0.07. However, ttMo transplantation resulted in a strong increase of the PI to 0.82±0.08 (n=7; P<0.001), with no (0%) detectable functional impairment. ttMo injected into nonimmunized mice had no effect. The strong arteriogenic response of ttMo transplantation into immunized mice was prevented when mice had been depleted of T-helper cells by CD4-antibody pretreatment (PI=0.50±0.08; n=17; P<0.001), supporting the hypothesis that transplanted cells interact with recipient lymphocytes. Transplantation of ttMo into pre-immunized mice strongly promotes arteriogenesis. This therapeutic approach is feasible and highly attractive for the alleviation of morbidity associated with vascular occlusive disease.

Tetanus Toxoid‐Pulsed Monocyte Vaccination for Augmentation of Collateral Vessel Growth

PubMed Central

Herold, Joerg; Francke, Alexander; Weinert, Soenke; Schmeisser, Alexander; Hebel, Katrin; Schraven, Burkhart; Roehl, Friedich‐Wilhelm; Strasser, Ruth H.; Braun‐Dullaeus, Ruediger C.

2014-01-01

Background The pathogenesis of collateral growth (arteriogenesis) has been linked to both the innate and adaptive immune systems. While therapeutic approaches for the augmentation of arteriogenesis have focused on innate immunity, exploiting both innate and adaptive immune responses has not been examined. We hypothesized that tetanus toxoid (tt) immunization of mice followed by transplantation of monocytes (Mo) exposed ex vivo to tt augments arteriogenesis after ligation of the hind limb. Methods and Results Mo were generated from nonimmunized BALB/c mice, exposed ex vivo to tt for 24 hours and intravenously injected (ttMo, 2.5×106) into the tail veins of tt‐immunized syngeneic mice whose hind limbs had been ligated 24 hours prior to transplantation. Laser Doppler perfusion imaging was applied, and a perfusion index (PI) was calculated (ratio ligated/unligated). Twenty‐one days after ligation, the arteriogenesis of untreated BALB/c mice was limited (PI=0.49±0.09). Hind limb function was impaired in 80% of animals. Injection of non‐engineered Mo insignificantly increased the PI to 0.56±0.07. However, ttMo transplantation resulted in a strong increase of the PI to 0.82±0.08 (n=7; P<0.001), with no (0%) detectable functional impairment. ttMo injected into nonimmunized mice had no effect. The strong arteriogenic response of ttMo transplantation into immunized mice was prevented when mice had been depleted of T‐helper cells by CD4‐antibody pretreatment (PI=0.50±0.08; n=17; P<0.001), supporting the hypothesis that transplanted cells interact with recipient lymphocytes. Conclusions Transplantation of ttMo into pre‐immunized mice strongly promotes arteriogenesis. This therapeutic approach is feasible and highly attractive for the alleviation of morbidity associated with vascular occlusive disease. PMID:24732919

A stochastic chemical dynamic approach to correlate autoimmunity and optimal vitamin-D range.

PubMed

Roy, Susmita; Shrinivas, Krishna; Bagchi, Biman

2014-01-01

Motivated by several recent experimental observations that vitamin-D could interact with antigen presenting cells (APCs) and T-lymphocyte cells (T-cells) to promote and to regulate different stages of immune response, we developed a coarse grained but general kinetic model in an attempt to capture the role of vitamin-D in immunomodulatory responses. Our kinetic model, developed using the ideas of chemical network theory, leads to a system of nine coupled equations that we solve both by direct and by stochastic (Gillespie) methods. Both the analyses consistently provide detail information on the dependence of immune response to the variation of critical rate parameters. We find that although vitamin-D plays a negligible role in the initial immune response, it exerts a profound influence in the long term, especially in helping the system to achieve a new, stable steady state. The study explores the role of vitamin-D in preserving an observed bistability in the phase diagram (spanned by system parameters) of immune regulation, thus allowing the response to tolerate a wide range of pathogenic stimulation which could help in resisting autoimmune diseases. We also study how vitamin-D affects the time dependent population of dendritic cells that connect between innate and adaptive immune responses. Variations in dose dependent response of anti-inflammatory and pro-inflammatory T-cell populations to vitamin-D correlate well with recent experimental results. Our kinetic model allows for an estimation of the range of optimum level of vitamin-D required for smooth functioning of the immune system and for control of both hyper-regulation and inflammation. Most importantly, the present study reveals that an overdose or toxic level of vitamin-D or any steroid analogue could give rise to too large a tolerant response, leading to an inefficacy in adaptive immune function.

MicroRNA regulation of immune events at conception.

PubMed

Robertson, Sarah A; Zhang, Bihong; Chan, Honyueng; Sharkey, David J; Barry, Simon C; Fullston, Tod; Schjenken, John E

2017-09-01

The reproductive tract environment at conception programs the developmental trajectory of the embryo, sets the course of pregnancy, and impacts offspring phenotype and health. Despite the fundamental importance of this stage of reproduction, the rate-limiting regulatory mechanisms operating locally to control fertility and fecundity are incompletely understood. Emerging studies highlight roles for microRNAs (miRNAs) in regulating reproductive and developmental processes and in modulating the quality and strength of the female immune response. Since endometrial receptivity and robust placentation require specific adaptation of the immune response, we hypothesize that miRNAs participate in establishing pregnancy through effects on key gene networks in immune cells. Our recent studies investigated miRNAs that are induced in the peri-conception environment, focusing on miRNAs that have immune-regulatory roles-particularly miR-223, miR-155, and miR-146a. Genetic mouse models deficient in individual miRNAs are proving informative in defining roles for these miRNAs in the generation and stabilization of regulatory T cells (Treg cells) that confer adaptive immune tolerance. Overlapping and redundant functions between miRNAs that target multiple genes, combined with multiple miRNAs targeting individual genes, indicate complex and sensitive regulatory networks. Although to date most data on miRNA regulation of reproductive events are from mice, conserved functions of miRNAs across species imply similar biological pathways operate in all mammals. Understanding the regulation and roles of miRNAs in the peri-conception immune response will advance our knowledge of how environmental determinants act at conception, and could have practical applications for animal breeding as well as human fertility. © 2017 Wiley Periodicals, Inc.

Intestinal mucosal atrophy and adaptation

PubMed Central

Shaw, Darcy; Gohil, Kartik; Basson, Marc D

2012-01-01

Mucosal adaptation is an essential process in gut homeostasis. The intestinal mucosa adapts to a range of pathological conditions including starvation, short-gut syndrome, obesity, and bariatric surgery. Broadly, these adaptive functions can be grouped into proliferation and differentiation. These are influenced by diverse interactions with hormonal, immune, dietary, nervous, and mechanical stimuli. It seems likely that clinical outcomes can be improved by manipulating the physiology of adaptation. This review will summarize current understanding of the basic science surrounding adaptation, delineate the wide range of potential targets for therapeutic intervention, and discuss how these might be incorporated into an overall treatment plan. Deeper insight into the physiologic basis of adaptation will identify further targets for intervention to improve clinical outcomes. PMID:23197881

Rapid Link of Innate Immune Signal to Adaptive Immunity by Brain–Fat Axis

PubMed Central

Kim, Min Soo; Yan, Jingqi; Wu, Wenhe; Zhang, Guo; Zhang, Yalin; Cai, Dongsheng

2015-01-01

Innate immunity signals induced by pathogen/damage-associated molecular patterns are essential for adaptive immune responses, but it is unclear if the brain plays a role in this process. Here we show that while tumor necrosis factor (TNF) quickly increased in the brain of mice following bacterial infection, intra-brain TNF delivery mimicked bacterial infection to rapidly increase peripheral lymphocytes, especially in the spleen and fat. Multiple mouse models revealed that hypothalamic responses to TNF were accountable for this increase of peripheral lymphocytes in response to bacterial infection. Finally, hypothalamic induction of lipolysis was found to mediate the brain's action in promoting this increase in peripheral adaptive immune response. Thus, the brain-fat axis is important for rapidly linking innate immunity to adaptive immunity. PMID:25848866

Natural killer cells in host defense against veterinary pathogens.

PubMed

Shekhar, Sudhanshu; Yang, Xi

2015-11-15

Natural Killer (NK) cells constitute a major subset of innate lymphoid cells that do not express the T- and B-cell receptors and play an important role in antimicrobial defense. NK cells not only induce early and rapid innate immune responses, but also communicate with dendritic cells to shape the adaptive immunity, thus bridging innate and adaptive immunity. Although the functional biology of NK cells is well-documented in a variety of infections in humans and mice, their role in protecting domestic animals from infectious agents is only beginning to be understood. In this article, we summarize the current state of knowledge about the contribution of NK cells in pathogen defense in domestic animals, especially cattle and pigs. Understanding the immunobiology of NK cells will translate into strategies to manipulate these cells for preventive and therapeutic purposes. Copyright © 2015 Elsevier B.V. All rights reserved.

Interactions between Autophagy and Inhibitory Cytokines

PubMed Central

Wu, Tian-tian; Li, Wei-Min; Yao, Yong-Ming

2016-01-01

Autophagy is a degradative pathway that plays an essential role in maintaining cellular homeostasis. Most early studies of autophagy focused on its involvement in age-associated degeneration and nutrient deprivation. However, the immunological functions of autophagy have become more widely studied in recent years. Autophagy has been shown to be an intrinsic cellular defense mechanism in the innate and adaptive immune responses. Cytokines belong to a broad and loose category of proteins and are crucial for innate and adaptive immunity. Inhibitory cytokines have evolved to permit tolerance to self while also contributing to the eradication of invading pathogens. Interactions between inhibitory cytokines and autophagy have recently been reported, revealing a novel mechanism by which autophagy controls the immune response. In this review, we discuss interactions between autophagy and the regulatory cytokines IL-10, transforming growth factor-β, and IL-27. We also mention possible interactions between two newly discovered cytokines, IL-35 and IL-37, and autophagy. PMID:27313501

Targeting cancer’s weaknesses (not its strengths): Therapeutic strategies suggested by the atavistic model

PubMed Central

Lineweaver, Charles H.; Davies, Paul C.W.; Vincent, Mark D.

2014-01-01

In the atavistic model of cancer progression, tumor cell dedifferentiation is interpreted as a reversion to phylogenetically earlier capabilities. The more recently evolved capabilities are compromised first during cancer progression. This suggests a therapeutic strategy for targeting cancer: design challenges to cancer that can only be met by the recently evolved capabilities no longer functional in cancer cells. We describe several examples of this target-the-weakness strategy. Our most detailed example involves the immune system. The absence of adaptive immunity in immunosuppressed tumor environments is an irreversible weakness of cancer that can be exploited by creating a challenge that only the presence of adaptive immunity can meet. This leaves tumor cells more vulnerable than healthy tissue to pathogenic attack. Such a target-the-weakness therapeutic strategy has broad applications, and contrasts with current therapies that target the main strength of cancer: cell proliferation. PMID:25043755

Ahr function in lymphocytes: emerging concepts

PubMed Central

Zhou, Liang

2015-01-01

The aryl hydrocarbon receptor (Ahr) is an important regulator of the development and function of both innate and adaptive immune cells through roles associated with Ahr's ability to respond to cellular and dietary ligands. Recent findings have revealed tissue and context-specific functions for Ahr in both homeostasis and in during an immune response. I review these findings here, and integrate them into the current understanding of the mechanisms that regulate Ahr transcription and function. I propose a conceptual framework in which Ahr function is determined by three factors: the amount of Ahr in any given cell, the abundance and potency of Ahr ligands within certain tissues, and the tissue microenvironment wherein Ahr+ cells reside. This complexity emphasizes the necessity cell-type specific genetic approaches towards the study of Ahr function. PMID:26700314

Widespread immunological functions of mast cells: fact or fiction?

PubMed

Rodewald, Hans-Reimer; Feyerabend, Thorsten B

2012-07-27

Immunological functions of mast cells are currently considered to be much broader than the original role of mast cells in IgE-driven allergic disease. The spectrum of proposed mast cell functions includes areas as diverse as the regulation of innate and adaptive immune responses, protective immunity against viral, microbial, and parasitic pathogens, autoimmunity, tolerance to graft rejection, promotion of or protection from cancer, wound healing, angiogenesis, cardiovascular diseases, diabetes, obesity, and others. The vast majority of in vivo mast cell data have been based on mast cell-deficient Kit mutant mice. However, work in new mouse mutants with unperturbed Kit function, which have a surprisingly normal immune system, has failed to corroborate some key immunological aspects, formerly attributed to mast cells. Here, we consider the implications of these recent developments for the state of the field as well as for future work, aiming at deciphering the physiological functions of mast cells. Copyright © 2012 Elsevier Inc. All rights reserved.

Functional analysis of HPV-like particle-activated Langerhans cells in vitro.

PubMed

Yan, Lisa; Woodham, Andrew W; Da Silva, Diane M; Kast, W Martin

2015-01-01

Langerhans cells (LCs) are antigen-presenting cells responsible for initiating an immune response against human papillomaviruses (HPVs) entering the epithelial layer in vivo as they are the first immune cell that HPV comes into contact with. LCs become activated in response to foreign antigens, which causes internal signaling resulting in the increased expression of co-stimulatory molecules and the secretion of inflammatory cytokines. Functionally activated LCs are then capable of migrating to the lymph nodes where they interact with antigen-specific T cells and initiate an adaptive T-cell response in vivo. However, HPV has evolved in a manner that suppresses LC function, and thus the induction of antigen-specific T cells is hindered. While many methods exist to monitor the activity of LCs in vitro, the migration and induction of cytotoxic T cells is ultimately indicative of a functional immune response. Here, methods in analyzing functional migration and induction of antigen-specific T cells after stimulation of LCs with HPV virus-like particles in vitro are described.

Developmental Bisphenol A Exposure Modulates Immune-Related Diseases

PubMed Central

Xu, Joella; Huang, Guannan; Guo, Tai L.

2016-01-01

Bisphenol A (BPA), used in polycarbonate plastics and epoxy resins, has a widespread exposure to humans. BPA is of concern for developmental exposure resulting in immunomodulation and disease development due to its ability to cross the placental barrier and presence in breast milk. BPA can use various mechanisms to modulate the immune system and affect diseases, including agonistic and antagonistic effects on many receptors (e.g., estrogen receptors), epigenetic modifications, acting on cell signaling pathways and, likely, the gut microbiome. Immune cell populations and function from the innate and adaptive immune system are altered by developmental BPA exposure, including decreased T regulatory (Treg) cells and upregulated pro- and anti-inflammatory cytokines and chemokines. Developmental BPA exposure can also contribute to the development of type 2 diabetes mellitus, allergy, asthma and mammary cancer disease by altering immune function. Multiple sclerosis and type 1 diabetes mellitus may also be exacerbated by BPA, although more research is needed. Additionally, BPA analogs, such as bisphenol S (BPS), have been increasing in use, and currently, little is known about their immune effects. Therefore, more studies should be conducted to determine if developmental exposure BPA and its analogs modulate immune responses and lead to immune-related diseases. PMID:29051427

Developmental Bisphenol A Exposure Modulates Immune-Related Diseases.

PubMed

Xu, Joella; Huang, Guannan; Guo, Tai L

2016-09-26

Bisphenol A (BPA), used in polycarbonate plastics and epoxy resins, has a widespread exposure to humans. BPA is of concern for developmental exposure resulting in immunomodulation and disease development due to its ability to cross the placental barrier and presence in breast milk. BPA can use various mechanisms to modulate the immune system and affect diseases, including agonistic and antagonistic effects on many receptors (e.g., estrogen receptors), epigenetic modifications, acting on cell signaling pathways and, likely, the gut microbiome. Immune cell populations and function from the innate and adaptive immune system are altered by developmental BPA exposure, including decreased T regulatory (Treg) cells and upregulated pro- and anti-inflammatory cytokines and chemokines. Developmental BPA exposure can also contribute to the development of type 2 diabetes mellitus, allergy, asthma and mammary cancer disease by altering immune function. Multiple sclerosis and type 1 diabetes mellitus may also be exacerbated by BPA, although more research is needed. Additionally, BPA analogs, such as bisphenol S (BPS), have been increasing in use, and currently, little is known about their immune effects. Therefore, more studies should be conducted to determine if developmental exposure BPA and its analogs modulate immune responses and lead to immune-related diseases.

[The adaptive pharmacological correction of functional disorders in young recruits with hypotrophy].

PubMed

Buchnov, A D; Grechko, A T; Murga, Ia T

2000-04-01

Low level of physical development, physiologic reserves, signs of psychical disadaptation, frequent functional disorders in cardiovascular system and gastrointestinal tract are noted in recruits with hypotrophy. Using of rapidly acting adaptogenes during 1 month (phytopreparation elixir "Altai" and "Vitavis" in tablets) significantly improves body state: increase in the level of physiologic reserves, physical working capacity, IMT, body unspecific resistance; improvement in indices of hemodynamics, metabolism and immunity; decrease in asthenization and psychical disadaptation. The state of adaptation and increased resistance in this recruit group remains during the following months of service.

Innate and adaptive immunity at Mucosal Surfaces of the Female Reproductive Tract: Stratification and Integration of Immune Protection against the Transmission of Sexually Transmitted Infections

PubMed Central

Hickey, DK; Patel, MV; Fahey, JV; Wira, CR

2011-01-01

This review examines the multiple levels of pre-existing immunity in the upper and lower female reproductive tract. In addition, we highlight the need for further research of innate and adaptive immune protection of mucosal surfaces in the female reproductive tract. Innate mechanisms include the mucus lining, a tight epithelial barrier and the secretion of antimicrobial peptides and cytokines by epithelial and innate immune cells. Stimulation of the innate immune system also serves to bridge the adaptive arm resulting in the generation of pathogen-specific humoral and cell-mediated immunity. Less understood are the multiple components that act in a coordinated way to provide a network of ongoing protection. Innate and adaptive immunity in the human female reproductive tract are influenced by the stage of menstrual cycle and are directly regulated by the sex steroid hormones, progesterone and estradiol. Furthermore, the effect of hormones on immunity is mediated both directly on immune and epithelial cells and indirectly by stimulating growth factor secretion from stromal cells. The goal of this review is to focus on the diverse aspects of the innate and adaptive immune systems that contribute to a unique network of protection throughout the female reproductive tract. PMID:21353708

Qa-1/HLA-E-restricted regulatory CD8+ T cells and self-nonself discrimination: an essay on peripheral T-cell regulation.

PubMed

Jiang, Hong; Chess, Leonard

2008-11-01

By discriminating self from nonself and controlling the magnitude and class of immune responses, the immune system mounts effective immunity against virtually any foreign antigens but avoids harmful immune responses to self. These are two equally important and related but distinct processes, which function in concert to ensure an optimal function of the immune system. Immunologically relevant clinical problems often occur because of failure of either process, especially the former. Currently, there is no unified conceptual framework to characterize the precise relationship between thymic negative selection and peripheral immune regulation, which is the basis for understanding self-non-self discrimination versus control of magnitude and class of immune responses. In this article, we explore a novel hypothesis of how the immune system discriminates self from nonself in the periphery during adaptive immunity. This hypothesis permits rational analysis of various seemingly unrelated biomedical problems inherent in immunologic disorders that cannot be uniformly interpreted by any currently existing paradigms. The proposed hypothesis is based on a unified conceptual framework of the "avidity model of peripheral T-cell regulation" that we originally proposed and tested, in both basic and clinical immunology, to understand how the immune system achieves self-nonself discrimination in the periphery.

Collaborating with the enemy: function of macrophages in the development of neoplastic disease.

PubMed

Eljaszewicz, Andrzej; Wiese, Małgorzata; Helmin-Basa, Anna; Jankowski, Michal; Gackowska, Lidia; Kubiszewska, Izabela; Kaszewski, Wojciech; Michalkiewicz, Jacek; Zegarski, Wojciech

2013-01-01

Due to the profile of released mediators (such as cytokines, chemokines, growth factors, etc.), neoplastic cells modulate the activity of immune system, directly affecting its components both locally and peripherally. This is reflected by the limited antineoplastic activity of the immune system (immunosuppressive effect), induction of tolerance to neoplastic antigens, and the promotion of processes associated with the proliferation of neoplastic tissue. Most of these responses are macrophages dependent, since these cells show proangiogenic properties, attenuate the adaptive response (anergization of naïve T lymphocytes, induction of Treg cell formation, polarization of immune response towards Th2, etc.), and support invasion and metastases formation. Tumor-associated macrophages (TAMs), a predominant component of leukocytic infiltrate, "cooperate" with the neoplastic tissue, leading to the intensified proliferation and the immune escape of the latter. This paper characterizes the function of macrophages in the development of neoplastic disease.

Role of T Cells in Malnutrition and Obesity

PubMed Central

Gerriets, Valerie A.; MacIver, Nancie J.

2014-01-01

Nutritional status is critically important for immune cell function. While obesity is characterized by inflammation that promotes metabolic syndrome including cardiovascular disease and insulin resistance, malnutrition can result in immune cell defects and increased risk of mortality from infectious diseases. T cells play an important role in the immune adaptation to both obesity and malnutrition. T cells in obesity have been shown to have an early and critical role in inducing inflammation, accompanying the accumulation of inflammatory macrophages in obese adipose tissue, which are known to promote insulin resistance. How T cells are recruited to adipose tissue and activated in obesity is a topic of considerable interest. Conversely, T cell number is decreased in malnourished individuals, and T cells in the setting of malnutrition have decreased effector function and proliferative capacity. The adipokine leptin, which is secreted in proportion to adipocyte mass, may have a key role in mediating adipocyte-T cell interactions in both obesity and malnutrition, and has been shown to promote effector T cell function and metabolism while inhibiting regulatory T cell proliferation. Additionally, key molecular signals are involved in T cell metabolic adaptation during nutrient stress; among them, the metabolic regulator AMP kinase and the mammalian target of rapamycin have critical roles in regulating T cell number, function, and metabolism. In summary, understanding how T cell number and function are altered in obesity and malnutrition will lead to better understanding of and treatment for diseases where nutritional status determines clinical outcome. PMID:25157251

Age-related changes in expression and function of Toll-like receptors in human skin

PubMed Central

Iram, Nousheen; Mildner, Michael; Prior, Marion; Petzelbauer, Peter; Fiala, Christian; Hacker, Stefan; Schöppl, Alice; Tschachler, Erwin; Elbe-Bürger, Adelheid

2012-01-01

Toll-like receptors (TLRs) initiate innate immune responses and direct subsequent adaptive immunity. They play a major role in cutaneous host defense against micro-organisms and in the pathophysiology of several inflammatory skin diseases. To understand the role of TLRs in the acquisition of immunological competence, we conducted a comprehensive study to evaluate TLR expression and function in the developing human skin before and after birth and compared it with adults. We found that prenatal skin already expresses the same spectrum of TLRs as adult skin. Strikingly, many TLRs were significantly higher expressed in prenatal (TLRs 1-5) and infant and child (TLRs 1 and 3) skin than in adult skin. Surprisingly, neither dendritic cell precursors in prenatal skin nor epidermal Langerhans cells and dermal dendritic cells in adult skin expressed TLRs 3 and 6, whereas the staining pattern and intensity of both TLRs in fetal basal keratinocytes was almost comparable to those of adults. Stimulation of primary human keratinocytes from fetal, neonatal and adult donors with selected TLR agonists revealed that the synthetic TLR3 ligand poly (I:C) specifically, mimicking viral double-stranded RNA, induced a significantly enhanced secretion of CXCL8/IL8, CXCL10/IP-10 and TNFα in fetal and neonatal keratinocytes compared with adult keratinocytes. This study demonstrates quantitative age-specific modifications in TLR expression and innate skin immune reactivity in response to TLR activation. Thus, antiviral innate immunity already in prenatal skin may contribute to protect the developing human body from viral infections in utero in a scenario where the adaptive immune system is not yet fully functional. PMID:23034637

Dendritic Cells: A Spot on Sialic Acid

PubMed Central

Crespo, Hélio J.; Lau, Joseph T. Y.; Videira, Paula A.

2013-01-01

Glycans decorating cell surface and secreted proteins and lipids occupy the juncture where critical host–host and host-pathogen interactions occur. The role of glycan epitopes in cell–cell and cell-pathogen adhesive events is already well-established, and cell surface glycan structures change rapidly in response to stimulus and inflammatory cues. Despite the wide acceptance that glycans are centrally implicated in immunity, exactly how glycans and their changes contribute to the overall immune response remains poorly defined. Sialic acids are unique sugars that usually occupy the terminal position of the glycan chains and may be modified by external factors, such as pathogens, or upon specific physiological cellular events. At cell surface, sialic acid-modified structures form the key fundamental determinants for a number of receptors with known involvement in cellular adhesiveness and cell trafficking, such as the Selectins and the Siglec families of carbohydrate recognizing receptors. Dendritic cells (DCs) preside over the transition from innate to the adaptive immune repertoires, and no other cell has such relevant role in antigen screening, uptake, and its presentation to lymphocytes, ultimately triggering the adaptive immune response. Interestingly, sialic acid-modified structures are involved in all DC functions, such as antigen uptake, DC migration, and capacity to prime T cell responses. Sialic acid content changes along DC differentiation and activation and, while, not yet fully understood, these changes have important implications in DC functions. This review focuses on the developmental regulation of DC surface sialic acids and how manipulation of DC surface sialic acids can affect immune-critical DC functions by altering antigen endocytosis, pathogen and tumor cell recognition, cell recruitment, and capacity for T cell priming. The existing evidence points to a potential of DC surface sialylation as a therapeutic target to improve and diversify DC-based therapies. PMID:24409183

Cytokine and cytokine receptor genes of adaptive immune response are differentially associated with breast cancer risk in American women of African and European ancestry

PubMed Central

Quan, Lei; Gong, Zhihong; Yao, Song; Bandera, Elisa V.; Zirpoli, Gary; Hwang, Helena; Roberts, Michelle; Ciupak, Gregory; Davis, Warren; Sucheston, Lara; Pawlish, Karen; Bovbjerg, Dana H.; Jandorf, Lina; Cabasag, Citadel; Coignet, Jean-Gabriel; Ambrosone, Christine B.; Hong, Chi-Chen

2014-01-01

Disparities in breast cancer biology are evident between American women of African ancestry (AA) and European ancestry (EA), and may be due, in part, to differences in immune function. To assess the potential role of constitutional host immunity on breast carcinogenesis, we tested associations between breast cancer risk and 47 single nucleotide polymorphisms (SNPs) in 26 cytokine-related genes of the adaptive immune system using 650 EA (n=335 cases) and 864 AA (n=458 cases) women from the Women's Circle of Health Study (WCHS). With additional participant accrual to the WCHS, promising SNPs from the initial analysis were evaluated in a larger sample size (1307 EAs and 1365 AAs). Multivariate logistic regression found SNPs in genes important for T helper type 1 (Th1) immunity (IFNGR2 rs1059293, IL15RA rs2296135, LTA rs1041981), Th2 immunity (IL4R rs1801275), and T regulatory cell-mediated immunosuppression (TGFB1 rs1800469), associated with breast cancer risk, mainly among AAs. The combined effect of these five SNPs was highly significant among AAs (P-trend=0.0005). When stratified by estrogen receptor (ER) status, LTA rs1041981 was associated with ER positive breast cancers among EAs and marginally among AAs. Among AA women only, IL15 rs10833 and IL15RA rs2296135 were associated with ER positive tumors, and IL12RB1 rs375947, IL15 rs10833 and TGFB1 rs1800469 were associated with ER negative tumors. Our study systematically identified genetic variants in the adaptive immune response pathway associated with breast cancer risk, which appears to differ by ancestry groups, menopausal status and ER status. PMID:23996684

Tumor-Associated Neutrophils in Human Lung Cancer

DTIC Science & Technology

2017-10-01

tumor inflammation, anti-tumor neutrophils, anti-tumor innate immune response. anti-tumor adaptive immune response, neutrophil and T cell interaction...Ottonello, 1992; van Egmond and Bakema, 2013) and by producing factors to recruit and acti- vate cells of the innate and adaptive immune system...dependent cell -mediated cytotoxicity (ADCC) [16], (iii) produce factors to recruit and activate cells of the innate and adaptive immune systems [17], and

Reciprocal Interactions of the Intestinal Microbiota and Immune System

PubMed Central

Maynard, Craig L.; Elson, Charles O.; Hatton, Robin D.; Weaver, Casey T.

2013-01-01

Preface Emergence of the adaptive immune system in vertebrates set the stage for evolution of an advanced symbiotic relationship with the intestinal microbiota. The defining features of specificity and memory that characterize adaptive immunity have afforded vertebrates mechanisms for efficiently tailoring immune responses to diverse types of microbes, whether to promote mutualism or host defense. These same attributes carry risk for immune-mediated diseases that are increasingly linked to the intestinal microbiota. Understanding how the adaptive immune system copes with the remarkable number and diversity of microbes that colonize the digestive tract, and how it integrates with more primitive innate immune mechanisms to maintain immune homeostasis, holds considerable promise for new approaches to modulate immune networks in order to treat and prevent disease. PMID:22972296

Interactions of the innate and adaptive arms of the immune system in the pathogenesis of spondyloarthritis

PubMed Central

Stoll, Matthew L

2011-01-01

The immune system can be divided into the innate and adaptive arms. Historically, most of the research into the pathogenesis of spondyloarthritis (SpA) and other types of chronic arthritis focused on the adaptive immune system. Recently, the pendulum has shifted, and much current work in SpA focuses on innate immunity. Herein, I summarize evidence demonstrating that both the innate and the adaptive arms of the immune system are involved in the pathogenesis of SpA, propose a mechanism in which both arms interact to maintain chronic arthritis, and discuss potential research directions. PMID:21269576

Alcohol, aging, and innate immunity.

PubMed

Boule, Lisbeth A; Kovacs, Elizabeth J

2017-07-01

The global population is aging: in 2010, 8% of the population was older than 65 y, and that is expected to double to 16% by 2050. With advanced age comes a heightened prevalence of chronic diseases. Moreover, elderly humans fair worse after acute diseases, namely infection, leading to higher rates of infection-mediated mortality. Advanced age alters many aspects of both the innate and adaptive immune systems, leading to impaired responses to primary infection and poor development of immunologic memory. An often overlooked, yet increasingly common, behavior in older individuals is alcohol consumption. In fact, it has been estimated that >40% of older adults consume alcohol, and evidence reveals that >10% of this group is drinking more than the recommended limit by the National Institute on Alcohol Abuse and Alcoholism. Alcohol consumption, at any level, alters host immune responses, including changes in the number, phenotype, and function of innate and adaptive immune cells. Thus, understanding the effect of alcohol ingestion on the immune system of older individuals, who are already less capable of combating infection, merits further study. However, there is currently almost nothing known about how drinking alters innate immunity in older subjects, despite innate immune cells being critical for host defense, resolution of inflammation, and maintenance of immune homeostasis. Here, we review the effects of aging and alcohol consumption on innate immune cells independently and highlight the few studies that have examined the effects of alcohol ingestion in aged individuals. © Society for Leukocyte Biology.

The innate and adaptive immune response to avian influenza virus

USDA-ARS?s Scientific Manuscript database

Protective immunity against viruses is mediated by the early innate immune responses and later on by the adaptive immune responses. The early innate immunity is designed to contain and limit virus replication in the host, primarily through cytokine and interferon production. Most all cells are cap...

MyD88-deficient Hydra reveal an ancient function of TLR signaling in sensing bacterial colonizers

PubMed Central

Franzenburg, Sören; Fraune, Sebastian; Künzel, Sven; Baines, John F.; Domazet-Lošo, Tomislav; Bosch, Thomas C. G.

2012-01-01

Toll-like receptor (TLR) signaling is one of the most important signaling cascades of the innate immune system of vertebrates. Studies in invertebrates have focused on the fruit fly Drosophila melanogaster and the nematode Caenorhabditis elegans, and there is little information regarding the evolutionary origin and ancestral function of TLR signaling. In Drosophila, members of the Toll-like receptor family are involved in both embryonic development and innate immunity. In C. elegans, a clear immune function of the TLR homolog TOL-1 is controversial and central components of vertebrate TLR signaling including the key adapter protein myeloid differentiation primary response gene 88 (MyD88) and the transcription factor NF-κB are not present. In basal metazoans such as the cnidarians Hydra magnipapillata and Nematostella vectensis, all components of the vertebrate TLR signaling cascade are present, but their role in immunity is unknown. Here, we use a MyD88 loss-of-function approach in Hydra to demonstrate that recognition of bacteria is an ancestral function of TLR signaling and that this process contributes to both host-mediated recolonization by commensal bacteria as well as to defense against bacterial pathogens. PMID:23112184

MyD88-deficient Hydra reveal an ancient function of TLR signaling in sensing bacterial colonizers.

PubMed

Franzenburg, Sören; Fraune, Sebastian; Künzel, Sven; Baines, John F; Domazet-Loso, Tomislav; Bosch, Thomas C G

2012-11-20

Toll-like receptor (TLR) signaling is one of the most important signaling cascades of the innate immune system of vertebrates. Studies in invertebrates have focused on the fruit fly Drosophila melanogaster and the nematode Caenorhabditis elegans, and there is little information regarding the evolutionary origin and ancestral function of TLR signaling. In Drosophila, members of the Toll-like receptor family are involved in both embryonic development and innate immunity. In C. elegans, a clear immune function of the TLR homolog TOL-1 is controversial and central components of vertebrate TLR signaling including the key adapter protein myeloid differentiation primary response gene 88 (MyD88) and the transcription factor NF-κB are not present. In basal metazoans such as the cnidarians Hydra magnipapillata and Nematostella vectensis, all components of the vertebrate TLR signaling cascade are present, but their role in immunity is unknown. Here, we use a MyD88 loss-of-function approach in Hydra to demonstrate that recognition of bacteria is an ancestral function of TLR signaling and that this process contributes to both host-mediated recolonization by commensal bacteria as well as to defense against bacterial pathogens.

The Transcription Factor EB Links Cellular Stress to the Immune Response



PubMed Central

Nabar, Neel R.; Kehrl, John H.

2017-01-01

The transcription factor EB (TFEB) is the master transcriptional regulator of autophagy and lysosome biogenesis. Recent advances have led to a paradigm shift in our understanding of lysosomes from a housekeeping cellular waste bin to a dynamically regulated pathway that is efficiently turned up or down based on cellular needs. TFEB coordinates the cellular response to nutrient deprivation and other forms of cell stress through the lysosome system, and regulates a myriad of cellular processes associated with this system including endocytosis, phagocytosis, autophagy, and lysosomal exocytosis. Autophagy and the endolysosomal system are critical to both the innate and adaptive arms of the immune system, with functions in effector cell priming and direct pathogen clearance. Recent studies have linked TFEB to the regulation of the immune response through the endolysosmal pathway and by direct transcriptional activation of immune related genes. In this review, we discuss the current understanding of TFEB’s function and the molecular mechanisms behind TFEB activation. Finally, we discuss recent advances linking TFEB to the immune response that positions lysosomal signaling as a potential target for immune modulation. PMID:28656016

The Transcription Factor EB Links Cellular Stress to the Immune Response

.

PubMed

Nabar, Neel R; Kehrl, John H

2017-06-01

The transcription factor EB (TFEB) is the master transcriptional regulator of autophagy and lysosome biogenesis. Recent advances have led to a paradigm shift in our understanding of lysosomes from a housekeeping cellular waste bin to a dynamically regulated pathway that is efficiently turned up or down based on cellular needs. TFEB coordinates the cellular response to nutrient deprivation and other forms of cell stress through the lysosome system, and regulates a myriad of cellular processes associated with this system including endocytosis, phagocytosis, autophagy, and lysosomal exocytosis. Autophagy and the endolysosomal system are critical to both the innate and adaptive arms of the immune system, with functions in effector cell priming and direct pathogen clearance. Recent studies have linked TFEB to the regulation of the immune response through the endolysosmal pathway and by direct transcriptional activation of immune related genes. In this review, we discuss the current understanding of TFEB's function and the molecular mechanisms behind TFEB activation. Finally, we discuss recent advances linking TFEB to the immune response that positions lysosomal signaling as a potential target for immune modulation.

A correlate of HIV-1 control consisting of both innate and adaptive immune parameters best predicts viral load by multivariable analysis in HIV-1 infected viremic controllers and chronically-infected non-controllers.

PubMed

Tomescu, Costin; Liu, Qin; Ross, Brian N; Yin, Xiangfan; Lynn, Kenneth; Mounzer, Karam C; Kostman, Jay R; Montaner, Luis J

2014-01-01

HIV-1 infected viremic controllers maintain durable viral suppression below 2000 copies viral RNA/ml without anti-retroviral therapy (ART), and the immunological factor(s) associated with host control in presence of low but detectable viral replication are of considerable interest. Here, we utilized a multivariable analysis to identify which innate and adaptive immune parameters best correlated with viral control utilizing a cohort of viremic controllers (median 704 viral RNA/ml) and non-controllers (median 21,932 viral RNA/ml) that were matched for similar CD4+ T cell counts in the absence of ART. We observed that HIV-1 Gag-specific CD8+ T cell responses were preferentially targeted over Pol-specific responses in viremic controllers (p = 0.0137), while Pol-specific responses were positively associated with viral load (rho = 0.7753, p = 0.0001, n = 23). Viremic controllers exhibited significantly higher NK and plasmacytoid dendritic cells (pDC) frequency as well as retained expression of the NK CD16 receptor and strong target cell-induced NK cell IFN-gamma production compared to non-controllers (p<0.05). Despite differences in innate and adaptive immune function however, both viremic controllers (p<0.05) and non-controller subjects (p<0.001) exhibited significantly increased CD8+ T cell activation and spontaneous NK cell degranulation compared to uninfected donors. Overall, we identified that a combination of innate (pDC frequency) and adaptive (Pol-specific CD8+ T cell responses) immune parameters best predicted viral load (R2 = 0.5864, p = 0.0021, n = 17) by a multivariable analysis. Together, this data indicates that preferential Gag-specific over Pol-specific CD8+ T cell responses along with a retention of functional innate subsets best predict host control over viral replication in HIV-1 infected viremic controllers compared to chronically-infected non-controllers.

Regulation of immunity and inflammation by hypoxia in immunological niches.

PubMed

Taylor, Cormac T; Colgan, Sean P

2017-12-01

Immunological niches are focal sites of immune activity that can have varying microenvironmental features. Hypoxia is a feature of physiological and pathological immunological niches. The impact of hypoxia on immunity and inflammation can vary depending on the microenvironment and immune processes occurring in a given niche. In physiological immunological niches, such as the bone marrow, lymphoid tissue, placenta and intestinal mucosa, physiological hypoxia controls innate and adaptive immunity by modulating immune cell proliferation, development and effector function, largely via transcriptional changes driven by hypoxia-inducible factor (HIF). By contrast, in pathological immunological niches, such as tumours and chronically inflamed, infected or ischaemic tissues, pathological hypoxia can drive tissue dysfunction and disease development through immune cell dysregulation. Here, we differentiate between the effects of physiological and pathological hypoxia on immune cells and the consequences for immunity and inflammation in different immunological niches. Furthermore, we discuss the possibility of targeting hypoxia-sensitive pathways in immune cells for the treatment of inflammatory disease.

Brain–immune interactions and the neural basis of disease-avoidant ingestive behaviour

PubMed Central

Pacheco-López, Gustavo; Bermúdez-Rattoni, Federico

2011-01-01

Neuro–immune interactions are widely manifested in animal physiology. Since immunity competes for energy with other physiological functions, it is subject to a circadian trade-off between other energy-demanding processes, such as neural activity, locomotion and thermoregulation. When immunity is challenged, this trade-off is tilted to an adaptive energy protecting and reallocation strategy that is identified as ‘sickness behaviour’. We review diverse disease-avoidant behaviours in the context of ingestion, indicating that several adaptive advantages have been acquired by animals (including humans) during phylogenetic evolution and by ontogenetic experiences: (i) preventing waste of energy by reducing appetite and consequently foraging/hunting (illness anorexia), (ii) avoiding unnecessary danger by promoting safe environments (preventing disease encounter by olfactory cues and illness potentiation neophobia), (iii) help fighting against pathogenic threats (hyperthermia/somnolence), and (iv) by associative learning evading specific foods or environments signalling danger (conditioned taste avoidance/aversion) and/or at the same time preparing the body to counteract by anticipatory immune responses (conditioning immunomodulation). The neurobiology behind disease-avoidant ingestive behaviours is reviewed with special emphasis on the body energy balance (intake versus expenditure) and an evolutionary psychology perspective. PMID:22042916

Active hexose correlated compound enhances tumor surveillance through regulating both innate and adaptive immune responses.

PubMed

Gao, Yunfei; Zhang, Dongqing; Sun, Buxiang; Fujii, Hajime; Kosuna, Ken-Ichi; Yin, Zhinan

2006-10-01

Active hexose correlated compound (AHCC) is a mixture of polysaccharides, amino acids, lipids and minerals derived from cocultured mycelia of several species of Basidiomycete mushrooms. AHCC has been implicated to modulate immune functions and plays a protective role against infection. However, the potential role of AHCC in tumor immune surveillance is unknown. In this study, C57BL/6 mice were orally administered AHCC or water, followed by tumor cell inoculation. We showed that compared to pure water-treated mice, AHCC treatment significantly delayed tumor development after inoculation of either melanoma cell line B16F0 or lymphoma cell line EL4. Treatment with AHCC enhanced both Ag-specific activation and proliferation of CD4(+) and CD8(+) T cells, increased the number of tumor Ag-specific CD8(+) T cells, and more importantly, increased the frequency of tumor Ag-specific IFN-gamma producing CD8(+) T cells. Interestingly, AHCC treatment also showed increased cell number of NK and gammadelta T cells, indicating the role of AHCC in activating these innate-like lymphocytes. In summary, our results demonstrate that AHCC can enhance tumor immune surveillance through regulating both innate and adaptive immune responses.

Basic science for the clinician 53: mast cells.

PubMed

Sigal, Leonard H

2011-10-01

Mast cells stand at the interface between the innate immune system and the acquired (adaptive) immune response, serving as sentinels detecting invaders and directing a concerted and coordinated response. Mast cells reside immediately under body surfaces and within lymph nodes, near blood vessels and nerves, perfectly situated to for early detection and defense. They secrete a wide array of prostanoids, cytokines, chemokines, and other proteins mediators and modifiers of a variety of immune and inflammatory functions and bear surface markers suggesting broad functions, including as antigen-presenting cells. Although usually not given their due in medical school lectures, there is great likelihood that mast cells will be implicated in the pathogenesis of rheumatoid arthritis, scleroderma, multiple sclerosis, and perhaps cancer. Thus, better insights into mast cell functions and mast cell-derived effector molecules should command our attention as we move forward in better understanding disease immunopathogenesis and directed intelligent therapeutics development.

The SYK tyrosine kinase: a crucial player in diverse biological functions

PubMed Central

Mócsai, Attila; Ruland, Jürgen; Tybulewicz, Victor L. J.

2016-01-01

Spleen tyrosine kinase (SYK) has been known to relay adaptive immune receptor signalling. However, recent reports indicate that SYK also mediates other, unexpectedly diverse biological functions including cellular adhesion, innate immune recognition, osteoclast maturation, platelet activation and vascular development. SYK is activated by C-type lectins and integrins, and activates novel targets including the CARD9/CARMA1–BCL10–MALT1 pathway and the NLRP3 inflammasome. Drosophila studies indicate evolutionary ancient origin of SYK-mediated signalling. Moreover, SYK has a crucial role in autoimmune diseases and haematological malignancies. This Review summarizes our current understanding of SYK functions and the translation of this knowledge for therapeutic purposes. PMID:20467426

Autophagy in immunity and inflammation

PubMed Central

Levine, Beth; Mizushima, Noboru; Virgin, Herbert W.

2011-01-01

Autophagy is an essential, homeostatic process by which cells break down their own components. Perhaps the most primordial function of this lysosomal degradation pathway is adaptation to nutrient deprivation. However, in complex multicellular organisms, the core molecular machinery of autophagy — the ‘autophagy proteins’ — orchestrates diverse aspects of cellular and organismal responses to other dangerous stimuli such as infection. Recent developments reveal a crucial role for the autophagy pathway and proteins in immunity and inflammation. They balance the beneficial and detrimental effects of immunity and inflammation, and thereby may protect against infectious, autoimmune and inflammatory diseases. PMID:21248839

Graft-versus-host disease: regulation by microbe-associated molecules and innate immune receptors.

PubMed

Penack, Olaf; Holler, Ernst; van den Brink, Marcel R M

2010-03-11

Acute graft-versus-host disease (GVHD) remains the major obstacle to a more favorable therapeutic outcome of allogeneic hematopoietic stem cell transplantation (HSCT). GVHD is characterized by tissue damage in gut, liver, and skin, caused by donor T cells that are critical for antitumor and antimicrobial immunity after HSCT. One obstacle in combating GVHD used to be the lack of understanding the molecular mechanisms that are involved in the initiation phase of this syndrome. Recent research has demonstrated that interactions between microbial-associated molecules (pathogen-associated molecular patterns [PAMPs]) and innate immune receptors (pathogen recognition receptors [PRRs]), such as NOD-like receptors (NLRs) and Toll-like receptors (TLRs), control adaptive immune responses in inflammatory disorders. Polymorphisms of the genes encoding NOD2 and TLR4 are associated with a higher incidence of GVHD in HSC transplant recipients. Interestingly, NOD2 regulates GVHD through its inhibitory effect on antigen-presenting cell (APC) function. These insights identify important mechanisms regarding the induction of GVHD through the interplay of microbial molecules and innate immunity, thus opening a new area for future therapeutic approaches. This review covers current knowledge of the role of PAMPs and PRRs in the control of adaptive immune responses during inflammatory diseases, particularly GVHD.

Cross-presentation of IgG-containing immune complexes

PubMed Central

Baker, Kristi; Rath, Timo; Lencer, Wayne I.; Fiebiger, Edda

2012-01-01

IgG is a molecule that functionally combines facets of both innate and adaptive immunity and therefore bridges both arms of the immune system. On the one hand, IgG is created by adaptive immune cells, but can be generated by B cells independently of T cell help. On the other hand, once secreted, IgG can rapidly deliver antigens into intracellular processing pathways, which enable efficient priming of T cell responses towards epitopes from the cognate antigen initially bound by the IgG. While this process has long been known to participate in CD4+ T cell activation, IgG-mediated delivery of exogenous antigens into a major histocompatibility complex (MHC) class I processing pathway has received less attention. The coordinated engagement of IgG with IgG receptors expressed on the cell-surface (FcγR) and within the endolysosomal system (FcRn) is a highly potent means to deliver antigen into processing pathways that promote cross-presentation of MHC class I and presentation of MHC class II-restricted epitopes within the same dendritic cell. This review focuses on the mechanisms by which IgG-containing immune complexes mediate such cross-presentation and the implications that this understanding has for manipulation of immune-mediated diseases that depend upon or are due to the activities of CD8+ T cells. PMID:22847331

Evolution of JAK-STAT Pathway Components: Mechanisms and Role in Immune System Development

PubMed Central

Liongue, Clifford; O'Sullivan, Lynda A.; Trengove, Monique C.; Ward, Alister C.

2012-01-01

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. PMID:22412924

Selenium Supplementation Restores Innate and Humoral Immune Responses in Footrot-Affected Sheep

PubMed Central

Hall, Jean A.; Vorachek, William R.; Stewart, Whitney C.; Gorman, M. Elena; Mosher, Wayne D.; Pirelli, Gene J.; Bobe, Gerd

2013-01-01

Dietary selenium (Se) alters whole-blood Se concentrations in sheep, dependent upon Se source and dosage administered, but little is known about effects on immune function. We used footrot (FR) as a disease model to test the effects of supranutritional Se supplementation on immune function. To determine the effect of Se-source (organic Se-yeast, inorganic Na-selenite or Na-selenate) and Se-dosage (1, 3, 5 times FDA-permitted level) on FR severity, 120 ewes with and 120 ewes without FR were drenched weekly for 62 weeks with different Se sources and dosages (30 ewes/treatment group). Innate immunity was evaluated after 62 weeks of supplementation by measuring neutrophil bacterial killing ability. Adaptive immune function was evaluated by immunizing sheep with keyhole limpet hemocyanin (KLH). The antibody titer and delayed-type hypersensitivity skin test to KLH were used to assess humoral immunity and cell-mediated immunity, respectively. At baseline, FR-affected ewes had lower whole-blood and serum-Se concentrations; this difference was not observed after Se supplementation. Se supplementation increased neutrophil bacterial killing percentages in FR-affected sheep to percentages observed in supplemented and non-supplemented healthy sheep. Similarly, Se supplementation increased KLH antibody titers in FR-affected sheep to titers observed in healthy sheep. FR-affected sheep demonstrated suppressed cell-mediated immunity at 24 hours after intradermal KLH challenge, although there was no improvement with Se supplementation. We did not consistently prevent nor improve recovery from FR over the 62 week Se-treatment period. In conclusion, Se supplementation does not prevent FR, but does restore innate and humoral immune functions negatively affected by FR. PMID:24340044

Dual RNA-seq reveals no plastic transcriptional response of the coccidian parasite Eimeria falciformis to host immune defenses.

PubMed

Ehret, Totta; Spork, Simone; Dieterich, Christoph; Lucius, Richard; Heitlinger, Emanuel

2017-09-05

Parasites can either respond to differences in immune defenses that exist between individual hosts plastically or, alternatively, follow a genetically canalized ("hard wired") program of infection. Assuming that large-scale functional plasticity would be discernible in the parasite transcriptome we have performed a dual RNA-seq study of the lifecycle of Eimeria falciformis using infected mice with different immune status as models for coccidian infections. We compared parasite and host transcriptomes (dual transcriptome) between naïve and challenge infected mice, as well as between immune competent and immune deficient ones. Mice with different immune competence show transcriptional differences as well as differences in parasite reproduction (oocyst shedding). Broad gene categories represented by differently abundant host genes indicate enrichments for immune reaction and tissue repair functions. More specifically, TGF-beta, EGF, TNF and IL-1 and IL-6 are examples of functional annotations represented differently depending on host immune status. Much in contrast, parasite transcriptomes were neither different between Coccidia isolated from immune competent and immune deficient mice, nor between those harvested from naïve and challenge infected mice. Instead, parasite transcriptomes have distinct profiles early and late in infection, characterized largely by biosynthesis or motility associated functional gene groups, respectively. Extracellular sporozoite and oocyst stages showed distinct transcriptional profiles and sporozoite transcriptomes were found enriched for species specific genes and likely pathogenicity factors. We propose that the niche and host-specific parasite E. falciformis uses a genetically canalized program of infection. This program is likely fixed in an evolutionary process rather than employing phenotypic plasticity to interact with its host. This in turn might limit the potential of the parasite to adapt to new host species or niches, forcing it to coevolve with its host.

Mycobacterium tuberculosis Transfer RNA Induces IL-12p70 via Synergistic Activation of Pattern Recognition Receptors within a Cell Network.

PubMed

Keegan, Caroline; Krutzik, Stephan; Schenk, Mirjam; Scumpia, Philip O; Lu, Jing; Pang, Yan Ling Joy; Russell, Brandon S; Lim, Kok Seong; Shell, Scarlet; Prestwich, Erin; Su, Dan; Elashoff, David; Hershberg, Robert M; Bloom, Barry R; Belisle, John T; Fortune, Sarah; Dedon, Peter C; Pellegrini, Matteo; Modlin, Robert L

2018-05-01

Upon recognition of a microbial pathogen, the innate and adaptive immune systems are linked to generate a cell-mediated immune response against the foreign invader. The culture filtrate of Mycobacterium tuberculosis contains ligands, such as M. tuberculosis tRNA, that activate the innate immune response and secreted Ags recognized by T cells to drive adaptive immune responses. In this study, bioinformatics analysis of gene-expression profiles derived from human PBMCs treated with distinct microbial ligands identified a mycobacterial tRNA-induced innate immune network resulting in the robust production of IL-12p70, a cytokine required to instruct an adaptive Th1 response for host defense against intracellular bacteria. As validated by functional studies, this pathway contained a feed-forward loop, whereby the early production of IL-18, type I IFNs, and IL-12p70 primed NK cells to respond to IL-18 and produce IFN-γ, enhancing further production of IL-12p70. Mechanistically, tRNA activates TLR3 and TLR8, and this synergistic induction of IL-12p70 was recapitulated by the addition of a specific TLR8 agonist with a TLR3 ligand to PBMCs. These data indicate that M. tuberculosis tRNA activates a gene network involving the integration of multiple innate signals, including types I and II IFNs, as well as distinct cell types to induce IL-12p70. Copyright © 2018 by The American Association of Immunologists, Inc.

[Relationships between venomous function and innate immune function].

PubMed

Goyffon, Max; Saul, Frederick; Faure, Grazyna

2015-01-01

Venomous function is investigated in relation to innate immune function in two cases selected from scorpion venom and serpent venom. In the first case, structural analysis of scorpion toxins and defensins reveals a close interrelation between both functions (toxic and innate immune system function). In the second case, structural and functional studies of natural inhibitors of toxic snake venom phospholipases A2 reveal homology with components of the innate immune system, leading to a similar conclusion. Although there is a clear functional distinction between neurotoxins, which act by targeting membrane ion channels, and the circulating defensins which protect the organism from pathogens, the scorpion short toxins and defensins share a common protein folding scaffold with a conserved cysteine-stabilized alpha-beta motif of three disulfide bridges linking a short alpha helix and an antiparallel beta sheet. Genomic analysis suggests that these proteins share a common ancestor (long venom toxins were separated from an early gene family which gave rise to separate short toxin and defensin families). Furthermore, a scorpion toxin has been experimentally synthetized from an insect defensin, and an antibacterial scorpion peptide, androctonin (whose structure is similar to that of a cone snail venom toxin), was shown to have a similar high affinity for the postsynaptic acetylcholine receptor of Torpedo sp. Natural inhibitors of phospholipase A2 found in the blood of snakes are associated with the resistance of venomous snakes to their own highly neurotoxic venom proteins. Three classes of phospholipases A2 inhibitors (PLI-α, PLI-β, PLI-γ) have been identified. These inhibitors display diverse structural motifs related to innate immune proteins including carbohydrate recognition domains (CRD), leucine rich repeat domains (found in Toll-like receptors) and three finger domains, which clearly differentiate them from components of the adaptive immune system. Thus, in structure, function and phylogeny, venomous function in both vertebrates and invertebrates are clearly interrelated with innate immune function. © Société de Biologie, 2016.

Regulatory immune cells in regulation of intestinal inflammatory response to microbiota

PubMed Central

Cong, Y; Liu, Z

2015-01-01

The intestinal lumen harbors nearly 100 trillion commensal bacteria that exert crucial function for health. An elaborate balance between immune responses and tolerance to intestinal microbiota is required to maintain intestinal homeostasis. This process depends on diverse regulatory mechanisms, including both innate and adaptive immunity. Dysregulation of the homeostasis between intestinal immune systems and microbiota has been shown to be associated with the development of inflammatory bowel diseases (IBD) in genetically susceptible populations. In this review, we discuss the recent progress reported in studies of distinct types of regulatory immune cells in the gut, including intestinal intraepithelial lymphocytes, Foxp3+ regulatory T cells, regulatory B cells, alternatively activated macrophages, dendritic cells, and innate lymphoid cells, and how dysfunction of this immune regulatory system contributes to intestinal diseases such as IBD. Moreover, we discuss the manipulation of these regulatory immune cells as a potential therapeutic method for management of intestinal inflammatory disorders. PMID:26080708

Regulatory immune cells in regulation of intestinal inflammatory response to microbiota.

PubMed

Sun, M; He, C; Cong, Y; Liu, Z

2015-09-01

The intestinal lumen harbors nearly 100 trillion commensal bacteria that exert crucial function for health. An elaborate balance between immune responses and tolerance to intestinal microbiota is required to maintain intestinal homeostasis. This process depends on diverse regulatory mechanisms, including both innate and adaptive immunity. Dysregulation of the homeostasis between intestinal immune systems and microbiota has been shown to be associated with the development of inflammatory bowel diseases (IBD) in genetically susceptible populations. In this review, we discuss the recent progress reported in studies of distinct types of regulatory immune cells in the gut, including intestinal intraepithelial lymphocytes, Foxp3(+) regulatory T cells, regulatory B cells, alternatively activated macrophages, dendritic cells, and innate lymphoid cells, and how dysfunction of this immune regulatory system contributes to intestinal diseases such as IBD. Moreover, we discuss the manipulation of these regulatory immune cells as a potential therapeutic method for management of intestinal inflammatory disorders.

Plasmacytoid pre-dendritic cells (pDC): from molecular pathways to function and disease association.

PubMed

Alculumbre, Solana; Raieli, Salvatore; Hoffmann, Caroline; Chelbi, Rabie; Danlos, François-Xavier; Soumelis, Vassili

2018-02-19

Plasmacytoid pre-dendritic cells (pDC) are a specialized DC population with a great potential to produce large amounts of type I interferon (IFN). pDC are involved in the initiation of antiviral immune responses through their interaction with innate and adaptive immune cell populations. In a context-dependent manner, pDC activation can induce their differentiation into mature DC able to induce both T cell activation or tolerance. In this review, we described pDC functions during immune responses and their implication in the clearance or pathogenicity of human diseases during infection, autoimmunity, allergy and cancer. We discuss recent advances in the field of pDC biology and their implication for future studies. Copyright © 2018 Elsevier Ltd. All rights reserved.

Heat shock protein vaccines against glioblastoma: from bench to bedside.

PubMed

Ampie, Leonel; Choy, Winward; Lamano, Jonathan B; Fakurnejad, Shayan; Bloch, Orin; Parsa, Andrew T

2015-07-01

Current adjuvant treatment regimens available for the treatment of glioblastoma are widely ineffective and offer a dismal prognosis. Advancements in conventional treatment strategies have only yielded modest improvements in overall survival. Immunotherapy remains a promising adjuvant in the treatment of GBM through eliciting tumor specific immune responses capable of producing sustained antitumor response while minimizing systemic toxicity. Heat shock proteins (HSP) function as intracellular chaperones and have been implicated in the activation of both innate and adaptive immune systems. Vaccines formulated from HSP-peptide complexes, derived from autologous tumor, have been applied to the field of immunotherapy for glioblastoma. The results from the phase I and II clinical trials have been promising. Here we review the role of HSP in cellular function and immunity, and its application in the treatment of glioblastoma.

Regulation of Dendritic Cell Function in Inflammation.

PubMed

Said, André; Weindl, Günther

2015-01-01

Dendritic cells (DC) are professional antigen presenting cells and link the innate and adaptive immune system. During steady state immune surveillance in skin, DC act as sentinels against commensals and invading pathogens. Under pathological skin conditions, inflammatory cytokines, secreted by surrounding keratinocytes, dermal fibroblasts, and immune cells, influence the activation and maturation of different DC populations including Langerhans cells (LC) and dermal DC. In this review we address critical differences in human DC subtypes during inflammatory settings compared to steady state. We also highlight the functional characteristics of human DC subsets in inflammatory skin environments and skin diseases including psoriasis and atopic dermatitis. Understanding the complex immunoregulatory role of distinct DC subsets in inflamed human skin will be a key element in developing novel strategies in anti-inflammatory therapy.

The in Vitro Inhibitory Effect of Ectromelia Virus Infection on Innate and Adaptive Immune Properties of GM-CSF-Derived Bone Marrow Cells Is Mouse Strain-Independent.

PubMed

Szulc-Dąbrowska, Lidia; Struzik, Justyna; Cymerys, Joanna; Winnicka, Anna; Nowak, Zuzanna; Toka, Felix N; Gieryńska, Małgorzata

2017-01-01

Ectromelia virus (ECTV) belongs to the Orthopoxvirus genus of the Poxviridae family and is a natural pathogen of mice. Certain strains of mice are highly susceptible to ECTV infection and develop mousepox, a lethal disease similar to smallpox of humans caused by variola virus. Currently, the mousepox model is one of the available small animal models for investigating pathogenesis of generalized viral infections. Resistance and susceptibility to ECTV infection in mice are controlled by many genetic factors and are associated with multiple mechanisms of immune response, including preferential polarization of T helper (Th) immune response toward Th1 (protective) or Th2 (non-protective) profile. We hypothesized that viral-induced inhibitory effects on immune properties of conventional dendritic cells (cDCs) are more pronounced in ECTV-susceptible than in resistant mouse strains. To this extent, we confronted the cDCs from resistant (C57BL/6) and susceptible (BALB/c) mice with ECTV, regarding their reactivity and potential to drive T cell responses following infection. Our results showed that in vitro infection of granulocyte-macrophage colony-stimulating factor-derived bone marrow cells (GM-BM-comprised of cDCs and macrophages) from C57BL/6 and BALB/c mice similarly down-regulated multiple genes engaged in DC innate and adaptive immune functions, including antigen uptake, processing and presentation, chemokines and cytokines synthesis, and signal transduction. On the contrary, ECTV infection up-regulated Il10 in GM-BM derived from both strains of mice. Moreover, ECTV similarly inhibited surface expression of major histocompatibility complex and costimulatory molecules on GM-BM, explaining the inability of the cells to attain full maturation after Toll-like receptor (TLR)4 agonist treatment. Additionally, cells from both strains of mice failed to produce cytokines and chemokines engaged in T cell priming and Th1/Th2 polarization after TLR4 stimulation. These data strongly suggest that in vitro modulation of GM-BM innate and adaptive immune functions by ECTV occurs irrespective of whether the mouse strain is susceptible or resistant to infection. Moreover, ECTV limits the GM-BM (including cDCs) capacity to stimulate protective Th1 immune response. We cannot exclude that this may be an important factor in the generation of non-protective Th2 immune response in susceptible BALB/c mice in vivo .

Food allergy: separating the science from the mythology.

PubMed

Brandtzaeg, Per

2010-07-01

Numerous genes are involved in innate and adaptive immunity and these have been modified over millions of years. During this evolution, the mucosal immune system has developed two anti-inflammatory strategies: immune exclusion by the use of secretory antibodies to control epithelial colonization of microorganisms and to inhibit the penetration of potentially harmful agents; and immunosuppression to counteract local and peripheral hypersensitivity against innocuous antigens, such as food proteins. The latter strategy is called oral tolerance when induced via the gut. Homeostatic mechanisms also dampen immune responses to commensal bacteria. The mucosal epithelial barrier and immunoregulatory network are poorly developed in newborns. The perinatal period is, therefore, critical with regard to the induction of food allergy. The development of immune homeostasis depends on windows of opportunity during which innate and adaptive immunity are coordinated by antigen-presenting cells. The function of these cells is not only orchestrated by microbial products but also by dietary constituents, including vitamin A and lipids, such as polyunsaturated omega-3 fatty acids. These factors may in various ways exert beneficial effects on the immunophenotype of the infant. The same is true for breast milk, which provides immune-inducing factors and secretory immunoglobulin A, which reinforces the gut epithelial barrier. It is not easy to dissect the immunoregulatory network and identify variables that lead to food allergy. This Review discusses efforts to this end and outlines the scientific basis for future food allergy prevention.

Aryl Hydrocarbon Receptor Promotes RORγt+ ILCs and Controls Intestinal Immunity and Inflammation

PubMed Central

Qiu, Ju; Zhou, Liang

2013-01-01

Unlike adaptive immune cells that require antigen recognition and functional maturation during infection, innate lymphoid cells (ILCs) usually respond to pathogens promptly and serve as the first line of defense in infectious diseases. RAR-related orphan receptors (RORγt)+ ILCs are one of the innate cell populations that have recently been intensively studied. During the fetal stage of development, RORγt+ ILCs (e.g., lymphoid tissue inducer-LTi cells) are required for lymphoid organogenesis. In adult mice, RORγt+ ILCs are abundantly present in the gut to exert immune defensive functions. Under certain circumstances, however, RORγt+ ILCs can be pathogenic and contribute to intestinal inflammation. Aryl hydrocarbon receptor (Ahr), a ligand-dependent transcriptional factor, is widely expressed by various immune and non-immune cells. In the gut, the ligand for Ahr can be derived/generated from diet, microflora, and/or host cells. Ahr has been shown to regulate different cell populations in the immune system including RORγt+ ILCs, T helper (Th)17/22 cells, γδT cells, regulatory T cells (Tregs), Tr1 cells, and antigen presenting cells (APCs). In this review, we will focus on the development and function of RORγt+ ILCs, and discuss the role of Ahr in intestinal immunity and inflammation in mice and in humans. Better understanding the function of Ahr in the gut is important for developing new therapeutic means to target Ahr in future treatment of infectious and autoimmune diseases. PMID:23975386

[Breast milk: its nutritional composition and functional properties].

PubMed

Tackoen, M

2012-09-01

Human milk is a complex biological fluid with thousands of components. The milk composition in the mammalian species is specific and adapted to the needs of the offspring. It contains macronutrients (proteins, lipids and carbohydrates), micronutrients (minerals and vitamins) and numerous biologically active substrates. Human milk not only covers the nutritional needs of the newborn but protects the baby against infection, inflammation and oxidative stress. It has immunomodulation properties and confers trophical protection to the intestinal mucosa. The newborn infant is particularly immature: innate immunity, adaptive immunity and intestinal immaturity. Human milk will offer this exogenous protective and immunomodulating source. The development of the composition of the intestinal microflora of the neonate will be impacted by pre- and probiotic components of human milk. Current scientific knowledge of human milk properties highlights interdependency of the different components, ontogeny of the intestinal function, development of the mucosal intestinal immune system, colonization by the intestinal microbiota and protection against pathogens. Quality of these interactions influences the newborn's short and long-term health status. The promotion of breastfeeding with the support of the Baby Friendly Hospital Initiative (BFHI) program and labeling has been shown to have positive impact in public health.

The split personality of NKT cells in malignancy, autoimmune and allergic disorders

PubMed Central

Subleski, Jeff J; Jiang, Qun; Weiss, Jonathan M; Wiltrout, Robert H

2011-01-01

NKT cells are a heterogeneous subset of specialized, self-reactive T cells, with innate and adaptive immune properties, which allow them to bridge innate and adaptive immunity and profoundly influence autoimmune and malignant disease outcomes. NKT cells mediate these activities through their ability to rapidly express pro- and anti-inflammatory cytokines that influence the type and magnitude of the immune response. Not only do NKT cells regulate the functions of other cell types, but experimental evidence has found NKT cell subsets can modulate the functions of other NKT subsets. Depending on underlying mechanisms, NKT cells can inhibit or exacerbate autoimmunity and malignancy, making them potential targets for disease intervention. NKT cells can respond to foreign and endogenous antigenic glycolipid signals that are expressed during pathogenic invasion or ongoing inflammation, respectively, allowing them to rapidly react to and influence a broad array of diseases. In this article we review the unique development and activation pathways of NKT cells and focus on how these attributes augment or exacerbate autoimmune disorders and malignancy. We also examine the growing evidence that NKT cells are involved in liver inflammatory conditions that can contribute to the development of malignancy. PMID:21995570

Proteome Comparisons between Hemolymph of Two Honeybee Strains (Apis mellifera ligustica) Reveal Divergent Molecular Basis in Driving Hemolymph Function and High Royal Jelly Secretion.

PubMed

Ararso, Zewdu; Ma, Chuan; Qi, Yuping; Feng, Mao; Han, Bin; Hu, Han; Meng, Lifeng; Li, Jianke

2018-01-05

Hemolymph is vital for the immunity of honeybees and offers a way to investigate their physiological status. To gain novel insight into the functionality and molecular details of the hemolymph in driving increased Royal Jelly (RJ) production, we characterized and compared hemolymph proteomes across the larval and adult ages of Italian bees (ITbs) and Royal Jelly bees (RJbs), a stock selected from ITbs for increasing RJ output. Unprecedented in-depth proteome was attained with the identification of 3394 hemolymph proteins in both bee lines. The changes in proteome support the general function of hemolymph to drive development and immunity across different ages. However, age-specific proteome settings have adapted to prime the distinct physiology for larvae and adult bees. In larvae, the proteome is thought to drive temporal immunity, rapid organogenesis, and reorganization of larval structures. In adults, the proteome plays key roles in prompting tissue development and immune defense in newly emerged bees, in gland maturity in nurse bees, and in carbohydrate energy production in forager bees. Between larval and adult samples of the same age, RJbs and ITbs have tailored distinct hemolymph proteome programs to drive their physiology. In particular, in day 4 larvae and nurse bees, a large number of highly abundant proteins are enriched in protein synthesis and energy metabolism in RJbs. This implies that they have adapted their proteome to initiate different developmental trajectories and high RJ secretion in response to selection for enhanced RJ production. Our hitherto unexplored in-depth proteome coverage provides novel insight into molecular details that drive hemolymph function and high RJ production by RJbs.

Alterations in dendritic cell function in aged mice: potential implications for immunotherapy design.

PubMed

Paula, Carine; Motta, Adriana; Schmitz, Carla; Nunes, Claudia P; Souza, Ana Paula; Bonorino, Cristina

2009-02-01

It is known that immune system functions decrease with age, and that adaptive immune responses, especially CD4+ T cell function, seem to be the main affected point in immunity with aging. Dendritic cells (DC) are the major antigen presenting cell (APC), and at least part of the defects observed in adaptive immunity of aged individuals could be due to diminished potential of bone marrow to generate new DC, or defects in DC function. In this study, we investigated if the ability of aged bone marrow (BM) to generate new DC in vitro, as well as aged BM-derived DC responses to lypopolysaccharide (LPS). Because DC are important tools in newly developing anti-tumor therapies, we also studied the ability of aged DC to phagocytose and present antigen from necrotic tumor cells. We found that aged BM generated fewer DC in vitro compared to young BM. While LPS-induced DC maturation is reduced in DC of aged mice, a high TNF-alpha production is observed in aged DC even without LPS stimulation. While phagocytosis of tumor cells is not affected by age, and DC derived from aged BM show a higher TNF-alpha production in response to phagocytosis, presentation of tumor antigens was decreased in aged DC. Because class II upregulation in response to phagocytosis was similar between aged and young DC, this could indicate an age associated processing defect in the exogenous pathway. These findings suggest that age of BM used to generate DC does not impair their phagocytic ability or TNF-alpha production, however leads to a decreased yield in mature DC, reduced response to LPS, and diminished antigen processing/presentation potential. Our results are relevant to optimization DC-based vaccine design for aged populations.

T cell responses in experimental viral retinitis: mechanisms, peculiarities and implications for gene therapy with viral vectors.

PubMed

Zinkernagel, Martin S; McMenamin, Paul G; Forrester, John V; Degli-Esposti, Mariapia A

2011-07-01

T lymphocytes play a decisive role in the course and clinical outcome of viral retinal infection. This review focuses on aspects of the adaptive cellular immune response against viral pathogens in the retina. Two distinct models to study adaptive cell mediated immune responses in viral retinitis are presented: (i) experimental retinitis induced by murine cytomegalovirus (MCMV), where the immune system prevents necrotizing damage to the retina and (ii) retinitis induced by the non-cytopathic lymphocytic choriomeningitis virus (LCMV), where the retinal microanatomy is compromised not by the virus, but by the immune response itself. From these studies it is clear that, in the context of viral infections, the cytotoxic T cell response against a pathogen in the retina does not differ from that seen in other organs, and that once such a response has been initiated, clearing of virus from retinal tissue has priority over preservation of retinal architecture and function. Furthermore, implications drawn from these models for gene therapy in retinal diseases are discussed. Copyright © 2011. Published by Elsevier Ltd.

Pangolin genomes and the evolution of mammalian scales and immunity

PubMed Central

Rayko, Mike; Tan, Tze King; Hari, Ranjeev; Komissarov, Aleksey; Wee, Wei Yee; Yurchenko, Andrey A.; Kliver, Sergey; Tamazian, Gaik; Antunes, Agostinho; Wilson, Richard K.; Warren, Wesley C.; Koepfli, Klaus-Peter; Minx, Patrick; Krasheninnikova, Ksenia; Kotze, Antoinette; Dalton, Desire L.; Vermaak, Elaine; Paterson, Ian C.; Dobrynin, Pavel; Sitam, Frankie Thomas; Rovie-Ryan, Jeffrine J.; Johnson, Warren E.; Yusoff, Aini Mohamed; Luo, Shu-Jin; Karuppannan, Kayal Vizi; Fang, Gang; Zheng, Deyou; Gerstein, Mark B.; Lipovich, Leonard; O'Brien, Stephen J.; Wong, Guat Jah

2016-01-01

Pangolins, unique mammals with scales over most of their body, no teeth, poor vision, and an acute olfactory system, comprise the only placental order (Pholidota) without a whole-genome map. To investigate pangolin biology and evolution, we developed genome assemblies of the Malayan (Manis javanica) and Chinese (M. pentadactyla) pangolins. Strikingly, we found that interferon epsilon (IFNE), exclusively expressed in epithelial cells and important in skin and mucosal immunity, is pseudogenized in all African and Asian pangolin species that we examined, perhaps impacting resistance to infection. We propose that scale development was an innovation that provided protection against injuries or stress and reduced pangolin vulnerability to infection. Further evidence of specialized adaptations was evident from positively selected genes involving immunity-related pathways, inflammation, energy storage and metabolism, muscular and nervous systems, and scale/hair development. Olfactory receptor gene families are significantly expanded in pangolins, reflecting their well-developed olfaction system. This study provides insights into mammalian adaptation and functional diversification, new research tools and questions, and perhaps a new natural IFNE-deficient animal model for studying mammalian immunity. PMID:27510566

Comparative Transcriptomic Analysis of Rectal Tissue from Beef Steers Revealed Reduced Host Immunity in Escherichia coli O157:H7 Super-Shedders

PubMed Central

Wang, Ou; Liang, Guanxiang; McAllister, Tim A.; Plastow, Graham; Stanford, Kim; Selinger, Brent; Guan, Le Luo

2016-01-01

Super-shedder cattle are a major disseminator of E. coli O157:H7 into the environment, and the terminal rectum has been proposed as the primary E. coli O157:H7 colonization site. This study aimed to identify host factors that are associated with the super-shedding process by comparing transcriptomic profiles in rectal tissue collected from 5 super-shedder cattle and 4 non-shedder cattle using RNA-Seq. In total, 17,859 ± 354 genes and 399 ± 16 miRNAs were detected, and 11,773 genes were expressed in all animals. Fifty-eight differentially expressed (DE) genes (false discovery rate < 0.05) including 11 up-regulated and 47 down-regulated (log 2 (fold change) ranged from -5.5 to 4.2), and 2 up-regulated DE miRNAs (log 2 (fold change) = 2.1 and 2.5, respectively) were identified in super-shedders compared to non-shedders. Functional analysis of DE genes revealed that 31 down-regulated genes were potentially associated with reduced innate and adaptive immune functions in super-shedders, including 13 lymphocytes membrane receptors, 3 transcription factors and 5 cytokines, suggesting the decreased key host immune functions in the rectal tissue of super-shedders, including decreased quantity and migration of immune cells such as lymphocytes, neutrophils and dendritic cells. The up-regulation of bta-miR-29d-3p and the down regulation of its predicted target gene, regulator of G-protein signaling 13, suggested a potential regulatory role of this miRNA in decreased migration of lymphocytes in super-shedders. Based on these findings, the rectal tissue of super-shedders may inherently exhibit less effective innate and adaptive immune protection. Further study is required to confirm if such effect on host immunity is due to the nature of the host itself or due to actions mediated by E. coli O157:H7. PMID:26959367

Comparative Transcriptomic Analysis of Rectal Tissue from Beef Steers Revealed Reduced Host Immunity in Escherichia coli O157:H7 Super-Shedders.

PubMed

Wang, Ou; Liang, Guanxiang; McAllister, Tim A; Plastow, Graham; Stanford, Kim; Selinger, Brent; Guan, Le Luo

2016-01-01

Super-shedder cattle are a major disseminator of E. coli O157:H7 into the environment, and the terminal rectum has been proposed as the primary E. coli O157:H7 colonization site. This study aimed to identify host factors that are associated with the super-shedding process by comparing transcriptomic profiles in rectal tissue collected from 5 super-shedder cattle and 4 non-shedder cattle using RNA-Seq. In total, 17,859 ± 354 genes and 399 ± 16 miRNAs were detected, and 11,773 genes were expressed in all animals. Fifty-eight differentially expressed (DE) genes (false discovery rate < 0.05) including 11 up-regulated and 47 down-regulated (log 2 (fold change) ranged from -5.5 to 4.2), and 2 up-regulated DE miRNAs (log 2 (fold change) = 2.1 and 2.5, respectively) were identified in super-shedders compared to non-shedders. Functional analysis of DE genes revealed that 31 down-regulated genes were potentially associated with reduced innate and adaptive immune functions in super-shedders, including 13 lymphocytes membrane receptors, 3 transcription factors and 5 cytokines, suggesting the decreased key host immune functions in the rectal tissue of super-shedders, including decreased quantity and migration of immune cells such as lymphocytes, neutrophils and dendritic cells. The up-regulation of bta-miR-29d-3p and the down regulation of its predicted target gene, regulator of G-protein signaling 13, suggested a potential regulatory role of this miRNA in decreased migration of lymphocytes in super-shedders. Based on these findings, the rectal tissue of super-shedders may inherently exhibit less effective innate and adaptive immune protection. Further study is required to confirm if such effect on host immunity is due to the nature of the host itself or due to actions mediated by E. coli O157:H7.

Novel Adaptive and Innate Immunity Targets in Hypertension

PubMed Central

Abais-Battad, Justine M.; Dasinger, John Henry; Fehrenbach, Daniel J.; Mattson, David L.

2017-01-01

Hypertension is a worldwide epidemic and global health concern as it is a major risk factor for the development of cardiovascular diseases. A relationship between the immune system and its contributing role to the pathogenesis of hypertension has been long established, but substantial advancements within the last few years have dissected specific causal molecular mechanisms. This review will briefly examine these recent studies exploring the involvement of either innate or adaptive immunity pathways. Such pathways to be discussed include innate immunity factors such as antigen presenting cells and pattern recognition receptors, adaptive immune elements including T and B lymphocytes, and more specifically, the emerging role of T regulatory cells, as well as the potential of cytokines and chemokines to serve as signaling messengers connecting innate and adaptive immunity. Together, we summarize these studies to provide new perspective for what will hopefully lead to more targeted approaches to manipulate the immune system as hypertensive therapy. PMID:28336371

Nutritional strategies to counter stress to the immune system in athletes, with special reference to football.

PubMed

Nieman, David C; Bishop, Nicolette C

2006-07-01

Although epidemiological data indicate that athletes are at increased risk of upper respiratory tract infection during periods of heavy training and the 1 - 2 week period following endurance race events, there is very limited information on the responses to football training and match-play. For several hours after heavy exertion, components of both the innate (e.g. natural killer cell activity and neutrophil oxidative burst activity) and adaptive (e.g. T and B cell function) immune system exhibit suppressed function. Although such responses to football training and competition do not appear to be as pronounced, variations in immune cell numbers and function are reported in professional footballers over the course of a season. Attempts have been made through nutritional means (e.g. glutamine, vitamins C and E, and carbohydrate supplementation) to attenuate immune changes following intensive exercise and thus lower the risk of upper respiratory tract infection. Carbohydrate supplementation during heavy exercise has emerged as a partial countermeasure and attenuates increases in blood neutrophil counts, stress hormones, and inflammatory cytokines, but has little effect on decrements in salivary IgA output or natural killer cell function. Animal research indicates that other nutritional components such as beta-glucan, quercetin, and curcumin warrant human investigations to determine if they are effective countermeasures to exercise-induced immune dysfunction.

The role of the immune system in central nervous system plasticity after acute injury.

PubMed

Peruzzotti-Jametti, Luca; Donegá, Matteo; Giusto, Elena; Mallucci, Giulia; Marchetti, Bianca; Pluchino, Stefano

2014-12-26

Acute brain injuries cause rapid cell death that activates bidirectional crosstalk between the injured brain and the immune system. In the acute phase, the damaged CNS activates resident and circulating immune cells via the local and systemic release of soluble mediators. This early immune activation is necessary to confine the injured tissue and foster the clearance of cellular debris, thus bringing the inflammatory reaction to a close. In the chronic phase, a sustained immune activation has been described in many CNS disorders, and the degree of this prolonged response has variable effects on spontaneous brain regenerative processes. The challenge for treating acute CNS damage is to understand how to optimally engage and modify these immune responses, thus providing new strategies that will compensate for tissue lost to injury. Herein we have reviewed the available information regarding the role and function of the innate and adaptive immune responses in influencing CNS plasticity during the acute and chronic phases of after injury. We have examined how CNS damage evolves along the activation of main cellular and molecular pathways that are associated with intrinsic repair, neuronal functional plasticity and facilitation of tissue reorganization. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Inherited BCL10 deficiency impairs hematopoietic and nonhematopoietic immunity

PubMed Central

Torres, Juan Manuel; Martinez-Barricarte, Rubén; García-Gómez, Sonia; Mazariegos, Marina S.; Itan, Yuval; Boisson, Bertrand; ρlvarez, Rita; Jiménez-Reinoso, Anaïs; del Pino, Lucia; Rodríguez-Pena, Rebeca; Ferreira, Antonio; Hernández-Jiménez, Enrique; Toledano, Victor; Cubillos-Zapata, Carolina; Díaz-Almirón, Mariana; López-Collazo, Eduardo; Unzueta-Roch, José L.; Sánchez-Ramón, Silvia; Regueiro, Jose R.; López-Granados, Eduardo; Casanova, Jean-Laurent; Pérez de Diego, Rebeca

2014-01-01

Heterotrimers composed of B cell CLL/lymphoma 10 (BCL10), mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1), and caspase recruitment domain–containing (CARD) family adaptors play a role in NF-κB activation and have been shown to be involved in both the innate and the adaptive arms of immunity in murine models. Moreover, individuals with inherited defects of MALT1, CARD9, and CARD11 present with immunological and clinical phenotypes. Here, we characterized a case of autosomal-recessive, complete BCL10 deficiency in a child with a broad immunodeficiency, including defects of both hematopoietic and nonhematopoietic immunity. The patient died at 3 years of age and was homozygous for a loss-of-expression, loss-of-function BCL10 mutation. The effect of BCL10 deficiency was dependent on the signaling pathway, and, for some pathways, the cell type affected. Despite the noted similarities to BCL10 deficiency in mice, including a deficient adaptive immune response, human BCL10 deficiency in this patient resulted in a number of specific features within cell populations. Treatment of the patient’s myeloid cells with a variety of pathogen-associated molecular pattern molecules (PAMPs) elicited a normal response; however, NF-κB–mediated fibroblast functions were dramatically impaired. The results of this study indicate that inherited BCL10 deficiency should be considered in patients with combined immunodeficiency with B cell, T cell, and fibroblast defects. PMID:25365219

Machine learning methods enable predictive modeling of antibody feature:function relationships in RV144 vaccinees.

PubMed

Choi, Ickwon; Chung, Amy W; Suscovich, Todd J; Rerks-Ngarm, Supachai; Pitisuttithum, Punnee; Nitayaphan, Sorachai; Kaewkungwal, Jaranit; O'Connell, Robert J; Francis, Donald; Robb, Merlin L; Michael, Nelson L; Kim, Jerome H; Alter, Galit; Ackerman, Margaret E; Bailey-Kellogg, Chris

2015-04-01

The adaptive immune response to vaccination or infection can lead to the production of specific antibodies to neutralize the pathogen or recruit innate immune effector cells for help. The non-neutralizing role of antibodies in stimulating effector cell responses may have been a key mechanism of the protection observed in the RV144 HIV vaccine trial. In an extensive investigation of a rich set of data collected from RV144 vaccine recipients, we here employ machine learning methods to identify and model associations between antibody features (IgG subclass and antigen specificity) and effector function activities (antibody dependent cellular phagocytosis, cellular cytotoxicity, and cytokine release). We demonstrate via cross-validation that classification and regression approaches can effectively use the antibody features to robustly predict qualitative and quantitative functional outcomes. This integration of antibody feature and function data within a machine learning framework provides a new, objective approach to discovering and assessing multivariate immune correlates.

Epithelial adhesion molecules and the regulation of intestinal homeostasis during neutrophil transepithelial migration

PubMed Central

Sumagin, Ronen; Parkos, Charles A

2014-01-01

Epithelial adhesion molecules play essential roles in regulating cellular function and maintaining mucosal tissue homeostasis. Some form epithelial junctional complexes to provide structural support for epithelial monolayers and act as a selectively permeable barrier separating luminal contents from the surrounding tissue. Others serve as docking structures for invading viruses and bacteria, while also regulating the immune response. They can either obstruct or serve as footholds for the immune cells recruited to mucosal surfaces. Currently, it is well appreciated that adhesion molecules collectively serve as environmental cue sensors and trigger signaling events to regulate epithelial function through their association with the cell cytoskeleton and various intracellular adapter proteins. Immune cells, particularly neutrophils (PMN) during transepithelial migration (TEM), can modulate adhesion molecule expression, conformation, and distribution, significantly impacting epithelial function and tissue homeostasis. This review discusses the roles of key intestinal epithelial adhesion molecules in regulating PMN trafficking and outlines the potential consequences on epithelial function. PMID:25838976

Pathological and therapeutic roles of innate lymphoid cells in diverse diseases.

PubMed

Kim, Jisu; Kim, Geon; Min, Hyeyoung

2017-11-01

Innate lymphoid cells (ILCs) are a recently defined type of innate-immunity cells that belong to the lymphoid lineage and have lymphoid morphology but do not express an antigen-specific B cell or T-cell receptor. ILCs regulate immune functions prior to the formation of adaptive immunity and exert effector functions through a cytokine release. ILCs have been classified into three groups according to the transcription factors that regulate their development and function and the effector cytokines they produce. Of note, ILCs resemble T helper (Th) cells, such as Th1, Th2, and Th17 cells, and show a similar dependence on transcription factors and distinct cytokine production. Despite their short history in immunology, ILCs have received much attention, and numerous studies have revealed biological functions of ILCs including host defense against pathogens, inflammation, tissue repair, and metabolic homeostasis. Here, we describe recent findings about the roles of ILCs in the pathogenesis of various diseases and potential therapeutic targets.

Machine Learning Methods Enable Predictive Modeling of Antibody Feature:Function Relationships in RV144 Vaccinees

PubMed Central

Choi, Ickwon; Chung, Amy W.; Suscovich, Todd J.; Rerks-Ngarm, Supachai; Pitisuttithum, Punnee; Nitayaphan, Sorachai; Kaewkungwal, Jaranit; O'Connell, Robert J.; Francis, Donald; Robb, Merlin L.; Michael, Nelson L.; Kim, Jerome H.; Alter, Galit; Ackerman, Margaret E.; Bailey-Kellogg, Chris

2015-01-01

The adaptive immune response to vaccination or infection can lead to the production of specific antibodies to neutralize the pathogen or recruit innate immune effector cells for help. The non-neutralizing role of antibodies in stimulating effector cell responses may have been a key mechanism of the protection observed in the RV144 HIV vaccine trial. In an extensive investigation of a rich set of data collected from RV144 vaccine recipients, we here employ machine learning methods to identify and model associations between antibody features (IgG subclass and antigen specificity) and effector function activities (antibody dependent cellular phagocytosis, cellular cytotoxicity, and cytokine release). We demonstrate via cross-validation that classification and regression approaches can effectively use the antibody features to robustly predict qualitative and quantitative functional outcomes. This integration of antibody feature and function data within a machine learning framework provides a new, objective approach to discovering and assessing multivariate immune correlates. PMID:25874406

Chronic exposure to dim light at night suppresses immune responses in Siberian hamsters.

PubMed

Bedrosian, Tracy A; Fonken, Laura K; Walton, James C; Nelson, Randy J

2011-06-23

Species have been adapted to specific niches optimizing survival and reproduction; however, urbanization by humans has dramatically altered natural habitats. Artificial light at night (LAN), termed 'light pollution', is an often overlooked, yet increasing disruptor of habitats, which perturbs physiological processes that rely on precise light information. For example, LAN alters the timing of reproduction and activity in some species, which decreases the odds of successful breeding and increases the threat of predation for these individuals, leading to reduced fitness. LAN also suppresses immune function, an important proxy for survival. To investigate the impact of LAN in a species naive to light pollution in its native habitat, immune function was examined in Siberian hamsters derived from wild-caught stock. After four weeks exposure to dim LAN, immune responses to three different challenges were assessed: (i) delayed-type hypersensitivity (DTH), (ii) lipopolysaccharide-induced fever, and (iii) bactericide activity of blood. LAN suppressed DTH response and reduced bactericide activity of blood after lipopolysaccharide treatment, in addition to altering daily patterns of locomotor activity, suggesting that human encroachment on habitats via night-time lighting may inadvertently compromise immune function and ultimately fitness.

Zinc as a Gatekeeper of Immune Function

PubMed Central

Wessels, Inga; Maywald, Martina; Rink, Lothar

2017-01-01

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. PMID:29186856

Fever and the thermal regulation of immunity: the immune system feels the heat

PubMed Central

Evans, Sharon S.; Repasky, Elizabeth A.; Fisher, Daniel T.

2016-01-01

Fever is a cardinal response to infection that has been conserved in warm and cold-blooded vertebrates for over 600 million years of evolution. The fever response is executed by integrated physiological and neuronal circuitry and confers a survival benefit during infection. Here, we review our current understanding of how the inflammatory cues delivered by the thermal element of fever stimulate innate and adaptive immune responses. We further highlight the unexpected multiplicity of roles of the pyrogenic cytokine interleukin-6 (IL-6), both during fever induction as well as during the mobilization of lymphocytes to the lymphoid organs that are the staging ground for immune defence. Finally, we discuss the emerging evidence that suggests the adrenergic signalling pathways associated with thermogenesis shape immune cell function. PMID:25976513

Innate immunity and effector and regulatory mechanisms involved in allergic contact dermatitis*

PubMed Central

Silvestre, Marilene Chaves; Sato, Maria Notomi; dos Reis, Vitor Manoel Silva

2018-01-01

Skin's innate immunity is the initial activator of immune response mechanisms, influencing the development of adaptive immunity. Some contact allergens are detected by Toll-like receptors (TLRs) and inflammasome NLR3. Keratinocytes participate in innate immunity and, in addition to functioning as an anatomical barrier, secrete cytokines, such as TNF, IL-1β, and IL-18, contributing to the development of Allergic Contact Dermatitis. Dendritic cells recognize and process antigenic peptides into T cells. Neutrophils cause pro-inflammatory reactions, mast cells induce migration/maturation of skin DCs, the natural killer cells have natural cytotoxic capacity, the γδ T cells favor contact with hapten during the sensitization phase, and the innate lymphoid cells act in the early stages by secreting cytokines, as well as act in inflammation and tissue homeostasis. The antigen-specific inflammation is mediated by T cells, and each subtype of T cells (Th1/Tc1, Th2/Tc2, and Th17/Tc17) activates resident skin cells, thus contributing to inflammation. Skin's regulatory T cells have a strong ability to inhibit the proliferation of hapten-specific T cells, acting at the end of the Allergic Contact Dermatitis response and in the control of systemic immune responses. In this review, we report how cutaneous innate immunity is the first line of defense and focus its role in the activation of the adaptive immune response, with effector response induction and its regulation. PMID:29723367

Characterisation of cell functions and receptors in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME).

PubMed

Hardcastle, Sharni Lee; Brenu, Ekua Weba; Johnston, Samantha; Nguyen, Thao; Huth, Teilah; Wong, Naomi; Ramos, Sandra; Staines, Donald; Marshall-Gradisnik, Sonya

2015-06-02

Abnormal immune function is often an underlying component of illness pathophysiology and symptom presentation. Functional and phenotypic immune-related alterations may play a role in the obscure pathomechanism of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME). The objective of this study was to investigate the functional ability of innate and adaptive immune cells in moderate and severe CFS/ME patients. The 1994 Fukuda criteria for CFS/ME were used to define CFS/ME patients. CFS/ME participants were grouped based on illness severity with 15 moderately affected (moderate) and 12 severely affected (severe) CFS/ME patients who were age and sex matched with 18 healthy controls. Flow cytometric protocols were used for immunological analysis of dendritic cells, monocytes and neutrophil function as well as measures of lytic proteins and T, natural killer (NK) and B cell receptors. CFS/ME patients exhibited alterations in NK receptors and adhesion markers and receptors on CD4(+)T and CD8(+)T cells. Moderate CFS/ME patients had increased CD8(+) CD45RA effector memory T cells, SLAM expression on NK cells, KIR2DL5(+) on CD4(+)T cells and BTLA4(+) on CD4(+)T central memory cells. Moderate CFS/ME patients also had reduced CD8(+)T central memory LFA-1, total CD8(+)T KLRG1, naïve CD4(+)T KLRG1 and CD56(dim)CD16(-) NK cell CD2(+) and CD18(+)CD2(+). Severe CFS/ME patients had increased CD18(+)CD11c(-) in the CD56(dim)CD16(-) NK cell phenotype and reduced NKp46 in CD56(bright)CD16(dim) NK cells. This research accentuated the presence of immunological abnormalities in CFS/ME and highlighted the importance of assessing functional parameters of both innate and adaptive immune systems in the illness.

In Silico Functional Networks Identified in Fish Nucleated Red Blood Cells by Means of Transcriptomic and Proteomic Profiling.

PubMed

Puente-Marin, Sara; Nombela, Iván; Ciordia, Sergio; Mena, María Carmen; Chico, Verónica; Coll, Julio; Ortega-Villaizan, María Del Mar

2018-04-09

Nucleated red blood cells (RBCs) of fish have, in the last decade, been implicated in several immune-related functions, such as antiviral response, phagocytosis or cytokine-mediated signaling. RNA-sequencing (RNA-seq) and label-free shotgun proteomic analyses were carried out for in silico functional pathway profiling of rainbow trout RBCs. For RNA-seq, a de novo assembly was conducted, in order to create a transcriptome database for RBCs. For proteome profiling, we developed a proteomic method that combined: (a) fractionation into cytosolic and membrane fractions, (b) hemoglobin removal of the cytosolic fraction, (c) protein digestion, and (d) a novel step with pH reversed-phase peptide fractionation and final Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometric (LC ESI-MS/MS) analysis of each fraction. Combined transcriptome- and proteome- sequencing data identified, in silico, novel and striking immune functional networks for rainbow trout nucleated RBCs, which are mainly linked to innate and adaptive immunity. Functional pathways related to regulation of hematopoietic cell differentiation, antigen presentation via major histocompatibility complex class II (MHCII), leukocyte differentiation and regulation of leukocyte activation were identified. These preliminary findings further implicate nucleated RBCs in immune function, such as antigen presentation and leukocyte activation.

In Silico Functional Networks Identified in Fish Nucleated Red Blood Cells by Means of Transcriptomic and Proteomic Profiling

PubMed Central

Puente-Marin, Sara; Ciordia, Sergio; Mena, María Carmen; Chico, Verónica; Coll, Julio

2018-01-01

Nucleated red blood cells (RBCs) of fish have, in the last decade, been implicated in several immune-related functions, such as antiviral response, phagocytosis or cytokine-mediated signaling. RNA-sequencing (RNA-seq) and label-free shotgun proteomic analyses were carried out for in silico functional pathway profiling of rainbow trout RBCs. For RNA-seq, a de novo assembly was conducted, in order to create a transcriptome database for RBCs. For proteome profiling, we developed a proteomic method that combined: (a) fractionation into cytosolic and membrane fractions, (b) hemoglobin removal of the cytosolic fraction, (c) protein digestion, and (d) a novel step with pH reversed-phase peptide fractionation and final Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometric (LC ESI-MS/MS) analysis of each fraction. Combined transcriptome- and proteome- sequencing data identified, in silico, novel and striking immune functional networks for rainbow trout nucleated RBCs, which are mainly linked to innate and adaptive immunity. Functional pathways related to regulation of hematopoietic cell differentiation, antigen presentation via major histocompatibility complex class II (MHCII), leukocyte differentiation and regulation of leukocyte activation were identified. These preliminary findings further implicate nucleated RBCs in immune function, such as antigen presentation and leukocyte activation. PMID:29642539

Depression as sickness behavior? A test of the host defense hypothesis in a high pathogen population.

PubMed

Stieglitz, Jonathan; Trumble, Benjamin C; Thompson, Melissa Emery; Blackwell, Aaron D; Kaplan, Hillard; Gurven, Michael

2015-10-01

Sadness is an emotion universally recognized across cultures, suggesting it plays an important functional role in regulating human behavior. Numerous adaptive explanations of persistent sadness interfering with daily functioning (hereafter "depression") have been proposed, but most do not explain frequent bidirectional associations between depression and greater immune activation. Here we test several predictions of the host defense hypothesis, which posits that depression is part of a broader coordinated evolved response to infection or tissue injury (i.e. "sickness behavior") that promotes energy conservation and reallocation to facilitate immune activation. In a high pathogen population of lean and relatively egalitarian Bolivian forager-horticulturalists, we test whether depression and its symptoms are associated with greater baseline concentration of immune biomarkers reliably associated with depression in Western populations (i.e. tumor necrosis factor alpha [TNF-α], interleukin-1 beta [IL-1β], interleukin-6 [IL-6], and C-reactive protein [CRP]). We also test whether greater pro-inflammatory cytokine responses to ex vivo antigen stimulation are associated with depression and its symptoms, which is expected if depression facilitates immune activation. These predictions are largely supported in a sample of older adult Tsimane (mean±SD age=53.2±11.0, range=34-85, n=649) after adjusting for potential confounders. Emotional, cognitive and somatic symptoms of depression are each associated with greater immune activation, both at baseline and in response to ex vivo stimulation. The association between depression and greater immune activation is therefore not unique to Western populations. While our findings are not predicted by other adaptive hypotheses of depression, they are not incompatible with those hypotheses and future research is necessary to isolate and test competing predictions. Copyright © 2015 Elsevier Inc. All rights reserved.

Pegylated Interferon α-2a Triggers NK-Cell Functionality and Specific T-Cell Responses in Patients with Chronic HBV Infection without HBsAg Seroconversion

PubMed Central

Bruder Costa, Juliana; Dufeu-Duchesne, Tania; Leroy, Vincent; Bertucci, Inga; Bouvier-Alias, Magali; Pouget, Noelle; Brevot-Lutton, Ophelie; Bourliere, Marc; Zoulim, Fabien

2016-01-01

Pegylated interferon α-2a (Peg-IFN-α) represents a therapeutic alternative to the prolonged use of nucleos(t)ide analog (NA) in chronic hepatitis B (CHB) infection. The mechanisms leading to a positive clinical outcome remain unclear. As immune responses are critical for virus control, we investigated the effects of Peg-IFN-α on both innate and adaptive immunity, and related it to the clinical evolution. The phenotypic and functional features of the dendritic cells (DCs), natural killer (NK) cells and HBV-specific CD4/CD8 T cells were analyzed in HBeAg-negative CHB patients treated for 48-weeks with NA alone or together with Peg-IFN-α, before, during and up to 2-years after therapy. Peg-IFN-α induced an early activation of DCs, a potent expansion of the CD56bright NK subset, and enhanced the activation and functionality of the CD56dim NK subset. Peg-IFN-α triggered an increase in the frequencies of Th1- and Th17-oriented HBV-specific CD4/CD8 T cells. Peg-IFN-α reversed the unresponsiveness of patients to a specific stimulation. Most of the parameters returned to baseline after the stop of Peg-IFN-α therapy. Peg-IFN-α impacts both innate and adaptive immunity, overcoming dysfunctional immune responses in CHB patients. These modulations were not associated with seroconversion, which questioned the benefit of the add-on Peg-IFN-α treatment. PMID:27348813

Expansions of NK-like αβT cells with chronologic aging: Novel lymphocyte effectors that compensate for functional deficits of conventional NK cells and T cells

PubMed Central

Vallejo, Abbe N.; Mueller, Robert G.; Hamel, David L.; Way, Amanda; Dvergsten, Jeffrey A.; Griffin, Patricia; Newman, Anne B.

2010-01-01

As the repertoire of αβT cell receptors (TCR) contracts with advancing age, there is an associated age-dependent accumulation of oligoclonal T cells expressing of a variety of receptors (NKR), normally expressed on natural killer (NK) cells. Evidences for differential regulation of expression of particular NKRs between T cells and NK cells suggest that NKR expression on T cells is physiologically programmed rather than a random event of the aging process. Experimental studies show NKRs on aged αβT cells may function either as independent receptors, and/or as costimulatory receptors to the TCR. Considering the reported deficits of conventional αβTCR-driven activation and also functional deficits of classical NK cells, NKR+ αβT cells likely represent novel immune effectors that are capable of combining innate and adaptive functions. Inasmuch as immunity is a determinant of individual fitness, the type and density of NKRs could be important contributing factors to the wide heterogeneity of health characteristics of older adults, ranging from institutionalized frail elders who are unable to mount immune responses to functionally independent community-dwelling elders who exhibit protective immunity. Understanding the biology of NKR+ αβT cells could lead to new avenues for age-specific intervention to improve protective immunity. PMID:20932941

Triggering the adaptive immune system with commensal gut bacteria protects against insulin resistance and dysglycemia.

PubMed

Pomié, Céline; Blasco-Baque, Vincent; Klopp, Pascale; Nicolas, Simon; Waget, Aurélie; Loubières, Pascale; Azalbert, Vincent; Puel, Anthony; Lopez, Frédéric; Dray, Cédric; Valet, Philippe; Lelouvier, Benjamin; Servant, Florence; Courtney, Michael; Amar, Jacques; Burcelin, Rémy; Garidou, Lucile

2016-06-01

To demonstrate that glycemia and insulin resistance are controlled by a mechanism involving the adaptive immune system and gut microbiota crosstalk. We triggered the immune system with microbial extracts specifically from the intestinal ileum contents of HFD-diabetic mice by the process of immunization. 35 days later, immunized mice were fed a HFD for up to two months in order to challenge the development of metabolic features. The immune responses were quantified. Eventually, adoptive transfer of immune cells from the microbiota-immunized mice to naïve mice was performed to demonstrate the causality of the microbiota-stimulated adaptive immune system on the development of metabolic disease. The gut microbiota of the immunized HFD-fed mice was characterized in order to demonstrate whether the manipulation of the microbiota to immune system interaction reverses the causal deleterious effect of gut microbiota dysbiosis on metabolic disease. Subcutaneous injection (immunization procedure) of ileum microbial extracts prevented hyperglycemia and insulin resistance in a dose-dependent manner in response to a HFD. The immunization enhanced the proliferation of CD4 and CD8 T cells in lymphoid organs, also increased cytokine production and antibody secretion. As a mechanism explaining the metabolic improvement, the immunization procedure reversed gut microbiota dysbiosis. Finally, adoptive transfer of immune cells from immunized mice improved metabolic features in response to HFD. Glycemia and insulin sensitivity can be regulated by triggering the adaptive immunity to microbiota interaction. This reduces the gut microbiota dysbiosis induced by a fat-enriched diet.

The stress-response sensor chop regulates the function and accumulation of myeloid-derived suppressor cells in tumors.

PubMed

Thevenot, Paul T; Sierra, Rosa A; Raber, Patrick L; Al-Khami, Amir A; Trillo-Tinoco, Jimena; Zarreii, Parisa; Ochoa, Augusto C; Cui, Yan; Del Valle, Luis; Rodriguez, Paulo C

2014-09-18

Adaptation of malignant cells to the hostile milieu present in tumors is an important determinant of their survival and growth. However, the interaction between tumor-linked stress and antitumor immunity remains poorly characterized. Here, we show the critical role of the cellular stress sensor C/EBP-homologous protein (Chop) in the accumulation and immune inhibitory activity of tumor-infiltrating myeloid-derived suppressor cells (MDSCs). MDSCs lacking Chop had decreased immune-regulatory functions and showed the ability to prime T cell function and induce antitumor responses. Chop expression in MDSCs was induced by tumor-linked reactive oxygen and nitrogen species and regulated by the activating-transcription factor-4. Chop-deficient MDSCs displayed reduced signaling through CCAAT/enhancer-binding protein-β, leading to a decreased production of interleukin-6 (IL-6) and low expression of phospho-STAT3. IL-6 overexpression restored immune-suppressive activity of Chop-deficient MDSCs. These findings suggest the role of Chop in tumor-induced tolerance and the therapeutic potential of targeting Chop in MDSCs for cancer immunotherapy. Copyright © 2014 Elsevier Inc. All rights reserved.

Elimination of tumor by CD47/PD-L1 dual-targeting fusion protein that engages innate and adaptive immune responses.

PubMed

Liu, Boning; Guo, Huaizu; Xu, Jin; Qin, Ting; Guo, Qingcheng; Gu, Nana; Zhang, Dapeng; Qian, Weizhu; Dai, Jianxin; Hou, Sheng; Wang, Hao; Guo, Yajun

The host immune system generally serves as a barrier against tumor formation. Programmed death-ligand 1 (PD-L1) is a critical "don't find me" signal to the adaptive immune system, whereas CD47 transmits an anti-phagocytic signal, known as the "don't eat me" signal, to the innate immune system. These and similar immune checkpoints are often overexpressed on human tumors. Thus, dual targeting both innate and adaptive immune checkpoints would likely maximize anti-tumor therapeutic effect and elicit more durable responses. Herein, based on the variable region of atezolizumab and consensus variant 1 (CV1) monomer, we constructed a dual-targeting fusion protein targeting both CD47 and PD-L1 using "Knobs-into-holes" technology, denoted as IAB. It was effective in inducing phagocytosis of tumor cells, stimulating T-cell activation and mediating antibody-dependent cell-mediated cytotoxicity in vitro. No obvious sign of hematological toxicity was observed in mice administered IAB at a dose of 100 mg/kg, and IAB exhibited potent antitumor activity in an immune-competent mouse model of MC38. Additionally, the anti-tumor effect of IAB was impaired by anti-CD8 antibody or clodronate liposomes, which implied that both CD8+ T cells and macrophages were required for the anti-tumor efficacy of IAB and IAB plays an essential role in the engagement of innate and adaptive immune responses. Collectively, these results demonstrate the capacity of an elicited endogenous immune response against tumors and elucidate essential characteristics of synergistic innate and adaptive immune response, and indicate dual blockade of CD47 and PD-L1 by IAB may be a synergistic therapy that activates both innate and adaptive immune response against tumors.

ID’ing Innate and Innate-like Lymphoid Cells

PubMed Central

Verykokakis, Mihalis; Zook, Erin C.; Kee, Barbara L.

2014-01-01

Summary The immune system can be divided into innate and adaptive components that differ in their rate and mode of cellular activation, with innate immune cells being the first responders to invading pathogens. Recent advances in the identification and characterization of innate lymphoid cells have revealed reiterative developmental programs that result in cells with effector fates that parallel those of adaptive lymphoid cells and are tailored to effectively eliminate a broad spectrum of pathogenic challenges. However, activation of these cells can also be associated with pathologies such as autoimmune disease. One major distinction between innate and adaptive immune system cells is the constitutive expression of ID proteins in the former and inducible expression in the latter. ID proteins function as antagonists of the E protein transcription factors that play critical roles in lymphoid specification as well as B and T-lymphocyte development. In this review, we examine the transcriptional mechanisms controlling the development of innate lymphocytes, including natural killer cells and the recently identified innate lymphoid cells (ILC1, ILC2, and ILC3), and innate-like lymphocytes, including natural killer T cells, with an emphasis on the known requirements for the ID proteins. PMID:25123285

ID'ing innate and innate-like lymphoid cells.

PubMed

Verykokakis, Mihalis; Zook, Erin C; Kee, Barbara L

2014-09-01

The immune system can be divided into innate and adaptive components that differ in their rate and mode of cellular activation, with innate immune cells being the first responders to invading pathogens. Recent advances in the identification and characterization of innate lymphoid cells have revealed reiterative developmental programs that result in cells with effector fates that parallel those of adaptive lymphoid cells and are tailored to effectively eliminate a broad spectrum of pathogenic challenges. However, activation of these cells can also be associated with pathologies such as autoimmune disease. One major distinction between innate and adaptive immune system cells is the constitutive expression of ID proteins in the former and inducible expression in the latter. ID proteins function as antagonists of the E protein transcription factors that play critical roles in lymphoid specification as well as B- and T-lymphocyte development. In this review, we examine the transcriptional mechanisms controlling the development of innate lymphocytes, including natural killer cells and the recently identified innate lymphoid cells (ILC1, ILC2, and ILC3), and innate-like lymphocytes, including natural killer T cells, with an emphasis on the known requirements for the ID proteins. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Zinc in Infection and Inflammation

PubMed Central

Gammoh, Nour Zahi; Rink, Lothar

2017-01-01

Micronutrient homeostasis is a key factor in maintaining a healthy immune system. Zinc is an essential micronutrient that is involved in the regulation of the innate and adaptive immune responses. The main cause of zinc deficiency is malnutrition. Zinc deficiency leads to cell-mediated immune dysfunctions among other manifestations. Consequently, such dysfunctions lead to a worse outcome in the response towards bacterial infection and sepsis. For instance, zinc is an essential component of the pathogen-eliminating signal transduction pathways leading to neutrophil extracellular traps (NET) formation, as well as inducing cell-mediated immunity over humoral immunity by regulating specific factors of differentiation. Additionally, zinc deficiency plays a role in inflammation, mainly elevating inflammatory response as well as damage to host tissue. Zinc is involved in the modulation of the proinflammatory response by targeting Nuclear Factor Kappa B (NF-κB), a transcription factor that is the master regulator of proinflammatory responses. It is also involved in controlling oxidative stress and regulating inflammatory cytokines. Zinc plays an intricate function during an immune response and its homeostasis is critical for sustaining proper immune function. This review will summarize the latest findings concerning the role of this micronutrient during the course of infections and inflammatory response and how the immune system modulates zinc depending on different stimuli. PMID:28629136

Zinc in Infection and Inflammation.

PubMed

Gammoh, Nour Zahi; Rink, Lothar

2017-06-17

Micronutrient homeostasis is a key factor in maintaining a healthy immune system. Zinc is an essential micronutrient that is involved in the regulation of the innate and adaptive immune responses. The main cause of zinc deficiency is malnutrition. Zinc deficiency leads to cell-mediated immune dysfunctions among other manifestations. Consequently, such dysfunctions lead to a worse outcome in the response towards bacterial infection and sepsis. For instance, zinc is an essential component of the pathogen-eliminating signal transduction pathways leading to neutrophil extracellular traps (NET) formation, as well as inducing cell-mediated immunity over humoral immunity by regulating specific factors of differentiation. Additionally, zinc deficiency plays a role in inflammation, mainly elevating inflammatory response as well as damage to host tissue. Zinc is involved in the modulation of the proinflammatory response by targeting Nuclear Factor Kappa B (NF-κB), a transcription factor that is the master regulator of proinflammatory responses. It is also involved in controlling oxidative stress and regulating inflammatory cytokines. Zinc plays an intricate function during an immune response and its homeostasis is critical for sustaining proper immune function. This review will summarize the latest findings concerning the role of this micronutrient during the course of infections and inflammatory response and how the immune system modulates zinc depending on different stimuli.

Iron Biology, Immunology, Aging, and Obesity: Four Fields Connected by the Small Peptide Hormone Hepcidin12

PubMed Central

Dao, Maria Carlota; Meydani, Simin Nikbin

2013-01-01

Iron status and immune response become impaired in situations that involve chronic inflammation, such as obesity or aging. Little is known, however, about the additional burden that obesity may place on the iron status and immune response in the elderly. This question is relevant given the rising numbers of elderly obese (BMI >30 kg/m2) individuals and the high prevalence of iron deficiency worldwide. Iron is necessary for proper function of both the innate and adaptive immune system. Hepcidin, a peptide hormone that regulates cellular iron export, is essential for the maintenance of iron homeostasis. Therefore, since immune cells require iron for proper function hepcidin may also play an important role in immune response. In this review, we summarize the evidence for hepcidin as a link between the fields of gerontology, obesity, iron biology, and immunology. We also identify several gaps in knowledge and unanswered questions pertaining to iron homeostasis and immunity in obese populations. Finally, we review studies that have shown the impact of weight loss, focusing on calorie restriction, iron homeostasis, and immunity. These studies are important both in elucidating mechanistic links between obesity and health impairments and identifying possible approaches to target immune impairment and iron deficiency as comorbidities of obesity. PMID:24228190

Neuroimmune Basis of Methamphetamine Toxicity

PubMed Central

Loftis, Jennifer M.; Janowsky, Aaron

2015-01-01

Although it is not known which antigen-specific immune responses (or if antigen-specific immune responses) are relevant or required for methamphetamine's neurotoxic effects, it is apparent that methamphetamine exposure is associated with significant effects on adaptive and innate immunity. Alterations in lymphocyte activity and number, changes in cytokine signaling, impairments in phagocytic functions, and glial activation and gliosis have all been reported. These drug-induced changes in immune response, particularly within the CNS, are now thought to play a critical role in the addiction process for methamphetamine dependence as well as for other substance use disorders. In Section 2, methamphetamine's effects on glial cell (e.g., microglia and astrocytes) activity and inflammatory signaling cascades are summarized, including how alterations in immune cell function can induce the neurotoxic and addictive effects of methamphetamine. Section 2 also describes neurotransmitter involvement in the modulation of methamphetamine's inflammatory effects. Section 3 discusses the very recent use of pharmacological and genetic animal models which have helped elucidate the behavioral effects of methamphetamine's neurotoxic effects and the role of the immune system. Section 4 is focused on the effects of methamphetamine on blood–brain barrier integrity and associated immune consequences. Clinical considerations such as the combined effects of methamphetamine and HIV and/or HCV on brain structure and function are included in Section 4. Finally, in Section 5, immune-based treatment strategies are reviewed, with a focus on vaccine development, neuroimmune therapies, and other anti-inflammatory approaches. PMID:25175865

The effects of stress hormones on immune function may be vital for the adaptive reconfiguration of the immune system during fight-or-flight behavior.

PubMed

Adamo, Shelley A

2014-09-01

Intense, short-term stress (i.e., robust activation of the fight-or-flight response) typically produces a transient decline in resistance to disease in animals across phyla. Chemical mediators of the stress response (e.g., stress hormones) help induce this decline, suggesting that this transient immunosuppression is an evolved response. However, determining the function of stress hormones on immune function is difficult because of their complexity. Nevertheless, evidence suggests that stress hormones help maintain maximal resistance to disease during the physiological changes needed to optimize the body for intense physical activity. Work on insects demonstrates that stress hormones both shunt resources away from the immune system during fight-or-flight responses as well as reconfigure the immune system. Reconfiguring the immune system minimizes the impact of the loss of these resources and reduces the increased costs of some immune functions due to the physiological changes demanded by the fight-or-flight response. For example, during the stress response of the cricket Gryllus texensis, some molecular resources are shunted away from the immune system and toward lipid transport, resulting in a reduction in resistance to disease. However, insects' immune cells (hemocytes) have receptors for octopamine (the insect stress neurohormone). Octopamine increases many hemocyte functions, such as phagocytosis, and these changes would tend to mitigate the decline in immunity due to the loss of molecular resources. Moreover, because the stress response generates oxidative stress, some immune responses are probably more costly when activated during a stress response (e.g., those that produce reactive molecules). Some of these immune responses are depressed during stress in crickets, while others, whose costs are probably not increased during a stress response, are enhanced. Some effects of stress hormones on immune systems may be better understood as examples of reconfiguration rather than as mediating a trade-off. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Models to Study NK Cell Biology and Possible Clinical Application.

PubMed

Zamora, Anthony E; Grossenbacher, Steven K; Aguilar, Ethan G; Murphy, William J

2015-08-03

Natural killer (NK) cells are large granular lymphocytes of the innate immune system, responsible for direct targeting and killing of both virally infected and transformed cells. NK cells rapidly recognize and respond to abnormal cells in the absence of prior sensitization due to their wide array of germline-encoded inhibitory and activating receptors, which differs from the receptor diversity found in B and T lymphocytes that is due to the use of recombination-activation gene (RAG) enzymes. Although NK cells have traditionally been described as natural killers that provide a first line of defense prior to the induction of adaptive immunity, a more complex view of NK cells is beginning to emerge, indicating they may also function in various immunoregulatory roles and have the capacity to shape adaptive immune responses. With the growing appreciation for the diverse functions of NK cells, and recent technological advancements that allow for a more in-depth understanding of NK cell biology, we can now begin to explore new ways to manipulate NK cells to increase their clinical utility. In this overview unit, we introduce the reader to various aspects of NK cell biology by reviewing topics ranging from NK cell diversity and function, mouse models, and the roles of NK cells in health and disease, to potential clinical applications. © 2015 by John Wiley & Sons, Inc. Copyright © 2015 John Wiley & Sons, Inc.

CD98 at the crossroads of adaptive immunity and cancer

PubMed Central

Cantor, Joseph M.; Ginsberg, Mark H.

2012-01-01

Adaptive immunity, a vertebrate specialization, adds memory and exquisite specificity to the basic innate immune responses present in invertebrates while conserving metabolic resources. In adaptive immunity, antigenic challenge requires extremely rapid proliferation of rare antigen-specific lymphocytes to produce large, clonally expanded effector populations that neutralize pathogens. Rapid proliferation and resulting clonal expansion are dependent on CD98, a protein whose well-conserved orthologs appear restricted to vertebrates. Thus, CD98 supports lymphocyte clonal expansion to enable protective adaptive immunity, an advantage that could account for the presence of CD98 in vertebrates. CD98 supports lymphocyte clonal expansion by amplifying integrin signals that enable proliferation and prevent apoptosis. These integrin-dependent signals can also provoke cancer development and invasion, anchorage-independence and the rapid proliferation of tumor cells. CD98 is highly expressed in many cancers and contributes to formation of tumors in experimental models. Strikingly, vertebrates, which possess highly conserved CD98 proteins, CD98-binding integrins and adaptive immunity, also display propensity towards invasive and metastatic tumors. In this Commentary, we review the roles of CD98 in lymphocyte biology and cancer. We suggest that the CD98 amplification of integrin signaling in adaptive immunity provides survival benefits to vertebrates, which, in turn, bear the price of increased susceptibility to cancer. PMID:22499670

Reinterpreting recent thymic emigrant function: defective or adaptive?

PubMed

Cunningham, Cody A; Helm, Eric Y; Fink, Pamela J

2018-04-01

Recent thymic emigrants (RTEs) are those peripheral T cells that have most recently completed thymic development and egress. Over the past decade, significant advances have been made in understanding the cell-extrinsic and cell-intrinsic requirements for RTE maturation to mature naïve (MN) T cells and in detailing the functional differences that characterize these two T cell populations. Much of this work has suggested that RTEs are hypo-functional versions of more mature T cells. However, recent evidence has indicated that rather than being defective T cells, RTEs are exquisitely adapted to their cellular niche. In this review, we argue that RTEs are not flawed mature T cells but are adapted to fill an underpopulated T cell compartment, while maintaining self tolerance and possessing the capacity to mount robust immune responses. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phospholipase C-β in immune cells.

PubMed

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.

Phospholipase C-β in Immune Cells

PubMed Central

Kawakami, Toshiaki; Xiao, Wenbin

2013-01-01

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. PMID:23981313

Nucleic Acid Immunity.

PubMed

Hartmann, G

2017-01-01

Organisms throughout biology need to maintain the integrity of their genome. From bacteria to vertebrates, life has established sophisticated mechanisms to detect and eliminate foreign genetic material or to restrict its function and replication. Tremendous progress has been made in the understanding of these mechanisms which keep foreign or unwanted nucleic acids from viruses or phages in check. Mechanisms reach from restriction-modification systems and CRISPR/Cas in bacteria and archaea to RNA interference and immune sensing of nucleic acids, altogether integral parts of a system which is now appreciated as nucleic acid immunity. With inherited receptors and acquired sequence information, nucleic acid immunity comprises innate and adaptive components. Effector functions include diverse nuclease systems, intrinsic activities to directly restrict the function of foreign nucleic acids (e.g., PKR, ADAR1, IFIT1), and extrinsic pathways to alert the immune system and to elicit cytotoxic immune responses. These effects act in concert to restrict viral replication and to eliminate virus-infected cells. The principles of nucleic acid immunity are highly relevant for human disease. Besides its essential contribution to antiviral defense and restriction of endogenous retroelements, dysregulation of nucleic acid immunity can also lead to erroneous detection and response to self nucleic acids then causing sterile inflammation and autoimmunity. Even mechanisms of nucleic acid immunity which are not established in vertebrates are relevant for human disease when they are present in pathogens such as bacteria, parasites, or helminths or in pathogen-transmitting organisms such as insects. This review aims to provide an overview of the diverse mechanisms of nucleic acid immunity which mostly have been looked at separately in the past and to integrate them under the framework nucleic acid immunity as a basic principle of life, the understanding of which has great potential to advance medicine. © 2017 Elsevier Inc. All rights reserved.

The impact of eicosanoids on the crosstalk between innate and adaptive immunity: the key roles of dendritic cells.

PubMed

Harizi, H; Gualde, N

2005-06-01

The innate immune response is essentially the first line of defense against an invading pathogen. Through specialized receptors, known as pattern recognition receptors, especially Toll-like receptors, specialized cells of myeloid origin, including macrophages and dendritic cells (DCs) are able to phagocytose microorganisms and induce an innate inflammatory response. Although B and T lymphocytes recognize tissue antigens with high specificity, they are unable to initiate immune responses. The decision to activate an appropriate immune response is made by unique DC, the most professional antigen-presenting cells (APCs) which control the responses of several types of lymphocytes and play central role in the transition between innate and adaptive immunity. Increased secretion of inflammatory endogenous mediators such as cytokines and arachidonic acid-derived lipid mediators, also termed eicosanoids, can activate APC, particularly DC, which in turn induce an adaptive immune response. There is an increasing evidence that eicosanoids play an important role in connecting innate and adaptive immunity by acting on cells of both systems. Prostanoids, a major class of eicosanoids, have a great impact on inflammatory and immune responses. PGE(2) is one of the best known and most well-characterized prostanoids in terms of immunomodulation. Although cytokines are known as key regulators of immunity, eicosanoids, including PGE(2), PGD(2), LTB(4), and LTC(4), may also affect cells of immune system by modulating cytokine release, cell differentiation, survival, migration, antigen presentation, and apoptosis. By acting on various aspects of immune and inflammatory reactions, these lipid mediators emerge as key regulators of the crosstalk between innate and adaptive immunity.

Immune response

MedlinePlus

Innate immunity; Humoral immunity; Cellular immunity; Immunity; Inflammatory response; Acquired (adaptive) immunity ... normal and usually does not react against them. INNATE IMMUNITY Innate, or nonspecific, immunity is the defense ...

Innate and adaptive immune correlates of vaccine and adjuvant-induced control of mucosal transmission of SIV in macaques.

PubMed

Sui, Yongjun; Zhu, Qing; Gagnon, Susan; Dzutsev, Amiran; Terabe, Masaki; Vaccari, Monica; Venzon, David; Klinman, Dennis; Strober, Warren; Kelsall, Brian; Franchini, Genoveffa; Belyakov, Igor M; Berzofsky, Jay A

2010-05-25

Adjuvant effects on innate as well as adaptive immunity may be critical for inducing protection against mucosal HIV and simian immunodeficiency virus (SIV) exposure. We therefore studied effects of Toll-like receptor agonists and IL-15 as mucosal adjuvants on both innate and adaptive immunity in a peptide/poxvirus HIV/SIV mucosal vaccine in macaques, and made three critical observations regarding both innate and adaptive correlates of protection: (i) adjuvant-alone without vaccine antigen impacted the intrarectal SIVmac251 challenge outcome, correlating with surprisingly long-lived APOBEC3G (A3G)-mediated innate immunity; in addition, even among animals receiving vaccine with adjuvants, viral load correlated inversely with A3G levels; (ii) a surprising threshold-like effect existed for vaccine-induced adaptive immunity control of viral load, and only antigen-specific polyfunctional CD8(+) T cells correlated with protection, not tetramer(+) T cells, demonstrating the importance of T-cell quality; (iii) synergy was observed between Toll-like receptor agonists and IL-15 for driving adaptive responses through the up-regulation of IL-15Ralpha, which can present IL-15 in trans, as well as for driving the innate A3G response. Thus, strategic use of molecular adjuvants can provide better mucosal protection through induction of both innate and adaptive immunity.

Innate T cell responses in human gut.

PubMed

Meresse, Bertrand; Cerf-Bensussan, Nadine

2009-06-01

One arm of the gut-associated immune system is represented by a vast collection of T lymphocytes which participate in the subtle interplay between innate and adaptive immune mechanisms and maintain homeostasis at the main body external surface. Mounting data are providing exciting new insight into the innate-like mechanisms which enable intestinal T cells to rapidly sense local conditions and which broaden the spectrum of their functions and regulation at this strategic location. Herein we discuss how innate-like T cell recognition by unconventional T cell subsets and expression of innate NK receptors might modulate immune T cell responses in the human normal or diseased intestine.

Open conformers: the hidden face of MHC-I molecules.

PubMed

Arosa, Fernando A; Santos, Susana G; Powis, Simon J

2007-03-01

A pool of MHC-I molecules present at the plasma membrane can dissociate from the peptide and/or the light chain, becoming open MHC-I conformers. Whereas peptide-bound MHC-I molecules have an important role in regulating adaptive and innate immune responses, through trans-interactions with T cell and NK cell receptors, the function of the open MHC-I conformers is less clear but seems to be related to their inherent ability to cis-associate, both with themselves and with other receptors. Here, we review data indicating the open MHC-I conformers as regulators of ligand-receptor interactions and discuss the biological implications for immune and non-immune cells. The likelihood that the MHC-I heavy chains have hidden functions that are determined by the amino acid sequence of the alpha1 and alpha2 domains are discussed.

Immunometabolic circuits in trained immunity.

PubMed

Arts, Rob J W; Joosten, Leo A B; Netea, Mihai G

2016-10-01

The classical view that only adaptive immunity can build immunological memory has recently been challenged. Both in organisms lacking adaptive immunity as well as in mammals, the innate immune system can adapt to mount an increased resistance to reinfection, a de facto innate immune memory termed trained immunity. Recent studies have revealed that rewiring of cellular metabolism induced by different immunological signals is a crucial step for determining the epigenetic changes underlying trained immunity. Processes such as a shift of glucose metabolism from oxidative phosphorylation to aerobic glycolysis, increased glutamine metabolism and cholesterol synthesis, play a crucial role in these processes. The discovery of trained immunity opens the door for the design of novel generations of vaccines, for new therapeutic strategies for the treatment of immune deficiency states, and for modulation of exaggerated inflammation in autoinflammatory diseases. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Responses to Microbial Challenges by SLAMF Receptors

PubMed Central

van Driel, Boaz Job; Liao, Gongxian; Engel, Pablo; Terhorst, Cox

2016-01-01

The SLAMF family (SLAMF) of cell surface glycoproteins is comprised of nine glycoproteins and while SLAMF1, 3, 5, 6, 7, 8, and 9 are self-ligand receptors, SLAMF2 and SLAMF4 interact with each other. Their interactions induce signal transduction networks in trans, thereby shaping immune cell–cell communications. Collectively, these receptors modulate a wide range of functions, such as myeloid cell and lymphocyte development, and T and B cell responses to microbes and parasites. In addition, several SLAMF receptors serve as microbial sensors, which either positively or negatively modulate the function of macrophages, dendritic cells, neutrophils, and NK cells in response to microbial challenges. The SLAMF receptor–microbe interactions contribute both to intracellular microbicidal activity as well as to migration of phagocytes to the site of inflammation. In this review, we describe the current knowledge on how the SLAMF receptors and their specific adapters SLAM-associated protein and EAT-2 regulate innate and adaptive immune responses to microbes. PMID:26834746

Novel innate and adaptive lymphocytes: The new players in the pathogenesis of inflammatory upper airway diseases.

PubMed

Liu, Y; Yao, Y; Wang, Z-C; Ning, Q; Liu, Z

2018-06-01

Host immunity (innate and adaptive immunity) plays essential roles in the pathogenesis of inflammatory upper airway diseases, including allergic rhinitis and chronic rhinosinusitis. Recently, the discovery of novel innate immune cells, particularly innate lymphoid cells, has renewed our view on the role of innate immunity in inflammatory upper airway diseases. Meanwhile, the identification of new subsets of T helper (Th) cells, including Th22, Th9 and follicular Th cells, and regulatory B cells in the adaptive immunity, has broadened our knowledge on the complex immune networks in inflammatory upper airway diseases. In this review, we focus on these newly identified innate and adaptive lymphocytes with their contributions to the immunological disturbance in allergic rhinitis and chronic rhinosinusitis. We further discuss the perspective for future research and potential clinical utility of regulating these novel lymphocytes for the treatment of allergic rhinitis and chronic rhinosinusitis. © 2018 John Wiley & Sons Ltd.

Enhanced innate immune responses in a brood parasitic cowbird species: degranulation and oxidative burst

USGS Publications Warehouse

Hahn, D. Caldwell; Summers, Scott G.; Genovese, Kenneth J.; He, Haiqi; Kogut, Michael H.

2013-01-01

We examined the relative effectiveness of two innate immune responses in two species of New World blackbirds (Passeriformes, Icteridae) that differ in resistance to West Nile virus (WNV). We measured degranulation and oxidative burst, two fundamental components of phagocytosis, and we predicted that the functional effectiveness of these innate immune responses would correspond to the species' relative resistance to WNV. The brown-headed cowbird (Molothrus ater), an obligate brood parasite, had previously shown greater resistance to infection with WNV, lower viremia and faster recovery when infected, and lower subsequent antibody titers than the red-winged blackbird (Agelaius phoeniceus), a close relative that is not a brood parasite. We found that cowbird leukocytes were significantly more functionally efficient than those of the blackbird leukocytes and 50% more effective at killing the challenge bacteria. These results suggest that further examination of innate immunity in the cowbird may provide insight into adaptations that underlie its greater resistance to WNV. These results support an eco-immunological interpretation that species like the cowbird, which inhabit ecological niches with heightened exposure to parasites, experience evolutionary selection for more effective immune responses.

Toll-like receptor 7 is required for effective adaptive immune responses that prevent persistent virus infection.

PubMed

Walsh, Kevin B; Teijaro, John R; Zuniga, Elina I; Welch, Megan J; Fremgen, Daniel M; Blackburn, Shawn D; von Tiehl, Karl F; Wherry, E John; Flavell, Richard A; Oldstone, Michael B A

2012-06-14

TLR7 is an innate signaling receptor that recognizes single-stranded viral RNA and is activated by viruses that cause persistent infections. We show that TLR7 signaling dictates either clearance or establishment of life-long chronic infection by lymphocytic choriomeningitis virus (LCMV) Cl 13 but does not affect clearance of the acute LCMV Armstrong 53b strain. TLR7(-/-) mice infected with LCMV Cl 13 remained viremic throughout life from defects in the adaptive antiviral immune response-notably, diminished T cell function, exacerbated T cell exhaustion, decreased plasma cell maturation, and negligible antiviral antibody production. Adoptive transfer of TLR7(+/+) LCMV immune memory cells that enhanced clearance of persistent LCMV Cl 13 infection in TLR7(+/+) mice failed to purge LCMV Cl 13 infection in TLR7(-/-) mice, demonstrating that a TLR7-deficient environment renders antiviral responses ineffective. Therefore, methods that promote TLR7 signaling are promising treatment strategies for chronic viral infections. Copyright © 2012 Elsevier Inc. All rights reserved.

Identification and characterization of polyclonal αβ T cells with dendritic cell properties

PubMed Central

Kuka, Mirela; Munitic, Ivana; Ashwell, Jonathan D.

2012-01-01

An efficient immune response requires coordination between innate and adaptive immunity, which act through cells different in origin and function. Here we report the identification of thymus-derived αβ TCR+ cells that express CD11c and MHC class II, and require FLT3L for development (TDC). TDC express genes heretofore found uniquely in T cells or DC, as well as a distinctive signature of cytotoxicity-related genes. Unlike other innate T cell subsets, TDC have a polyclonal TCR repertoire andrespond to cognate antigens. However, they differ from conventional T cells in that they do not require help from antigen-presenting cells, respond to TLR-mediated stimulation by producing IL-12 and process and present antigen. The physiologic relevance of TDC, found in mice and humans, is still under investigation, but the fact that they combine key features of T and DC cells suggests that they provide a bridge between the innate and adaptive immune systems. PMID:23187623

Immune Responses to HCV and Other Hepatitis Viruses

PubMed Central

Park, Su-Hyung; Rehermann, Barbara

2014-01-01

Summary Five human hepatitis viruses cause most acute and chronic liver disease worldwide. Over the past 25 years hepatitis C virus (HCV) in particular has received much interest because of its ability to persist in most immunocompetent adults and the lack of a protective vaccine. Here we examine innate and adaptive immune responses to HCV infection. Although HCV activates an innate immune response, it employs an elaborate set of mechanisms to evade interferon (IFN)-based antiviral immunity. By comparing innate and adaptive immune responses to HCV with those to hepatitis A and B viruses, we suggest that prolonged innate immune activation impairs the development of successful adaptive immune responses. Comparative immunology furthermore provides insights into the maintenance of immune protection. We conclude by discussing prospects for an HCV vaccine and future research needs for the hepatitis viruses. PMID:24439265

The Involvement of MicroRNAs in Modulation of Innate and Adaptive Immunity in Systemic Lupus Erythematosus and Lupus Nephritis.

PubMed

Honarpisheh, Mohsen; Köhler, Paulina; von Rauchhaupt, Ekaterina; Lech, Maciej

2018-01-01

Noncoding RNAs (ncRNAs), including microRNAs (miRNAs), represent a family of RNA molecules that do not translate into protein. Nevertheless, they have the ability to regulate gene expression and play an essential role in immune cell differentiation and function. MicroRNAs were found to be differentially expressed in various tissues, and changes in their expression have been associated with several pathological processes. Yet, their roles in systemic lupus erythematosus (SLE) and lupus nephritis (LN) remain to be elucidated. Both SLE and LN are characterized by a complex dysfunction of the innate and adaptive immunity. Recently, significant findings have been made in understanding SLE through the use of genetic variant identification and expression pattern analysis and mouse models, as well as epigenetic analyses. Abnormalities in immune cell responses, cytokine and chemokine production, cell activation, and apoptosis have been linked to a unique expression pattern of a number of miRNAs that have been implicated in the immune pathogenesis of this autoimmune disease. The recent evidence that significantly increased the understanding of the pathogenesis of SLE drives a renewed interest in efficient therapy targets. This review aims at providing an overview of the current state of research on the expression and role of miRNAs in the immune pathogenesis of SLE and LN.

The Involvement of MicroRNAs in Modulation of Innate and Adaptive Immunity in Systemic Lupus Erythematosus and Lupus Nephritis

PubMed Central

Köhler, Paulina; von Rauchhaupt, Ekaterina

2018-01-01

Noncoding RNAs (ncRNAs), including microRNAs (miRNAs), represent a family of RNA molecules that do not translate into protein. Nevertheless, they have the ability to regulate gene expression and play an essential role in immune cell differentiation and function. MicroRNAs were found to be differentially expressed in various tissues, and changes in their expression have been associated with several pathological processes. Yet, their roles in systemic lupus erythematosus (SLE) and lupus nephritis (LN) remain to be elucidated. Both SLE and LN are characterized by a complex dysfunction of the innate and adaptive immunity. Recently, significant findings have been made in understanding SLE through the use of genetic variant identification and expression pattern analysis and mouse models, as well as epigenetic analyses. Abnormalities in immune cell responses, cytokine and chemokine production, cell activation, and apoptosis have been linked to a unique expression pattern of a number of miRNAs that have been implicated in the immune pathogenesis of this autoimmune disease. The recent evidence that significantly increased the understanding of the pathogenesis of SLE drives a renewed interest in efficient therapy targets. This review aims at providing an overview of the current state of research on the expression and role of miRNAs in the immune pathogenesis of SLE and LN. PMID:29854836

Visceral Inflammation and Immune Activation Stress the Brain

PubMed Central

Holzer, Peter; Farzi, Aitak; Hassan, Ahmed M.; Zenz, Geraldine; Jačan, Angela; Reichmann, Florian

2017-01-01

Stress refers to a dynamic process in which the homeostasis of an organism is challenged, the outcome depending on the type, severity, and duration of stressors involved, the stress responses triggered, and the stress resilience of the organism. Importantly, the relationship between stress and the immune system is bidirectional, as not only stressors have an impact on immune function, but alterations in immune function themselves can elicit stress responses. Such bidirectional interactions have been prominently identified to occur in the gastrointestinal tract in which there is a close cross-talk between the gut microbiota and the local immune system, governed by the permeability of the intestinal mucosa. External stressors disturb the homeostasis between microbiota and gut, these disturbances being signaled to the brain via multiple communication pathways constituting the gut–brain axis, ultimately eliciting stress responses and perturbations of brain function. In view of these relationships, the present article sets out to highlight some of the interactions between peripheral immune activation, especially in the visceral system, and brain function, behavior, and stress coping. These issues are exemplified by the way through which the intestinal microbiota as well as microbe-associated molecular patterns including lipopolysaccharide communicate with the immune system and brain, and the mechanisms whereby overt inflammation in the GI tract impacts on emotional-affective behavior, pain sensitivity, and stress coping. The interactions between the peripheral immune system and the brain take place along the gut–brain axis, the major communication pathways of which comprise microbial metabolites, gut hormones, immune mediators, and sensory neurons. Through these signaling systems, several transmitter and neuropeptide systems within the brain are altered under conditions of peripheral immune stress, enabling adaptive processes related to stress coping and resilience to take place. These aspects of the impact of immune stress on molecular and behavioral processes in the brain have a bearing on several disturbances of mental health and highlight novel opportunities of therapeutic intervention. PMID:29213271

Aryl hydrocarbon receptor promotes RORγt⁺ group 3 ILCs and controls intestinal immunity and inflammation.

PubMed

Qiu, Ju; Zhou, Liang

2013-11-01

Unlike adaptive immune cells that require antigen recognition and functional maturation during infection, innate lymphoid cells (ILCs) usually respond to pathogens promptly and serve as the first line of defense in infectious diseases. RAR-related orphan receptor (RORγt)⁺ group 3 ILCs are one of the innate cell populations that have recently been intensively studied. During the fetal stage of development, RORγt⁺ group 3 ILCs (e.g., lymphoid tissue inducer cells) are required for lymphoid organogenesis. In adult mice, RORγt⁺ group 3 ILCs are abundantly present in the gut to exert immune defensive functions. Under certain circumstances, however, RORγt⁺ group 3 ILCs can be pathogenic and contribute to intestinal inflammation. Aryl hydrocarbon receptor (Ahr), a ligand-dependent transcriptional factor, is widely expressed by various immune and non-immune cells. In the gut, the ligand for Ahr can be derived/generated from diet, microflora, and/or host cells. Ahr has been shown to regulate different cell populations in the immune system including RORγt⁺ group 3 ILCs, T helper (Th)17/22 cells, γδT cells, regulatory T cells (Tregs), Tr1 cells, and antigen presenting cells. In this review, we will focus on the development and function of RORγt⁺ group 3 ILCs, and discuss the role of Ahr in intestinal immunity and inflammation in mice and in humans. A better understanding of the function of Ahr in the gut is important for developing new therapeutic means to target Ahr in future treatment of infectious and autoimmune diseases.

A Brief Journey through the Immune System

PubMed Central

Yatim, Karim M.

2015-01-01

This review serves as an introduction to an Immunology Series for the Nephrologist published in CJASN. It provides a brief overview of the immune system, how it works, and why it matters to kidneys. This review describes in broad terms the main divisions of the immune system (innate and adaptive), their cellular and tissue components, and the ways by which they function and are regulated. The story is told through the prism of evolution in order to relay to the reader why the immune system does what it does and why imperfections in the system can lead to renal disease. Detailed descriptions of cell types, molecules, and other immunologic curiosities are avoided as much as possible in an effort to not detract from the importance of the broader concepts that define the immune system and its relationship to the kidney. PMID:25845377

Emerging concepts on the role of innate immunity in the prevention and control of HIV infection.

PubMed

Ackerman, Margaret E; Dugast, Anne-Sophie; Alter, Galit

2012-01-01

While neutralizing antibodies can provide sterilizing protection from HIV infection via their variable domains, the antibody constant domain provides a functional link between innate and adaptive immunity and offers a means to harness the potent antiviral properties of a wide spectrum of innate immune effector cells. There has been a growing appreciation of the role of these effector mechanisms across fields from cancer immunotherapy to autoimmunity and infectious disease, as well as speculation that this mechanism may be responsible for the protection observed in the RV144 HIV vaccine trial. This review summarizes these extraneutralizing humoral immune activities, progress in defining the importance of these effector mechanisms during progression in HIV infection, and the potential impact that such vaccine-induced immune responses may have on protection from infection.

IKKβ-induced inflammation impacts the kinetics but not the magnitude of the immune response to a viral vector

PubMed Central

Hopewell, Emily L.; Bronk, Crystina C.; Massengill, Michael; Engelman, Robert W.; Beg, Amer A.

2012-01-01

Microbial adjuvants in vaccines activate key transcription factors, including NF-κB and interferon response factors (IRFs). However, the individual role of these transcription factor pathways in promoting adaptive immunity by adjuvants is not clear. It is widely believed that induction of a strong inflammatory response potentiates an adaptive immune response. In this study, we sought to determine whether activation of the pro-inflammatory inhibitor of κB kinase β (IKKβ) canonical NF-κB pathway promoted vaccine-induced immune responses. An adenovirus expressing constitutively-activated IKKβ (AdIKK) induced robust DC maturation and high expression of key cytokines compared to a control virus. In vivo, AdIKK triggered rapid inflammation after pulmonary infection, increased leukocyte entry into draining LNs, and enhanced early antibody and T-cell responses. Notably, AdIKK did not influence the overall magnitude of the adaptive immune response. These results indicate that induction of inflammation by IKKβ/NF-κB in this setting impacts the kinetics but not the magnitude of adaptive immune responses. These findings therefore help define the individual role of a key pathway induced by vaccine adjuvants in promoting adaptive immunity. PMID:22161279

Tricking the balance: NK cells in anti-cancer immunity.

PubMed

Pahl, Jens; Cerwenka, Adelheid

2017-01-01

Natural Killer (NK) cells are classically considered innate immune effector cells involved in the first line of defense against infected and malignant cells. More recently, NK cells have emerged to acquire properties of adaptive immunity in response to certain viral infections such as expansion of specific NK cell subsets and long-lasting virus-specific responses to secondary challenges. NK cells distinguish healthy cells from abnormal cells by measuring the net input of activating and inhibitory signals perceived from target cells through NK cell surface receptors. Acquisition of activating ligands in combination with reduced expression of MHC class I molecules on virus-infected and cancer cells activates NK cell cytotoxicity and release of immunostimulatory cytokines like IFN-γ. In the cancer microenvironment however, NK cells become functionally impaired by inhibitory factors produced by immunosuppressive immune cells and cancer cells. Here we review recent progress on the role of NK cells in cancer immunity. We describe regulatory factors of the tumor microenvironment on NK cell function which determine cancer cell destruction or escape from immune recognition. Finally, recent strategies that focus on exploiting NK cell anti-cancer responses for immunotherapeutic approaches are outlined. Copyright © 2015 Elsevier GmbH. All rights reserved.

Host-selected mutations converging on a global regulator drive an adaptive leap towards symbiosis in bacteria

PubMed Central

Sabrina Pankey, M; Foxall, Randi L; Ster, Ian M; Perry, Lauren A; Schuster, Brian M; Donner, Rachel A; Coyle, Matthew; Cooper, Vaughn S; Whistler, Cheryl A

2017-01-01

Host immune and physical barriers protect against pathogens but also impede the establishment of essential symbiotic partnerships. To reveal mechanisms by which beneficial organisms adapt to circumvent host defenses, we experimentally evolved ecologically distinct bioluminescent Vibrio fischeri by colonization and growth within the light organs of the squid Euprymna scolopes. Serial squid passaging of bacteria produced eight distinct mutations in the binK sensor kinase gene, which conferred an exceptional selective advantage that could be demonstrated through both empirical and theoretical analysis. Squid-adaptive binK alleles promoted colonization and immune evasion that were mediated by cell-associated matrices including symbiotic polysaccharide (Syp) and cellulose. binK variation also altered quorum sensing, raising the threshold for luminescence induction. Preexisting coordinated regulation of symbiosis traits by BinK presented an efficient solution where altered BinK function was the key to unlock multiple colonization barriers. These results identify a genetic basis for microbial adaptability and underscore the importance of hosts as selective agents that shape emergent symbiont populations. DOI: http://dx.doi.org/10.7554/eLife.24414.001 PMID:28447935

Effects of ionizing radiation on the immune system with special emphasis on the interaction of dendritic and T cells.

PubMed

Manda, Katrin; Glasow, Annegret; Paape, Daniel; Hildebrandt, Guido

2012-01-01

Dendritic cells (DCs), as professional antigen-presenting cells, are members of the innate immune system and function as key players during the induction phase of adaptive immune responses. Uptake, processing, and presentation of antigens direct the outcome toward either tolerance or immunity. The cells of the immune system are among the most highly radiosensitive cells in the body. For high doses of ionizing radiation (HD-IR) both immune-suppressive effects after whole body irradiation and possible immune activation during tumor therapy were observed. On the other hand, the effects of low doses of ionizing radiation (LD-IR) on the immune system are controversial and seem to show high variability among different individuals and species. There are reports revealing that protracted LD-IR can result in radioresistance. But immune-suppressive effects of chronic LD-IR are also reported, including the killing or sensitizing of certain cell types. This article shall review the current knowledge of radiation-induced effects on the immune system, paying special attention to the interaction of DCs and T cells.

Malondialdehyde epitopes as targets of immunity and the implications for atherosclerosis

PubMed Central

Binder, Christoph J.

2018-01-01

Accumulating evidence suggests that oxidation-specific epitopes (OSEs) constitute a novel class of damage-associated molecular patterns (DAMPs) generated during high oxidative stress but also in the physiological process of apoptosis. To deal with the potentially harmful consequences of such epitopes, the immune system has developed several mechanisms to protect from OSEs and to orchestrate their clearance, including IgM natural antibodies and both cellular and membrane-bound receptors. Here, we focus on malondialdehyde (MDA) epitopes as prominent examples of OSEs that trigger both innate and adaptive immune responses. First, we review the mechanism of MDA generation, the different types of adducts on various biomolecules and provide relevant examples for physiological carriers of MDA such as apoptotic cells, microvesicles (MV) or oxidized low-density lipoproteins (LDL). Based on recent insights, we argue that MDA epitopes contribute to the maintenance of homeostatic functions by acting as markers of elevated oxidative stress and tissue damage. We discuss multiple lines of evidence that MDA epitopes are pro-inflammatory and thus important targets of innate and adaptive immune responses. Finally, we illustrate the relevance of MDA epitopes in human pathologies by describing their capacity to drive inflammatory processes in atherosclerosis and highlighting protective mechanisms of immunity that could be exploited for therapeutic purposes. PMID:27235680

The enduring tale of T cells in HIV immunopathogenesis

PubMed Central

Vajpayee, Madhu; Negi, Neema; Kurapati, Sravya

2013-01-01

HIV continues to be a major health problem worldwide even today. Owing to the intricate nature of its interactions with the immune system, HIV has remained an enigma that cleverly utilizes the host machinery to survive. Its ability to evade the host immune system, at both levels, innate and adaptive, allows the pathogen to replicate and transmit from one host to another. It has been shown that HIV has multipronged effects especially on the adaptive immunity, with CD4+ T cells being the worst affected T cell populations. Various analyses have revealed that the exposure to HIV results in clonal expansion and excessive activation of the immune system. Also, an abnormal process of differentiation has been observed suggestive of an alteration and blocks in the maturation of various T cell subsets. Additionally, HIV has shown to accelerate immunosenescence and exhaustion of the overtly activated T cells. Apart from causing phenotypic changes, HIV has adverse effects on the functional aspect of the immune system, with evidences implicating it in the loss of the capacity of T cells to secrete various antiviral cytokines and chemokines. However, there continues to be many aspects of the immunopathogenesis of HIV that are still unknown and thus require further research to convert the malaise of HIV into a manageable epidemic. PMID:24434321

Role of leptin as a link between metabolism and the immune system.

PubMed

Pérez-Pérez, Antonio; Vilariño-García, Teresa; Fernández-Riejos, Patricia; Martín-González, Jenifer; Segura-Egea, Juan José; Sánchez-Margalet, Víctor

2017-06-01

Leptin is an adipocyte-derived hormone not only with an important role in the central control of energy metabolism, but also with many pleiotropic effects in different physiological systems. One of these peripheral functions of leptin is a regulatory role in the interplay between energy metabolism and the immune system, being a cornerstone of the new field of immunometabolism. Leptin receptor is expressed throughout the immune system and the regulatory effects of leptin include cells from both the innate and adaptive immune system. Leptin is one of the adipokines responsible for the inflammatory state found in obesity that predisposes not only to type 2 diabetes, metabolic syndrome and cardiovascular disease, but also to autoimmune and allergic diseases. Leptin is an important mediator of the immunosuppressive state in undernutrition status. Placenta is the second source of leptin and it may play a role in the immunomodulation during pregnancy. Finally, recent work has pointed to the participation of leptin and leptin receptor in the pathophysiology of inflammation in oral biology. Therefore, leptin and leptin receptor should be considered for investigation as a marker of inflammation and immune activation in the frontier of innate-adaptive system, and as possible targets for intervention in the immunometabolic mediated pathophysiology. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

PubMed

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.

Galectin-9-CD44 interaction enhances stability and function of adaptive regulatory T cells | Center for Cancer Research

Cancer.gov

The β-galactoside-binding protein galectin-9 is critical in regulating the immune response, but the mechanism by which it functions remains unclear. We have demonstrated that galectin-9 is highly expressed by induced regulatory T cells (iTreg) and was crucial for the generation and function of iTreg cells, but not natural regulatory T (nTreg) cells. Galectin-9 expression

Innate Lymphoid Cells: A Promising New Regulator in Fibrotic Diseases.

PubMed

Zhang, Yi; Tang, Jun; Tian, Zhiqiang; van Velkinburgh, Jennifer C; Song, Jianxun; Wu, Yuzhang; Ni, Bing

2016-09-02

Fibrosis is a consequence of chronic inflammation and the persistent accumulation of extracellular matrix, for which the cycle of tissue injury and repair becomes a predominant feature. Both the innate and adaptive immune systems play key roles in the progress of fibrosis. The recently identified subsets of innate lymphoid cells (ILCs), which are mainly localize to epithelial surfaces, have been characterized as regulators of chronic inflammation and tissue remodeling, representing a functional bridge between the innate and adaptive immunity. Moreover, recent research has implicated ILCs as potential contributing factors to several kinds of fibrosis diseases, such as hepatic fibrosis and pulmonary fibrosis. Here, we will summarize and discuss the key roles of ILCs and their related factors in fibrotic diseases and their potential for translation to the clinic.

Dendritic Cell Immune Responses in HIV-1 Controllers.

PubMed

Martin-Gayo, Enrique; Yu, Xu G

2017-02-01

Robust HIV-1-specific CD8 T cell responses are currently regarded as the main correlate of immune defense in rare individuals who achieve natural, drug-free control of HIV-1; however, the mechanisms that support evolution of such powerful immune responses are not well understood. Dendritic cells (DCs) are specialized innate immune cells critical for immune recognition, immune regulation, and immune induction, but their possible contribution to HIV-1 immune defense in controllers remains ill-defined. Recent studies suggest that myeloid DCs from controllers have improved abilities to recognize HIV-1 through cytoplasmic immune sensors, resulting in more potent, cell-intrinsic type I interferon secretion in response to viral infection. This innate immune response may facilitate DC-mediated induction of highly potent antiviral HIV-1-specific T cells. Moreover, protective HLA class I isotypes restricting HIV-1-specific CD8 T cells may influence DC function through specific interactions with innate myelomonocytic MHC class I receptors from the leukocyte immunoglobulin-like receptor family. Bi-directional interactions between dendritic cells and HIV-1-specific T cells may contribute to natural HIV-1 immune control, highlighting the importance of a fine-tuned interplay between innate and adaptive immune activities for effective antiviral immune defense.

Interferon regulatory factor 5-dependent immune responses in the draining lymph node protect against West Nile virus infection.

PubMed

Thackray, Larissa B; Shrestha, Bimmi; Richner, Justin M; Miner, Jonathan J; Pinto, Amelia K; Lazear, Helen M; Gale, Michael; Diamond, Michael S

2014-10-01

Upon activation of Toll-like and RIG-I-like receptor signaling pathways, the transcription factor IRF5 translocates to the nucleus and induces antiviral immune programs. The recent discovery of a homozygous mutation in the immunoregulatory gene guanine exchange factor dedicator of cytokinesis 2 (Dock2mu/mu) in several Irf5-/- mouse colonies has complicated interpretation of immune functions previously ascribed to IRF5. To define the antiviral functions of IRF5 in vivo, we infected backcrossed Irf5-/-×Dock2wt/wt mice (here called Irf5-/- mice) and independently generated CMV-Cre Irf5fl/fl mice with West Nile virus (WNV), a pathogenic neurotropic flavivirus. Compared to congenic wild-type animals, Irf5-/- and CMV-Cre Irf5fl/fl mice were more vulnerable to WNV infection, and this phenotype was associated with increased infection in peripheral organs, which resulted in higher virus titers in the central nervous system. The loss of IRF5, however, was associated with only small differences in the type I interferon response systemically and in the draining lymph node during WNV infection. Instead, lower levels of several other proinflammatory cytokines and chemokines, as well as fewer and less activated immune cells, were detected in the draining lymph node 2 days after WNV infection. WNV-specific antibody responses in Irf5-/- mice also were blunted in the context of live or inactivated virus infection and this was associated with fewer antigen-specific memory B cells and long-lived plasma cells. Our results with Irf5-/- mice establish a key role for IRF5 in shaping the early innate immune response in the draining lymph node, which impacts the spread of virus infection, optimal B cell immunity, and disease pathogenesis. Although the roles of IRF3 and IRF7 in orchestrating innate and adaptive immunity after viral infection are established, the function of the related transcription factor IRF5 remains less certain. Prior studies in Irf5-/- mice reported conflicting results as to the contribution of IRF5 in regulating type I interferon and adaptive immune responses. The lack of clarity may stem from a recently discovered homozygous loss-of-function mutation of the immunoregulatory gene Dock2 in several colonies of Irf5-/- mice. Here, using a mouse model with a deficiency in IRF5 and wild-type Dock2 alleles, we investigated how IRF5 modulates West Nile virus (WNV) pathogenesis and host immune responses. Our in vivo studies indicate that IRF5 has a key role in shaping the early proinflammatory cytokine response in the draining lymph node, which impacts immunity and control of WNV infection. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

A surgeons' guide to renal transplant immunopathology, immunology, and immunosuppression.

PubMed

Gaber, Lillian W; Knight, Richard J; Patel, Samir J

2013-12-01

The response to allografting involves adaptive and innate immune mechanisms. In the adaptive system, activated T cells differentiate to cytotoxic effectors that attack the graft and trigger B cells to differentiation to plasma cells that produce anti-HLA antibodies. The innate immune system recognizes antigens in a non-specific manner and recruits immune cells to the graft through the productions of chemotactic factors, and activation of cytokines and the complement cascade. In the kidney the tubules and the endothelium are the targets of the rejection response. Immune suppression is effective in modulating the adaptive immune system effect on graft histology. Copyright © 2013 Elsevier Inc. All rights reserved.

Evolutionary plasticity of insect immunity.

PubMed

Vilcinskas, Andreas

2013-02-01

Many insect genomes have been sequenced and the innate immune responses of several species have been studied by transcriptomics, inviting the comparative analysis of immunity-related genes. Such studies have demonstrated significant evolutionary plasticity, with the emergence of novel proteins and protein domains correlated with insects adapting to both abiotic and biotic environmental stresses. This review article focuses on effector molecules such as antimicrobial peptides (AMPs) and proteinase inhibitors, which display greater evolutionary dynamism than conserved components such as immunity-related signaling molecules. There is increasing evidence to support an extended role for insect AMPs beyond defense against pathogens, including the management of beneficial endosymbionts. The total number of AMPs varies among insects with completed genome sequences, providing intriguing examples of immunity gene expansion and loss. This plasticity is discussed in the context of recent developments in evolutionary ecology suggesting that the maintenance and deployment of immune responses reallocates resources from other fitness-related traits thus requiring fitness trade-offs. Based on our recent studies using both model and non-model insects, I propose that insect immunity genes can be lost when alternative defense strategies with a lower fitness penalty have evolved, such as the so-called social immunity in bees, the chemical sanitation of the microenvironment by some beetles, and the release of antimicrobial secondary metabolites in the hemolymph. Conversely, recent studies provide evidence for the expansion and functional diversification of insect AMPs and proteinase inhibitors to reflect coevolution with a changing pathosphere and/or adaptations to habitats or food associated with microbial contamination. Copyright © 2012 Elsevier Ltd. All rights reserved.

Bench-to-bedside review: Functional relationships between coagulation and the innate immune response and their respective roles in the pathogenesis of sepsis

PubMed Central

Opal, Steven M; Esmon, Charles T

2003-01-01

The innate immune response system is designed to alert the host rapidly to the presence of an invasive microbial pathogen that has breached the integument of multicellular eukaryotic organisms. Microbial invasion poses an immediate threat to survival, and a vigorous defense response ensues in an effort to clear the pathogen from the internal milieu of the host. The innate immune system is able to eradicate many microbial pathogens directly, or innate immunity may indirectly facilitate the removal of pathogens by activation of specific elements of the adaptive immune response (cell-mediated and humoral immunity by T cells and B cells). The coagulation system has traditionally been viewed as an entirely separate system that has arisen to prevent or limit loss of blood volume and blood components following mechanical injury to the circulatory system. It is becoming increasingly clear that coagulation and innate immunity have coevolved from a common ancestral substrate early in eukaryotic development, and that these systems continue to function as a highly integrated unit for survival defense following tissue injury. The mechanisms by which these highly complex and coregulated defense strategies are linked together are the focus of the present review. PMID:12617738

Nutritional support to maintain proper immune status during intense training.

PubMed

Gleeson, Michael

2013-01-01

Prolonged exercise and heavy training are associated with depressed immune function which can increase the risk of picking up minor infections. To maintain robust immunity, athletes should eat a well-balanced diet sufficient to meet their energy, carbohydrate, protein, and micronutrient requirements. Dietary deficiencies of protein and specific micronutrients have long been associated with immune dysfunction and an adequate intake of iron, zinc, and vitamins A, D, E, B6 and B12 is particularly important in the maintenance of immune function. Consuming carbohydrate during prolonged strenuous exercise attenuates rises in stress hormones and appears to limit the degree of exercise-induced immune depression. Similar effects can be seen with daily ingestion of high-dose antioxidant vitamin supplements, though concerns have been expressed that excessive antioxidant intake may impair exercise training adaptations. It is safe to say with reasonable confidence that individual amino acids, colostrum, Echinacea, and zinc are unlikely to boost immunity or reduce infection risk in athletes. The ingestion of carbohydrate during exercise and daily consumption of probiotic and plant polyphenol (e.g. quercetin)-containing supplements or foodstuffs (e.g. non-alcoholic beer) currently offer the best chance of success. This approach is likely to be most effective for individuals who are particularly prone to illness. Copyright © 2013 Nestec Ltd., Vevey/S. Karger AG, Basel.

C-type lectins: their network and roles in pathogen recognition and immunity.

PubMed

Mayer, Sabine; Raulf, Marie-Kristin; Lepenies, Bernd

2017-02-01

C-type lectins (CTLs) represent the most complex family of animal/human lectins that comprises 17 different groups. During evolution, CTLs have developed by diversification to cover a broad range of glycan ligands. However, ligand binding by CTLs is not necessarily restricted to glycans as some CTLs also bind to proteins, lipids, inorganic molecules, or ice crystals. CTLs share a common fold that harbors a Ca 2+ for contact to the sugar and about 18 invariant residues in a phylogenetically conserved pattern. In vertebrates, CTLs have numerous functions, including serum glycoprotein homeostasis, pathogen sensing, and the initiation of immune responses. Myeloid CTLs in innate immunity are mainly expressed by antigen-presenting cells and play a prominent role in the recognition of a variety of pathogens such as fungi, bacteria, viruses, and parasites. However, myeloid CTLs such as the macrophage inducible CTL (Mincle) or Clec-9a may also bind to self-antigens and thus contribute to immune homeostasis. While some CTLs induce pro-inflammatory responses and thereby lead to activation of adaptive immune responses, other CTLs act as inhibitory receptors and dampen cellular functions. Since CTLs are key players in pathogen recognition and innate immunity, targeting CTLs may be a promising strategy for cell-specific delivery of drugs or vaccine antigens and to modulate immune responses.

The neonate versus adult mammalian immune system in cardiac repair and regeneration.

PubMed

Sattler, Susanne; Rosenthal, Nadia

2016-07-01

The immune system is a crucial player in tissue homeostasis and wound healing. A sophisticated cascade of events triggered upon injury ensures protection from infection and initiates and orchestrates healing. While the neonatal mammal can readily regenerate damaged tissues, adult regenerative capacity is limited to specific tissue types, and in organs such as the heart, adult wound healing results in fibrotic repair and loss of function. Growing evidence suggests that the immune system greatly influences the balance between regeneration and fibrotic repair. The neonate mammalian immune system has impaired pro-inflammatory function, is prone to T-helper type 2 responses and has an immature adaptive immune system skewed towards regulatory T cells. While these characteristics make infants susceptible to infection and prone to allergies, it may also provide an immunological environment permissive of regeneration. In this review we will give a comprehensive overview of the immune cells involved in healing and regeneration of the heart and explore differences between the adult and neonate immune system that may explain differences in regenerative ability. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel. Copyright © 2016 Elsevier B.V. All rights reserved.

Antigenic Variation and Immune Escape in the MTBC

PubMed Central

2017-01-01

Microbes that infect other organisms encounter host immune responses, and must overcome or evade innate and adaptive immune responses to successfully establish infection. Highly successful microbial pathogens, including M. tuberculosis, are able to evade adaptive immune responses (mediated by antibodies and/or T lymphocytes) and thereby establish long-term chronic infection. One mechanism that diverse pathogens use to evade adaptive immunity is antigenic variation, in which structural variants emerge that alter recognition by established immune responses and allow those pathogens to persist and/or to infect previously-immune hosts. Despite the wide use of antigenic variation by diverse pathogens, this mechanism appears to be infrequent in M. tuberculosis, as indicated by findings that known and predicted human T cell epitopes in this organism are highly conserved, although there are exceptions. These findings have implications for diagnostic tests that are based on measuring host immune responses, and for vaccine design and development. PMID:29116635

Eda haplotypes in three-spined stickleback are associated with variation in immune gene expression

PubMed Central

Robertson, Shaun; Bradley, Janette E.; MacColl, Andrew D. C.

2017-01-01

Haplotypes underlying local adaptation and speciation are predicted to have numerous phenotypic effects, but few genes involved have been identified, with much work to date concentrating on visible, morphological, phenotypes. The link between genes controlling these adaptive morphological phenotypes and the immune system has seldom been investigated, even though changes in the immune system could have profound adaptive consequences. The Eda gene in three-spined stickleback is one of the best studied major adaptation genes; it directly controls bony plate architecture and has been associated with additional aspects of adaptation to freshwater. Here, we exposed F2 hybrids, used to separate Eda genotype from genetic background, to contrasting conditions in semi-natural enclosures. We demonstrate an association between the Eda haplotype block and the expression pattern of key immune system genes. Furthermore, low plated fish grew less and experienced higher burdens of a common ectoparasite with fitness consequences. Little is currently known about the role of the immune system in facilitating adaptation to novel environments, but this study provides an indication of its potential importance. PMID:28195171

Serotonin mediated immunoregulation and neural functions: Complicity in the aetiology of autism spectrum disorders.

PubMed

Jaiswal, Preeti; Mohanakumar, Kochupurackal P; Rajamma, Usha

2015-08-01

Serotonergic system has long been implicated in the aetiology of autism spectrum disorders (ASD), since platelet hyperserotonemia is consistently observed in a subset of autistic patients, who respond well to selective serotonin reuptake inhibitors. Apart from being a neurotransmitter, serotonin functions as a neurotrophic factor directing brain development and as an immunoregulator modulating immune responses. Serotonin transporter (SERT) regulates serotonin level in lymphoid tissues to ensure its proper functioning in innate and adaptive responses. Immunological molecules such as cytokines in turn regulate the transcription and activity of SERT. Dysregulation of serotonergic system could trigger signalling cascades that affect normal neural-immune interactions culminating in neurodevelopmental and neural connectivity defects precipitating behavioural abnormalities, or the disease phenotypes. Therefore, we suggest that a better understanding of the cross talk between serotonergic genes, immune systems and serotonergic neurotransmission will open wider avenues to develop pharmacological leads for addressing the core ASD behavioural deficits. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dendritic cells and macrophages in the kidney: a spectrum of good and evil

PubMed Central

Rogers, NM; Ferenbach, DA; Isenberg, JS; Thomson, AW; Hughes, J

2015-01-01

Renal dendritic cells (DC) and macrophages (Mac) represent a constitutive, extensive and contiguous network of innate immune cells that provide sentinel and immune intelligence function. They induce and regulate inflammatory responses to freely-filtered antigenic material and protect the kidney from infection. Tissue–resident or infiltrating DC and Mac are key to the initiation and propagation of renal disease, as well as essential contributors to subsequent tissue regeneration regardless of its etiology and pathogenesis. Their identification, functional and phenotypic distinction, interplay and relationship with effector and regulatory adaptive immune cells is complex and incompletely understood. This review discusses both the common and distinct characteristics of these cells, as well as recent key advances in the field that have identified renal-specific functions of DC and Mac that enable these important, phagocytic, antigen-presenting, cells to mediate or mitigate intrinsic kidney disease. We also identify priority areas for further investigation and prospects for translational and therapeutic application of acquired knowledge. PMID:25266210

Change in the immune function of porcine iliac artery endothelial cells infected with porcine circovirus type 2 and its inhibition on monocyte derived dendritic cells maturation

PubMed Central

Liu, Shiyu; Zou, Zhanming; Zhu, Linlin; Liu, Xinyu; Zhou, Shuanghai

2017-01-01

Porcine circovirus-associated disease is caused by porcine circovirus type 2 (PCV2) infection, which targets iliac artery endothelial cells (PIECs); it leads to severe immunopathologies and is associated with major economic losses in the porcine industry. Here, we report that in vitro PCV2 infection of PIECs causes cell injury, which affects DC function as well as adaptive immunity. Specifically, PCV2 infection downregulated PIEC antigen-presenting molecule expression, upregulated cytokines involved in the immune and inflammatory response causing cell damage and repair, and altered the migratory capacity of PIECs. In addition, PCV2-infected PIECs inhibited DC maturation, enhanced the endocytic ability of DCs, and weakened the stimulatory effect of DCs on T lymphocytes. Together, these findings indicate that profound functional impairment of DCs in the presence of PCV2-infected PIECs may be a potential pathogenic mechanism associated with PCV2-induced porcine disease. PMID:29073194

Trans-nodal migration of resident dendritic cells into medullary interfollicular regions initiates immunity to influenza vaccine

PubMed Central

Woodruff, Matthew C.; Heesters, Balthasar A.; Herndon, Caroline N.; Groom, Joanna R.; Thomas, Paul G.; Luster, Andrew D.; Turley, Shannon J.

2014-01-01

Dendritic cells (DCs) are well established as potent antigen-presenting cells critical to adaptive immunity. In vaccination approaches, appropriately stimulating lymph node–resident DCs (LNDCs) is highly relevant to effective immunization. Although LNDCs have been implicated in immune response, their ability to directly drive effective immunity to lymph-borne antigen remains unclear. Using an inactive influenza vaccine model and whole node imaging approaches, we observed surprising responsiveness of LNDC populations to vaccine arrival resulting in a transnodal repositioning into specific antigen collection sites within minutes after immunization. Once there, LNDCs acquired viral antigen and initiated activation of viral specific CD4+ T cells, resulting in germinal center formation and B cell memory in the absence of skin migratory DCs. Together, these results demonstrate an unexpected stimulatory role for LNDCs where they are capable of rapidly locating viral antigen, driving early activation of T cell populations, and independently establishing functional immune response. PMID:25049334

Engineering Immunity: Modulating Dendritic Cell Subsets and Lymph Node Response to Direct Immune-polarization and Vaccine Efficacy

PubMed Central

Leleux, Jardin; Atalis, Alexandra; Roy, Krishnendu

2017-01-01

While successful vaccines have been developed against many pathogens, there are still many diseases and pathogenic infections that are highly evasive to current vaccination strategies. Thus, more sophisticated approaches to control the type and quality of vaccine-induced immune response must be developed. Dendritic cells (DCs) are the sentinels of the body and play a critical role in immune response generation and direction by bridging innate and adaptive immunity. It is now well recognized that DCs can be separated into many subgroups, each of which has a unique function. Better understanding of how various DC subsets, in lymphoid organs and in the periphery, can be targeted through controlled delivery; and how these subsets modulate and control the resulting immune response could greatly enhance our ability to develop new, effective vaccines against complex diseases. In this review, we provide an overview of DC subset biology and discuss current immunotherapeutic strategies that utilize DC targeting to modulate and control immune responses. PMID:26489733

Ancient Origins of Vertebrate-Specific Innate Antiviral Immunity

PubMed Central

Mukherjee, Krishanu; Korithoski, Bryan; Kolaczkowski, Bryan

2014-01-01

Animals deploy various molecular sensors to detect pathogen infections. RIG-like receptor (RLR) proteins identify viral RNAs and initiate innate immune responses. The three human RLRs recognize different types of RNA molecules and protect against different viral pathogens. The RLR protein family is widely thought to have originated shortly before the emergence of vertebrates and rapidly diversified through a complex process of domain grafting. Contrary to these findings, here we show that full-length RLRs and their downstream signaling molecules were present in the earliest animals, suggesting that the RLR-based immune system arose with the emergence of multicellularity. Functional differentiation of RLRs occurred early in animal evolution via simple gene duplication followed by modifications of the RNA-binding pocket, many of which may have been adaptively driven. Functional analysis of human and ancestral RLRs revealed that the ancestral RLR displayed RIG-1-like RNA-binding. MDA5-like binding arose through changes in the RNA-binding pocket following the duplication of the ancestral RLR, which may have occurred either early in Bilateria or later, after deuterostomes split from protostomes. The sensitivity and specificity with which RLRs bind different RNA structures has repeatedly adapted throughout mammalian evolution, suggesting a long-term evolutionary arms race with viral RNA or other molecules. PMID:24109602

Innate lymphoid cells in asthma: Will they take your breath away?

PubMed Central

Kim, Hye Young; Umetsu, Dale. T.; Dekruyff, Rosemarie H.

2016-01-01

Asthma is a complex and heterogeneous disease that is characterized by airway hyperreactivity (AHR) and airway inflammation. Although asthma was long thought to be driven by allergen-reactive Th2 cells, it has recently become clear that the pathogenesis of asthma is more complicated and associated with multiple pathways and cell types. A very exciting recent development was the discovery of innate lymphoid cells (ILCs) as key players in the pathogenesis of asthma. ILCs do not express antigen receptors but react promptly to “danger signals” from inflamed tissue and produce an array of cytokines that direct the ensuing immune response. The roles of ILCs may differ in distinct asthma phenotypes. ILC2s may be critical for initiation of adaptive immune responses in inhaled allergen-driven AHR, but may also function independently of adaptive immunity, mediating influenza-induced AHR. ILC2s also contribute to resolution of lung inflammation through their production of amphiregulin. Obesity-induced asthma, is associated with expansion of IL-17A-producing ILC3s in the lungs. Furthermore, ILCs may also contribute to steroid-resistant asthma. Although the precise roles of ILCs in different types of asthma are still under investigation, it is clear that inhibition of ILC function represents a potential target that could provide novel treatments for asthma. PMID:26891006

Ontogeny and function of murine epidermal Langerhans cells.

PubMed

Kaplan, Daniel H

2017-09-19

Langerhans cells (LCs) are epidermis-resident antigen-presenting cells that share a common ontogeny with macrophages but function as dendritic cells (DCs). Their development, recruitment and retention in the epidermis is orchestrated by interactions with keratinocytes through multiple mechanisms. LC and dermal DC subsets often show functional redundancy, but LCs are required for specific types of adaptive immune responses when antigen is concentrated in the epidermis. This Review will focus on those developmental and functional properties that are unique to LCs.

Type 1 Diabetes and Its Multi-Factorial Pathogenesis: The Putative Role of NK Cells

PubMed Central

Marca, Valeria La; Gianchecchi, Elena

2018-01-01

Type 1 diabetes (T1D) affects millions of people worldwide and is the prevalent form of all pediatric diabetes diagnoses. T1D is recognized to have an autoimmune etiology, since failure in specific self-tolerance mechanisms triggers immune reactions towards self-antigens and causes disease onset. Among all the different immunocytes involved in T1D etiopathogenesis, a relevant role of natural killer cells (NKs) is currently emerging. NKs represent the interface between innate and adaptive immunity; they intervene in the defense against infections and present, at the same time, typical features of the adaptive immune cells, such as expansion and generation of memory cells. Several recent studies, performed both in animal models and in human diabetic patients, revealed aberrations in NK cell frequency and functionality in the peripheral blood and in damaged tissues, suggesting their possible redirection towards affected tissues. NKs oscillate from a quiescent to an activated state through a delicate balance of activating and inhibitory signals transduced via surface receptors. Further accurate investigations are needed to elucidate the exact role of NKs in T1D, in order to develop novel immune-based therapies able to reduce the disease risk or delay its onset. PMID:29534427

Type 1 Diabetes and Its Multi-Factorial Pathogenesis: The Putative Role of NK Cells.

PubMed

Marca, Valeria La; Gianchecchi, Elena; Fierabracci, Alessandra

2018-03-10

Type 1 diabetes (T1D) affects millions of people worldwide and is the prevalent form of all pediatric diabetes diagnoses. T1D is recognized to have an autoimmune etiology, since failure in specific self-tolerance mechanisms triggers immune reactions towards self-antigens and causes disease onset. Among all the different immunocytes involved in T1D etiopathogenesis, a relevant role of natural killer cells (NKs) is currently emerging. NKs represent the interface between innate and adaptive immunity; they intervene in the defense against infections and present, at the same time, typical features of the adaptive immune cells, such as expansion and generation of memory cells. Several recent studies, performed both in animal models and in human diabetic patients, revealed aberrations in NK cell frequency and functionality in the peripheral blood and in damaged tissues, suggesting their possible redirection towards affected tissues. NKs oscillate from a quiescent to an activated state through a delicate balance of activating and inhibitory signals transduced via surface receptors. Further accurate investigations are needed to elucidate the exact role of NKs in T1D, in order to develop novel immune-based therapies able to reduce the disease risk or delay its onset.

The major histocompatibility complex class Ib molecule HLA-E at the interface between innate and adaptive immunity.

PubMed

Sullivan, L C; Clements, C S; Rossjohn, J; Brooks, A G

2008-11-01

The non-classical major histocompatibility complex (MHC) class I molecule human leucocyte antigen (HLA)-E is the least polymorphic of all the MHC class I molecules and acts as a ligand for receptors of both the innate and the adaptive immune systems. The recognition of self-peptides complexed to HLA-E by the CD94-NKG2A receptor expressed by natural killer (NK) cells represents a crucial checkpoint for immune surveillance by NK cells. However, HLA-E can also be recognised by the T-cell receptor expressed by alphabeta CD8 T cells and therefore can play a role in the adaptive immune response to invading pathogens. The recent resolution of HLA-E in complex with both innate and adaptive ligands has provided insight into the dual role of this molecule in immunity.

Metabolic Adaptations of CD4+ T Cells in Inflammatory Disease

PubMed Central

Dumitru, Cristina; Kabat, Agnieszka M.; Maloy, Kevin J.

2018-01-01

A controlled and self-limiting inflammatory reaction generally results in removal of the injurious agent and repair of the damaged tissue. However, in chronic inflammation, immune responses become dysregulated and prolonged, leading to tissue destruction. The role of metabolic reprogramming in orchestrating appropriate immune responses has gained increasing attention in recent years. Proliferation and differentiation of the T cell subsets that are needed to address homeostatic imbalance is accompanied by a series of metabolic adaptations, as T cells traveling from nutrient-rich secondary lymphoid tissues to sites of inflammation experience a dramatic shift in microenvironment conditions. How T cells integrate information about the local environment, such as nutrient availability or oxygen levels, and transfer these signals to functional pathways remains to be fully understood. In this review, we discuss how distinct subsets of CD4+ T cells metabolically adapt to the conditions of inflammation and whether these insights may pave the way to new treatments for human inflammatory diseases. PMID:29599783

The in Vitro Inhibitory Effect of Ectromelia Virus Infection on Innate and Adaptive Immune Properties of GM-CSF-Derived Bone Marrow Cells Is Mouse Strain-Independent

PubMed Central

Szulc-Dąbrowska, Lidia; Struzik, Justyna; Cymerys, Joanna; Winnicka, Anna; Nowak, Zuzanna; Toka, Felix N.; Gieryńska, Małgorzata

2017-01-01

Ectromelia virus (ECTV) belongs to the Orthopoxvirus genus of the Poxviridae family and is a natural pathogen of mice. Certain strains of mice are highly susceptible to ECTV infection and develop mousepox, a lethal disease similar to smallpox of humans caused by variola virus. Currently, the mousepox model is one of the available small animal models for investigating pathogenesis of generalized viral infections. Resistance and susceptibility to ECTV infection in mice are controlled by many genetic factors and are associated with multiple mechanisms of immune response, including preferential polarization of T helper (Th) immune response toward Th1 (protective) or Th2 (non-protective) profile. We hypothesized that viral-induced inhibitory effects on immune properties of conventional dendritic cells (cDCs) are more pronounced in ECTV-susceptible than in resistant mouse strains. To this extent, we confronted the cDCs from resistant (C57BL/6) and susceptible (BALB/c) mice with ECTV, regarding their reactivity and potential to drive T cell responses following infection. Our results showed that in vitro infection of granulocyte-macrophage colony-stimulating factor-derived bone marrow cells (GM-BM—comprised of cDCs and macrophages) from C57BL/6 and BALB/c mice similarly down-regulated multiple genes engaged in DC innate and adaptive immune functions, including antigen uptake, processing and presentation, chemokines and cytokines synthesis, and signal transduction. On the contrary, ECTV infection up-regulated Il10 in GM-BM derived from both strains of mice. Moreover, ECTV similarly inhibited surface expression of major histocompatibility complex and costimulatory molecules on GM-BM, explaining the inability of the cells to attain full maturation after Toll-like receptor (TLR)4 agonist treatment. Additionally, cells from both strains of mice failed to produce cytokines and chemokines engaged in T cell priming and Th1/Th2 polarization after TLR4 stimulation. These data strongly suggest that in vitro modulation of GM-BM innate and adaptive immune functions by ECTV occurs irrespective of whether the mouse strain is susceptible or resistant to infection. Moreover, ECTV limits the GM-BM (including cDCs) capacity to stimulate protective Th1 immune response. We cannot exclude that this may be an important factor in the generation of non-protective Th2 immune response in susceptible BALB/c mice in vivo. PMID:29312229

The role of the innate immune system in destruction of pancreatic beta cells in NOD mice and humans with type I diabetes

PubMed Central

Tai, Ningwen; Wong, F. Susan; Wen, Li

2016-01-01

Type 1 diabetes (T1D) is an organ-specific autoimmune disease characterized by T cell-mediated destruction of the insulin-producing pancreatic β cells. A combination of genetic and environmental factors eventually leads to the loss of functional β cells mass and hyperglycemia. Both innate and adaptive immunity are involved in the development of T1D. In this review, we have highlighted the most recent findings on the role of innate immunity, especially the pattern recognition receptors (PRRs), in disease development. In murine models and human studies, different PRRs, such as toll-like receptors (TLRs) and nucleotide-binding domain, leucine-rich repeat-containing (or NOD-like) receptors (NLRs), have different roles in the pathogenesis of T1D. These PRRs play a critical role in defending against infection by sensing specific ligands derived from exogenous microorganisms to induce innate immune responses and shape adaptive immunity. Animal studies have shown that TLR7, TLR9, MyD88 and NLPR3 play a disease-predisposing role in T1D, while controversial results have been found with other PRRs, such as TLR2, TLR3, TLR4, TLR5 and others. Human studies also shown that TLR2, TLR3 and TLR4 are expressed in either islet β cells or infiltrated immune cells, indicating the innate immunity plays a role in β cell autoimmunity. Furthermore, some human genetic studies showed a possible association of TLR3, TLR7, TLR8 or NLRP3 genes, at single nucleotide polymorphism (SNP) level, with human T1D. Increasing evidence suggest that the innate immunity modulates β cell autoimmunity. Thus, targeting pathways of innate immunity may provide novel therapeutic strategies to fight this disease. PMID:27021275

Staphylococcus aureus innate immune evasion is lineage-specific: a bioinfomatics study.

PubMed

McCarthy, Alex J; Lindsay, Jodi A

2013-10-01

Staphylococcus aureus is a major human pathogen, and is targeted by the host innate immune system. In response, S. aureus genomes encode dozens of secreted proteins that inhibit complement, chemotaxis and neutrophil activation resulting in successful evasion of innate immune responses. These proteins include immune evasion cluster proteins (IEC; Chp, Sak, Scn), staphylococcal superantigen-like proteins (SSLs), phenol soluble modulins (PSMs) and several leukocidins. Biochemical studies have indicated that genetic variants of these proteins can have unique functions. To ascertain the scale of genetic variation in secreted immune evasion proteins, whole genome sequences of 88 S. aureus isolates, representing 25 clonal complex (CC) lineages, in the public domain were analysed across 43 genes encoding 38 secreted innate immune evasion protein complexes. Twenty-three genes were variable, with between 2 and 15 variants, and the variants had lineage-specific distributions. They include genes encoding Eap, Ecb, Efb, Flipr/Flipr-like, Hla, Hld, Hlg, Sbi, Scin-B/C and 13 SSLs. Most of these protein complexes inhibit complement, chemotaxis and neutrophil activation suggesting that isolates from each S. aureus lineage respond to the innate immune system differently. In contrast, protein complexes that lyse neutrophils (LukSF-PVL, LukMF, LukED and PSMs) were highly conserved, but can be carried on mobile genetic elements (MGEs). MGEs also encode proteins with narrow host-specificities arguing that their acquisition has important roles in host/environmental adaptation. In conclusion, this data suggests that each lineage of S. aureus evades host immune responses differently, and that isolates can adapt to new host environments by acquiring MGEs and the immune evasion protein complexes that they encode. Cocktail therapeutics that targets multiple variant proteins may be the most appropriate strategy for controlling S. aureus infections. Copyright © 2013 Elsevier B.V. All rights reserved.

Long noncoding RNA in hematopoiesis and immunity.

PubMed

Satpathy, Ansuman T; Chang, Howard Y

2015-05-19

Dynamic gene expression during cellular differentiation is tightly coordinated by transcriptional and post-transcriptional mechanisms. An emerging theme is the central role of long noncoding RNAs (lncRNAs) in the regulation of this specificity. Recent advances demonstrate that lncRNAs are expressed in a lineage-specific manner and control the development of several cell types in the hematopoietic system. Moreover, specific lncRNAs are induced to modulate innate and adaptive immune responses. lncRNAs can function via RNA-DNA, RNA-RNA, and RNA-protein target interactions. As a result, they affect several stages of gene regulation, including chromatin modification, mRNA biogenesis, and protein signaling. We discuss recent advances, future prospects, and challenges in understanding the roles of lncRNAs in immunity and immune-mediated diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

Homeostatic Immunity and the Microbiota.

PubMed

Belkaid, Yasmine; Harrison, Oliver J

2017-04-18

The microbiota plays a fundamental role in the induction, education, and function of the host immune system. In return, the host immune system has evolved multiple means by which to maintain its symbiotic relationship with the microbiota. The maintenance of this dialogue allows the induction of protective responses to pathogens and the utilization of regulatory pathways involved in the sustained tolerance to innocuous antigens. The ability of microbes to set the immunological tone of tissues, both locally and systemically, requires tonic sensing of microbes and complex feedback loops between innate and adaptive components of the immune system. Here we review the dominant cellular mediators of these interactions and discuss emerging themes associated with our current understanding of the homeostatic immunological dialogue between the host and its microbiota. Published by Elsevier Inc.

Histone deacetylases as regulators of inflammation and immunity.

PubMed

Shakespear, Melanie R; Halili, Maria A; Irvine, Katharine M; Fairlie, David P; Sweet, Matthew J

2011-07-01

Histone deacetylases (HDACs) remove an acetyl group from lysine residues of target proteins to regulate cellular processes. Small-molecule inhibitors of HDACs cause cellular growth arrest, differentiation and/or apoptosis, and some are used clinically as anticancer drugs. In animal models, HDAC inhibitors are therapeutic for several inflammatory diseases, but exacerbate atherosclerosis and compromise host defence. Loss of HDAC function has also been linked to chronic lung diseases in humans. These contrasting effects might reflect distinct roles for individual HDACs in immune responses. Here, we review the current understanding of innate and adaptive immune pathways that are regulated by classical HDAC enzymes. The objective is to provide a rationale for targeting (or not targeting) individual HDAC enzymes with inhibitors for future immune-related applications. Copyright © 2011 Elsevier Ltd. All rights reserved.

CD22 and Siglec-G in B cell function and tolerance

PubMed Central

Poe, Jonathan C.; Tedder, Thomas F.

2012-01-01

The immune system has evolved into two main arms, the primitive innate arm that is the first line of defense but relatively short-lived and broad acting, and the advanced adaptive arm that generates immunologic “memory” allowing rapid, specific recall responses. T cell-independent type-2 (TI-2) antigens (Ags) invoke innate immune responses. However, due to its “at the ready” nature, how the innate arm of the immune system maintains tolerance to potentially abundant host TI-2 Ags remains elusive. Therefore, it is important to define the mechanisms that establish innate immune tolerance. This review highlights recent insights into B cell tolerance to theoretical self TI-2 Ags, and examines how the B cell-restricted Siglecs, CD22 and Siglec-G, might contribute to this process. PMID:22677186

Homeostatic immunity and the microbiota

PubMed Central

Belkaid, Yasmine; Harrison, Oliver J.

2017-01-01

The microbiota plays a fundamental role in the induction, education and function of the host immune system. In return, the host immune system has evolved multiple means by which to maintain its symbiotic relationship with the microbiota. The maintenance of this dialogue allows the induction of protective responses to pathogens and the utilization of regulatory pathways involved in the sustained tolerance to innocuous antigens. The ability of microbes to set the immunological tone of tissues, both locally and systemically, requires tonic sensing of microbes and complex feedback loops between innate and adaptive components of the immune system. In this review, we will highlight the dominant cellular mediators of these interactions and discuss emerging themes associated with our current understanding of the homeostatic immunological dialogue between the host and its microbiota. PMID:28423337

The role of the thymus in allogeneic hematopoietic stem cell transplantation.

PubMed

Krenger, Werner; Holländer, Georg A

2010-07-19

Allogeneic haematopoietic stem cell transplantation (HSCT) is used to treat an increasing number of congenital and acquired disorders of the haematopoietic system. Even though cytoreductive conditioning regimens vary in intensity, all clinically used protocols invariably cause side effects that compromise transiently or long-term the response of the natural and the adaptive immune systems. However, in the context of the reconstruction of immunity, the generation of naïve T cells constitutes a slow process, and requires a functionally competent thymus. Unfortunately, regular thymic function is frequently suppressed by transplant-related toxicities. Most notably, graft-versus-host disease (GVHD) causes a state of posttransplantation immune deficiency. Here we discuss preclinical allogeneic HSCT models and clinical observations that have contributed to a detailed understanding of the cellular and molecular mechanisms responsible for the thymic dysfunction caused by acute GVHD. An in-depth knowledge of the mechanisms that control regular thymopoiesis and, conversely, affect thymus function is expected to provide the factual basis for the design of innovative therapies to recover T-cell numbers and function following allogeneic HSCT.

Quantifying Adaptive and Innate Immune Responses in HIV-Infected Participants Using a Novel High Throughput Assay.

PubMed

Yong, Michelle K; Cameron, Paul U; Spelman, Tim; Elliott, Julian H; Fairley, Christopher K; Boyle, Jeffrey; Miyamasu, Misato; Lewin, Sharon R

2016-01-01

HIV infection is characterised by persistent immune dysfunction of both the adaptive and innate immune responses. The aim of this study was to evaluate these responses using a novel high throughput assay in healthy controls and HIV-infected individuals prior to and following anti-retroviral treatment (ART). Cross-sectional study. Whole blood was assessed using the QuantiFERON Monitor® (QFM) assay containing adaptive and innate immunostimulants. Interferon (IFN)-γ levels (IU/mL) were measured by enzyme-linked immunosorbent assay (ELISA). We recruited HIV-infected participants (n = 20 off ART and viremic; n = 59 on suppressive ART) and HIV-uninfected controls (n = 229). Median IFN-γ production was significantly higher in HIV-infected participants compared to controls (IFN-γ 512 vs 223 IU/ml, p<0.0001), but within the HIV-infected participants there was no difference between those on or off ART (median IFN-γ 512 vs 593 IU/ml p = 0.94). Amongst the HIV-infected participants, IFN-γ production was higher in individuals with CD4 count>350 compared to <350 cells/μL (IFN-γ IU/ml 561 vs 259 p = 0.02) and in males compared to females (IFN-γ 542 vs 77 IU/ml p = 0.04). There were no associations between IFN-γ production and age, plasma HIV RNA, nadir CD4 count or duration of HIV infection. Using a multivariable analysis, neither CD4 nor sex were independently predictive of IFN-γ production. Using a high throughput assay which assesses both adaptive and innate immune function, we showed elevated IFN-γ production in HIV-infected patients both on and off ART. Further research is warranted to determine if changes in QuantiFERON Monitor® are associated with clinical outcomes.

Phenotypic, ultra-structural and functional characterization of bovine peripheral blood dendritic cell subsets

USDA-ARS?s Scientific Manuscript database

Dendritic cells (DC) are multifunctional cells that bridge the gap between innate and adaptive immune systems. In bovine, significant information is lacking on the precise identity and role of peripheral blood DC subsets. In this study, we identify and characterize bovine peripheral blood DC subsets...

Cytomegalovirus immune evasion by perturbation of endosomal trafficking

PubMed Central

Lučin, Pero; Mahmutefendić, Hana; Blagojević Zagorac, Gordana; Ilić Tomaš, Maja

2015-01-01

Cytomegaloviruses (CMVs), members of the herpesvirus family, have evolved a variety of mechanisms to evade the immune response to survive in infected hosts and to establish latent infection. They effectively hide infected cells from the effector mechanisms of adaptive immunity by eliminating cellular proteins (major histocompatibility Class I and Class II molecules) from the cell surface that display viral antigens to CD8 and CD4 T lymphocytes. CMVs also successfully escape recognition and elimination of infected cells by natural killer (NK) cells, effector cells of innate immunity, either by mimicking NK cell inhibitory ligands or by downregulating NK cell-activating ligands. To accomplish these immunoevasion functions, CMVs encode several proteins that function in the biosynthetic pathway by inhibiting the assembly and trafficking of cellular proteins that participate in immune recognition and thereby, block their appearance at the cell surface. However, elimination of these proteins from the cell surface can also be achieved by perturbation of their endosomal route and subsequent relocation from the cell surface into intracellular compartments. Namely, the physiological route of every cellular protein, including immune recognition molecules, is characterized by specific features that determine its residence time at the cell surface. In this review, we summarize the current understanding of endocytic trafficking of immune recognition molecules and perturbations of the endosomal system during infection with CMVs and other members of the herpesvirus family that contribute to their immune evasion mechanisms. PMID:25263490

Actin Engine in Immunological Synapse

PubMed Central

Piragyte, Indre

2012-01-01

T cell activation and function require physical contact with antigen presenting cells at a specialized junctional structure known as the immunological synapse. Once formed, the immunological synapse leads to sustained T cell receptor-mediated signalling and stabilized adhesion. High resolution microscopy indeed had a great impact in understanding the function and dynamic structure of immunological synapse. Trends of recent research are now moving towards understanding the mechanical part of immune system, expanding our knowledge in mechanosensitivity, force generation, and biophysics of cell-cell interaction. Actin cytoskeleton plays inevitable role in adaptive immune system, allowing it to bear dynamic and precise characteristics at the same time. The regulation of mechanical engine seems very complicated and overlapping, but it enables cells to be very sensitive to external signals such as surface rigidity. In this review, we focus on actin regulators and how immune cells regulate dynamic actin rearrangement process to drive the formation of immunological synapse. PMID:22916042

An evolutionary perspective on the systems of adaptive immunity.

PubMed

Müller, Viktor; de Boer, Rob J; Bonhoeffer, Sebastian; Szathmáry, Eörs

2018-02-01

We propose an evolutionary perspective to classify and characterize the diverse systems of adaptive immunity that have been discovered across all major domains of life. We put forward a new function-based classification according to the way information is acquired by the immune systems: Darwinian immunity (currently known from, but not necessarily limited to, vertebrates) relies on the Darwinian process of clonal selection to 'learn' by cumulative trial-and-error feedback; Lamarckian immunity uses templated targeting (guided adaptation) to internalize heritable information on potential threats; finally, shotgun immunity operates through somatic mechanisms of variable targeting without feedback. We argue that the origin of Darwinian (but not Lamarckian or shotgun) immunity represents a radical innovation in the evolution of individuality and complexity, and propose to add it to the list of major evolutionary transitions. While transitions to higher-level units entail the suppression of selection at lower levels, Darwinian immunity re-opens cell-level selection within the multicellular organism, under the control of mechanisms that direct, rather than suppress, cell-level evolution for the benefit of the individual. From a conceptual point of view, the origin of Darwinian immunity can be regarded as the most radical transition in the history of life, in which evolution by natural selection has literally re-invented itself. Furthermore, the combination of clonal selection and somatic receptor diversity enabled a transition from limited to practically unlimited capacity to store information about the antigenic environment. The origin of Darwinian immunity therefore comprises both a transition in individuality and the emergence of a new information system - the two hallmarks of major evolutionary transitions. Finally, we present an evolutionary scenario for the origin of Darwinian immunity in vertebrates. We propose a revival of the concept of the 'Big Bang' of vertebrate immunity, arguing that its origin involved a 'difficult' (i.e. low-probability) evolutionary transition that might have occurred only once, in a common ancestor of all vertebrates. In contrast to the original concept, we argue that the limiting innovation was not the generation of somatic diversity, but the regulatory circuitry needed for the safe operation of amplifiable immune responses with somatically acquired targeting. Regulatory complexity increased abruptly by genomic duplications at the root of the vertebrate lineage, creating a rare opportunity to establish such circuitry. We discuss the selection forces that might have acted at the origin of the transition, and in the subsequent stepwise evolution leading to the modern immune systems of extant vertebrates. © 2017 The Authors. Biological Reviews published by John Wiley & Sons Ltd on behalf of Cambridge Philosophical Society.

Statistical Physics of T-Cell Development and Pathogen Specificity

NASA Astrophysics Data System (ADS)

Košmrlj, Andrej; Kardar, Mehran; Chakraborty, Arup K.

2013-04-01

In addition to an innate immune system that battles pathogens in a nonspecific fashion, higher organisms, such as humans, possess an adaptive immune system to combat diverse (and evolving) microbial pathogens. Remarkably, the adaptive immune system mounts pathogen-specific responses, which can be recalled upon reinfection with the same pathogen. It is difficult to see how the adaptive immune system can be preprogrammed to respond specifically to a vast and unknown set of pathogens. Although major advances have been made in understanding pertinent molecular and cellular phenomena, the precise principles that govern many aspects of an immune response are largely unknown. We discuss complementary approaches from statistical mechanics and cell biology that can shed light on how key components of the adaptive immune system, T cells, develop to enable pathogen-specific responses against many diverse pathogens. The mechanistic understanding that emerges has implications for how host genetics may influence the development of T cells with differing responses to the human immunodeficiency virus (HIV) infection.

Senescence in immune priming and attractiveness in a beetle.

PubMed

Daukšte, J; Kivleniece, I; Krama, T; Rantala, M J; Krams, I

2012-07-01

Age-related decline in immune activity is referred to as immunosenescence and has been observed for both the adaptive immune response of vertebrates and the innate immune system of invertebrates. Because maintaining a basic level of immune defence and mounting an immune response is costly, optimal investment in immune function should vary over a wide range of individual states such as the individual's age. In this study, we tested whether the immune response and immunological priming within individuals become less efficient with age using mealworm beetles, Tenebrio molitor, as a model organism. We also tested whether ageing and immunological priming affected the odours produced by males. We found that young males of T. molitor were capable of mounting an immune response a sterile nylon monofilament implant with the potential to exhibit a simple form of immune memory through mechanisms of immune priming. Older males did not increase their immune response to a second immune challenge, which negatively affected their sexual attractiveness and remaining life span. Our results indicate that the immune system of older males in T. molitor is less effective, suggesting complex evolutionary trade-offs between ageing, immune response and sexual attractiveness. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

The Effects of Environment and Physiological Cyclicity on the Immune System of Viperinae

PubMed Central

Kobolkuti, Lorand; Cadar, Daniel; Czirjak, Gabor; Niculae, Mihaela; Kiss, Timea; Sandru, Carmen; Spinu, Marina

2012-01-01

One of the important aspects of species' survival is connected with global climate changes, which also conditions the epidemiology of infectious diseases. Poikilotherms are exposed, as other species, to climatic influence, especially due to their physiological peculiarities such as important stages of their life cycle: hibernation, shedding, and active phase. The immune system serves as an accurate indicator of the health status and stress levels in these species. This study aimed to monitor the changes of innate (leukocyte subpopulations and total immune globulins) and adaptive immunity (in vitro leukocyte blast transformation) of two viper species, V. berus berus and V. ammodytes ammodytes, endemic in Europe and spread in different regions of Romania during their three major life cycles, hibernation, shedding, and active phase. The results indicated that seasonal variance and cycle rather than species and regional distribution influence the functionality of the immune system. PMID:22547989

Kidney dendritic cells in acute and chronic renal disease.

PubMed

Hochheiser, Katharina; Tittel, André; Kurts, Christian

2011-06-01

Dendritic cells are not only the master regulators of adaptive immunity, but also participate profoundly in innate immune responses. Much has been learned about their basic immunological functions and their roles in various diseases. Comparatively little is still known about their role in renal disease, despite their obvious potential to affect immune responses in the kidney, and immune responses that are directed against renal components. Kidney dendritic cells form an abundant network in the renal tubulointerstitium and constantly survey the environment for signs of injury or infection, in order to alert the immune system to the need to initiate defensive action. Recent studies have identified a role for dendritic cells in several murine models of acute renal injury and chronic nephritis. Here we summarize the current knowledge on the role of kidney dendritic cells that has been obtained from the study of murine models of renal disease. © 2010 The Authors. Journal compilation © 2010 Blackwell Publishing Ltd.

Zinc Signals and Immunity.

PubMed

Maywald, Martina; Wessels, Inga; Rink, Lothar

2017-10-24

Zinc homeostasis is crucial for an adequate function of the immune system. Zinc deficiency as well as zinc excess result in severe disturbances in immune cell numbers and activities, which can result in increased susceptibility to infections and development of especially inflammatory diseases. This review focuses on the role of zinc in regulating intracellular signaling pathways in innate as well as adaptive immune cells. Main underlying molecular mechanisms and targets affected by altered zinc homeostasis, including kinases, caspases, phosphatases, and phosphodiesterases, will be highlighted in this article. In addition, the interplay of zinc homeostasis and the redox metabolism in affecting intracellular signaling will be emphasized. Key signaling pathways will be described in detail for the different cell types of the immune system. In this, effects of fast zinc flux, taking place within a few seconds to minutes will be distinguish from slower types of zinc signals, also designated as "zinc waves", and late homeostatic zinc signals regarding prolonged changes in intracellular zinc.

The effects of commensal bacteria on innate immune responses in the female genital tract

PubMed Central

Mirmonsef, P; Gilbert, D; Zariffard, MR; Hamaker, BR; Kaur, A; Landay, AL; Spear, GT

2013-01-01

The innate and adaptive immune systems are important mechanisms for resistance to pathogens in the female lower genital tract. Lactobacilli at this site help maintain a healthy vagina by producing several factors including lactic acid. Indeed, bacterial vaginosis, a condition in which the genital microbiota is altered, is strongly associated with increased rates of a number of infections including HIV. However, the precise factors that contribute to increased rates of microbial and viral infections in bacterial vaginosis remain to be elucidated. We have studied the effects of bacterial microbiota in the lower genital tract on innate immunity and have found that Toll-like receptor ligands and short chain fatty acids, produced by bacterial microbiota, have dramatic effects on immune function. In this review, we will discuss these results, in addition to some recent articles that we believe will enhance our understanding of how microbes might interact with the immune system. PMID:21143335

Enhancement of infectious disease vaccines through TLR9-dependent recognition of CpG DNA.

PubMed

McCluskie, M J; Krieg, A M

2006-01-01

The adaptive immune system-with its remarkable ability to generate antigen-specific antibodies and T lymphocytes against pathogens never before "seen" by an organism-is one of the marvels of evolution. However, to generate these responses, the adaptive immune system requires activation by the innate immune system. Toll-like receptors (TLRs) are perhaps the best-understood family of innate immune receptors for detecting infections and stimulating adaptive immune responses. TLR9 appears to have evolved to recognize infections by a subtle structural difference between eukaryotic and prokaryotic/viral DNA; only the former frequently methylates CpG dinucleotides. Used as vaccine adjuvants, synthetic oligodeoxynucleotide (ODN) ligands for TLR9--CpG ODN--greatly enhance the speed and strength of the immune responses to vaccination.

Nutrition, diet and immunosenescence.

PubMed

Maijó, Mònica; Clements, Sarah J; Ivory, Kamal; Nicoletti, Claudio; Carding, Simon R

2014-01-01

Ageing is characterized by immunosenescence and the progressive decline in immunity in association with an increased frequency of infections and chronic disease. This complex process affects both the innate and adaptive immune systems with a progressive decline in most immune cell populations and defects in activation resulting in loss of function. Although host genetics and environmental factors, such as stress, exercise and diet can impact on the onset or course of immunosenescence, the mechanisms involved are largely unknown. This review focusses on identifying the most significant aspects of immunosenescence and on the evidence that nutritional intervention might delay this process, and consequently improve the quality of life of the elderly. Copyright © 2014. Published by Elsevier Ireland Ltd.

What is really in control of skin immunity: lymphocytes, dendritic cells, or keratinocytes? facts and controversies.

PubMed

Rupec, Rudolf A; Boneberger, Susanne; Ruzicka, Thomas

2010-01-01

The pathophysiology of atopic dermatitis is still under discussion. Although it is widely accepted that environmental factors and a genetic predisposition are essential, the role of the innate and adaptive immune system and the functional cascade of the cells involved is still unclear. A concept that integrates all immune cells as equally essential has allure. In addition, barrier abnormalities due to mutations of the gene coding for filaggrin and down-regulation of antimicrobial peptides, such as LL-37 and beta-defensins 2 and 3, were very recently found to be relevant for the pathogenesis of atopic dermatitis. Copyright 2010 Elsevier Inc. All rights reserved.

Comprehensive proteome analysis of lysosomes reveals the diverse function of macrophages in immune responses.

PubMed

Gao, Yanpan; Chen, Yanyu; Zhan, Shaohua; Zhang, Wenhao; Xiong, Feng; Ge, Wei

2017-01-31

Phagocytosis and autophagy in macrophages have been shown to be essential to both innate and adaptive immunity. Lysosomes are the main catabolic subcellular organelles responsible for degradation and recycling of both extracellular and intracellular material, which are the final steps in phagocytosis and autophagy. However, the molecular mechanisms underlying lysosomal functions after infection remain obscure. In this study, we conducted a quantitative proteomics analysis of the changes in constitution and glycosylation of proteins in lysosomes derived from murine RAW 264.7 macrophage cells treated with different types of pathogens comprising examples of bacteria (Listeria monocytogenes, L. m), DNA viruses (herpes simplex virus type-1, HSV-1) and RNA viruses (vesicular stomatitis virus, VSV). In total, 3,704 lysosome-related proteins and 300 potential glycosylation sites on 193 proteins were identified. Comparative analysis showed that the aforementioned pathogens induced distinct alterations in the proteome of the lysosome, which is closely associated with the immune functions of macrophages, such as toll-like receptor activation, inflammation and antigen-presentation. The most significant changes in proteins and fluctuations in glycosylation were also determined. Furthermore, Western blot analysis showed that the changes in expression of these proteins were undetectable at the whole cell level. Thus, our study provides unique insights into the function of lysosomes in macrophage activation and immune responses.

Immune functions of insect βGRPs and their potential application.

PubMed

Rao, Xiang-Jun; Zhan, Ming-Yue; Pan, Yue-Min; Liu, Su; Yang, Pei-Jin; Yang, Li-Ling; Yu, Xiao-Qiang

2018-06-01

Insects rely completely on the innate immune system to sense the foreign bodies and to mount the immune responses. Germ-line encoded pattern recognition receptors play crucial roles in recognizing pathogen-associated molecular patterns. Among them, β-1,3-glucan recognition proteins (βGRPs) and gram-negative bacteria-binding proteins (GNBPs) belong to the same pattern recognition receptor family, which can recognize β-1,3-glucans. Typical insect βGRPs are comprised of a tandem carbohydrate-binding module in the N-terminal and a glucanase-like domain in the C-terminal. The former can recognize triple-helical β-1,3-glucans, whereas the latter, which normally lacks the enzymatic activity, can recruit adapter proteins to initiate the protease cascade. According to studies, insect βGRPs possess at least three types of functions. Firstly, some βGRPs cooperate with peptidoglycan recognition proteins to recognize the lysine-type peptidoglycans upstream of the Toll pathway. Secondly, some directly recognize fungal β-1,3-glucans to activate the Toll pathway and melanization. Thirdly, some form the 'attack complexes' with other immune effectors to promote the antifungal defenses. The current review will focus on the discovery of insect βGRPs, functions of some well-characterized members, structure-function studies and their potential application. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bridging innate NK cell functions with adaptive immunity.

PubMed

Marcenaro, Emanuela; Carlomagno, Simona; Pesce, Silvia; Moretta, Alessandro; Sivori, Simona

2011-01-01

Killer Ig-like receptors (KIRs) are major human NK receptors displaying either inhibitory or activating functions which recognize allotypic determinants of HLA-class I molecules. Surprisingly, NK cell treatment with CpG-ODN (TLR9 ligands) results in selective down-modulation of KIR3DL2, its co-internalization with CpG-ODN and its translocation to TLR9-rich early endosomes. This novel KIR-associated function may offer clues to better understand the possible role of certain KIRs and also emphasizes the involvement of NK cells in the course of microbial infections. NK cells are involved not only in innate immune responses against viruses and tumors but also participate in the complex network of cell-to cell interaction that leads to the development of adaptive immune responses. In this context the interaction of NK cells with DC appears to play a crucial role in the acquisition of CCR7, a chemokine receptor that enables NK cells to migrate towards lymph nodes in response to CCL19 and/or CCL21. Analysis of NK cell clones revealed that KIR-mismatched but not KIR-matched NK cells acquire CCR7. These data have important implications in haploidentical haematopoietic stem cell transplantation (HSCT), in which KIR-mismatched NK cells may acquire the ability to migrate to secondary lymphoid compartments (SLCs), where they can kill recipient's antigen presenting cells (APCs) and T cells thus preventing graft versus host (and host vs. graft) reactions.

Newly identified CpG ODNs, M5-30 and M6-395, stimulate mouse immune cells to secrete TNF-alpha and enhance Th1-mediated immunity.

PubMed

Choi, Sun-Shim; Chung, Eunkyung; Jung, Yu-Jin

2010-08-01

Bacterial CpG motifs are known to induce both innate and adaptive immunity in infected hosts via toll-like receptor 9 (TLR9). Because small oligonucleotides (ODNs) mimicking bacterial CpG motifs are easily synthesized, they have found use as immunomodulatory agents in a number of disease models. We have developed a novel bioinformatics approach to identify effective CpG ODN sequences and evaluate their function as TLR9 ligands in a murine system. Among the CpG ODNs we identified, M5-30 and M6-395 showed significant ability to stimulate TNF-alpha and IFN-gamma production in a mouse macrophage cell line and mouse splenocytes, respectively. We also found that these CpG ODNs activated cells through the canonical NF-kappa B signaling pathway. Moreover, both CpG ODNs were able to induce Th1-mediated immunity in Mycobacterium tuberculosis (Mtb)-infected mice. Our results demonstrate that M5-30 and M6-395 function as TLR9-specific ligands, making them useful in the study of TLR9 functionality and signaling in mice.

Sexual conflict and correlated evolution between male persistence and female resistance traits in the seed beetle Callosobruchus maculatus.

PubMed

Dougherty, Liam R; van Lieshout, Emile; McNamara, Kathryn B; Moschilla, Joe A; Arnqvist, Göran; Simmons, Leigh W

2017-05-31

Traumatic mating (or copulatory wounding) is an extreme form of sexual conflict whereby male genitalia physically harm females during mating. In such species females are expected to evolve counter-adaptations to reduce male-induced harm. Importantly, female counter-adaptations may include both genital and non-genital traits. In this study, we examine evolutionary associations between harmful male genital morphology and female reproductive tract morphology and immune function across 13 populations of the seed beetle Callosobruchus maculatus We detected positive correlated evolution between the injuriousness of male genitalia and putative female resistance adaptations across populations. Moreover, we found evidence for a negative relationship between female immunity and population productivity, which suggests that investment in female resistance may be costly due to the resource trade-offs that are predicted between immunity and reproduction. Finally, the degree of female tract scarring (harm to females) was greater in those populations with both longer aedeagal spines and a thinner female tract lining. Our results are thus consistent with a sexual arms race, which is only apparent when both male and female traits are taken into account. Importantly, our study provides rare evidence for sexually antagonistic coevolution of male and female traits at the within-species level. © 2017 The Author(s).

Sexual conflict and correlated evolution between male persistence and female resistance traits in the seed beetle Callosobruchus maculatus

PubMed Central

van Lieshout, Emile; Moschilla, Joe A.; Arnqvist, Göran

2017-01-01

Traumatic mating (or copulatory wounding) is an extreme form of sexual conflict whereby male genitalia physically harm females during mating. In such species females are expected to evolve counter-adaptations to reduce male-induced harm. Importantly, female counter-adaptations may include both genital and non-genital traits. In this study, we examine evolutionary associations between harmful male genital morphology and female reproductive tract morphology and immune function across 13 populations of the seed beetle Callosobruchus maculatus. We detected positive correlated evolution between the injuriousness of male genitalia and putative female resistance adaptations across populations. Moreover, we found evidence for a negative relationship between female immunity and population productivity, which suggests that investment in female resistance may be costly due to the resource trade-offs that are predicted between immunity and reproduction. Finally, the degree of female tract scarring (harm to females) was greater in those populations with both longer aedeagal spines and a thinner female tract lining. Our results are thus consistent with a sexual arms race, which is only apparent when both male and female traits are taken into account. Importantly, our study provides rare evidence for sexually antagonistic coevolution of male and female traits at the within-species level. PMID:28539510

CXCR3+CD4+ T cells mediate innate immune function in the pathophysiology of liver ischemia/reperfusion injury.

PubMed

Zhai, Yuan; Shen, Xiu-da; Hancock, Wayne W; Gao, Feng; Qiao, Bo; Lassman, Charles; Belperio, John A; Strieter, Robert M; Busuttil, Ronald W; Kupiec-Weglinski, Jerzy W

2006-05-15

Ischemia-reperfusion injury (IRI), an innate immune-dominated inflammatory response, develops in the absence of exogenous Ags. The recently highlighted role of T cells in IRI raises a question as to how T lymphocytes interact with the innate immune system and function with no Ag stimulation. This study dissected the mechanism of innate immune-induced T cell recruitment and activation in rat syngeneic orthotopic liver transplantation (OLT) model. Liver IRI was induced after cold storage (24-36 h) at 4 degrees C in University of Wisconsin solution. Gene products contributing to IRI were identified by cDNA microarray at 4-h posttransplant. IRI triggered increased intrahepatic expression of CXCL10, along with CXCL9 and 11. The significance of CXCR3 ligand induction was documented by the ability of neutralizing anti-CXCR3 Ab treatment to ameliorate hepatocellular damage and improve 14-day survival of 30-h cold-stored OLTs (95 vs 40% in controls; p < 0.01). Immunohistology analysis confirmed reduced CXCR3+ and CD4+ T cell infiltration in OLTs after treatment. Interestingly, anti-CXCR3 Ab did not suppress innate immune activation in the liver, as evidenced by increased levels of IL-1beta, IL-6, inducible NO synthase, and multiple neutrophil/monokine-targeted chemokine programs. In conclusion, this study demonstrates a novel mechanism of T cell recruitment and function in the absence of exogenous Ag stimulation. By documenting that the execution of innate immune function requires CXCR3+CD4+ T cells, it highlights the critical role of CXCR3 chemokine biology for the continuum of innate to adaptive immunity in the pathophysiology of liver IRI.

Evasion of adaptive and innate immune response mechanisms by γ-herpesviruses

PubMed Central

Feng, Pinghui; Moses, Ashlee; Früh, Klaus

2015-01-01

γ-Herpesviral immune evasion mechanisms are optimized to support the acute, lytic and the longterm, latent phase of infection. During acute infection, specific immune modulatory proteins limit, but also exploit, the antiviral activities of cell intrinsic innate immune responses as well as those of innate and adaptive immune cells. During latent infection, a restricted gene expression program limits immune targeting and cis-acting mechanisms to reduce the antigen presentation as well as antigenicity of latency-associated proteins. Here, we will review recent progress in our understanding of γ-herpesviral immune evasion strategies. PMID:23735334

Memory and Specificity in the Insect Immune System: Current Perspectives and Future Challenges.

PubMed

Cooper, Dustin; Eleftherianos, Ioannis

2017-01-01

The immune response of a host to a pathogen is typically described as either innate or adaptive. The innate form of the immune response is conserved across all organisms, including insects. Previous and recent research has focused on the nature of the insect immune system and the results imply that the innate immune response of insects is more robust and specific than previously thought. Priming of the insect innate immune system involves the exposure of insects to dead or a sublethal dose of microbes in order to elicit an initial response. Comparing subsequent infections in primed insects to non-primed individuals indicates that the insect innate immune response may possess some of the qualities of an adaptive immune system. Although some studies demonstrate that the protective effects of priming are due to a "loitering" innate immune response, others have presented more convincing elements of adaptivity. While an immune mechanism capable of producing the same degree of recognition specificity as seen in vertebrates has yet to be discovered in insects, a few interesting cases have been identified and discussed.

CRISPR adaptive immune systems of Archaea

PubMed Central

Vestergaard, Gisle; Garrett, Roger A; Shah, Shiraz A

2014-01-01

CRISPR adaptive immune systems were analyzed for all available completed genomes of archaea, which included representatives of each of the main archaeal phyla. Initially, all proteins encoded within, and proximal to, CRISPR-cas loci were clustered and analyzed using a profile–profile approach. Then cas genes were assigned to gene cassettes and to functional modules for adaptation and interference. CRISPR systems were then classified primarily on the basis of their concatenated Cas protein sequences and gene synteny of the interference modules. With few exceptions, they could be assigned to the universal Type I or Type III systems. For Type I, subtypes I-A, I-B, and I-D dominate but the data support the division of subtype I-B into two subtypes, designated I-B and I-G. About 70% of the Type III systems fall into the universal subtypes III-A and III-B but the remainder, some of which are phyla-specific, diverge significantly in Cas protein sequences, and/or gene synteny, and they are classified separately. Furthermore, a few CRISPR systems that could not be assigned to Type I or Type III are categorized as variant systems. Criteria are presented for assigning newly sequenced archaeal CRISPR systems to the different subtypes. Several accessory proteins were identified that show a specific gene linkage, especially to Type III interference modules, and these may be cofunctional with the CRISPR systems. Evidence is presented for extensive exchange having occurred between adaptation and interference modules of different archaeal CRISPR systems, indicating the wide compatibility of the functionally diverse interference complexes with the relatively conserved adaptation modules. PMID:24531374

Diversity in T cell memory: An embarrassment of riches

PubMed Central

Jameson, Stephen C.; Masopust, David

2010-01-01

The adaptive immune response meets the needs of the organism to generate effector cells capable of controlling pathogens, but also leads to production of memory cells, which mediate more effective protection during rechallenge. In this review we focus on the generation, maintenance and function of memory T cells, with a special emphasis on the increasing evidence for great diversity among functional memory T cell subsets. PMID:20064446

Evolution of the CRISPR-Cas adaptive immunity systems in prokaryotes: models and observations on virus-host coevolution.

PubMed

Koonin, Eugene V; Wolf, Yuri I

2015-01-01

CRISPR-Cas is an adaptive immunity system in prokaryotes that functions via a unique mechanism which involves incorporation of foreign DNA fragments into CRISPR arrays and subsequent utilization of transcripts of these inserts (known as spacers) as guide RNAs to cleave the cognate selfish element genome. Multiple attempts have been undertaken to explore the coevolution of viruses and microbial hosts carrying CRISPR-Cas using mathematical models that employ either systems of differential equations or an agent-based approach, or combinations thereof. Analysis of these models reveals highly complex co-evolutionary dynamics that ensues from the combination of the heritability of the CRISPR-mediated adaptive immunity with the existence of different degrees of immunity depending on the number of cognate spacers and the cost of carrying a CRISPR-Cas locus. Depending on the details of the models, a variety of testable, sometimes conflicting predictions have been made on the dependence of the degree of immunity and the benefit of maintaining CRISPR-Cas on the abundance and diversity of hosts and viruses. Some of these predictions have already been directly validated experimentally. In particular, both the reality of the virus-host arms race, with viruses escaping resistance and hosts reacquiring it through the capture of new spacers, and the fitness cost of CRISPR-Cas due to the curtailment of beneficial HGT have been reproduced in the laboratory. However, to test the predictions of the models more specifically, detailed studies of coevolving populations of microbes and viruses both in nature and in the laboratory are essential. Such analyses are expected to yield disagreements with the predictions of the current, oversimplified models and to trigger a new round of theoretical developments.

Immunosuppression after Sepsis: Systemic Inflammation and Sepsis Induce a Loss of Naïve T-Cells but No Enduring Cell-Autonomous Defects in T-Cell Function

PubMed Central

Markwart, Robby; Condotta, Stephanie A.; Requardt, Robert P.; Borken, Farina; Schubert, Katja; Weigel, Cynthia; Bauer, Michael; Griffith, Thomas S.; Förster, Martin; Brunkhorst, Frank M.; Badovinac, Vladimir P.; Rubio, Ignacio

2014-01-01

Sepsis describes the life-threatening systemic inflammatory response (SIRS) of an organism to an infection and is the leading cause of mortality on intensive care units (ICU) worldwide. An acute episode of sepsis is characterized by the extensive release of cytokines and other mediators resulting in a dysregulated immune response leading to organ damage and/or death. This initial pro-inflammatory burst often transits into a state of immune suppression characterised by loss of immune cells and T-cell dysfunction at later disease stages in sepsis survivors. However, despite these appreciations, the precise nature of the evoked defect in T-cell immunity in post-acute phases of SIRS remains unknown. Here we present an in-depth functional analysis of T-cell function in post-acute SIRS/sepsis. We document that T-cell function is not compromised on a per cell basis in experimental rodent models of infection-free SIRS (LPS or CpG) or septic peritonitis. Transgenic antigen-specific T-cells feature an unaltered cytokine response if challenged in vivo and ex vivo with cognate antigens. Isolated CD4+/CD8+ T-cells from post-acute septic animals do not exhibit defects in T-cell receptor-mediated activation at the the level of receptor-proximal signalling, activation marker upregulation or expansion. However, SIRS/sepsis induced transient lymphopenia and gave rise to an environment of immune attenuation at post acute disease stages. Thus, systemic inflammation has an acute impact on T-cell numbers and adaptive immunity, but does not cause major cell-autonomous enduring functional defects in T-cells. PMID:25541945

Autologous Stem Cell Transplantation Disrupts Adaptive Immune Responses during Rebound Simian/Human Immunodeficiency Virus Viremia.

PubMed

Reeves, Daniel B; Peterson, Christopher W; Kiem, Hans-Peter; Schiffer, Joshua T

2017-07-01

Primary HIV-1 infection induces a virus-specific adaptive/cytolytic immune response that impacts the plasma viral load set point and the rate of progression to AIDS. Combination antiretroviral therapy (cART) suppresses plasma viremia to undetectable levels that rebound upon cART treatment interruption. Following cART withdrawal, the memory component of the virus-specific adaptive immune response may improve viral control compared to primary infection. Here, using primary infection and treatment interruption data from macaques infected with simian/human immunodeficiency virus (SHIV), we observe a lower peak viral load but an unchanged viral set point during viral rebound. The addition of an autologous stem cell transplant before cART withdrawal alters viral dynamics: we found a higher rebound set point but similar peak viral loads compared to the primary infection. Mathematical modeling of the data that accounts for fundamental immune parameters achieves excellent fit to heterogeneous viral loads. Analysis of model output suggests that the rapid memory immune response following treatment interruption does not ultimately lead to better viral containment. Transplantation decreases the durability of the adaptive immune response following cART withdrawal and viral rebound. Our model's results highlight the impact of the endogenous adaptive immune response during primary SHIV infection. Moreover, because we capture adaptive immune memory and the impact of transplantation, this model will provide insight into further studies of cure strategies inspired by the Berlin patient. IMPORTANCE HIV patients who interrupt combination antiretroviral therapy (cART) eventually experience viral rebound, the return of viral loads to pretreatment levels. However, the "Berlin patient" remained free of HIV rebound over a decade after stopping cART. His cure is attributed to leukemia treatment that included an HIV-resistant stem cell transplant. Inspired by this case, we studied the impact of stem cell transplantation in a macaque simian/HIV (SHIV) system. Using a mechanistic mathematical model, we found that while primary infection generates an adaptive immune memory response, stem cell transplantation disrupts this learned immunity. The results have implications for HIV cure regimens based on stem cell transplantation. Copyright © 2017 American Society for Microbiology.

Autologous Stem Cell Transplantation Disrupts Adaptive Immune Responses during Rebound Simian/Human Immunodeficiency Virus Viremia

PubMed Central

Peterson, Christopher W.; Kiem, Hans-Peter

2017-01-01

ABSTRACT Primary HIV-1 infection induces a virus-specific adaptive/cytolytic immune response that impacts the plasma viral load set point and the rate of progression to AIDS. Combination antiretroviral therapy (cART) suppresses plasma viremia to undetectable levels that rebound upon cART treatment interruption. Following cART withdrawal, the memory component of the virus-specific adaptive immune response may improve viral control compared to primary infection. Here, using primary infection and treatment interruption data from macaques infected with simian/human immunodeficiency virus (SHIV), we observe a lower peak viral load but an unchanged viral set point during viral rebound. The addition of an autologous stem cell transplant before cART withdrawal alters viral dynamics: we found a higher rebound set point but similar peak viral loads compared to the primary infection. Mathematical modeling of the data that accounts for fundamental immune parameters achieves excellent fit to heterogeneous viral loads. Analysis of model output suggests that the rapid memory immune response following treatment interruption does not ultimately lead to better viral containment. Transplantation decreases the durability of the adaptive immune response following cART withdrawal and viral rebound. Our model's results highlight the impact of the endogenous adaptive immune response during primary SHIV infection. Moreover, because we capture adaptive immune memory and the impact of transplantation, this model will provide insight into further studies of cure strategies inspired by the Berlin patient. IMPORTANCE HIV patients who interrupt combination antiretroviral therapy (cART) eventually experience viral rebound, the return of viral loads to pretreatment levels. However, the “Berlin patient” remained free of HIV rebound over a decade after stopping cART. His cure is attributed to leukemia treatment that included an HIV-resistant stem cell transplant. Inspired by this case, we studied the impact of stem cell transplantation in a macaque simian/HIV (SHIV) system. Using a mechanistic mathematical model, we found that while primary infection generates an adaptive immune memory response, stem cell transplantation disrupts this learned immunity. The results have implications for HIV cure regimens based on stem cell transplantation. PMID:28404854

The murine polyomavirus microRNA locus is required to promote viruria during the acute phase of infection.

PubMed

Burke, James M; Bass, Clovis R; Kincaid, Rodney P; Ulug, Emin T; Sullivan, Christopher S

2018-06-06

Polyomaviruses (PyVs) can cause serious disease in immunosuppressed hosts. Several pathogenic PyVs encode microRNAs (miRNAs), small RNAs that regulate gene expression via RNA silencing. Despite recent advances in understanding the activities of PyV miRNAs, the biological functions of PyV miRNAs during in vivo infections are mostly unknown. Studies presented here use murine polyomavirus (MuPyV) as a model to assess the roles of the PyV miRNAs in a natural host. This analysis reveals that a MuPyV mutant that is unable to express miRNAs has enhanced viral DNA loads in select tissues at late times after infection. This is consistent with the PyV miRNAs functioning to reduce viral replication during the persistent phase of infection in a natural host. Additionally, the MuPyV miRNA locus promotes viruria during the acute phase of infection as evidenced by a defect in shedding during infection with the miRNA mutant virus. The viruria defect of the miRNA mutant virus could be rescued by infecting Rag2-/- mice. These findings implicate the miRNA locus as functioning in both the persistent and acute phases of infection and suggest a role for MuPyV miRNA in evading the adaptive immune response. IMPORTANCE MicroRNAs are expressed by diverse viruses, but for only a few is there any understanding of their in vivo function. PyVs can cause serious disease in immunocompromised hosts. Therefore, increased knowledge of how these viruses interact with the immune response is of clinical relevance. Here we show a novel activity for a viral miRNA locus in promoting virus shedding. This work indicates that in addition to any role for the PyV miRNA locus in long-term persistence, that it also has biological activity during the acute phase. As this mutant phenotype is alleviated by infection of mice lacking an adaptive immune response, our work also connects the in vivo activity of the PyV miRNA locus to the immune response. Given that PyV-associated disease is associated with alterations in the immune response, our findings help to better understand how the balance between PyVs and the immune response becomes altered in pathogenic states. Copyright © 2018 American Society for Microbiology.

Protective and destructive immunity in the periodontium: Part 1--innate and humoral immunity and the periodontium.

PubMed

Teng, Y-T A

2006-03-01

Based on the results of recent research in the field, the present paper will discuss the protective and destructive aspects of the innate vs. adaptive (humoral and cell-mediated) immunity associated with the bacterial virulent factors or antigenic determinants during periodontal pathogenesis. Attention will be focused on: (i) the Toll-like receptors (TLR), the innate immune repertoire for recognizing the unique molecular patterns of microbial components that trigger innate and adaptive immunity for effective host defenses, in some general non-oral vs. periodontal microbial infections; (ii) T-cell-mediated immunity, Th-cytokines, and osteoclastogenesis in periodontal disease progression; and (iii) some molecular techniques developed and used to identify critical microbial virulence factors or antigens associated with host immunity (using Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis as the model species). Therefore, further understanding of the molecular interactions and mechanisms associated with the host's innate and adaptive immune responses will facilitate the development of new and innovative therapeutics for future periodontal treatments.

Close Encounters of Lymphoid Cells and Bacteria

PubMed Central

Cruz-Adalia, Aranzazu; Veiga, Esteban

2016-01-01

During infections, the first reaction of the host against microbial pathogens is carried out by innate immune cells, which recognize conserved structures on pathogens, called pathogen-associated molecular patterns. Afterward, some of these innate cells can phagocytose and destroy the pathogens, secreting cytokines that would modulate the immune response to the challenge. This rapid response is normally followed by the adaptive immunity, more specific and essential for a complete pathogen clearance in many cases. Some innate immune cells, usually named antigen-presenting cells, such as macrophages or dendritic cells, are able to process internalized invaders and present their antigens to lymphocytes, triggering the adaptive immune response. Nevertheless, the traditional boundary of separated roles between innate and adaptive immunity has been blurred by several studies, showing that very specialized populations of lymphocytes (cells of the adaptive immunity) behave similarly to cells of the innate immunity. These “innate-like” lymphocytes include γδ T cells, invariant NKT cells, B-1 cells, mucosal-associated invariant T cells, marginal zone B cells, and innate response activator cells, and together with the newly described innate lymphoid cells are able to rapidly respond to bacterial infections. Strikingly, our recent data suggest that conventional CD4+ T cells, the paradigm of cells of the adaptive immunity, also present innate-like behavior, capturing bacteria in a process called transinfection. Transinfected CD4+ T cells digest internalized bacteria like professional phagocytes and secrete large amounts of proinflammatory cytokines, protecting for further bacterial challenges. In the present review, we will focus on the data showing such innate-like behavior of lymphocytes following bacteria encounter. PMID:27774092

Mining the human gut microbiota for effector strains that shape the immune system

PubMed Central

Ahern, Philip P.; Faith, Jeremiah J.; Gordon, Jeffrey I.

2014-01-01

Summary The gut microbiota co-develops with the immune system beginning at birth. Mining the microbiota for bacterial strains responsible for shaping the structure and dynamic operations of the innate and adaptive arms of the immune system represents a formidable combinatorial problem but one that needs to be overcome to advance mechanistic understanding of microbial community-immune system co-regulation, and in order to develop new diagnostic and therapeutic approaches that promote health. Here, we discuss a scalable, less biased approach for identifying effector strains in complex microbial communities that impact immune function. The approach begins by identifying uncultured human fecal microbiota samples that transmit immune phenotypes to germ-free mice. Clonally-arrayed sequenced collections of bacterial strains are constructed from representative donor microbiota. If the collection transmits phenotypes, effector strains are identified by testing randomly generated subsets with overlapping membership in individually-housed germ-free animals. Detailed mechanistic studies of effector strain-host interactions can then be performed. PMID:24950201

Innate Immune Sensing and Response to Influenza

PubMed Central

Pulendran, Bali; Maddur, Mohan S.

2015-01-01

Influenza viruses pose a substantial threat to human and animal health worldwide. Recent studies in mouse models have revealed an indispensable role for the innate immune system in defense against influenza virus. Recognition of the virus by innate immune receptors in a multitude of cell types activates intricate signaling networks, functioning to restrict viral replication. Downstream effector mechanisms include activation of innate immune cells and, induction and regulation of adaptive immunity. However, uncontrolled innate responses are associated with exaggerated disease, especially in pandemic influenza virus infection. Despite advances in the understanding of innate response to influenza in the mouse model, there is a large knowledge gap in humans, particularly in immunocom-promised groups such as infants and the elderly. We propose here, the need for further studies in humans to decipher the role of innate immunity to influenza virus, particularly at the site of infection. These studies will complement the existing work in mice and facilitate the quest to design improved vaccines and therapeutic strategies against influenza. PMID:25078919

Innate immune sensing and response to influenza.

PubMed

Pulendran, Bali; Maddur, Mohan S

2015-01-01

Influenza viruses pose a substantial threat to human and animal health worldwide. Recent studies in mouse models have revealed an indispensable role for the innate immune system in defense against influenza virus. Recognition of the virus by innate immune receptors in a multitude of cell types activates intricate signaling networks, functioning to restrict viral replication. Downstream effector mechanisms include activation of innate immune cells and, induction and regulation of adaptive immunity. However, uncontrolled innate responses are associated with exaggerated disease, especially in pandemic influenza virus infection. Despite advances in the understanding of innate response to influenza in the mouse model, there is a large knowledge gap in humans, particularly in immunocompromised groups such as infants and the elderly. We propose here, the need for further studies in humans to decipher the role of innate immunity to influenza virus, particularly at the site of infection. These studies will complement the existing work in mice and facilitate the quest to design improved vaccines and therapeutic strategies against influenza.

Regulation of obesity-related insulin resistance with gut anti-inflammatory agents.

PubMed

Luck, Helen; Tsai, Sue; Chung, Jason; Clemente-Casares, Xavier; Ghazarian, Magar; Revelo, Xavier S; Lei, Helena; Luk, Cynthia T; Shi, Sally Yu; Surendra, Anuradha; Copeland, Julia K; Ahn, Jennifer; Prescott, David; Rasmussen, Brittany A; Chng, Melissa Hui Yen; Engleman, Edgar G; Girardin, Stephen E; Lam, Tony K T; Croitoru, Kenneth; Dunn, Shannon; Philpott, Dana J; Guttman, David S; Woo, Minna; Winer, Shawn; Winer, Daniel A

2015-04-07

Obesity has reached epidemic proportions, but little is known about its influence on the intestinal immune system. Here we show that the gut immune system is altered during high-fat diet (HFD) feeding and is a functional regulator of obesity-related insulin resistance (IR) that can be exploited therapeutically. Obesity induces a chronic phenotypic pro-inflammatory shift in bowel lamina propria immune cell populations. Reduction of the gut immune system, using beta7 integrin-deficient mice (Beta7(null)), decreases HFD-induced IR. Treatment of wild-type HFD C57BL/6 mice with the local gut anti-inflammatory, 5-aminosalicyclic acid (5-ASA), reverses bowel inflammation and improves metabolic parameters. These beneficial effects are dependent on adaptive and gut immunity and are associated with reduced gut permeability and endotoxemia, decreased visceral adipose tissue inflammation, and improved antigen-specific tolerance to luminal antigens. Thus, the mucosal immune system affects multiple pathways associated with systemic IR and represents a novel therapeutic target in this disease. Copyright © 2015 Elsevier Inc. All rights reserved.

Defensins and Other Antimicrobial Peptides at the Ocular Surface

PubMed Central

McDermott, Alison M.

2006-01-01

Although constantly exposed to the environment and “foreign bodies” such as contact lenses and unwashed fingertips, the ocular surface succumbs to infection relatively infrequently. This is, in large part, due to a very active and robust innate immune response mounted at the ocular surface. Studies over the past 20 years have revealed that small peptides with antimicrobial activity are a major component of the human innate immune response system. The ocular surface is no exception, with peptides of the defensin and cathelicidin families being detected in the tear film and secreted by corneal and conjunctival epithelial cells. There is also much evidence to suggest that the role of some antimicrobial peptides is not restricted to direct killing of pathogens, but, rather, that they function in various aspects of the immune response, including recruitment of immune cells, and through actions on dendritic cells provide a link to adaptive immunity. A role in wound healing is also supported. In this article, the properties, mechanisms of actions and functional roles of antimicrobial peptides are reviewed, with particular emphasis on the potential multifunctional roles of defensins and LL-37 (the only known human cathelicidin) at the ocular surface. PMID:17216098

Host Immune Response to Influenza A Virus Infection.

PubMed

Chen, Xiaoyong; Liu, Shasha; Goraya, Mohsan Ullah; Maarouf, Mohamed; Huang, Shile; Chen, Ji-Long

2018-01-01

Influenza A viruses (IAVs) are contagious pathogens responsible for severe respiratory infection in humans and animals worldwide. Upon detection of IAV infection, host immune system aims to defend against and clear the viral infection. Innate immune system is comprised of physical barriers (mucus and collectins), various phagocytic cells, group of cytokines, interferons (IFNs), and IFN-stimulated genes, which provide first line of defense against IAV infection. The adaptive immunity is mediated by B cells and T cells, characterized with antigen-specific memory cells, capturing and neutralizing the pathogen. The humoral immune response functions through hemagglutinin-specific circulating antibodies to neutralize IAV. In addition, antibodies can bind to the surface of infected cells and induce antibody-dependent cell-mediated cytotoxicity or complement activation. Although there are neutralizing antibodies against the virus, cellular immunity also plays a crucial role in the fight against IAVs. On the other hand, IAVs have developed multiple strategies to escape from host immune surveillance for successful replication. In this review, we discuss how immune system, especially innate immune system and critical molecules are involved in the antiviral defense against IAVs. In addition, we highlight how IAVs antagonize different immune responses to achieve a successful infection.

Regulatory T cells in atherosclerosis: critical immune regulatory function and therapeutic potential.

PubMed

Spitz, Charlotte; Winkels, Holger; Bürger, Christina; Weber, Christian; Lutgens, Esther; Hansson, Göran K; Gerdes, Norbert

2016-03-01

Atherosclerosis is a chronic inflammatory disease that is mediated by innate and adaptive immune responses. The disease is characterized by sub-endothelial accumulation and modification of lipids in the artery wall triggering an inflammatory reaction which promotes lesion progression and eventual plaque rupture, thrombus formation, and the respective clinical sequelae such as myocardial infarction or stroke. During the past decade, T-cell-mediated immune responses, especially control of pro-inflammatory signals by regulatory T cells (Tregs), have increasingly attracted the interest of experimental and clinical researchers. By suppression of T cell proliferation and secretion of anti-inflammatory cytokines, such as interleukin-10 (IL-10) and transforming growth factor-β, Tregs exert their atheroprotective properties. Atherosclerosis-prone, hyperlipidemic mice harbor systemically less Tregs compared to wild-type mice, suggesting an imbalance of immune cells which affects local and systemic inflammatory and potentially metabolic processes leading to atherogenesis. Restoring or increasing Treg frequency and enhancing their suppressive capacity by various modulations may pose a promising approach for treating inflammatory conditions such as cardiovascular diseases. In this review, we briefly summarize the immunological basics of atherosclerosis and introduce the role and contribution of different subsets of T cells. We then discuss experimental data and current knowledge pertaining to Tregs in atherosclerosis and perspectives on manipulating the adaptive immune system to alleviate atherosclerosis and cardiovascular disease.

Antibodies: From novel repertoires to defining and refining the structure of biologically important targets.

PubMed

Conroy, Paul J; Law, Ruby H P; Caradoc-Davies, Tom T; Whisstock, James C

2017-03-01

Antibodies represent a highly successful class of molecules that bind a wide-range of targets in therapeutic-, diagnostic- and research-based applications. The antibody repertoire is composed of the building blocks required to develop an effective adaptive immune response against foreign insults. A number of species have developed novel genetic and structural mechanisms from which they derive these antibody repertoires, however, traditionally antibodies are isolated from human, and rodent sources. Due to their high-value therapeutic, diagnostic, biotechnological and research applications, much innovation has resulted in techniques and approaches to isolate novel antibodies. These approaches are bolstered by advances in our understanding of species immune repertoires, next generation sequencing capacity, combinatorial antibody discovery and high-throughput screening. Structural determination of antibodies and antibody-antigen complexes has proven to be pivotal to our current understanding of the immune repertoire for a range of species leading to advances in man-made libraries and fine tuning approaches to develop antibodies from immune-repertoires. Furthermore, the isolation of antibodies directed against antigens of importance in health, disease and developmental processes, has yielded a plethora of structural and functional insights. This review highlights the significant contribution of antibody-based crystallography to our understanding of adaptive immunity and its application to providing critical information on a range of human-health related indications. Copyright © 2017 Elsevier Inc. All rights reserved.

Evolution of RNA- and DNA-guided antivirus defense systems in prokaryotes and eukaryotes: common ancestry vs convergence.

PubMed

Koonin, Eugene V

2017-02-10

Complementarity between nucleic acid molecules is central to biological information transfer processes. Apart from the basal processes of replication, transcription and translation, complementarity is also employed by multiple defense and regulatory systems. All cellular life forms possess defense systems against viruses and mobile genetic elements, and in most of them some of the defense mechanisms involve small guide RNAs or DNAs that recognize parasite genomes and trigger their inactivation. The nucleic acid-guided defense systems include prokaryotic Argonaute (pAgo)-centered innate immunity and CRISPR-Cas adaptive immunity as well as diverse branches of RNA interference (RNAi) in eukaryotes. The archaeal pAgo machinery is the direct ancestor of eukaryotic RNAi that, however, acquired additional components, such as Dicer, and enormously diversified through multiple duplications. In contrast, eukaryotes lack any heritage of the CRISPR-Cas systems, conceivably, due to the cellular toxicity of some Cas proteins that would get activated as a result of operon disruption in eukaryotes. The adaptive immunity function in eukaryotes is taken over partly by the PIWI RNA branch of RNAi and partly by protein-based immunity. In this review, I briefly discuss the interplay between homology and analogy in the evolution of RNA- and DNA-guided immunity, and attempt to formulate some general evolutionary principles for this ancient class of defense systems. This article was reviewed by Mikhail Gelfand and Bojan Zagrovic.

A narrow repertoire of transcriptional modules responsive to pyogenic bacteria is impaired in patients carrying loss-of-function mutations in MYD88 or IRAK4

PubMed Central

Alsina, L; Israelsson, E; Altman, MC; Dang, KK; Ghandil, P; Israel, L; von Bernuth, H; Baldwin, N; Qin, H; Jin, Z; Banchereau, R; Anguiano, E; Ionan, A; Abel, L; Puel, A; Picard, C; Pascual, V; Casanova, JL; Chaussabel, D

2014-01-01

Loss of function in the kinase IRAK-4 or the adapter MyD88 in humans interrupts a pathway critical for pathogen sensing and ignition of inflammation. Yet patients with loss of function mutations are surprisingly only susceptible to a limited range of pathogens. We employed a systems approach to investigate transcriptome responses following in vitro exposure of patients’ blood to Toll-like receptor and interleukin-1 receptor agonists, and whole pathogens. Responses to purified agonists were globally abolished but variable residual responses were present following exposure to whole pathogens. Further dissection of the latter responses identified a narrow repertoire of immune transcriptional programs affected by loss of MyD88 or IRAK-4 function. This work introduces the use of a systems approach for the global assessment of innate immune responses, and the characterization of human primary immunodeficiencies. PMID:25344726

Exploring the read-write genome: mobile DNA and mammalian adaptation.

PubMed

Shapiro, James A

2017-02-01

The read-write genome idea predicts that mobile DNA elements will act in evolution to generate adaptive changes in organismal DNA. This prediction was examined in the context of mammalian adaptations involving regulatory non-coding RNAs, viviparous reproduction, early embryonic and stem cell development, the nervous system, and innate immunity. The evidence shows that mobile elements have played specific and sometimes major roles in mammalian adaptive evolution by generating regulatory sites in the DNA and providing interaction motifs in non-coding RNA. Endogenous retroviruses and retrotransposons have been the predominant mobile elements in mammalian adaptive evolution, with the notable exception of bats, where DNA transposons are the major agents of RW genome inscriptions. A few examples of independent but convergent exaptation of mobile DNA elements for similar regulatory rewiring functions are noted.

IL-22 from T cells: better late than never.

PubMed

Honda, Kenya

2012-12-14

Interleukin-22 (IL-22) enhances mucosal barrier function and is important in antimicrobial host defense. In this issue of Immunity, Basu et al. (2012) reveal that Th22 cells are the critical adaptive source of IL-22 during late-phase infection by Citrobacter rodentium. Copyright © 2012 Elsevier Inc. All rights reserved.

Measuring bovine gamma delta T cell function at the site of Mycobacterium bovis infection

USDA-ARS?s Scientific Manuscript database

The causative agent of tuberculosis (TB) in cattle is Mycobacterium bovis. The characteristic lesions of bovine TB are well-organized pulmonary granulomas. Gamma delta T cells are a unique subset of nonconventional T cells that play major roles in both the innate and adaptive arms of the immune sys...

Innate immunological function of TH2 cells in vivo

USDA-ARS?s Scientific Manuscript database

Th2 cells produce IL-13 when stimulated by papain or house dust mites (HDM) and induce eosinophilic inflammation. This innate response of cells of the adaptive immune system is dependent on IL-33-, not T cell receptor-, based stimulation. While type 2 innate lymphoid cells (ILC2s) are the dominant ...

Phenotype and function of CD209+ bovine blood dendritic cells, monocyte-derived-dendritic cells and monocyte-derived macrophages

USDA-ARS?s Scientific Manuscript database

Phylogenic comparisons of the mononuclear phagocyte system (MPS) of humans and mice demonstrate phenotypic divergence of dendritic cell (DC) subsets that play similar roles in innate and adaptive immunity. Although differing in phenotype, DC can be classified into four groups according to ontogeny a...