scholarly journals Immunomodulation by Gut Microbiota: Role of Toll-Like Receptor Expressed by T Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Mariagrazia Valentini ◽  
Alessia Piermattei ◽  
Gabriele Di Sante ◽  
Giuseppe Migliara ◽  
Giovanni Delogu ◽  
...  
Keyword(s):  
T Cells ◽  
Immune System ◽  
Gut Microbiota ◽  
Cell Types ◽  
Mutual Regulation ◽  
Close Relationship ◽  
Numerous Cell ◽  
Specific Receptors ◽  
And Function

A close relationship exists between gut microbiota and immune responses. An imbalance of this relationship can determine local and systemic immune diseases. In fact the immune system plays an essential role in maintaining the homeostasis with the microbiota that normally resides in the gut, while, at the same time, the gut microbiota influences the immune system, modulating number and function of effector and regulatory T cells. To achieve this aim, mutual regulation between immune system and microbiota is achieved through several mechanisms, including the engagement of toll-like receptors (TLRs), pathogen-specific receptors expressed on numerous cell types. TLRs are able to recognize ligands from commensal or pathogen microbiota to maintain the tolerance or trigger the immune response. In this review, we summarize the latest evidences about the role of TLRs expressed in adaptive T cells, to understand how the immune system promotes intestinal homeostasis, fights invasion by pathogens, and is modulated by the intestinal microbiota.

scholarly journals Microbiota and Hypertension: Role of the Sympathetic Nervous System and the Immune System

2020 ◽  
Author(s):  
Iñaki Robles-Vera ◽  
Marta Toral ◽  
Juan Duarte
Keyword(s):  
T Cells ◽  
Nervous System ◽  
Immune System ◽  
Sympathetic Nervous System ◽  
Gut Microbiota ◽  
Current Knowledge ◽  
Vascular Inflammation ◽  
T Helper 17 ◽  
Sympathetic Nervous

Abstract There are numerous studies indicating a direct association between hypertension and gut microbiota in both animal models and humans. In this review, we focused on the imbalance in the gut microbiota composition relative to healthy state or homeostasis, termed dysbiosis, associated with hypertension and discuss the current knowledge regarding how microbiota regulates blood pressure (BP), involving the sympathetic nervous system and the immune system. The profile of ecological parameters and bacterial genera composition of gut dysbiosis in hypertension varies according to the experimental model of hypertension. Recent evidence supports that gut microbiota can protect or promote the development of hypertension by interacting with gut secondary lymph organs and altering T helper 17/regulatory T cells polarization, with subsequent changes in T cells infiltration in vascular tissues. Here, we also describe the bidirectional communication between the microbiome and the host via the sympathetic nervous system and its role in BP regulation. Dysbiosis in hypertension is mainly associated with reduced proportions of short-chain fatty acid-producing bacteria, mainly acetate- and butyrate-producing bacteria, and an increased enrichment of the genes for lipopolysaccharide biosynthesis and export, lending to moderate endotoxemia. The role of these metabolic and structural products in both immune and sympathetic system regulation and vascular inflammation was also analyzed. Overall, gut microbiota is now recognized as a well-established target to dietary interventions with prebiotics or probiotics to reduce BP.

scholarly journals Role of Methylation in Pro- and Anti-Cancer Immunity

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 545
Author(s):  
Ali Mehdi ◽  
Shafaat A. Rabbani
Keyword(s):  
T Cells ◽  
Transcriptional Regulation ◽  
Immune Cells ◽  
Cell Types ◽  
Rna Methylation ◽  
Dna And Rna ◽  
Cancer Immunity ◽  
Anti Cancer ◽  
And Function

DNA and RNA methylation play a vital role in the transcriptional regulation of various cell types including the differentiation and function of immune cells involved in pro- and anti-cancer immunity. Interactions of tumor and immune cells in the tumor microenvironment (TME) are complex. TME shapes the fate of tumors by modulating the dynamic DNA (and RNA) methylation patterns of these immune cells to alter their differentiation into pro-cancer (e.g., regulatory T cells) or anti-cancer (e.g., CD8+ T cells) cell types. This review considers the role of DNA and RNA methylation in myeloid and lymphoid cells in the activation, differentiation, and function that control the innate and adaptive immune responses in cancer and non-cancer contexts. Understanding the complex transcriptional regulation modulating differentiation and function of immune cells can help identify and validate therapeutic targets aimed at targeting DNA and RNA methylation to reduce cancer-associated morbidity and mortality.

Role of the 807 C/T Polymorphism of the α2 Gene in Platelet GP Ia Collagen Receptor Expression and Function

1999 ◽  
Vol 81 (06) ◽  
pp. 951-956 ◽  
Author(s):  
J. Corral ◽  
R. González-Conejero ◽  
J. Rivera ◽  
F. Ortuño ◽  
P. Aparicio ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Cell Types ◽  
Receptor Expression ◽  
Case Control Studies ◽  
Platelet Surface ◽  
Vitro Analysis ◽  
And Function ◽  
In Vitro Analysis

SummaryThe variability of the platelet GP Ia/IIa density has been associated with the 807 C/T polymorphism (Phe 224) of the GP Ia gene in American Caucasian population. We have investigated the genotype and allelic frequencies of this polymorphism in Spanish Caucasians. The T allele was found in 35% of the 284 blood donors analyzed. We confirmed in 159 healthy subjects a significant association between the 807 C/T polymorphism and the platelet GP Ia density. The T allele correlated with high number of GP Ia molecules on platelet surface. In addition, we observed a similar association of this polymorphism with the expression of this protein in other blood cell types. The platelet responsiveness to collagen was determined by “in vitro” analysis of the platelet activation and aggregation response. We found no significant differences in these functional platelet parameters according to the 807 C/T genotype. Finally, results from 3 case/control studies involving 302 consecutive patients (101 with coronary heart disease, 104 with cerebrovascular disease and 97 with deep venous thrombosis) determined that the 807 C/T polymorphism of the GP Ia gene does not represent a risk factor for arterial or venous thrombosis.

Microbiota-Immune System Interactions in Human Neurological Disorders

2020 ◽  
Vol 19 (7) ◽  
pp. 509-526
Author(s):  
Qin Huang ◽  
Fang Yu ◽  
Di Liao ◽  
Jian Xia
Keyword(s):  
Immune System ◽  
Gut Microbiota ◽  
Neurological Disorders ◽  
Brain Function ◽  
Neurological Diseases ◽  
Host Immune System ◽  
Gut Dysbiosis ◽  
Characteristic Features ◽  
Novel Therapeutic Strategies

: Recent studies implicate microbiota-brain communication as an essential factor for physiology and pathophysiology in brain function and neurodevelopment. One of the pivotal mechanisms about gut to brain communication is through the regulation and interaction of gut microbiota on the host immune system. In this review, we will discuss the role of microbiota-immune systeminteractions in human neurological disorders. The characteristic features in the development of neurological diseases include gut dysbiosis, the disturbed intestinal/Blood-Brain Barrier (BBB) permeability, the activated inflammatory response, and the changed microbial metabolites. Neurological disorders contribute to gut dysbiosis and some relevant metabolites in a top-down way. In turn, the activated immune system induced by the change of gut microbiota may deteriorate the development of neurological diseases through the disturbed gut/BBB barrier in a down-top way. Understanding the characterization and identification of microbiome-immune- brain signaling pathways will help us to yield novel therapeutic strategies by targeting the gut microbiome in neurological disease.

The paracaspase MALT1 in psoriasis

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Stephan Hailfinger ◽  
Klaus Schulze-Osthoff
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Transcription Factors ◽  
Skin Disease ◽  
Cell Types ◽  
Cytokine Receptors ◽  
Molecular Scaffold ◽  
Therapeutic Implications ◽  
Stimulation Of

Abstract Psoriasis is a frequent autoimmune-related skin disease, which involves various cell types such as T cells, keratinocytes and dendritic cells. Genetic variations, such as mutations of CARD14, can promote the development of the disease. CARD14 mutations as well as the stimulation of immune and cytokine receptors activate the paracaspase MALT1, a potent activator of the transcription factors NF-κB and AP-1. The disease-promoting role of MALT1 for psoriasis is mediated by both its protease activity as well as its molecular scaffold function. Here, we review the importance of MALT1-mediated signaling and its therapeutic implications in psoriasis.

A Crucial Role for Diet in the Relationship Between Gut Microbiota and Cardiometabolic Disease

2020 ◽  
Vol 71 (1) ◽  
pp. 149-161 ◽  
Author(s):  
Ilias Attaye ◽  
Sara-Joan Pinto-Sietsma ◽  
Hilde Herrema ◽  
Max Nieuwdorp
Keyword(s):  
Gut Microbiota ◽  
Global Scale ◽  
Cardiometabolic Disease ◽  
Microbiota Composition ◽  
Dietary Interventions ◽  
Fermentable Carbohydrates ◽  
Cost Efficient ◽  
And Function ◽  
Gut Microbiota Composition

Cardiometabolic disease (CMD), such as type 2 diabetes mellitus and cardiovascular disease, contributes significantly to morbidity and mortality on a global scale. The gut microbiota has emerged as a potential target to beneficially modulate CMD risk, possibly via dietary interventions. Dietary interventions have been shown to considerably alter gut microbiota composition and function. Moreover, several diet-derived microbial metabolites are able to modulate human metabolism and thereby alter CMD risk. Dietary interventions that affect gut microbiota composition and function are therefore a promising, novel, and cost-efficient method to reduce CMD risk. Studies suggest that fermentable carbohydrates can beneficially alter gut microbiota composition and function, whereas high animal protein and high fat intake negatively impact gut microbiota function and composition. This review focuses on the role of macronutrients (i.e., carbohydrate, protein, and fat) and dietary patterns (e.g., vegetarian/vegan and Mediterranean diet) in gut microbiota composition and function in the context of CMD.

scholarly journals Gastric Hyperplasia and Increased Proliferative Responses of Lymphocytes in Mice Lacking the COOH-terminal Ankyrin Domain of NF-κB2

1997 ◽  
Vol 186 (7) ◽  
pp. 999-1014 ◽  
Author(s):  
Hideaki Ishikawa ◽  
Daniel Carrasco ◽  
Estefania Claudio ◽  
Rolf-Peter Ryseck ◽  
Rodrigo Bravo
Keyword(s):  
T Cells ◽  
Lymphocyte Proliferation ◽  
Cytokine Production ◽  
Cell Types ◽  
Homozygous Deletion ◽  
Binding Activity ◽  
Activated T Cells ◽  
Physiological Relevance

The nfkb2 gene encodes the p100 precursor which produces the p52 protein after proteolytic cleavage of its COOH-terminal domain. Although the p52 product can act as an alternative subunit of NF-κB, the p100 precursor is believed to function as an inhibitor of Rel/NF-κB activity by cytoplasmic retention of Rel/NF-κB complexes, like other members of the IκB family. However, the physiological relevance of the p100 precursor as an IκB molecule has not been understood. To assess the role of the precursor in vivo, we generated, by gene targeting, mice lacking p100 but still containing a functional p52 protein. Mice with a homozygous deletion of the COOH-terminal ankyrin repeats of NF-κB2 (p100−/−) had marked gastric hyperplasia, resulting in early postnatal death. p100−/− animals also presented histopathological alterations of hematopoietic tissues, enlarged lymph nodes, increased lymphocyte proliferation in response to several stimuli, and enhanced cytokine production in activated T cells. Dramatic induction of nuclear κB–binding activity composed of p52-containing complexes was found in all tissues examined and also in stimulated lymphocytes. Thus, the p100 precursor is essential for the proper regulation of p52-containing Rel/NF-κB complexes in various cell types and its absence cannot be efficiently compensated for by other IκB proteins.

The interplay between gut microbiota and the immune system in liver transplant recipients and its role in infections

2021 ◽  
Author(s):  
Giuseppe Ancona ◽  
Laura Alagna ◽  
Andrea Lombardi ◽  
Emanuele Palomba ◽  
Valeria Castelli ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Immune System ◽  
Liver Disease ◽  
Gut Microbiota ◽  
Liver Transplant ◽  
Bacterial Infections ◽  
Multidrug Resistant ◽  
Transplant Recipients ◽  
Liver Transplant Recipients

Liver transplantation (LT) is a life-saving strategy for patients with end-stage liver disease, hepatocellular carcinoma and acute liver failure. LT success can be hampered by several short-term and long-term complications. Among them, bacterial infections, especially due to multidrug-resistant germs, are particularly frequent with a prevalence between 19 and 33% in the first 100 days after transplantation. In the last decades, a number of studies have highlighted how gut microbiota (GM) is involved in several essential functions to ensure the intestinal homeostasis, becoming one of the most important virtual metabolic organs. GM works through different axes with other organs, and the gut-liver axis is among the most relevant and investigated ones. Any alteration or disruption of GM is defined as dysbiosis. Peculiar phenotypes of GM dysbiosis have been associated to several liver conditions and complications, such as chronic hepatitis, fatty liver disease, cirrhosis and hepatocellular carcinoma. Moreover, there is growing evidence of the crucial role of GM in shaping the immune response, both locally and systemically, against pathogens. This paves the way to the manipulation of GM as a therapeutic instrument to modulate the infectious risk and outcome. In this minireview we provide an overview of the current understanding on the interplay between gut microbiota and the immune system in liver transplant recipients and the role of the former in infections.

scholarly journals The Microbiotic Highway to Health—New Perspective on Food Structure, Gut Microbiota, and Host Inflammation

Nutrients ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1590 ◽  
Author(s):  
Nina Hansen ◽  
Anette Sams
Keyword(s):  
Immune System ◽  
Gut Microbiota ◽  
Dietary Habits ◽  
Gut Hormones ◽  
Host Immune System ◽  
Inflammatory Conditions ◽  
Food Structure ◽  
New Perspective ◽  
And Function ◽  
The Impact

This review provides evidence that not only the content of nutrients but indeed the structural organization of nutrients is a major determinant of human health. The gut microbiota provides nutrients for the host by digesting food structures otherwise indigestible by human enzymes, thereby simultaneously harvesting energy and delivering nutrients and metabolites for the nutritional and biological benefit of the host. Microbiota-derived nutrients, metabolites, and antigens promote the development and function of the host immune system both directly by activating cells of the adaptive and innate immune system and indirectly by sustaining release of monosaccharides, stimulating intestinal receptors and secreting gut hormones. Multiple indirect microbiota-dependent biological responses contribute to glucose homeostasis, which prevents hyperglycemia-induced inflammatory conditions. The composition and function of the gut microbiota vary between individuals and whereas dietary habits influence the gut microbiota, the gut microbiota influences both the nutritional and biological homeostasis of the host. A healthy gut microbiota requires the presence of beneficial microbiotic species as well as vital food structures to ensure appropriate feeding of the microbiota. This review focuses on the impact of plant-based food structures, the “fiber-encapsulated nutrient formulation”, and on the direct and indirect mechanisms by which the gut microbiota participate in host immune function.

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