Role of Toll-like receptors, NOD-like receptors and RIG-I-like receptors in endothelial cells and systemic infections

2009 ◽  
Vol 102 (12) ◽  
pp. 1103-1109 ◽  
Author(s):  
Julia Eitel ◽  
Karolin Meixenberger ◽  
Norbert Suttorp ◽  
Bastian Opitz
Keyword(s):  
Endothelial Cells ◽  
Current Knowledge ◽  
Adaptive Immune Response ◽  
Vascular Diseases ◽  
Innate Immune ◽  
Toll Like Receptors ◽  
Surface Molecules ◽  
Adaptive Immune ◽  
Systemic Infections

SummaryBacteraemia and viraemia are characterised by pathogens entering the bloodstream. Endothelial cells are among the first cells coming into contact with the microbes and also some endogenous molecules which are released by tissue damage. As part of the innate immune system, endothelial cells respond to these contacts by producing inflammatory mediators and expressing surface molecules. The initial sensing of microbial and endogenous danger-associated molecules is mediated by so-called pattern recognition receptors (PRRs). PRRs can be classified in different protein families such as the Toll-like receptors, the NODlike receptors and the RIG-I-like receptors. By activating inflammatory gene transcription and posttranslational processing, PRRs control the immediate innate immune reaction and also the subsequent adaptive immune response. Here we describe the current knowledge of extra-and intracellular PRRs in endothelial cells and their potential role in sepsis and vascular diseases.

Toll-like receptors in ocular surface diseases: overview and new findings

2011 ◽  
Vol 120 (10) ◽  
pp. 441-450 ◽  
Author(s):  
Alessandro Lambiase ◽  
Alessandra Micera ◽  
Marta Sacchetti ◽  
Flavio Mantelli ◽  
Stefano Bonini
Keyword(s):  
Immune Response ◽  
Ocular Surface ◽  
Current Knowledge ◽  
Adaptive Immune Response ◽  
Allergic Diseases ◽  
Innate Immune ◽  
Microbial Pathogens ◽  
Toll Like Receptors ◽  
Inflammatory Conditions ◽  
New Findings

The ocular surface is the first line of defence in the eye against environmental microbes. The ocular innate immune system consists of a combination of anatomical, mechanical and immunological defence mechanisms. TLRs (Toll-like receptors), widely expressed by the ocular surface, are able to recognize microbial pathogens and to trigger the earliest immune response leading to inflammation. Increasing evidence highlights the crucial role of TLRs in regulating innate immune responses during ocular surface infective and non-infective inflammatory conditions. In addition, recent observations have shown that TLRs modulate the adaptive immune response, also playing an important role in ocular autoimmune and allergic diseases. One of the main goals of ocular surface treatment is to control the inflammatory reaction in order to preserve corneal integrity and transparency. Recent experimental evidence has shown that specific modulation of TLR pathways induces an improvement in several ocular inflammatory conditions, such as allergic conjunctivitis, suggesting new therapeutic anti-inflammatory strategies. The purpose of the present review is to summarize the current knowledge of TLRs at the ocular surface and to propose them as potential targets of therapy for ocular inflammatory conditions.

Nonclassical monocytes in cardiovascular physiology and disease

2021 ◽  
Vol 320 (5) ◽  
pp. C761-C770
Author(s):  
Sibgha Tahir ◽  
Sabine Steffens
Keyword(s):  
Adaptive Immune Response ◽  
Short Review ◽  
Vital Role ◽  
Innate Immune ◽  
Vascular Integrity ◽  
Vascular Homeostasis ◽  
Adaptive Immune ◽  
Heterogeneous Cell Population ◽  
Distinct Cell

Monocytes are a heterogeneous cell population of innate immune cells with distinct cell surface markers that help them in carrying out different functions. In humans, there are three well-characterized subsets, namely, classical (CD14++CD16−), intermediate (CD14++CD16+), and nonclassical (CD14+ CD16++) monocytes. There is an emerging focus on the not yet well explored nonclassical monocytes that maintain vascular integrity by slowly patrolling on the endothelium, reacting to inflammatory signals, and clearing cell debris. In this manner, they are not only crucial for vascular homeostasis but also play a vital role in wound healing and resolution of inflammation by linking innate to adaptive immune response. Although they have been shown to be protective, yet they are also associated with inflammatory disease progression. This short review will give an insight about the emerging role of nonclassical monocytes in vascular homeostasis, inflammation, and protection in the context of cardiovascular disease.

Toll-like receptors and diabetes: a therapeutic perspective

2011 ◽  
Vol 122 (5) ◽  
pp. 203-214 ◽  
Author(s):  
Mohan R. Dasu ◽  
Sandra Ramirez ◽  
Roslyn R. Isseroff
Keyword(s):  
Immune Responses ◽  
Inflammatory Responses ◽  
Adaptive Immune Response ◽  
Innate Immune ◽  
Undiagnosed Diabetes ◽  
Innate Immune Responses ◽  
Toll Like Receptors ◽  
Adaptive Immune ◽  
Molecular Patterns ◽  
Therapeutic Perspective

Diabetes is a mutifactorial metabolic disorder that leads to a number of complications. Diabetes is estimated to affect 36 million people in the U.S.A., and the prevalence of diagnosed and undiagnosed diabetes is at 9.3% and continues to rise. Evidence from experimental animal models as well as humans has indicated that systemic inflammation plays a role in the pathophysiological processes of diabetes and is facilitated by innate immune responses. TLRs (Toll-like receptors) are key innate immune receptors that recognize conserved PAMPs (pathogen-associated molecular patterns), induce inflammatory responses essential for host defences and initiate an adaptive immune response. Although TLR expression is increased in a plethora of inflammatory disorders, the effects of metabolic aberrations on TLRs and their role in diabetes and its complications is still emerging. In the present paper, we provide a systematic review on how TLRs play a detrimental role in the pathogenic processes [increased blood sugar, NEFAs (non-esterified ‘free’ fatty acids), cytokines and ROS (reactive oxygen species)] that manifest diabetes. Furthermore, we will highlight some of the therapeutic strategies targeted at decreasing TLRs to abrogate inflammation in diabetes that may eventually result in decreased complications.

Extra- and intracellular innate immune recognition in endothelial cells

2007 ◽  
Vol 98 (08) ◽  
pp. 319-326 ◽  
Author(s):  
Stefan Hippenstiel ◽  
Julia Eitel ◽  
Norbert Suttorp ◽  
Bastian Opitz
Keyword(s):  
Pattern Recognition ◽  
Endothelial Cells ◽  
Potential Role ◽  
Current Knowledge ◽  
Vascular Diseases ◽  
Innate Immune ◽  
Surveillance Systems ◽  
Immune Recognition ◽  
Multicellular Organisms ◽  
Intracellular Infections

SummaryThe innate immune system represents the principal sensor of infections in multicellular organisms and might also mediate responses to some endogenous molecules. In this context, endothelial cells are among the first cells coming into contact with microbial or endogenous (danger-associated) molecules or whole pathogens entering the bloodstream. Since many bacteria and viruses invade the endothelium, endothelial cells are equipped with both extracellular and cytosolic surveillance systems capable of sensing microbial components, and endogenous danger-associated molecules. The receptor molecules, called pattern recognition receptors (PRRs), are classified as transmembrane or cytosolic molecules. While the transmembrane PRRs recognize extracellular and membrane-enclosed foreign organisms, the cytosolic PRRs appear to sense intracellular infections. Here we focus on both PRR classes in general, and outline the current knowledge of extra- and intracellular pattern recognition in endothelial cells and its potential role in vascular diseases and sepsis.

scholarly journals Adaptive Immunity: The Role of Toll-Like Receptors

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yamaguchi R ◽  
◽  
Sakamoto A ◽  
Yamaguchi R ◽  
Haraguchi M ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Autoimmune Diseases ◽  
Adaptive Immunity ◽  
Th17 Cells ◽  
Adaptive Immune Response ◽  
Toll Like Receptors ◽  
Adaptive Immune ◽  
Interleukin 23

The central mediators of the adaptive immune response are T cells. The clonal expansion of T cells required for adaptive immunity results from the innate immune response, which is triggered by the stimulation of Toll-Like Receptors (TLRs). The adaptive immune response can cause autoimmune diseases, and Th17 cells are known to contribute to several autoimmune diseases. Pathogenic Th17 cells are induced by Interleukin 23 (IL-23) and IL-1Β. Resiquimod (a TLR7/8 agonist) significantly enhances IL-23 production by human macrophages, and lipopolysaccharide (a TLR4 agonist) slightly enhances it. Interestingly, IL-23 levels are significantly attenuated after sequential stimulation with lipopolysaccharide and resiquimod, indicating cross-talk between the TLR4 and TLR7/8 signaling pathways. In this review, we discuss the pivotal role of TLRs in triggering innate immunity and inducing adaptive immunity, leading to autoimmune diseases.

scholarly journals Toll-Like Receptors Signaling Contributes to Immunopathogenesis of HBV Infection

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Yasuteru Kondo ◽  
Yoshiyuki Ueno ◽  
Tooru Shimosegawa
Keyword(s):  
Immune Response ◽  
Intracellular Signaling ◽  
Adaptive Immune Response ◽  
Innate Immune ◽  
Hbv Infection ◽  
Microbial Pathogens ◽  
Immune Recognition ◽  
Toll Like Receptors ◽  
Adaptive Immune ◽  
Complex Interactions

Innate and adaptive immune systems have important role in the pathogenesis of acute and chronic infection with hepatitis B virus (HBV). These immune responses are mediated through complex interactions between the innate immune response and adaptive immune response. Toll-like receptors (TLRs) are a family of innate immune-recognition receptors that recognize the molecular patterns associated with microbial pathogens. So far, TLR1 to 13 were found in human or mice and investigated to detect the target molecules and the downstream mechanisms of these unique systems. Stimulation by their ligands initiates the activation of complex networks of intracellular signaling transduction and innate and adaptive immune-related cells (NK, NK-T, monocytes, dendritic cells, T cells, B cells, and Tregs, etc.). However, reports on such relationships between HBV and TLRs have been relatively rare in comparison to those on HCV and TLRs, but have recently been increasing. Thus, a review of TLRs involved in the pathogenesis of HBV infection may be needed toward better understanding of the immunopathogenesis of HBV infection.

scholarly journals Role of the Innate Immunity Signaling Pathway in the Pathogenesis of Sjögren’s Syndrome

2021 ◽  
Vol 22 (6) ◽  
pp. 3090
Author(s):  
Toshimasa Shimizu ◽  
Hideki Nakamura ◽  
Atsushi Kawakami
Keyword(s):  
Immune Responses ◽  
Sjögren's Syndrome ◽  
Sjogren’S Syndrome ◽  
Sjogren's Syndrome ◽  
Innate Immune ◽  
Type I ◽  
Type I Ifn ◽  
Adaptive Immune ◽  
Sjögren‘S Syndrome

Sjögren’s syndrome (SS) is a systemic autoimmune disease characterized by chronic inflammation of the salivary and lacrimal glands and extra-glandular lesions. Adaptive immune response including T- and B-cell activation contributes to the development of SS. However, its pathogenesis has not yet been elucidated. In addition, several patients with SS present with the type I interferon (IFN) signature, which is the upregulation of the IFN-stimulated genes induced by type I IFN. Thus, innate immune responses including type I IFN activity are associated with SS pathogenesis. Recent studies have revealed the presence of activation pattern recognition receptors (PRRs) including Toll-like receptors, RNA sensor retinoic acid-inducible gene I and melanoma differentiation-associated gene 5, and inflammasomes in infiltrating and epithelial cells of the salivary glands among patients with SS. In addition, the activation of PRRs via the downstream pathway such as the type I IFN signature and nuclear factor kappa B can directly cause organ inflammation, and it is correlated with the activation of adaptive immune responses. Therefore, this study assessed the role of the innate immune signal pathway in the development of inflammation and immune abnormalities in SS.

scholarly journals The role of epigenetic modifications for the pathogenesis of Crohn's disease

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
M. Hornschuh ◽  
E. Wirthgen ◽  
M. Wolfien ◽  
K. P. Singh ◽  
O. Wolkenhauer ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Adaptive Immune Response ◽  
Adaptive Immune ◽  
Bowel Diseases ◽  
Inflammatory Bowel ◽  
New Biomarkers ◽  
Insight Into ◽  
Specific Evaluation

AbstractEpigenetics has become a promising field for finding new biomarkers and improving diagnosis, prognosis, and drug response in inflammatory bowel disease. The number of people suffering from inflammatory bowel diseases, especially Crohn's disease, has increased remarkably. Crohn's disease is assumed to be the result of a complex interplay between genetic susceptibility, environmental factors, and altered intestinal microbiota, leading to dysregulation of the innate and adaptive immune response. While many genetic variants have been identified to be associated with Crohn's disease, less is known about the influence of epigenetics in the pathogenesis of this disease. In this review, we provide an overview of current epigenetic studies in Crohn's disease. In particular, we enable a deeper insight into applied bioanalytical and computational tools, as well as a comprehensive update toward the cell-specific evaluation of DNA methylation and histone modifications.

scholarly journals Assessment of the pulmonary adaptive immune response to Cladosporium cladosporioides infection using an experimental mouse model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaoping Ma ◽  
Jing Hu ◽  
Yan Yu ◽  
Chengdong Wang ◽  
Yu Gu ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Adaptive Immune Response ◽  
Pulmonary Hemorrhage ◽  
Cladosporium Cladosporioides ◽  
Th2 Cells ◽  
Intercellular Adhesion Molecule ◽  
Post Inoculation ◽  
Adaptive Immune ◽  
Systemic Infections

AbstractCladosporium cladosporioides causes asthma and superficial and deep infections, mostly in immunodeficient individuals and animals. This study aimed to investigate whether C. cladosporioides spores can enter the lungs through pulmonary circulation and influence pulmonary immune response. We intravenously injected mice with C. cladosporioides spore suspension and conducted several assays on the lungs. Pulmonary hemorrhage symptoms and congestion were most severe on days 1, 2, and 3 post-inoculation (PI). Extensive inflammatory cell infiltration occurred throughout the period of infection. More spores and hyphae colonizing the lungs were detected on days 1, 2, and 3 PI, and fewer spores and hyphae were observed within 21 d of infection. Numerous macrophages, dendritic cells, and neutrophils were observed on day 5 PI, along with upregulation of CD54, an intercellular adhesion molecule. Th1 and Th2 cells increased after infection; specifically, Th2 cells increased considerably on day 5 PI. These results suggest that days 2 and 5 PI represent the inflammatory peak in the lungs and that the Th2 and Th1 signaling pathways are potentially involved in pulmonary immune responses. In conclusion, the further adaptive immune responses played important roles in establishing effective pulmonary immunity against C. cladosporioides systemic infections based on innate immune responses.

IMMU-22. THE IMPACT OF MICROGLIA MODULATION ON GBM PROGRESSION IN SYNGENEIC MOUSE MODELS

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi96-vi96
Author(s):  
Marie-Françoise Ritz ◽  
Tala Shekarian ◽  
Tomás A Martins ◽  
Philip Schmassmann ◽  
Gregor Hutter
Keyword(s):  
Mouse Models ◽  
Tumor Development ◽  
Adaptive Immune Response ◽  
Tamoxifen Treatment ◽  
Mouse Strains ◽  
Intracerebral Injection ◽  
Adaptive Immune ◽  
Tumor Immune Microenvironment ◽  
The Impact

Abstract BACKGROUND The tumor immune microenvironment (TME) of Glioblastoma consists of almost myeloid-derived macrophages and microglia called TAMs. We have shown that the disruption of CD47-Sirpα-axis induces an antitumor activity of TAMs against GBM in immune-deficient mice, through increases of phagocytosis of tumor cells by TAMs. We have aimed to study the role of microglia and its activation/depletion on GBM progression, in the syngeneic GBM model in immune-competent mice. We have studied the interplay of innate and adaptive immune response after activation and depletion of microglia and the effect on tumor progression and outcome of the mice. MATERIAL AND METHODS We used different colonies of genetically modified immunocompetent mouse strains to genetically activate/deplete microglia in the tumor context. We generated Sall1 CreERT2/fl mice and Cre-negative littermates. The application of Tamoxifen in this constellation leads to the excision of the transcription factor Sall1 and subsequent enhanced microglia activity. Conversely, we generated Sall1 CreERT2 x Csf1r fl/fl animals and the respective heterozygous and Cre-negative littermates in which Tamoxifen treatment leads to inactivation of microglia through the deletion of Csf1r. Glioblastoma tumors were induced by intracerebral injection of GL261, CT2A, or retrovirus-induced PDGF-Akt in pups and Tamoxifen treatment was started once the tumors were detected. RESULTS We observed a survival advantage in tumor-bearing mice after activation of microglia in Sall1 CreERT/fl animals compared to Cre-negative littermates. Genetic depletion of microglia in this model resulted in a shorter lifespan in microglia-depleted animals compared to Cre-negative littermates. Furthermore, the iTME in these tumors is subjected to scRNAseq analysis to identify mechanistic insights. CONCLUSION Microglia are important players in tumor development and progression of glioblastoma in mouse models. These cells may be targeted in future immunotherapeutic approaches for patients.

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