scholarly journals Crosstalk between toll-like receptors and hypoxia-dependent pathways in health and disease

2016 ◽  
Vol 64 (2) ◽  
pp. 369-375 ◽  
Author(s):  
Bianca Crifo ◽  
Cormac T Taylor
Keyword(s):  
Immune Response ◽  
Signaling Pathways ◽  
Adaptive Immunity ◽  
Inflammatory Responses ◽  
Current Knowledge ◽  
Toll Like Receptor ◽  
Toll Like Receptors ◽  
Innate And Adaptive Immunity ◽  
Infection And Inflammation ◽  
Health And Disease

Toll-like receptors (TLRs) play an important role in shaping the host immune response to infection and inflammation. Tissue hypoxia is a common microenvironmental feature of infected and inflamed tissues. Furthermore, hypoxia significantly impacts the development of immune and inflammatory responses through the regulation of host innate and adaptive immunity. Here, we will discuss current knowledge in relation to the crosstalk that exists between toll-like receptor- and hypoxia-dependent signaling pathways in health and disease.

scholarly journals Immunology of the canine eye in health and disease: a concise review

2019 ◽  
Vol 64 (No. 1) ◽  
pp. 1-17
Author(s):  
P. Dall’Ara ◽  
L. Turin
Keyword(s):  
Immune Response ◽  
Anterior Chamber ◽  
Adaptive Immunity ◽  
Local Immune Response ◽  
Innate And Adaptive Immunity ◽  
Concise Review ◽  
Competent Cells ◽  
Health And Disease ◽  
And Control ◽  
Detrimental Impact

The canine eye is an immune-privileged organ that is provided with systems to prevent and control the local immune response, which could have a detrimental impact. The entry of blood-derived antigens is hindered by the blood-ocular barriers and potential invading pathogens are tackled by local antimicrobial molecules. Despite the existence of numerous immune-competent cells, the anterior chamber of the eye is characterised by low responsiveness. This review is focused on the innate and adaptive immunity employed to control health and disease in the canine eye.

scholarly journals Cell Surface Expression of Endosomal Toll-Like Receptors—A Necessity or a Superfluous Duplication?

2021 ◽  
Vol 11 ◽  
Author(s):  
Matylda Barbara Mielcarska ◽  
Magdalena Bossowska-Nowicka ◽  
Felix Ngosa Toka
Keyword(s):  
Immune Response ◽  
Cell Membrane ◽  
Cell Surface ◽  
Signaling Pathways ◽  
Distinct Group ◽  
Cell Types ◽  
Cysteine Proteases ◽  
Cell Surface Expression ◽  
Critical Event ◽  
Toll Like Receptors

Timely and precise delivery of the endosomal Toll-like receptors (TLRs) to the ligand recognition site is a critical event in mounting an effective antimicrobial immune response, however, the same TLRs should maintain the delicate balance of avoiding recognition of self-nucleic acids. Such sensing is widely known to start from endosomal compartments, but recently enough evidence has accumulated supporting the idea that TLR-mediated signaling pathways originating in the cell membrane may be engaged in various cells due to differential expression and distribution of the endosomal TLRs. Therefore, the presence of endosomal TLRs on the cell surface could benefit the host responses in certain cell types and/or organs. Although not fully understood why, TLR3, TLR7, and TLR9 may occur both in the cell membrane and intracellularly, and it seems that activation of the immune response can be initiated concurrently from these two sites in the cell. Furthermore, various forms of endosomal TLRs may be transported to the cell membrane, indicating that this may be a normal process orchestrated by cysteine proteases—cathepsins. Among the endosomal TLRs, TLR3 belongs to the evolutionary distinct group and engages a different protein adapter in the signaling cascade. The differently glycosylated forms of TLR3 are transported by UNC93B1 to the cell membrane, unlike TLR7, TLR8, and TLR9. The aim of this review is to reconcile various views on the cell surface positioning of endosomal TLRs and add perspective to the implication of such receptor localization on their function, with special attention to TLR3. Cell membrane-localized TLR3, TLR7, and TLR9 may contribute to endosomal TLR-mediated inflammatory signaling pathways. Dissecting this signaling axis may serve to better understand mechanisms influencing endosomal TLR-mediated inflammation, thus determine whether it is a necessity for immune response or simply a circumstantial superfluous duplication, with other consequences on immune response.

scholarly journals Directed attenuation to enhance vaccine immunity

2021 ◽  
Vol 17 (2) ◽  
pp. e1008602
Author(s):  
Rustom Antia ◽  
Hasan Ahmed ◽  
James J. Bull
Keyword(s):  
Immune Response ◽  
Genetic Engineering ◽  
Adaptive Immunity ◽  
Immune Evasion ◽  
Viral Infections ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Innate And Adaptive Immunity ◽  
Live Attenuated Vaccines

Many viral infections can be prevented by immunizing with live, attenuated vaccines. Early methods of attenuation were hit-and-miss, now much improved by genetic engineering. However, even current methods operate on the principle of genetic harm, reducing the virus’s ability to grow. Reduced viral growth has the undesired side-effect of reducing the host immune response below that of infection with wild-type. Might some methods of attenuation instead lead to an increased immune response? We use mathematical models of the dynamics of virus with innate and adaptive immunity to explore the tradeoff between attenuation of virus pathology and immunity. We find that modification of some virus immune-evasion pathways can indeed reduce pathology yet enhance immunity. Thus, attenuated vaccines can, in principle, be directed to be safe yet create better immunity than is elicited by the wild-type virus.

scholarly journals Transcriptome Analysis for Genes Associated with Small Ruminant Lentiviruses Infection in Goats of Carpathian Breed

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2054
Author(s):  
Monika Olech ◽  
Katarzyna Ropka-Molik ◽  
Tomasz Szmatoła ◽  
Katarzyna Piórkowska ◽  
Jacek Kuźmak
Keyword(s):  
Gene Expression ◽  
Immune Response ◽  
Signaling Pathways ◽  
Signaling Pathway ◽  
Proviral Load ◽  
Cytokine Production ◽  
Small Ruminant ◽  
Receptor Signaling ◽  
Toll Like Receptor ◽  
Receptor Signaling Pathway

Small ruminant lentiviruses (SRLV) are economically important viral pathogens of sheep and goats. SRLV infection may interfere in the innate and adaptive immunity of the host, and genes associated with resistance or susceptibility to infection with SRLV have not been fully recognized. The presence of animals with relatively high and low proviral load suggests that some host factors are involved in the control of virus replication. To better understand the role of the genes involved in the host response to SRLV infection, RNA sequencing (RNA-seq) method was used to compare whole gene expression profiles in goats carrying both a high (HPL) and low (LPL) proviral load of SRLV and uninfected animals. Data enabled the identification of 1130 significant differentially expressed genes (DEGs) between control and LPL groups: 411 between control and HPL groups and 1434 DEGs between HPL and LPL groups. DEGs detected between the control group and groups with a proviral load were found to be significantly enriched in several gene ontology (GO) terms, including an integral component of membrane, extracellular region, response to growth factor, inflammatory and innate immune response, transmembrane signaling receptor activity, myeloid differentiation primary response gene 88 (MyD88)-dependent toll-like receptor signaling pathway as well as regulation of cytokine secretion. Our results also demonstrated significant deregulation of selected pathways in response to viral infection. The presence of SRLV proviral load in blood resulted in the modification of gene expression belonging to the toll-like receptor signaling pathway, the tumor necrosis factor (TNF) signaling pathway, the cytokine-cytokine receptor interaction, the phagosome, the Ras signaling pathway, the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) (PI3K-Akt) signaling pathway and rheumatoid arthritis. It is worth mentioning that the most predominant in all pathways were genes represented by toll-like receptors, tubulins, growth factors as well as interferon gamma receptors. DEGs detected between LPL and HPL groups were found to have significantly enriched regulation of signaling receptor activity, the response to toxic substances, nicotinamide adenine dinucleotide (NADH) dehydrogenase complex assembly, cytokine production, vesicle, and vacuole organization. In turn, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway tool classified DEGs that enrich molecular processes such as B and T-cell receptor signaling pathways, natural killer cell-mediated cytotoxicity, Fc gamma R-mediated phagocytosis, toll-like receptor signaling pathways, TNF, mammalian target of rapamycin (mTOR) signaling and forkhead box O (Foxo) signaling pathways, etc. Our data indicate that changes in SRLV proviral load induced altered expression of genes related to different biological processes such as immune response, inflammation, cell locomotion, and cytokine production. These findings provide significant insights into defense mechanisms against SRLV infection. Furthermore, these data can be useful to develop strategies against SRLV infection by selection of animals with reduced SRLV proviral concentration that may lead to a reduction in the spread of the virus.

scholarly journals Lysosomal trafficking regulator Lyst links membrane trafficking to toll-like receptor–mediated inflammatory responses

2016 ◽  
Vol 214 (1) ◽  
pp. 227-244 ◽  
Author(s):  
Andreas Westphal ◽  
Weijia Cheng ◽  
Jinbo Yu ◽  
Guntram Grassl ◽  
Martina Krautkrämer ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Membrane Trafficking ◽  
Inflammatory Responses ◽  
Functional Integration ◽  
Receptor Signaling ◽  
Toll Like Receptor ◽  
Tlr Signaling ◽  
Lysosomal Trafficking ◽  
Phagosomal Maturation ◽  
Chediak Higashi Syndrome

Subcellular compartmentalization of receptor signaling is an emerging principle in innate immunity. However, the functional integration of receptor signaling pathways into membrane trafficking routes and its physiological relevance for immune responses is still largely unclear. In this study, using Lyst-mutant beige mice, we show that lysosomal trafficking regulator Lyst links endolysosomal organization to the selective control of toll-like receptor 3 (TLR3)– and TLR4-mediated proinflammatory responses. Consequently, Lyst-mutant mice showed increased susceptibility to bacterial infection and were largely resistant to endotoxin-induced septic shock. Mechanistic analysis revealed that Lyst specifically controls TLR3- and TLR4-induced endosomal TRIF (TIR domain–containing adapter-inducing interferon β) signaling pathways. Loss of functional Lyst leads to dysregulated phagosomal maturation, resulting in a failure to form an activation-induced Rab7+ endosomal/phagosomal compartment. This specific Rab7+ compartment was further demonstrated to serve as a major site for active TRIF signaling events, thus linking phagosomal maturation to specific TLR signaling pathways. The immunoregulatory role of Lyst on TLR signaling pathways was confirmed in human cells by CRISPR/Cas9-mediated gene inactivation. As mutations in LYST cause human Chédiak-Higashi syndrome, a severe immunodeficiency, our findings also contribute to a better understanding of human disease mechanisms.

Introduction to Clinical Immunology: Overview of the Immune Response, Autoimmune Conditions, and Immunosuppressive Therapeutics for Rheumatic Diseases

2016 ◽  
Author(s):  
Steven K. Lundy ◽  
Alison Gizinski ◽  
David A. Fox
Keyword(s):  
Immune Response ◽  
Immune System ◽  
T Cell ◽  
Immune Responses ◽  
Autoimmune Diseases ◽  
Adaptive Immunity ◽  
Cell Populations ◽  
Hematopoietic Stem ◽  
Innate And Adaptive Immunity ◽  
Adaptive Immune

The immune system is a complex network of cells and mediators that must balance the task of protecting the host from invasive threats. From a clinical perspective, many diseases and conditions have an obvious link to improper functioning of the immune system, and insufficient immune responses can lead to uncontrolled acute and chronic infections. The immune system may also be important in tumor surveillance and control, cardiovascular disease, health complications related to obesity, neuromuscular diseases, depression, and dementia. Thus, a working knowledge of the role of immunity in disease processes is becoming increasingly important in almost all aspects of clinical practice. This review provides an overview of the immune response and discusses immune cell populations and major branches of immunity, compartmentalization and specialized immune niches, antigen recognition in innate and adaptive immunity, immune tolerance toward self antigens, inflammation and innate immune responses, adaptive immune responses and helper T (Th) cell subsets, components of the immune response that are important targets of treatment in autoimmune diseases, mechanisms of action of biologics used to treat autoimmune diseases and their approved uses, and mechanisms of other drugs commonly used in the treatment of autoimmune diseases. Figures show the development of erythrocytes, platelets, lymphocytes, and other immune system cells originating from hematopoietic stem cells that first reside in the fetal liver and later migrate to the bone marrow, antigen–major histocompatibility complex recognition by T cell receptor control of T cell survival and activation, and Th cells as central determinants of the adaptive immune response toward different stimuli. Tables list cell populations involved in innate and adaptive immunity, pattern recognition receptors with known ligands, autoantibody-mediated human diseases: examples of pathogenic mechanisms, selected Food and Drug Administration–approved autoimmune disease indications for biologics, and mechanism of action of biologics used to treat autoimmune diseases.   This review contains 3 highly rendered figures, 5 tables, and 64 references.

scholarly journals Genetic Polymorphisms of Toll-like receptors 2 and 9 as Susceptibility Factors for the Development of Ankylosing Spondylitis and Psoriatic Arthritis

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Camila F. Oliveira-Toré ◽  
Amarilis G. Moraes ◽  
Gabriela F. Martinez ◽  
Janisleya S. F. Neves ◽  
Luciana C. Macedo ◽  
...  
Keyword(s):  
Immune Response ◽  
Psoriatic Arthritis ◽  
Ankylosing Spondylitis ◽  
Genetic Polymorphisms ◽  
Inflammatory Responses ◽  
Strong Association ◽  
Adaptive Immune Response ◽  
Inflammatory Rheumatic Diseases ◽  
Toll Like Receptors ◽  
Immunological Mechanisms

Introduction. Ankylosing spondylitis (AS) and psoriatic arthritis (PsA) are classified as spondyloarthritis (SpA), a group of inflammatory rheumatic diseases with complex genetic etiology. Toll-like receptors (TLRs) have an important role in the mechanism of innate immunity and may influence inflammatory responses. Polymorphisms in TLR genes that lead to changes in these receptors or that interfere with the transcription rates of mRNA TLR may be involved in the chronic inflammatory immune response observed in SpA. Currently, there is a lack of studies associating genetic polymorphisms in TLRs and SpA. Objective. Therefore, this case-control study is aimed at analyzing the influence of the respective SNPs on TLR2 rs5743708, TLR6 rs5743810, and TLR9 rs5743836 and rs187084 in the immunopathogenesis of SpA. Methods. The polymorphisms genotyped by PCR-RFLP were TLR2 rs5743708, TLR6 rs5743810, and TLR9 rs5743836 and rs187084. The HLA-B∗27 was performed by PCR-SSP. Results. Logistic regression analysis showed a strong association between SNPs in TLR2 and TLR9 and susceptibility to SpA (OR=12.56; CI=6.5-25.9 and OR=1.62; CI=1.20-2.21, respectively). No association was observed among HLA-B∗27 and TLR polymorphisms (p=0.72), nor among BASDAI and TLR polymorphisms (p=0.85). Discussion. Our findings suggest that polymorphisms in TLR2 and TLR9 genes may contribute to the immunopathogenesis of the SpA. The rs187084, rs5743836, and rs5743708 polymorphisms were associated with the risk of SpA development, in this study, and lead to significant changes in the innate and adaptive immune response profile, as well as the maintenance of the regulation of immunological mechanisms. Conclusion. The polymorphism rs5743708 for the TLR2 and the rs187084_rs5743836 TLR9 haplotypes appear to be involved in the development of clinical forms of SpA and can be a possible therapeutic target for the spondyloarthritis.

scholarly journals A Novel Combination of Vitamin C, Curcumin and Glycyrrhizic Acid Potentially Regulates Immune and Inflammatory Response Associated with Coronavirus Infections: A Perspective from System Biology Analysis

Nutrients ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1193 ◽  
Author(s):  
Liang Chen ◽  
Chun Hu ◽  
Molly Hood ◽  
Xue Zhang ◽  
Lu Zhang ◽  
...  
Keyword(s):  
Immune Response ◽  
Vitamin C ◽  
Inflammatory Response ◽  
Signaling Pathways ◽  
System Biology ◽  
Glycyrrhizic Acid ◽  
Inflammatory Responses ◽  
Mapk Signaling ◽  
Gene Target

Novel coronaviruses (CoV) have emerged periodically around the world in recent years. The recurrent spreading of CoVs imposes an ongoing threat to global health and the economy. Since no specific therapy for these CoVs is available, any beneficial approach (including nutritional and dietary approach) is worth investigation. Based on recent advances in nutrients and phytonutrients research, a novel combination of vitamin C, curcumin and glycyrrhizic acid (VCG Plus) was developed that has potential against CoV infection. System biology tools were applied to explore the potential of VCG Plus in modulating targets and pathways relevant to immune and inflammation responses. Gene target acquisition, gene ontology and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment were conducted consecutively along with network analysis. The results show that VCG Plus can act on 88 hub targets which are closely connected and associated with immune and inflammatory responses. Specifically, VCG Plus has the potential to regulate innate immune response by acting on NOD-like and Toll-like signaling pathways to promote interferons production, activate and balance T-cells, and regulate the inflammatory response by inhibiting PI3K/AKT, NF-κB and MAPK signaling pathways. All these biological processes and pathways have been well documented in CoV infections studies. Therefore, our findings suggest that VCG Plus may be helpful in regulating immune response to combat CoV infections and inhibit excessive inflammatory responses to prevent the onset of cytokine storm. However, further in vitro and in vivo experiments are warranted to validate the current findings with system biology tools. Our current approach provides a new strategy in predicting formulation rationale when developing new dietary supplements.

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