scholarly journals Toll-like receptors and their role in carcinogenesis and anti-tumor treatment

2009 ◽  
Vol 14 (2) ◽  
Author(s):  
Anna Wolska ◽  
Ewa Lech-Marańda ◽  
Tadeusz Robak
Keyword(s):  
Molecular Structures ◽  
Neoplastic Disease ◽  
Adapter Proteins ◽  
Adaptive Responses ◽  
Toll Like Receptors ◽  
Disease Treatment ◽  
Tlr Agonists ◽  
Disease Therapy ◽  
Molecular Patterns ◽  
Large Groups

AbstractToll-like receptors (TLRs) have been described as major components of the innate immune system, recognizing the conserved molecular structures found in the large groups of pathogens called pathogen-associated molecular patterns (PAMPs). TLR expression is ubiquitous, from epithelial to immunocompetent cells. TLR ligation triggers several adapter proteins and downstream kinases, leading to the induction of key pro-inflammatory mediators but also anti-inflammatory and anti-tumor cytokines. The result of this activation goes beyond innate immunity to shape the adaptive responses against pathogens and tumor cells, and maintains host homeostasis via cell debris utilization. TLRs have already become potent targets in infectious disease treatment and vaccine therapy and in neoplastic disease treatment, due to their ability to enhance antigen presentation. However, some studies show the dual effect of TLR stimulation on malignant cells: they can be proapoptotic or promote survival under different conditions. It is therefore crucial to design further studies assessing the biology of these receptors in normal and transformed cells. The established role of TLRs in human disease therapy is based on TLR7 and TLR4 agonists, respectively for the novel treatment of some types of skin cancer and for the anti-hepatitis B virus vaccine. Some clinical trials involving TLR agonists as potent enhancers of the anti-tumor response in solid tumors have begun.

scholarly journals Image-recognizing receptors of the innate immunity and their role in immunotherapy (review)

2020 ◽  
pp. 4-15
Author(s):  
О.Ю. Филатов ◽  
В.А. Назаров
Keyword(s):  
Innate Immunity ◽  
Membrane Surface ◽  
Immune Defense ◽  
Molecular Structures ◽  
Membrane Receptors ◽  
Toll Like Receptors ◽  
Lectin Receptors ◽  
Wide Range ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns

Данная статья обобщает накопившуюся на сегодняшний день информацию о многообразии образраспознающих рецепторов, их роли в регуляции иммунной системы. Распознавание патогена врожденным иммунитетом происходит с помощью рецепторов к широкому спектру антигенов за счет выделения нескольких высоко консервативных структур микроорганизмов. Эти структуры были названы патоген-ассоциированные образы (Patogen-Associated Molecular Patterns - PAMP). Наиболее изученными являются липополисахарид грамм отрицательных бактерий (LPS), липотейхоевые кислоты, пептидогликан (PGN), CpG мотивы ДНК и РНК. Рецепторы, распознающие PAMP, называются PRR. Данная группа рецепторов также распознает молекулы, образующиеся при повреждении собственных тканей. Такие молекулярные структуры называются Damage-Associated Molecular Patterns (DAMP), или образы, ассоциированные с повреждением. В качестве DAMP могут выступать белки теплового шока, хроматин, фрагменты ДНК. В зависимости от локализации, образраспознающие рецепторы принято разделять на: расположенные на мембране Toll-подобные рецепторы (Toll-like receptors, TLR) и рецепторы лектина С-типа (C-type lectin receptors, CLR), а также расположенные в цитоплазме NOD-подобные рецепторы (NOD-like receptors, NLR) и цитоплазматические РНК- и ДНК-сенсоры. Сегодня у человека известно 10 типов TLR, часть из которых расположена на поверхности (TLR1-TLR6, TLR10) большинства клеток, в том числе макрофагов, В-лимфоцитов и дендритных клеток, а часть - в эндосомах (TLR3, TLR7-TLR9). CLR представляет из себя семейство рецепторов, расположенных на мембране и имеющих домены распознавания углеводов (CRD), или структурно сходные лектиноподобные домены типа C (CTLD). В данном семействе рецепторов принято по происхождению и структуре выделять 17 групп. CLR активно участвуют в противогрибковой иммунной защите, а также они играют роль в защите и от других типов микроорганизмов. NOD (нуклеотидсвязывающий и олигомеризационный домен)-подобные рецепторы расположены в цитоплазме. Благодаря этим рецепторам, патоген, который избежал распознавания на поверхности мембраны, сталкивается со вторым уровнем распознавания уже внутри клетки. В данной статье рассматриваются пути активации образраспознающих рецепторов, их эффекты и применение данных эффектов в медицине. This article summarizes currently available information about the variety of image-recognizing receptors and their role in regulation of the immune system. Pathogen recognition by the innate immunity is mediated by receptors to a wide range of antigens via recognition of several highly conservative structures of microorganisms. These structures were named pathogen-associated images or PAMP (pathogen-associated molecular pattern). The best studied types of such structures include lipopolysaccharide (LPS) of gram-negative bacteria, lipoteichoic acids, peptidoglycan (PGN), and CpG DNA and RNA motifs. PAMP-recognizing receptors (PRRS) are a group of receptors, which also recognize molecules released during damage of host tissues. Such molecular structures are called DAMPS (damage-associated molecular patterns) or damage-associated images. Heat shock proteins, chromatin, and DNA fragments may act as DAMPS. Depending on the localization, image-recognizing receptors are generally classified as membrane-located Toll-like receptors (TLR) and C-type lectin receptors (CLR), as well as cytoplasmic NOD-like receptors (NLR) and cytoplasmic RNA and DNA sensors. Today, 10 types of human TLR are known. Some of them are located on the surface (TLR1-TLR6, TLR10) of most cells, including macrophages, B-cells, and dendritic cells, and some are present in endosomes (TLR3, TLR7-TLR9). CLR is a family of membrane receptors that have carbohydrate recognition domains (CRD) or structurally similar lectin-like type C domains (CTLD). Seventeen groups are distinguished within this receptor family based on their origin and structure. CLRs are actively involved in antifungal immune defense and also play a role in protection against other types of microorganisms. NOD (nucleotide-binding and oligomerization domain)-like receptors are present in the cytoplasm. These receptors provide the second level of recognition inside the cell for the pathogens that have escaped recognition on the membrane surface. This article discusses activation pathways of image-recognizing receptors, their effects, and the use of such effects in medicine.

scholarly journals Role of toll-like receptors in human iris pigment epithelial cells and their response to pathogen-associated molecular patterns

2014 ◽  
Vol 11 (1) ◽  
pp. 20 ◽  
Author(s):  
Kelly Mai ◽  
Jeanie JY Chui ◽  
Nick Di Girolamo ◽  
Peter J McCluskey ◽  
Denis Wakefield
Keyword(s):  
Epithelial Cells ◽  
Toll Like Receptors ◽  
Pigment Epithelial ◽  
Human Iris ◽  
Molecular Patterns ◽  
Pigment Epithelial Cells

scholarly journals Toll-Like Receptors and Myocardial Inflammation

2011 ◽  
Vol 2011 ◽  
pp. 1-21 ◽  
Author(s):  
Yan Feng ◽  
Wei Chao
Keyword(s):  
Animal Studies ◽  
Myocardial Injury ◽  
Myocardial Inflammation ◽  
Septic Cardiomyopathy ◽  
Toll Like Receptors ◽  
Tlr Signaling ◽  
Animal Data ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns

Toll-like receptors (TLRs) are a member of the innate immune system. TLRs detect invading pathogens through the pathogen-associated molecular patterns (PAMPs) recognition and play an essential role in the host defense. TLRs can also sense a large number of endogenous molecules with the damage-associated molecular patterns (DAMPs) that are produced under various injurious conditions. Animal studies of the last decade have demonstrated that TLR signaling contributes to the pathogenesis of the critical cardiac conditions, where myocardial inflammation plays a prominent role, such as ischemic myocardial injury, myocarditis, and septic cardiomyopathy. This paper reviews the animal data on (1) TLRs, TLR ligands, and the signal transduction system and (2) the important role of TLR signaling in these critical cardiac conditions.

scholarly journals Revisiting Platelets and Toll-Like Receptors (TLRs): At the Interface of Vascular Immunity and Thrombosis

2020 ◽  
Vol 21 (17) ◽  
pp. 6150 ◽  
Author(s):  
Kathryn Hally ◽  
Sebastien Fauteux-Daniel ◽  
Hind Hamzeh-Cognasse ◽  
Peter Larsen ◽  
Fabrice Cognasse
Keyword(s):  
Platelet Function ◽  
Immune Modulation ◽  
Human Platelets ◽  
Toll Like Receptors ◽  
Methodological Issues ◽  
Vascular Integrity ◽  
Danger Signals ◽  
Research Questions ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns

While platelet function has traditionally been described in the context of maintaining vascular integrity, recent evidence suggests that platelets can modulate inflammation in a much more sophisticated and nuanced manner than previously thought. Some aspects of this expanded repertoire of platelet function are mediated via expression of Toll-like receptors (TLRs). TLRs are a family of pattern recognition receptors that recognize pathogen-associated and damage-associated molecular patterns. Activation of these receptors is crucial for orchestrating and sustaining the inflammatory response to both types of danger signals. The TLR family consists of 10 known receptors, and there is at least some evidence that each of these are expressed on or within human platelets. This review presents the literature on TLR-mediated platelet activation for each of these receptors, and the existing understanding of platelet-TLR immune modulation. This review also highlights unresolved methodological issues that potentially contribute to some of the discrepancies within the literature, and we also suggest several recommendations to overcome these issues. Current understanding of TLR-mediated platelet responses in influenza, sepsis, transfusion-related injury and cardiovascular disease are discussed, and key outstanding research questions are highlighted. In summary, we provide a resource—a “researcher’s toolkit”—for undertaking further research in the field of platelet-TLR biology.

scholarly journals Wnt Signaling in Leukemia and Its Bone Marrow Microenvironment

2020 ◽  
Vol 21 (17) ◽  
pp. 6247
Author(s):  
Yongsheng Ruan ◽  
Hye Na Kim ◽  
Heather Ogana ◽  
Yong-Mi Kim
Keyword(s):  
Stem Cells ◽  
Wnt Signaling ◽  
Stromal Cells ◽  
Critical Role ◽  
Neoplastic Disease ◽  
Leukemic Stem Cells ◽  
Hematopoietic Stem ◽  
Disease Therapy ◽  
Wnt Pathways

Leukemia is an aggressive hematologic neoplastic disease. Therapy-resistant leukemic stem cells (LSCs) may contribute to the relapse of the disease. LSCs are thought to be protected in the leukemia microenvironment, mainly consisting of mesenchymal stem/stromal cells (MSC), endothelial cells, and osteoblasts. Canonical and noncanonical Wnt pathways play a critical role in the maintenance of normal hematopoietic stem cells (HSC) and LSCs. In this review, we summarize recent findings on the role of Wnt signaling in leukemia and its microenvironment and provide information on the currently available strategies for targeting Wnt signaling.

scholarly journals Mal and MyD88: adapter proteins involved in signal transduction by Toll-like receptors

2003 ◽  
Vol 9 (1) ◽  
pp. 55-59 ◽  
Author(s):  
Luke A.J. O'Neill ◽  
Aisling Dunne ◽  
Michael Edjeback ◽  
Pearl Gray ◽  
Caroline Jefferies ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Adapter Proteins ◽  
Toll Like Receptors

scholarly journals Bacterial Pathogen-associated Molecular Patterns Stimulate Biological Activity of Orthopaedic Wear Particles by Activating Cognate Toll-like Receptors

2010 ◽  
Vol 285 (42) ◽  
pp. 32378-32384 ◽  
Author(s):  
Edward M. Greenfield ◽  
Michelle A. Beidelschies ◽  
Joscelyn M. Tatro ◽  
Victor M. Goldberg ◽  
Amy G. Hise
Keyword(s):  
Biological Activity ◽  
Bacterial Pathogen ◽  
Wear Particles ◽  
Toll Like Receptors ◽  
Molecular Patterns

scholarly journals Role of Toll-Like Receptors in Actuating Stem/Progenitor Cell Repair Mechanisms: Different Functions in Different Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Fabio Sallustio ◽  
Claudia Curci ◽  
Alessandra Stasi ◽  
Giuseppe De Palma ◽  
Chiara Divella ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Therapeutic Potential ◽  
Toll Like Receptors ◽  
Repair Mechanisms ◽  
Specific Tissue ◽  
The Many ◽  
Pathological Environment ◽  
Molecular Patterns

Toll-like receptors (TLRs) represent one of the bridges that regulate the cross-talk between the innate and adaptive immune systems. TLRs interact with molecules shared and preserved by the pathogens of origin but also with endogenous molecules (damage/danger-associated molecular patterns (DAMPs)) that derive from injured tissues. This is probably why TLRs have been found to be expressed on several kinds of stem/progenitor cells (SCs). In these cells, the role of TLRs in the regulation of the basal motility, proliferation, differentiation processes, self-renewal, and immunomodulation has been demonstrated. In this review, we analyze the many different functions that the TLRs assume in SCs, pointing out that they can have different effects, depending on the background and on the kind of ligands that they recognize. Moreover, we discuss the TLR involvement in the response of SC to specific tissue damage and in the reparative processes, as well as how the identification of molecules mediating the differential function of TLR signaling could be decisive for the development of new therapeutic strategies. Considering the available studies on TLRs in SCs, here we address the importance of TLRs in sensing an injury by stem/progenitor cells and in determining their behavior and reparative activity, which is dependent on the conditions. Therefore, it could be conceivable that SCs employed in therapy could be potentially exposed to TLR ligands, which might modulate their therapeutic potential in vivo. In this context, to modulate SC proliferation, survival, migration, and differentiation in the pathological environment, we need to better understand the mechanisms of action of TLRs on SCs and learn how to control these receptors and their downstream pathways in a precise way. In this manner, in the future, cell therapy could be improved and made safer.

scholarly journals Toll-Like Receptors in Angiogenesis

2011 ◽  
Vol 11 ◽  
pp. 981-991 ◽  
Author(s):  
Karsten Grote ◽  
Harald Schütt ◽  
Bernhard Schieffer
Keyword(s):  
Lupus Erythematosus ◽  
Acute Infection ◽  
Critical Role ◽  
Cell Types ◽  
Immune Defense ◽  
Toll Like Receptors ◽  
Inflammatory Disorders ◽  
Repair Mechanisms ◽  
New Treatment ◽  
Molecular Patterns

Toll-like receptors (TLRs) are known as pattern-recognition receptors related to the Toll protein ofDrosophila. After recognition of pathogen-associated molecular patterns of microbial origin, the TLRs alert the immune system, and initiate innate and adaptive immune responses. The TLR system, though, is not confined solely to the leukocyte-mediated immune defense against exogenous pathogens. Besides myeloid cells, TLR expression has been reported in multiple tissues and cell types, including epithelial and endothelial cells. Moreover, despite the microbial patterns that are commonly accepted as TLR ligands, there is increasing evidence that TLRs also recognize host-derived molecules. In this regard, recent studies point to an involvement of TLRs in various chronic inflammatory disorders and cardiovascular diseases, including atherosclerosis, rheumatoid arthritis, systemic lupus erythematosus, and even cancer. A common feature of these disorders is an enhanced so-called inflammation-induced angiogenesis. However, inflammation-induced angiogenesis is not solely a key component of pathogen defense during acute infection or chronic inflammatory disorders, but also plays a critical role in repair mechanisms, e.g., wound healing and subsequent tissue regeneration. Interestingly, the latest research could coincidentally demonstrate that TLR activation promotes angiogenesis in various inflammatory settings in response to both exogenous and endogenous ligands, although the precise mode of action of TLRs in this context still remains ambiguous. The objective of this review is to present evidence for the implication of TLRs in angiogenesis during physiological and pathophysiological processes, and the potential clinical relevance for new treatment regimes involving TLR modulation.

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