scholarly journals Metabolic programming in dendritic cells tailors immune responses and homeostasis

2021 ◽  
Author(s):  
Sofie Hedlund Møller ◽  
Limei Wang ◽  
Ping-Chih Ho
Keyword(s):  
Immune Responses ◽  
Current Knowledge ◽  
Cell Metabolism ◽  
Tumor Biology ◽  
Metabolic Programming ◽  
Dc Functions ◽  
Peripheral Tissues ◽  
Metabolic Phenotypes ◽  
Context Specific ◽  
Extracellular Environment

AbstractIt is being increasingly acknowledged that immune cells depend on certain metabolic traits to perform their functions and that the extracellular environment can influence cell metabolism and vice versa. Dendritic cell (DC) subsets traffic through highly diverse environments from the bone marrow, where they develop, to the various peripheral tissues, where they differentiate and capture antigens, before they migrate to the lymph node to present antigens and prime T cells. It is plausible that DC subsets modulate their stimulatory abilities in response to unique metabolic programming. The metabolic requirements of DCs are just recently being discovered, and subset- and context-specific metabolic phenotypes in DCs are highly intertwined with DC functions. In this review, we present the current knowledge on the intrinsic and extrinsic determinants of DC metabolism, how they regulate DC function with examples from tumor biology and in interaction with the microbiota, and discuss how this can be applied therapeutically.

scholarly journals Cardiac Cell Therapy: Insights into the Mechanisms of Tissue Repair

2021 ◽  
Vol 22 (3) ◽  
pp. 1201
Author(s):  
Hsuan Peng ◽  
Kazuhiro Shindo ◽  
Renée R. Donahue ◽  
Ahmed Abdel-Latif
Keyword(s):  
Stem Cell ◽  
Immune Responses ◽  
Tissue Repair ◽  
Molecular Mechanisms ◽  
Clinical Evidence ◽  
Current Knowledge ◽  
Cell Delivery ◽  
Cardiac Cell Therapy ◽  
Stem Cell Treatment

Stem cell-based cardiac therapies have been extensively studied in recent years. However, the efficacy of cell delivery, engraftment, and differentiation post-transplant remain continuous challenges and represent opportunities to further refine our current strategies. Despite limited long-term cardiac retention, stem cell treatment leads to sustained cardiac benefit following myocardial infarction (MI). This review summarizes the current knowledge on stem cell based cardiac immunomodulation by highlighting the cellular and molecular mechanisms of different immune responses to mesenchymal stem cells (MSCs) and their secretory factors. This review also addresses the clinical evidence in the field.

scholarly journals Molecular Characterization of Dendritic Cell-Derived Exosomes

1999 ◽  
Vol 147 (3) ◽  
pp. 599-610 ◽  
Author(s):  
Clotilde Théry ◽  
Armelle Regnault ◽  
Jérôme Garin ◽  
Joseph Wolfers ◽  
Laurence Zitvogel ◽  
...  
Keyword(s):  
Dendritic Cell ◽  
Heat Shock ◽  
Immune Responses ◽  
Milk Fat ◽  
Protein Composition ◽  
Antitumor Effects ◽  
Peripheral Tissues ◽  
Peptide Mass ◽  
Dc Maturation

Exosomes are membrane vesicles secreted by hematopoietic cells upon fusion of late multivesicular endosomes with the plasma membrane. Dendritic cell (DC)-derived exosomes induce potent antitumor immune responses in mice, resulting in the regression of established tumors (Zitvogel, L., A. Regnault, A. Lozier, J. Wolfers, C. Flament, D. Tenza, P. Ricciardi-Castagnoli, G. Raposo, and S. Amigorena. 1998. Nat. Med. 4:594–600). To unravel the molecular basis of exosome-induced immune stimulation, we now analyze the regulation of their production during DC maturation and characterize extensively their protein composition by peptide mass mapping. Exosomes contain several cytosolic proteins (including annexin II, heat shock cognate protein hsc73, and heteromeric G protein Gi2α), as well as different integral or peripherally associated membrane proteins (major histocompatiblity complex class II, Mac-1 integrin, CD9, milk fat globule-EGF-factor VIII [MFG-E8]). MFG-E8, the major exosomal component, binds integrins expressed by DCs and macrophages, suggesting that it may be involved in exosome targeting to these professional antigen-presenting cells. Another exosome component is hsc73, a cytosolic heat shock protein (hsp) also present in DC endocytic compartments. hsc73 was shown to induce antitumor immune responses in vivo, and therefore could be involved in the exosome's potent antitumor effects. Finally, exosome production is downregulated upon DC maturation, indicating that in vivo, exosomes are produced by immature DCs in peripheral tissues. Thus, DC-derived exosomes accumulate a defined subset of cellular proteins reflecting their endosomal biogenesis and accounting for their biological function.

scholarly journals The Mycobacterium tuberculosis PE_PGRS Protein Family Acts as an Immunological Decoy to Subvert Host Immune Response

2022 ◽  
Vol 23 (1) ◽  
pp. 525
Author(s):  
Tarina Sharma ◽  
Anwar Alam ◽  
Aquib Ehtram ◽  
Anshu Rani ◽  
Sonam Grover ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Immune Responses ◽  
Current Knowledge ◽  
Immune Effector ◽  
Host Immune Responses ◽  
Intrinsically Disordered ◽  
Multiple Strategies ◽  
Latent Stage ◽  
Immune Mediated ◽  
Critical Edge

Mycobacterium tuberculosis (M.tb) is a successful pathogen that can reside within the alveolar macrophages of the host and can survive in a latent stage. The pathogen has evolved and developed multiple strategies to resist the host immune responses. M.tb escapes from host macrophage through evasion or subversion of immune effector functions. M.tb genome codes for PE/PPE/PE_PGRS proteins, which are intrinsically disordered, redundant and antigenic in nature. These proteins perform multiple functions that intensify the virulence competence of M.tb majorly by modulating immune responses, thereby affecting immune mediated clearance of the pathogen. The highly repetitive, redundant and antigenic nature of PE/PPE/PE_PGRS proteins provide a critical edge over other M.tb proteins in terms of imparting a higher level of virulence and also as a decoy molecule that masks the effect of effector molecules, thereby modulating immuno-surveillance. An understanding of how these proteins subvert the host immunological machinery may add to the current knowledge about M.tb virulence and pathogenesis. This can help in redirecting our strategies for tackling M.tb infections.

scholarly journals The complex functions of microRNA-150 in allergy, autoimmunity and immune tolerance

2021 ◽  
Vol 5 (4) ◽  
pp. 195-221
Author(s):  
Katarzyna Nazimek ◽  
Keyword(s):  
Immune Responses ◽  
Immune Tolerance ◽  
Therapeutic Potential ◽  
Current Knowledge ◽  
Signaling Cascades ◽  
Cell Functions ◽  
Regulatory Circuits ◽  
Complex Functions ◽  
Genetic Level

<abstract> <p>At present, special efforts are being made to develop the strategies allowing for activation of long-lasting antigen-specific immune tolerance in therapy of allergic and autoimmune diseases. Some of these therapeutic approaches are aimed at modulating cell functions at genetic level by using miRNA-based and miRNA-targeting treatments. Simultaneously, the crucial role of extracellular vesicles as natural miRNA conveyors is highlighted for induction of antigen-specific immune tolerance, especially that they appear to be easily manipulatable for therapeutic applications. Among other immune-related miRNAs, miR-150 is getting special attention as it is differently expressed by immune cells at various stages of their maturation and differentiation. In addition, miR-150 is involved in different signaling cascades orchestrating humoral and cell-mediated mechanisms of both innate and adaptive immune responses. Therefore, miR-150 is considered a master regulator of immunity in mammals. Currently, physiological miR-150-dependent regulatory circuits and causes of their malfunctioning that underlie the pathogenesis of allergic and autoimmune disorders are being unraveled. Thus, present review summarizes the current knowledge of the role of miR-150 in the pathogenesis and complications of these diseases. Furthermore, the involvement of miR-150 in regulation of immune responses to allergens and self-antigens and in induction of antigen-specific immune tolerance is discussed with the special emphasis on the therapeutic potential of this miRNA.</p> </abstract>

scholarly journals Regulatory Immune Cells in Idiopathic Pulmonary Fibrosis: Friends or Foes?

2021 ◽  
Vol 12 ◽  
Author(s):  
Chiel van Geffen ◽  
Astrid Deißler ◽  
Markus Quante ◽  
Harald Renz ◽  
Dominik Hartl ◽  
...  
Keyword(s):  
Immune System ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Immune Responses ◽  
Immune Cells ◽  
Current Knowledge ◽  
Suppressor Cells ◽  
Interstitial Lung Diseases ◽  
Stromal Stem Cells

The immune system is receiving increasing attention for interstitial lung diseases, as knowledge on its role in fibrosis development and response to therapies is expanding. Uncontrolled immune responses and unbalanced injury-inflammation-repair processes drive the initiation and progression of idiopathic pulmonary fibrosis. The regulatory immune system plays important roles in controlling pathogenic immune responses, regulating inflammation and modulating the transition of inflammation to fibrosis. This review aims to summarize and critically discuss the current knowledge on the potential role of regulatory immune cells, including mesenchymal stromal/stem cells, regulatory T cells, regulatory B cells, macrophages, dendritic cells and myeloid-derived suppressor cells in idiopathic pulmonary fibrosis. Furthermore, we review the emerging role of regulatory immune cells in anti-fibrotic therapy and lung transplantation. A comprehensive understanding of immune regulation could pave the way towards new therapeutic or preventive approaches in idiopathic pulmonary fibrosis.

Arginase 1 is expressed in myelocytes/metamyelocytes and localized in gelatinase granules of human neutrophils

Blood ◽  
2006 ◽  
Vol 109 (7) ◽  
pp. 3084-3087 ◽  
Author(s):  
Lars C. Jacobsen ◽  
Kim Theilgaard-Mönch ◽  
Erik I. Christensen ◽  
Niels Borregaard
Keyword(s):  
Nitric Oxide ◽  
Immune Responses ◽  
Tissue Regeneration ◽  
Human Neutrophils ◽  
Arginase 1 ◽  
Tnf Α ◽  
Activated Neutrophils ◽  
Factor Α ◽  
Oxide Synthase ◽  
Extracellular Environment

Abstract Arginase 1 (ARG1) metabolizes arginine, thus reducing the availability of arginine as a substrate for nitric oxide synthase (NOS). The decreased production of nitric oxide (NO) by NOS and the production of ornithine by ARG1 affect immune responses and tissue regeneration at sites of infection, respectively. We here demonstrate that ARG1 is synthesized in myelocytes/metamyelocytes and is stored in gelatinase granules. In accordance with this, activated neutrophils coreleased ARG1 and gelatinase to the extracellular environment on stimulation with phorbol-12-myristate 13-acetate (PMA), formyl-methionyl-leucyl-phenylalanine (fMLP), or tumor necrosis factor α (TNF-α). Overall, these findings define ARG1 as a genuine gelatinase granule protein and support a model in which activated neutrophils release ARG1 at sites of infection to modulate immune responses and promote tissue regeneration.

The immune response and the evaluation of acquired immunity against gastrointestinal nematodes in cattle: a review

Parasitology ◽  
2000 ◽  
Vol 120 (7) ◽  
pp. 25-42 ◽  
Author(s):  
E. CLAEREBOUT ◽  
J. VERCRUYSSE
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Protective Immunity ◽  
Current Knowledge ◽  
Small Ruminants ◽  
Gastrointestinal Nematodes ◽  
Gastrointestinal Parasites ◽  
Acquired Immunity ◽  
Immunological Parameters ◽  
Iga Response

The present review discusses the immune responses to gastrointestinal nematodes in cattle and the different immunological and parasitological parameters used to assess acquired immunity. Measuring acquired immunity to gastrointestinal nematodes in cattle (e.g. for the evaluation of candidate parasite vaccines) is hampered by the limited understanding of bovine immune responses against gastrointestinal parasites. In this paper the available data on protective immunity against gastrointestinal nematodes, and especially Ostertagia ostertagi, in cattle are compared with the current knowledge of protective immune responses against gastrointestinal nematodes in rodent models and small ruminants. In contrast to the immune response in mice, which is controlled by T helper 2 (Th2) lymphocytes and results in mast cell- or goblet cell- mediated expulsion of adult worms, bovine immune responses to O. ostertagi do not show a clear Th2 cytokine profile, nor do they result in rapid expulsion of the parasite. The first manifestation of immunity to O. ostertagi in calves is a reduction of worm fecundity, possibly regulated by the local IgA response. Worm numbers are only reduced after a prolonged period of host–parasite contact, and there are indications that O. ostertagi actively suppresses the host's immune response. Until the mechanisms of protective immunity against O. ostertagi are revealed, the use of immunological parameters to estimate acquired immunity in cattle is based on their correlation with parasitological parameters and on extrapolation from rodent and small ruminant models. Assessing the resistance of calves against a challenge infection by means of parasitological parameters is probably still the most accurate way to measure acquired immunity against gastrointestinal nematodes.

scholarly journals Human Dendritic Cells: Ontogeny and Their Subsets in Health and Disease

2018 ◽  
Vol 6 (4) ◽  
pp. 88 ◽  
Author(s):  
Sandra Solano-Gálvez ◽  
Sonia Tovar-Torres ◽  
María Tron-Gómez ◽  
Ariane Weiser-Smeke ◽  
Diego Álvarez-Hernández ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Immune Responses ◽  
Cd8 T Cells ◽  
Current Knowledge ◽  
Lymphoid Organ ◽  
Heterogeneous Population ◽  
Health And Disease ◽  
Human Dendritic Cells ◽  
Activation Status

Dendritic cells (DCs) are a type of cells derived from bone marrow that represent 1% or less of the total hematopoietic cells of any lymphoid organ or of the total cell count of the blood or epithelia. Dendritic cells comprise a heterogeneous population of cells localized in different tissues where they act as sentinels continuously capturing antigens to present them to T cells. Dendritic cells are uniquely capable of attracting and activating naïve CD4+ and CD8+ T cells to initiate and modulate primary immune responses. They have the ability to coordinate tolerance or immunity depending on their activation status, which is why they are also considered as the orchestrating cells of the immune response. The purpose of this review is to provide a general overview of the current knowledge on ontogeny and subsets of human dendritic cells as well as their function and different biological roles.

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