scholarly journals Immune System Modulation and Viral Persistence in Bats: Understanding Viral Spillover

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 192 ◽  
Author(s):  
Sonu Subudhi ◽  
Noreen Rapin ◽  
Vikram Misra
Keyword(s):  
Viral Load ◽  
Immune System ◽  
Virus Replication ◽  
Defense Mechanisms ◽  
Molecular Mechanisms ◽  
Viral Persistence ◽  
Latently Infected ◽  
Unique Nature ◽  
Immune System Modulation ◽  
Perfect Storm

Bats harbor a myriad of viruses and some of these viruses may have spilled over to other species including humans. Spillover events are rare and several factors must align to create the “perfect storm” that would ultimately lead to a spillover. One of these factors is the increased shedding of virus by bats. Several studies have indicated that bats have unique defense mechanisms that allow them to be persistently or latently infected with viruses. Factors leading to an increase in the viral load of persistently infected bats would facilitate shedding of virus. This article reviews the unique nature of bat immune defenses that regulate virus replication and the various molecular mechanisms that play a role in altering the balanced bat–virus relationship.

scholarly journals Diversity of molecular mechanisms used by anti-CRISPR proteins: the tip of an iceberg?

2020 ◽  
Vol 48 (2) ◽  
pp. 507-516 ◽  
Author(s):  
Pierre Hardouin ◽  
Adeline Goulet
Keyword(s):  
Immune System ◽  
Structure Function ◽  
Defense Mechanisms ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Arms Race ◽  
Allosteric Inhibitors ◽  
Fundamental Knowledge ◽  
Attack And Defense ◽  
Fine Tune

Bacteriophages (phages) and their preys are engaged in an evolutionary arms race driving the co-adaptation of their attack and defense mechanisms. In this context, phages have evolved diverse anti-CRISPR proteins to evade the bacterial CRISPR–Cas immune system, and propagate. Anti-CRISPR proteins do not share much resemblance with each other and with proteins of known function, which raises intriguing questions particularly relating to their modes of action. In recent years, there have been many structure–function studies shedding light on different CRISPR–Cas inhibition strategies. As the anti-CRISPR field of research is rapidly growing, it is opportune to review the current knowledge on these proteins, with particular emphasis on the molecular strategies deployed to inactivate distinct steps of CRISPR–Cas immunity. Anti-CRISPR proteins can be orthosteric or allosteric inhibitors of CRISPR–Cas machineries, as well as enzymes that irreversibly modify CRISPR–Cas components. This repertoire of CRISPR–Cas inhibition mechanisms will likely expand in the future, providing fundamental knowledge on phage–bacteria interactions and offering great perspectives for the development of biotechnological tools to fine-tune CRISPR–Cas-based gene edition.

scholarly journals Molecular Mechanisms of Possible Action of Phenolic Compounds in COVID-19 Protection and Prevention

2021 ◽  
Vol 22 (22) ◽  
pp. 12385
Author(s):  
Nikola Gligorijevic ◽  
Mirjana Radomirovic ◽  
Olgica Nedic ◽  
Marija Stojadinovic ◽  
Urmila Khulal ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Clinical Trials ◽  
Immune System ◽  
Intracellular Signaling ◽  
Molecular Mechanisms ◽  
Specific Antibodies ◽  
Major Class ◽  
Pathogenic Virus ◽  
Antiviral Activities ◽  
Immune System Modulation

The worldwide outbreak of COVID-19 was caused by a pathogenic virus called Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). Therapies against SARS-CoV-2 target the virus or human cells or the immune system. However, therapies based on specific antibodies, such as vaccines and monoclonal antibodies, may become inefficient enough when the virus changes its antigenicity due to mutations. Polyphenols are the major class of bioactive compounds in nature, exerting diverse health effects based on their direct antioxidant activity and their effects in the modulation of intracellular signaling. There are currently numerous clinical trials investigating the effects of polyphenols in prophylaxis and the treatment of COVID-19, from symptomatic, via moderate and severe COVID-19 treatment, to anti-fibrotic treatment in discharged COVID-19 patients. Antiviral activities of polyphenols and their impact on immune system modulation could serve as a solid basis for developing polyphenol-based natural approaches for preventing and treating COVID-19.

A short overview of vitamin C and selected cells of the immune system

Open Medicine ◽  
2011 ◽  
Vol 6 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Voja Pavlovic ◽  
M. Sarac
Keyword(s):  
Immune System ◽  
Vitamin C ◽  
Defense Mechanisms ◽  
Molecular Mechanisms ◽  
The Body ◽  
Water Soluble ◽  
Toxicological Effects ◽  
Positive Effects ◽  
Wide Range ◽  
Vitamin C Supplementation

AbstractVitamin C (ascorbic acid) is an essential water-soluble nutrient that primarily exerts its effect on a host defense mechanisms and immune homeostasis and is the most important physiological antioxidant. Stable intake of vitamin C is essential for life in humans because the body does not synthesize it. Even the numerous studies have demonstrated that vitamin C supplementation stimulates the immune system, prevents DNA damage and significantly decreases the risk of a wide range of pathologies; the potential protective mechanisms are still largely unknown. This review summarizes the recently known facts about the role of vitamin C on the selected cells of the immune system and potential molecular mechanisms involved. Further, in this review, many new data about the positive effects of vitamin C on the immune system, potential toxicological effects, vitamin C supplementation in disease development, as well as some proposed mechanisms of vitamin C activity, are discussed.

scholarly journals T Cell Activation and Regulation of HIV-1: Same Effectors with Distinct Outcomes

1999 ◽  
Vol 10 (suppl c) ◽  
pp. 25C-32C ◽  
Author(s):  
Jean-François Fortin ◽  
Benoit Barbeau ◽  
Gilles A Robichaud ◽  
Michel J Tremblay
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Immune System ◽  
Virus Replication ◽  
T Cell Activation ◽  
Cell Activation ◽  
Molecular Mechanisms ◽  
Nuclear Factor ◽  
Cellular Transcription ◽  
Hiv 1

The molecular mechanisms that regulate the function of the immune system and human immunodeficiency virus type-1 (HIV-1) gene expression are diverse and complicated. However, replication of HIV-1 is controlled by many of the same regulatory signals that play a crucial role in the transcriptional regulation of the immune system. For example, the viral promoter, as is the case for the immune system, is subject to complex regulation by combinations of cellular transcription factors that may quantitatively and/or qualitatively differ depending on cell types (eg, macrophages versus T lymphocytes) and cell states (eg, undifferentiated versus differentiated or quiescent versus activated). The present review discusses the regulation of HIV-1 gene expression by nuclear factor-kappa Band nuclear factor of activated T cells, and proposes that selective interference of these two cellular transcription factors may be a route to abrogate virus replication without disrupting normal cellular functions. A better understanding of the regulation of HIV-1 gene expression is of utmost importance for the design of molecular approaches that will effectively abrogate virus replication and, ultimately, disease progression.

scholarly journals Formulating Strategies to Tackle COVID-19 Pandemic by Understanding its Molecular Mechanisms: A Review

2020 ◽  
Vol 13 (4) ◽  
pp. 1809-1813
Author(s):  
Eko Fuji Ariyanto ◽  
Muhammad Hasan Bashari
Keyword(s):  
Immune System ◽  
Severe Acute Respiratory Syndrome ◽  
Virus Replication ◽  
Health Problem ◽  
Molecular Mechanisms ◽  
Preventive Measures ◽  
Virus Entry ◽  
Comprehensive Analysis ◽  
Hand Washing ◽  
Protective Equipment

Coronavirus disease 2019 (COVID-19) is the current biggest health problem that has caused pandemic in hundreds of countries worldwide. Important efforts for COVID-19 prevention and management have been implemented by WHO and many countries; however, the number of new cases is still increasing. The objective of this review is to formulate appropriate strategies to tackle COVID-19 pandemic using molecular mechanisms-based approach. COVID-19 preventive measures aim to avoid virus entry to human cells by applying physical distancing, hand washing and personal protective equipment, maintaining good immune system by balanced nutrition and physical exercise, developing vaccine against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) based on comprehensive analysis on SARS-CoV-2 antigen presentation and subsequent immunological cascades, considering the patients’ clinical condition including biomolecular parameters, and developing drugs by designing inhibitors for SARS-CoV-2 proteins responsible for virus replication and transcription.

scholarly journals Investigating Molecular Mechanisms of Immunotoxicity and the Utility of ToxCast for Immunotoxicity Screening of Chemicals Added to Food

2021 ◽  
Vol 18 (7) ◽  
pp. 3332
Author(s):  
Olga V. Naidenko ◽  
David Q. Andrews ◽  
Alexis M. Temkin ◽  
Tasha Stoiber ◽  
Uloma Igara Uche ◽  
...  
Keyword(s):  
Immune System ◽  
High Throughput ◽  
Environmental Protection Agency ◽  
High Throughput Screening ◽  
Molecular Mechanisms ◽  
Specific Activity ◽  
Laboratory Animals ◽  
In Vitro Assays ◽  
Toxicological Studies

The development of high-throughput screening methodologies may decrease the need for laboratory animals for toxicity testing. Here, we investigate the potential of assessing immunotoxicity with high-throughput screening data from the U.S. Environmental Protection Agency ToxCast program. As case studies, we analyzed the most common chemicals added to food as well as per- and polyfluoroalkyl substances (PFAS) shown to migrate to food from packaging materials or processing equipment. The antioxidant preservative tert-butylhydroquinone (TBHQ) showed activity both in ToxCast assays and in classical immunological assays, suggesting that it may affect the immune response in people. From the PFAS group, we identified eight substances that can migrate from food contact materials and have ToxCast data. In epidemiological and toxicological studies, PFAS suppress the immune system and decrease the response to vaccination. However, most PFAS show weak or no activity in immune-related ToxCast assays. This lack of concordance between toxicological and high-throughput data for common PFAS indicates the current limitations of in vitro screening for analyzing immunotoxicity. High-throughput in vitro assays show promise for providing mechanistic data relevant for immune risk assessment. In contrast, the lack of immune-specific activity in the existing high-throughput assays cannot validate the safety of a chemical for the immune system.

scholarly journals Involvement of Probiotics and Postbiotics in the Immune System Modulation

Biologics ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 89-110
Author(s):  
Neslihan Yeşilyurt ◽  
Birsen Yılmaz ◽  
Duygu Ağagündüz ◽  
Raffaele Capasso
Keyword(s):  
Immune System ◽  
Pharmaceutical Industry ◽  
Intestinal Microbiota ◽  
Health Benefits ◽  
The Body ◽  
Future Research ◽  
Immune Systems ◽  
Advantages And Disadvantages ◽  
Immune System Modulation ◽  
Molecular Patterns

Intestinal microbiota interacts with other systems, especially the immune system, which is responsible for protecting the body by recognizing “stranger” (pathogen associated molecular patterns-PAMPs) and “danger” (damage-associated molecular patterns-DAMPs) molecular motifs. In this manner, it plays an important role in the pathogenesis of various diseases and health. Despite the use of probiotics that modulate the intestinal microbiota in providing health benefits and in the treatment of diseases, there are some possible concerns about the possibility of developing adverse effects, especially in people with suppressed immune systems. Since probiotics provide health benefits with bioactive compounds, studies are carried out on the use of products containing non-living probiotic microorganisms (paraprobiotics) and/or their metabolites (postbiotics) instead of probiotic products. It is even reported that these microbial compounds have more immunomodulatory activities than living microorganisms via some possible mechanism and eliminates some disadvantages of probiotics. Considering the increasing use of functional foods in health and disease, further studies are needed with respect to the benefits and advantages of parabiotic and/or postbiotic use in the food and pharmaceutical industry as well as immune system modulation. Although probiotics have been extensive studied for a long time, it seems that postbiotics are promising tools for future research and applications according to the recent literature. This review aimed to evaluate the interaction of probiotics and postbiotics with the immune systems and also their advantages and disadvantages in the area of food-pharmaceutical industry and immune system modulation.

Synaptic Transmission in the Immune System

e-Neuroforum ◽  
2017 ◽  
Vol 23 (4) ◽  
Author(s):  
Jens Rettig ◽  
David R. Stevens
Keyword(s):  
Nervous System ◽  
Immune System ◽  
Synaptic Transmission ◽  
Molecular Mechanisms ◽  
Secretory Granules ◽  
Neuroendocrine Cells ◽  
Regulated Exocytosis ◽  
Protein Receptor ◽  
Immunological Synapses ◽  
Immunological Diseases

AbstractThe release of neurotransmitters at synapses belongs to the most important processes in the central nervous system. In the last decades much has been learned about the molecular mechanisms which form the basis for this fundamental process. Highly regulated exocytosis, based on the SNARE (soluble N-ethylmaleimide-sensitive attachment protein receptor) complex and its regulatory molecules is the signature specialization of the nervous system and is shared by neurons and neuroendocrine cells. Cells of the immune system use a similar mechanism to release cytotoxic materials from secretory granules at contacts with virally or bacterially infected cells or cancer cells, in order to remove these threats. These contact zones have been termed immunological synapses in reference to the highly specific targeted exocytosis of effector molecules. Recent findings indicate that mutations in SNARE or SNARE-interacting proteins are the basis of a number of devastating immunological diseases. While SNARE complexes are ubiquitous and mediate a wide variety of membrane fusion events it is surprising that in many cases the SNARE proteins involved in immunological synapses are the same molecules which mediate regulated exocytosis of transmitters and hormones in neurons and neuroendocrine cells. These similarities raise the possibility that results obtained at immunological synapses may be applicable, in particular in the area of presynaptic function, to neuronal synapses. Since immunological synapses (IS) are assembled and disassembled in about a half an hour, the use of immune cells isolated from human blood allows not only the study of the molecular mechanisms of synaptic transmission in human cells, but is particularly suited to the examination of the assembly and disassembly of these “synapses” via live imaging. In this overview we discuss areas of similarity between synapses of the nervous and immune systems and in the process will refer to results of our experiments of the last few years.

scholarly journals Expression of Phosphocitrate-Targeted Genes in Osteoarthritis Menisci

2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Yubo Sun ◽  
David R. Mauerhan ◽  
Nury M. Steuerwald ◽  
Jane Ingram ◽  
Jeffrey S. Kneisl ◽  
...  
Keyword(s):  
Immune System ◽  
Molecular Mechanisms ◽  
Fibroblast Growth Factor Receptor ◽  
Collagen Type ◽  
Skeletal Development ◽  
Growth Factor Receptor ◽  
Type Ii ◽  
Immune System Activation ◽  
System Activation ◽  
Disease Modifying

Phosphocitrate (PC) inhibited calcium crystal-associated osteoarthritis (OA) in Hartley guinea pigs. However, the molecular mechanisms remain elusive. This study sought to determine PC targeted genes and the expression of select PC targeted genes in OA menisci to test hypothesis that PC exerts its disease modifying activity in part by reversing abnormal expressions of genes involved in OA. We found that PC downregulated the expression of numerous genes classified in immune response, inflammatory response, and angiogenesis, including chemokine (C-C motif) ligand 5, Fc fragment of IgG, low affinity IIIb receptor (FCGR3B), and leukocyte immunoglobulin-like receptor, subfamily B member 3 (LILRB3). In contrast, PC upregulated the expression of many genes classified in skeletal development, including collagen type II alpha1, fibroblast growth factor receptor 3 (FGFR3), and SRY- (sex determining region Y-) box 9 (SOX-9). Immunohistochemical examinations revealed higher levels of FCGR3B and LILRB3 and lower level of SOX-9 in OA menisci. These findings indicate that OA is a disease associated with immune system activation and decreased expression of SOX-9 gene in OA menisci. PC exerts its disease modifying activity on OA, at least in part, by targeting immune system activation and the production of extracellular matrix and selecting chondroprotective proteins.

Determination of HE4-mediated roles in tumor immune system modulation in Epithelial Ovarian Cancer (EOC)

2015 ◽  
Vol 139 (3) ◽  
pp. 591
Author(s):  
Anze Urh ◽  
Nicole Romano ◽  
KyuKwang Kim ◽  
Jennifer Ribeiro ◽  
Christina Raker ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Immune System ◽  
Epithelial Ovarian Cancer ◽  
Immune System Modulation
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