scholarly journals Thioester-Containing Proteins in the Drosophila melanogaster Immune Response against the Pathogen Photorhabdus

Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 85
Author(s):  
Ioannis Eleftherianos ◽  
Upasana Sachar
Keyword(s):  
Drosophila Melanogaster ◽  
Immune Surveillance ◽  
Fruit Fly ◽  
Research Field ◽  
Innate Immune ◽  
Host Immune System ◽  
Innate Immune Signaling ◽  
Microbe Interactions ◽  
Host Microbe Interactions

The fruit fly Drosophila melanogaster forms a magnificent model for interpreting conserved host innate immune signaling and functional processes in response to microbial assaults. In the broad research field of host-microbe interactions, model hosts are used in conjunction with a variety of pathogenic microorganisms to disentangle host immune system activities and microbial pathogenicity strategies. The pathogen Photorhabdus is considered an established model for analyzing bacterial virulence and symbiosis due to its unique life cycle that extends between two invertebrate hosts: an insect and a parasitic nematode. In recent years, particular focus has been given to the mechanistic participation of the D. melanogaster thioester-containing proteins (TEPs) in the overall immune capacity of the fly upon response against the pathogen Photorhabdus alone or in combination with its specific nematode vector Heterorhabditis bacteriophora. The original role of certain TEPs in the insect innate immune machinery was linked to the antibacterial and antiparasite reaction of the mosquito malaria vector Anopheles gambiae; however, revamped interest in the immune competence of these molecules has recently emerged from the D. melanogaster-Photorhabdus infection system. Here, we review the latest findings on this topic with the expectation that such information will refine our understanding of the evolutionary immune role of TEPs in host immune surveillance.

scholarly journals Glycans in Virus-Host Interactions: A Structural Perspective

2021 ◽  
Vol 8 ◽  
Author(s):  
Nathaniel L. Miller ◽  
Thomas Clark ◽  
Rahul Raman ◽  
Ram Sasisekharan
Keyword(s):  
Immune System ◽  
Host Cells ◽  
Host Immune System ◽  
Host Interactions ◽  
Viral Glycoproteins ◽  
Microbe Interactions ◽  
Host Microbe Interactions ◽  
Anti Hiv ◽  
Structural Perspective

Many interactions between microbes and their hosts are driven or influenced by glycans, whose heterogeneous and difficult to characterize structures have led to an underappreciation of their role in these interactions compared to protein-based interactions. Glycans decorate microbe glycoproteins to enhance attachment and fusion to host cells, provide stability, and evade the host immune system. Yet, the host immune system may also target these glycans as glycoepitopes. In this review, we provide a structural perspective on the role of glycans in host-microbe interactions, focusing primarily on viral glycoproteins and their interactions with host adaptive immunity. In particular, we discuss a class of topological glycoepitopes and their interactions with topological mAbs, using the anti-HIV mAb 2G12 as the archetypical example. We further offer our view that structure-based glycan targeting strategies are ready for application to viruses beyond HIV, and present our perspective on future development in this area.

scholarly journals Essential role of HCMV deubiquitinase in promoting oncogenesis by targeting anti-viral innate immune signaling pathways

2017 ◽  
Vol 8 (10) ◽  
pp. e3078-e3078 ◽  
Author(s):  
Puja Kumari ◽  
Irene Saha ◽  
Athira Narayanan ◽  
Sathish Narayanan ◽  
Akinori Takaoka ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Essential Role ◽  
Innate Immune ◽  
Immune Signaling ◽  
Innate Immune Signaling

The role of lipids in host microbe interactions

10.2741/4559 ◽  
2017 ◽  
Vol 22 (9) ◽  
pp. 1581-1598
Author(s):  
Jochen Mattner
Keyword(s):  
Microbe Interactions ◽  
Host Microbe Interactions

Studies on the Role of Carbohydrates in Host-Microbe Interactions

1986 ◽  
pp. 297-309 ◽  
Author(s):  
Peter Albersheim ◽  
Alan G. Darvill ◽  
Janice K. Sharp ◽  
Keith R. Davis ◽  
Steven H. Doares
Keyword(s):  
Microbe Interactions ◽  
Host Microbe Interactions

scholarly journals Optimal integration between host physiology and functions of the gut microbiome

2020 ◽  
Vol 375 (1808) ◽  
pp. 20190594 ◽  
Author(s):  
Samantha S. Fontaine ◽  
Kevin D. Kohl
Keyword(s):  
Microbial Communities ◽  
Physiological Function ◽  
Biological Organization ◽  
Theme Issue ◽  
Microbe Interactions ◽  
Host Physiology ◽  
Host Microbe Interactions ◽  
Host Evolution ◽  
Physiological Systems

Host-associated microbial communities have profound impacts on animal physiological function, especially nutrition and metabolism. The hypothesis of ‘symmorphosis’, which posits that the physiological systems of animals are regulated precisely to meet, but not exceed, their imposed functional demands, has been used to understand the integration of physiological systems across levels of biological organization. Although this idea has been criticized, it is recognized as having important heuristic value, even as a null hypothesis, and may, therefore, be a useful tool in understanding how hosts evolve in response to the function of their microbiota. Here, through a hologenomic lens, we discuss how the idea of symmorphosis may be applied to host-microbe interactions. Specifically, we consider scenarios in which host physiology may have evolved to collaborate with the microbiota to perform important functions, and, on the other hand, situations in which services have been completely outsourced to the microbiota, resulting in relaxed selection on host pathways. Following this theoretical discussion, we finally suggest strategies by which these currently speculative ideas may be explicitly tested to further our understanding of host evolution in response to their associated microbial communities. This article is part of the theme issue ‘The role of the microbiome in host evolution’.

scholarly journals Mitochondrial Iron in Human Health and Disease

2019 ◽  
Vol 81 (1) ◽  
pp. 453-482 ◽  
Author(s):  
Diane M. Ward ◽  
Suzanne M. Cloonan
Keyword(s):  
Human Health ◽  
Mammalian Cells ◽  
Molecular Mechanisms ◽  
Innate Immune ◽  
Biological Functions ◽  
Mitochondrial Homeostasis ◽  
Innate Immune Signaling ◽  
Mitochondrial Iron ◽  
Health And Disease

Mitochondria are an iconic distinguishing feature of eukaryotic cells. Mitochondria encompass an active organellar network that fuses, divides, and directs a myriad of vital biological functions, including energy metabolism, cell death regulation, and innate immune signaling in different tissues. Another crucial and often underappreciated function of these dynamic organelles is their central role in the metabolism of the most abundant and biologically versatile transition metals in mammalian cells, iron. In recent years, cellular and animal models of mitochondrial iron dysfunction have provided vital information in identifying new proteins that have elucidated the pathways involved in mitochondrial homeostasis and iron metabolism. Specific signatures of mitochondrial iron dysregulation that are associated with disease pathogenesis and/or progression are becoming increasingly important. Understanding the molecular mechanisms regulating mitochondrial iron pathways will help better define the role of this important metal in mitochondrial function and in human health and disease.

scholarly journals Mucosal microbial parasites/symbionts in health and disease: an integrative overview

Parasitology ◽  
2019 ◽  
Vol 146 (9) ◽  
pp. 1109-1115 ◽  
Author(s):  
Robert P. Hirt
Keyword(s):  
Host Interactions ◽  
Detection Techniques ◽  
Symbiotic Relationships ◽  
Life Styles ◽  
Mucosal Surfaces ◽  
Microbe Interactions ◽  
Health And Disease ◽  
Host Microbe Interactions ◽  
Species Being

AbstractMicrobial parasites adapted to thrive at mammalian mucosal surfaces have evolved multiple times from phylogenetically distant lineages into various extracellular and intracellular life styles. Their symbiotic relationships can range from commensalism to parasitism and more recently some host–parasites interactions are thought to have evolved into mutualistic associations too. It is increasingly appreciated that this diversity of symbiotic outcomes is the product of a complex network of parasites–microbiota–host interactions. Refinement and broader use of DNA based detection techniques are providing increasing evidence of how common some mucosal microbial parasites are and their host range, with some species being able to swap hosts, including from farm and pet animals to humans. A selection of examples will illustrate the zoonotic potential for a number of microbial parasites and how some species can be either disruptive or beneficial nodes in the complex networks of host–microbe interactions disrupting or maintaining mucosal homoeostasis. It will be argued that mucosal microbial parasitic diversity will represent an important resource to help us dissect through comparative studies the role of host–microbe interactions in both human health and disease.

scholarly journals LANA and hnRNP A1 Regulate the Translation of LANA mRNA through G-Quadruplexes

2019 ◽  
Vol 94 (3) ◽  
Author(s):  
Prerna Dabral ◽  
Jay Babu ◽  
Andrew Zareie ◽  
Subhash C. Verma
Keyword(s):  
Viral Genome ◽  
Immune Surveillance ◽  
Class I ◽  
Nuclear Antigen ◽  
Host Immune System ◽  
Immune Recognition ◽  
Hnrnp A1 ◽  
Multifunctional Protein ◽  
G Quadruplex

ABSTRACT During the latent phase, Kaposi’s sarcoma-associated herpes virus (KSHV) maintains itself inside the host by escaping the host immune surveillance mechanism through restricted protein expression. Latency-associated nuclear antigen (LANA), the most abundantly expressed protein, is essential for viral persistence, as it plays important roles in latent viral DNA replication and efficient segregation of the viral genome to the daughter cells following cell division. KSHV evades immune detection by maintaining the levels of LANA protein below a threshold required for detection by the host immune system but sufficient to maintain the viral genome. LANA achieves this by controlling its expression through regulation of its promoters and by inhibiting its presentation through interaction with the proteins of class I and class II major histocompatibility complex (MHC) pathways. In this study, we identified a mechanism of LANA expression and restricted immune recognition through formation of G-quadruplexes in LANA mRNA. We show that the formation of these stable structures in LANA mRNA inhibits its translation to control antigen presentation, which was supported by treatment of cells with TMPyP4, a G-quadruplex-stabilizing ligand. We identified heterogenous ribonucleoprotein A1 (hnRNP A1) as a G-quadruplex-unwinding helicase, which unfolds these stable secondary structures to regulate LANA translation. IMPORTANCE LANA, the most abundantly expressed protein during latency, is a multifunctional protein which is absolutely required for the persistence of KSHV in the host cell. Even though the functions of LANA in aiding pathogenesis of the virus have been extensively studied, the mechanism of how LANA escapes host’s immune surveillance is not fully understood. This study sheds light on the autoregulatory role of LANA to modulate its expression and immune evasion through formation of G-quadruplexes in its mRNA. We used G-quadruplex-stabilizing ligand to define the inhibition in LANA expression and presentation on the cell surface through MHC class I. We defined the autoregulatory role of LANA and identified a cellular RNA helicase, hnRNP A1, regulating the translation of LANA mRNA. This interaction of hnRNP A1 with LANA mRNA could be exploited for controlling KSHV latency.

scholarly journals How Ah Receptor Ligand Specificity Became Important in Understanding Its Physiological Function

2020 ◽  
Vol 21 (24) ◽  
pp. 9614
Author(s):  
Iain A. Murray ◽  
Gary H. Perdew
Keyword(s):  
Physiological Function ◽  
Innate Immune ◽  
Ah Receptor ◽  
Ligand Specificity ◽  
Aryl Hydrocarbon ◽  
Innate Immune Signaling ◽  
Tryptophan Metabolites ◽  
Barrier Tissues ◽  
Endogenous Metabolites

Increasingly, the aryl hydrocarbon receptor (AHR) is being recognized as a sensor for endogenous and pseudo-endogenous metabolites, and in particular microbiota and host generated tryptophan metabolites. One proposed explanation for this is the role of the AHR in innate immune signaling within barrier tissues in response to the presence of microorganisms. A number of cytokine/chemokine genes exhibit a combinatorial increase in transcription upon toll-like receptors and AHR activation, supporting this concept. The AHR also plays a role in the enhanced differentiation of intestinal and dermal epithelium leading to improved barrier function. Importantly, from an evolutionary perspective many of these tryptophan metabolites exhibit greater activation potential for the human AHR when compared to the rodent AHR. These observations underscore the importance of the AHR in barrier tissues and may lead to pharmacologic therapeutic intervention.

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