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Viral Infection and Apoptosis

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ISBN: 9783038426554 9783038426547 Year: Pages: 270 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Biology
Added to DOAB on : 2018-01-24 14:12:08
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Apoptosis is a form of programmed cell death that enables the removal of damaged, infected, or otherwise unwanted cells in a controlled manner. Apoptosis can be initiated by multiple independent pathways that ultimately converge at a point where proteolytic enzymes belonging to the caspase family are activated, which dismantle the apoptotic cell.Multicellular organism have employed apoptotic mechanisms during host defence in response to viral infection to limit or prevent viral spread and replication. Consequently, viruses have evolved sophisticated molecular countermeasures to disarm host apoptotic defences, and this series of reviews and primary research articles in this Special Issue explores the intricate molecular interplay between viruses and their hosts when they battle for control of host apoptotic check-points.

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Apoptosis --- caspase --- host defence

Metal economy in host-microbe interactions

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889194971 Year: Pages: 215 DOI: 10.3389/978-2-88919-497-1 Language: English
Publisher: Frontiers Media SA
Subject: Internal medicine --- Science (General)
Added to DOAB on : 2015-11-16 15:44:59
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From simple inorganic catalysts to vital biological cofactors, divalent transition metals are instrumental to electron transfers, catalysis and signaling. Their natural ability to bind, exchange and react with organic molecules including oxygen requires from living cells to regulate uptake with metabolic activities, sensing and chaperoning, distributing and storing, or excreting excess to prevent detrimental biochemical reactions. Since transition metal deficiency and overload both limit cell growth it is no surprise that the immune system evolved a dual strategy, of metal starvation or intoxication, to thwart microbial invasions. Like environmental metal availability determined biological use it also shaped host-microbe metal economy: Fe and Mn, available early in evolution and still required rather ubiquitously, are generally withheld by host in response to infection; Zn and Cu, which became bioavailable later, essentially to eukaryotic cells may be bombarded toward invaders. Successful microbial pathogens have evolved elaborate counter-measures to cope with host metal defenses. This research topic aims to review and discuss metal currencies in host-microbe interactions focusing on new findings about micro-organism pathogenesis determinants in the face of host innate strategies to interfere with microbial physiology.

Keywords

metal --- Virulence --- host --- pathogen --- transporter --- exporter --- regulation

Cell Signaling in Host-Pathogen Interactions: The Host Point of View

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889454556 Year: Pages: 414 DOI: 10.3389/978-2-88945-455-6 Language: English
Publisher: Frontiers Media SA
Subject: Medicine (General) --- Allergy and Immunology --- Science (General) --- Microbiology
Added to DOAB on : 2018-11-16 17:17:57
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The ability of pathogens, such as parasites, bacteria, fungi and viruses to invade, persist and adapt in both invertebrate and vertebrate hosts is multifactorial and depends on both pathogen and host fitness. Communication between a pathogen and its host relies on a wide and dynamic array of molecular interactions. Through this constant communication most pathogens evolved to be relatively benign, whereas killing of its host by a pathogen represents a failure to adapt. Pathogens are lethal to their host when their interaction has not been long enough for adaptation. Evolution has selected conserved immune receptors that recognize signature patterns of pathogens as non-self elements and initiate host innate responses aimed at eradicating infection. Conversely, pathogens evolved mechanisms to evade immune recognition and subvert cytokine secretion in order to survive, replicate and cause disease. The cell signaling machinery is a critical component of the immune system that relays information from the receptors to the nucleus where transcription of key immune genes is activated. Host cells have developed signal transduction systems to maintain homeostasis with pathogens. Most cellular processes and cell signaling pathways are tightly regulated by protein phosphorylation in which protein kinases are key protagonists. Pathogens have developed multiple mechanisms to subvert important signal transduction pathways such as the mitogen activated protein kinase (MAPK) and the nuclear factor kB (NF-kB) pathways. Pathogens also secrete effectors that manipulate actin cytoskeleton and its regulators, hijack cell cycle machinery and alter vesicular trafficking. This research topic focuses on the cellular signaling mechanisms that are essential for host immunity and their subversion by pathogens.

Host-adapted metabolism and its regulation in Bacterial Pathogens

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889195381 Year: Pages: 176 DOI: 10.3389/978-2-88919-538-1 Language: English
Publisher: Frontiers Media SA
Subject: Internal medicine --- Science (General)
Added to DOAB on : 2016-01-19 14:05:46
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Pathogens adapt their metabolism rapidly to the host. Our topic covers these phenomenon regarding extracellular and intracellular pathogens as well as general methods to elucidate different metabolic adaptation processes - an essential guide for any scientist wanting to keep abreast of recent developments in infection biology.

Use of Saliva in Diagnosis of Periodontitis: Cumulative Use of Bacterial and Host-Derived Biomarkers

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889451241 Year: Pages: 105 DOI: 10.3389/978-2-88945-124-1 Language: English
Publisher: Frontiers Media SA
Subject: Internal medicine --- Science (General)
Added to DOAB on : 2017-07-06 13:27:36
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Periodontitis is an infection-induced inflammatory disease of the tooth supporting tissues. Treatment of periodontal diseases and regeneration of the effected tissues can be possible only in the early diagnosis of the disease. If left undiagnosed or untreated, periodontitis leads to irreversible soft and hard tissue destruction and finally to tooth loss. Saliva is known to contain inflammatory mediators, host tissue and cell degradation products as well as microbial metabolites and enzymes, reflecting the health status of the oral cavity. In this topic, in collaboration with the well-known scientists working on the field of salivary diagnostics, we demonstrate evidence on monitoring periodontitis by salivary analysis.

Human Polyomaviruses and Papillomaviruses

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ISBN: 9783038972204 9783038972211 Year: Pages: 196 DOI: 10.3390/books978-3-03897-221-1 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Biology --- Oncology
Added to DOAB on : 2018-09-21 09:25:07
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The interest in human polyomaviruses (HPyV) has seen a renaissance because of new species that have been isolated and their previously unknown association with diseases. Likewise, the increasing evidence for the association of human papillomaviruses (HPV) with oropharyngeal cancer has sparked the attention of researchers and clinicians. The Special Issue “Human Polyomaviruses and Papillomaviruses” presents studies describing the nuclear egress of BK polyomavirus mediated by the viral agnoprotein and the cellular -SNAP protein. In addition, a study examines the promoter activity of two different variants of human polyomavirus 9 in different cell lines. This Special Issue offers an interesting perspective on the epidemiology of HR-HPV in different cancers and on the mechanisms by which these viruses target host cell proteins to replicate their genome, express their genes, interfere with autophagy, and induce cancer. Other topics that are highlighted include the role of co-factors, such as smoking and co-infection, novel therapeutic strategies, and surface immunoregulatory proteins, chemokines, and cytokines as possible biomarkers to determine the stage of a tumor and to predict clinical outcomes.

Host-Guest Polymer Complexes

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ISBN: 9783038971948 9783038971955 Year: Pages: 258 DOI: 10.3390/books978-3-03897-195-5 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Chemistry (General)
Added to DOAB on : 2018-10-02 11:29:02
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I enthusiastically invite you to contribute to a Special Issue of the open-access journal Polymers, focusing on “Host–Guest Polymer Complexes”, which I and two of my former PhD students, Drs. Alper Gurarslan and Ganesh Narayanan, are editing. We hope to include papers describing the syntheses, characterization, and use of host–guest polymer complexes, as well as factors that are important to their formation. Submissions that describe unusual and unique applications of host–guest polymer complexes using hosts other than traditional ones: cyclodextrins, cucurbiturils, urea, thiourea, cyclotriphosphazines, etc., are particularly encouraged.I hope that you accept our invitation to make this Special Issue one that will introduce, effectively summarize, and increase interest in this important area of polymer science.

Interaction of Trypanosoma cruzi with Host Cells

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889193370 Year: Pages: 97 DOI: 10.3389/978-2-88919-337-0 Language: English
Publisher: Frontiers Media SA
Subject: Medicine (General) --- Allergy and Immunology --- Science (General) --- Microbiology
Added to DOAB on : 2013-09-03 13:00:53
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Trypanosoma cruzi is a pathogenic protozoan of the Trypanosomatidade Family, which is the etiological agent of Chagas’ disease. Chagas’ disease stands out for being endemic among countries in Latin America, affecting about 15 million people. Recently, Chagas has become remarkable in European countries as well due to cases of transmission via infected blood transfusion. An important factor that has exacerbated the epidemiological picture in Brazil, Colombia and Venezuela is infection after the oral intake of contaminated foods such as sugar cane, açai and bacaba juices. Trypanosoma cruzi is an intracellular protozoan that exhibits a complex life cycle, involving multiple developmental stages found in both vertebrate and invertebrate hosts. In vertebrate hosts, the trypomastigote form invades a large variety of nucleated cells using multiple mechanisms. The invasion process involves several steps: (a) attraction of the protozoan to interact with the host cell surface; (b) parasite-host cell recognition; (c) adhesion of the parasite to the host cell surface; (d) cell signalling events that culminate in the internalization of the parasite through endocytic processes; (e) biogenesis of a large vacuole where the parasite is initially located, and is also known as parasitophorous vacuole (PV); (f) participation of endocytic pathway components in the internalization process; (g) participation of cytoskeleton components in the internalization process; (h) transformation of the trypomastigote into the amastigote form within the PV; (i) lysis of the membrane of the PV; (j) multiplication of amastigotes within the host cell in direct contact with cell structures and organelles; (k) transformation of amastigotes into trypomastigotes, and (l) rupture of the host cell releasing trypomastigotes into the extracellular space. The kinetics of the interaction process and even the fate of the parasite within the cell vary according to the nature of the host cell and its state of immunological activation.

Antimicrobial Peptides

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ISBN: 9783038420729 9783038420736 Year: Pages: 336 DOI: 10.3390/books978-3-03842-073-6 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Added to DOAB on : 2015-10-22 10:29:38
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Antimicrobial peptides (AMPs) are gene-encoded, ancient (and important) mediators of innate host defense that exert direct or indirect antimicrobial action as well as possessing other important biologic activities (e.g., neutralization of endotoxin and anti-biofilm action) that help to protect vertebrates, invertebrates and plants from invading pathogens. While the emergence of multi-antibiotic resistant pathogens (and the desperate need to develop new anti-infectives) has been a recent force driving the field, interest in AMPs has an earlier origin in studies of how phagocytes kill bacteria by oxygen-independent processes. AMPs responsible for such killing of microbes by rabbit and human neutrophils were later purified by Ganz, Selsted and Lehrer, which they termed defensins; at the time of this writing, literally thousands of defensin-based publications can be found in the scientific literature! The initial reports on defensins and the earlier report by Boman’s group on the purification and action of an insect AMP represented a historical and defining point for the AMP field as they, in hindsight, demanded the recognition of AMP research as a unique discipline that has important linkages to other important fields of medicine, especially those of microbiology, infectious diseases and immunology. On a personal note, I remember conferences on phagocytes and host defense in the early 1980s where the topic of AMPs was relegated to one short session in a five day period! Now, we have hundreds of international “AMPologists” with expertise in chemistry, biochemistry, molecular and structural biology, cell biology, microbiology, pharmacology, or medicine who have built their research careers around AMPs and can now attend international conferences dedicated to advances in AMP research.

Gram-positive phages: From isolation to application

Authors: ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889194933 Year: Pages: 120 DOI: 10.3389/978-2-88919-493-3 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Microbiology
Added to DOAB on : 2015-11-16 15:44:59
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Phage biology is one of the most significant and fundamental aspects of biological research and is often used as a platform for model studies relating to more complex biological entities. For this reason, phage biology has enjoyed focused attention and significant advances have been made in the areas of phage genomics, transcriptomics and the development and characterisation of phage-resistance mechanisms. In recent years, considerable research has been performed to increase our understanding of the interactions of these phages with their hosts using genomic, biochemical and structural approaches. Such multidisciplinary approaches are core to developing a full understanding of the processes that govern phage infection, information that may be harnessed to develop anti-phage strategies that may be applied in food fermentations or applied in a positive sense in phage therapy applications. The co-evolutionary processes of these phages and their hosts have also been a considerable focus of research in recent years. Such data has promoted a deeper understanding of the means by which these phages attach to and infect their hosts and permitted the development of effective anti-phage strategies. Furthermore, the presence and activity of host-encoded phage-resistance systems that operate at various stages of the phage cycle and the potential for the application of such systems consolidates the value of research in this area. Conversely, phages and their components have been applied as therapeutic agents against a number of pathogens including, among others, Clostridium difficile, Lactococcus garviae, Mycobacterium spp., Listeria spp. and the possibilities and limitations of these systems will be explored in this topic. Additionally, phage therapeutic approaches have been applied to the prevention of development of food spoilage organisms in the brewing and beverage sectors and exhonorate the positive applications of phages in the industrial setting. This research topic is aimed to address the most current issues as well as the most recent advances in the research of phages infecting Gram-positive bacteria covering areas such as phages in food fermentations, their impact in industry, phage ecology, genomics, evolution, structural analysis, phage-host interactions and the application of phages and components thereof as therapeutic agents against human and animal pathogens.

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