The Autophagy Pathway: Bacterial Pathogen Immunity and Evasion PDF Download

Author: Chinnaswamy Jagannath
Publisher: Frontiers Media SA
ISBN: 2889716856
Category : Science
Languages : en
Pages : 155

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Author: William T. Jackson
Publisher: John Wiley & Sons
ISBN: 1118677641
Category : Science
Languages : en
Pages : 364

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Book Description
The relationship between infection and immunity and autophagy, a pathway of cellular homeostasis and stress response, has been a rapidly growing field of study over the last decade. While some cellular processes are pro- or anti-infection, autophagy has been proven to be both: a part of the innate immune response against some microbes, and a cellular pathway subverted by some pathogens to promote their own replication. Autophagy, Infection, and the Immune Response provides a unified overview of the roles of cellular autophagy during microbial infection. Introductory chapters ground the reader by delineating the autophagic pathway from a cellular perspective, and by listing assays available for measuring autophagy. Subsequent chapters address virus interactions with autophagy machinery, the various roles of autophagy parasitic infection, and interactions of bacteria with the autophagic pathway. Concluding chapters explore the relationships of autophagy to systemic immune responses, including antigen presentation, ER stress, and production of IFN-gamma. Designed as a resource for those interested in initiating studies on the relationship between autophagy and infection or immunity, Autophagy, Infection, and the Immune Response combines practical state-of the art technique descriptions with an overview of the wide variety of known interactions between pathogens and the autophagic pathway.

Author: Beth Levine
Publisher: Springer Science & Business Media
ISBN: 3642003028
Category : Medical
Languages : en
Pages : 345

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Book Description
Autophagy is a fundamental biological process that enables cells to autodigest their own cytosol during starvation and other forms of stress. It has a growing spectrum of acknowledged roles in immunity, aging, development, neurodegeneration, and cancer biology. An immunological role of autophagy was first recognized with the discovery of autophagy’s ability to sanitize the cellular interior by killing intracellular microbes. Since then, the repertoire of autophagy’s roles in immunity has been vastly expanded to include a diverse but interconnected portfolio of regulatory and effector functions. Autophagy is an effector of Th1/Th2 polarization; it fuels MHC II presentation of cytosolic (self and microbial) antigens; it shapes central tolerance; it affects B and T cell homeostasis; it acts both as an effector and a regulator of Toll-like receptor and other innate immunity receptor signaling; and it may help ward off chronic inflammatory disease in humans. With such a multitude of innate and adaptive immunity functions, the study of autophagy in immunity is one of the most rapidly growing fields of contemporary immunological research. This book introduces the reader to the fundamentals of autophagy, guides a novice and the well-informed reader alike through different immunological aspects of autophagy as well as the countermeasures used by highly adapted pathogens to fight autophagy, and provides the expert with the latest, up-to-date information on the specifics of the leading edge of autophagy research in infection and immunity.

Author: Cheryl Lynn Birmingham
Publisher:
ISBN: 9780494447727
Category : Cytology
Languages : en
Pages : 388

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Book Description
Autophagy is a cytosolic degradation pathway responsible for delivering proteins and organelles to the lysosome for degradation. Recently, this pathway has been shown to be an important component of innate immunity. In this thesis, I study two intracellular pathogens with very different lifestyles and compare how they interact with autophagy. Salmonella enterica serovar Typhimurium is a vacuole-adapted pathogen that replicates in the Salmonella -containing vacuole (SCV) in host cells. During in vitro infection of epithelial cells, a population of bacteria damages the SCV and replicates in the cytosol. I show here that bacteria in damaged SCVs are targeted by autophagy. This serves to protect the cytosol from bacterial colonization and restricts bacterial replication in this cell-type. Furthermore, damage to the SCV membrane appears to act as a signal to recruit autophagy. Listeria monocytogenes is a cytosol-adapted pathogen that lyses the phagosome and replicates in the cytosol. Listeriolysin O (LLO) and bacterial phospholipases C (PLCs) form pores in the phagosomal membrane to mediate this escape. Once in the cytosol, L. monocytogenes expresses ActA to mediate actin-based motility and intercellular spread. In macrophages, a significant population of bacteria is targeted by autophagy during phagosomal escape in an LLO-dependent manner. However, once in the cytosol, L. monocytogenes is able to evade autophagy. ActA is sufficient but not necessary for autophagy evasion. Accordingly, bacterial PLCs also play a role in autophagy evasion. During infection of macrophages, we observed that a small population of L. monocytogenes replicates in Spacious Listeria -containing Phagosomes (SLAPs). LLO is essential for SLAP formation and inhibits the maturation of these compartments by forming pores in the SLAP membrane. Furthermore, we found that impaired LLO expression allows slow bacterial replication in vacuoles in an autophagy-dependent manner. Therefore, SLAPs appear to represent a 'stalemate' between bacterial virulence (LLO activity) and host innate immunity (autophagy). SLAP-like structures were observed during persistent L. monocytogenes infection of immuno-deficient mice. This work provides insights into signals that target autophagy to intracellular pathogens and mechanisms by which pathogens have evolved to evade this innate immune mechanism. Furthermore, this research suggests a possible mechanism for the establishment of persistent infection.

Author: Jun Cui
Publisher: Springer Nature
ISBN: 981150606X
Category : Medical
Languages : en
Pages : 203

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Book Description
This book discusses novel concepts and discoveries concerning the regulation of innate immunity by autophagy and autophagy-related proteins. In the past decade, there have been major advances in our understanding of the molecular mechanisms of autophagy and its physiological functions. This book highlights emerging studies on the underlying mechanisms of autophagy regulation of innate immunity, including inflammation, antiviral immunity and anti-bacterial responses and the signaling pathways that prompt or inhibit the initiation and progression of related diseases. It also offers new ideas and strategies for future drugs based on manipulating autophagy, especially selective autophagy mediated by cargo receptors. Providing a comprehensive overview of the autophagy regulation of innate immunity, it is a valuable resource for graduate students and researchers in the fields of immunology, cell biology and translational medicine.

Author: Pedro Escoll
Publisher: Caister Academic Press Limited
ISBN: 9781910190692
Category : Medical
Languages : en
Pages : 0

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Book Description
Expert international authors critically review the most important current research in bacterial evasion of the host immune response. Topics range from an overview of the seven most important bacterial secretion systems to a thorough review of evsaion by mycobacteria. Essential reading for everyone involved in bacterial pathogenesis research.

Author: Inka Sastalla
Publisher: Frontiers Media SA
ISBN: 2889199916
Category : Immunologic diseases. Allergy
Languages : en
Pages : 192

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Book Description
Bacterial pathogenicity factors are functionally diverse. They may facilitate the adhesion and colonization of bacteria, influence the host immune response, assist spreading of the bacterium by e.g. evading recognition by immune cells, or allow bacteria to dwell within protected niches inside the eukaryotic cell. Exotoxins can be single polypeptides or heteromeric protein complexes that act on different parts of the cells. At the cell surface, they may insert into the membrane to cause damage; bind to receptors to initiate their uptake; or facilitate the interaction with other cell types. For example, bacterial superantigens specifically bind to major histocompatibility complex (MHC) II molecules on the surface of antigen presenting cells and the T cell receptor, while cytolysins cause pore formation. For intracellular activity, exotoxins need to be translocated across the eukaryotic membrane. Gram-negative bacteria can directly inject effector proteins in a receptor-independent manner by use of specialized needle apparatus such as bacterial type II, III, or type IV secretion systems. Other methods of translocation include the phagocytic uptake of bacteria followed by toxin secretion, or receptor-mediated endocytosis which allows the targeting of distinct cell types. Receptor-based uptake is initiated by the binding of heteromeric toxin complexes to the cell surface and completed by the translocation of the effector protein(s) across the endosomal membrane. In the cytosol, toxins interact with specific eukaryotic target proteins to cause post-translational modifications that often result in the manipulation of cellular signalling cascades and inflammatory responses. It has become evident that the actions of some bacterial toxins may exceed their originally assumed cytotoxic function. For example, pore-forming toxins do not only cause cytolysis, but may also induce autophagy, pyroptosis, or activation of the MAPK pathways, resulting in adjustment of the host immune response to infection and modification of inflammatory responses both locally and systemically. Other recently elucidated examples of the immunomodulatory function of cell death-inducing exotoxins include TcdB of Clostridium difficile which activates the inflammasome through modification of cellular Rho GTPases, or the Staphyloccocus d-toxin which activates mast cells. The goal of this research topic was to gather current knowledge on the interaction of bacterial exotoxins and effector proteins with the host immune system. The following 16 research and review articles in this special issue describe mechanisms of immune modification and evasion and provide an overview over the complexity of bacterial toxin interaction with different cells of the immune system.

Author: Institute of Medicine
Publisher: National Academies Press
ISBN: 0309211093
Category : Medical
Languages : en
Pages : 560

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Book Description
A single tick bite can have debilitating consequences. Lyme disease is the most common disease carried by ticks in the United States, and the number of those afflicted is growing steadily. If left untreated, the diseases carried by ticks-known as tick-borne diseases-can cause severe pain, fatigue, neurological problems, and other serious health problems. The Institute of Medicine held a workshop October 11-12, 2010, to examine the state of the science in Lyme disease and other tick-borne diseases.

Author: Jose Luis Subiza
Publisher: Frontiers Media SA
ISBN: 2889712311
Category : Medical
Languages : en
Pages : 195

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Dr. Jose Luis Subiza is the founder and CEO of Inmunotek SL. The other Topic Editors declare no competing interests with regard to the Research Topic subject.

Author: Chihiro Sasakawa
Publisher: Springer Science & Business Media
ISBN: 3642018467
Category : Medical
Languages : en
Pages : 263

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Book Description
Our gut is colonized by numerous bacteria throughout our life, and the gut epithelium is constantly exposed to foreign microbes and dietary antigens. Thus, the gut epithelium acts as a barrier against microbial invaders and is equipped with various innate defense systems. Resident commensal and foreign invading bacteria interact intimately with the gut epithelium and can impact host cellular and innate immune responses. From the perspective of many pathogenic bacteria, the gut epithelium serves as an infectious foothold and port of entry for disseminate into deeper tissues. In some instances when the intestinal defense activity and host immune system become compromised, even commensal and opportunistic pathogenic bacteria can cross the barrier and initiate local and systematic infectious diseases. Conversely, some highly pathogenic bacteria, such as those highlighted in this book, are able to colonize or invade the intestinal epithelium despite the gut barrier function is intact. Therefore, the relationship between the defensive activity of the intestinal epithelium against microbes and the pathogenesis of infective microbes becomes the basis for maintaining a healthy life. The authors offer an overview of the current topics related to major gastric and enteric pathogens, while highlighting their highly evolved host (human)-adapted infectious processes. Clearly, an in-depth study of bacterial infectious strategies, as well as the host cellular and immune responses, presented in each chapter of this book will provide further insight into the critical roles of the host innate and adaptive immune systems and their importance in determining the severity or completely preventing infectious diseases. Furthermore, under the continuous threat of emerging and re-emerging infectious diseases, the topic of gut-bacteria molecular interactions will provide various clues and ideas for the development of new therapeutic strategies.