50  Years of Lassa Fever Research.
50 Years of Lassa Fever Research. Curr Top Microbiol Immunol. 2020 May 27;: Authors: Garry RF Abstract Lassa fever was first described as a clinical entity fifty years ago. The causative agent Lassa virus was isolated from these first known cases. This chapter reviews the key publications on Lassa fever research that appeared in the scientific literature at that time and over the ensuing decades. PMID: 32458151 [PubMed - as supplied by publisher] (Source: Current Topics in Microbiology and Immunology)
Source: Current Topics in Microbiology and Immunology - May 29, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

A Unified Nomenclature for Injectisome-Type Type III Secretion Systems.
Authors: Wagner S, Diepold A Abstract The independent naming of components of injectisome-type type III secretion systems in different bacterial species has resulted in considerable confusion, impeding accessibility of the literature and hindering communication between scientists of the same field. A unified nomenclature had been proposed by Hueck more than 20 years ago. It found little attention for many years, but usage was sparked again by recent reviews and an international type III secretion meeting in 2016. Here, we propose that the field consistently switches to an extended version of this nomenclature ...
Source: Current Topics in Microbiology and Immunology - May 19, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Physiological and Pathological Functions of CARD9 Signaling in the Innate Immune System.
Authors: Vornholz L, Ruland J Abstract Caspase recruitment domain protein 9 (CARD9) forms essential signaling complexes in the innate immune system that integrate cues from C-type lectin receptors and specific intracellular pattern recognition receptors. These CARD9-mediated signals are pivotal for host defense against fungi, and they mediate immunity against certain bacteria, viruses and parasites. Furthermore, CARD9-regulated pathways are involved in sterile inflammatory responses critical for immune homeostasis and can control pro- and antitumor immunity in cancer microenvironments. Consequently, multiple geneti...
Source: Current Topics in Microbiology and Immunology - May 19, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Revisiting Old Questions and New Approaches to Investigate the Fungal Cell Wall Construction.
Authors: Blatzer M, Beauvais A, Henrissat B, Latgé JP Abstract The beginning of our understanding of the cell wall construction came from the work of talented biochemists in the 70-80's. Then came the era of sequencing. Paradoxically, the accumulation of fungal genomes complicated rather than solved the mystery of cell wall construction, by revealing the involvement of a much higher number of proteins than originally thought. The situation has become even more complicated since it is now recognized that the cell wall is an organelle whose composition continuously evolves with the changes in the environment o...
Source: Current Topics in Microbiology and Immunology - May 19, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Lassa Virus Genetics.
Authors: Klitting R, Mehta SB, Oguzie JU, Oluniyi PE, Pauthner MG, Siddle KJ, Andersen KG, Happi CT, Sabeti PC Abstract In a pattern repeated across a range of ecological niches, arenaviruses have evolved a compact four-gene genome to orchestrate a complex life cycle in a narrow range of susceptible hosts. A number of mammalian arenaviruses cross-infect humans, often causing a life-threatening viral hemorrhagic fever. Among this group of geographically bound zoonoses, Lassa virus has evolved a unique niche that leads to significant and sustained human morbidity and mortality. As a biosafety level 4 pathogen, direct...
Source: Current Topics in Microbiology and Immunology - May 19, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

GPI Anchored Proteins in Aspergillus fumigatus and Cell Wall Morphogenesis.
Authors: Samalova M, Carr P, Bromley M, Blatzer M, Moya-Nilges M, Latgé JP, Mouyna I Abstract Glycosylphosphatidylinositol (GPI) anchored proteins are a class of proteins attached to the extracellular leaflet of the plasma membrane via a post-translational modification, the glycolipid anchor. GPI anchored proteins are expressed in all eukaryotes, from fungi to plants and animals. They display very diverse functions ranging from enzymatic activity, signaling, cell adhesion, cell wall metabolism, and immune response. In this review, we investigated for the first time an exhaustive list of all the GPI anchored ...
Source: Current Topics in Microbiology and Immunology - May 19, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Role of Lymphoid Structure in Skin Immunity.
Authors: Egawa G, Kabashima K Abstract The skin is the outermost organ of the body and is exposed to many kinds of external pathogens. To manage this, the skin contains multiple types of immune cells. To achieve sufficient induction of cutaneous adaptive immune responses, the antigen presentation/recognition in the skin is an essential process. Recent studies have expanded our knowledge of how T cells survey their cognate antigens in the skin. In addition, the formation of a lymphoid cluster, named inducible skin-associated lymphoid tissue (iSALT), has been reported during skin inflammation. Although iSALT may not ...
Source: Current Topics in Microbiology and Immunology - May 11, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Chronic Inflammation in Mucosal Tissues: Barrier Integrity, Inducible Lymphoid Tissues, and Immune Surveillance.
Authors: Chakraborty R, Lo DD Abstract An interesting phenomenon of chronic inflammation is that the associated cytokines can simultaneously promote inflammatory cell recruitment and tissue pathology as well as tissue regeneration and development of inducible organized lymphoid tissues (tertiary lymphoid organs or TLO), demonstrating the remarkable dynamics of the immune interactions with host tissues. In mucosal tissues, chronic immune-mediated inflammation can present a mixed inflammatory pathology including neutrophil infiltrates along with the lymphocytic aggregates. The factors driving this pattern may involve...
Source: Current Topics in Microbiology and Immunology - May 11, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Aspergillus fumigatus DHN-Melanin.
Authors: Chamilos G, Carvalho A Abstract Dihydroxynaphthalene melanin (DHN-melanin) is an integral component of the conidial cell wall surface, which has a central role in the pathogenicity of the major human airborne fungal pathogen Aspergillus fumigatus. Although the biosynthetic pathway for A. fumigatus DHN-melanin production has been well characterized, the molecular interactions of DHN-melanin with the immune system have been incompletely understood. Recent studies demonstrated that apart from concealing immunostimulatory cell wall polysaccharides, calcium sequestration by DHN-melanin inhibits essential host e...
Source: Current Topics in Microbiology and Immunology - May 11, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Recognition of Mycobacteria by Dendritic Cell Immunoactivating Receptor.
Authors: Toyonaga K, Yamasaki S Abstract Mycobacteria have unique lipids on their cell walls, and the structures and physiological activities of these lipid components have been the subject of many studies. Although the host receptors for mycobacterial lipid have long been elusive, in recent years C-type lectin receptors (CLRs) have been reported to recognize these components. The dendritic cell immunoactivating receptor (DCAR), a CLR member, is encoded by Clec4b1. DCAR, which was identified in 2003, is reported to be associated with the immunoreceptor tyrosine-based activation motif (ITAM)-containing adaptor prote...
Source: Current Topics in Microbiology and Immunology - April 19, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Messenger RNA-Based Vaccines Against Infectious Diseases.
Authors: Alameh MG, Weissman D, Pardi N Abstract In vitro-transcribed, messenger RNA-based infectious disease vaccines have the potential to successfully address many of the weaknesses of traditional vaccine platforms, such as the lack of potency and/or durability of vaccine protection, time-consuming, and expensive manufacturing, and, in some cases, safety issues. This optimism is fueled by a great deal of impressive recent data demonstrating that mRNA vaccines have many of the attributes that are necessary for a viable new vaccine class for human use. This review briefly describes mRNA vaccine types, discusses th...
Source: Current Topics in Microbiology and Immunology - April 19, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Outcomes of RIP Kinase Signaling During Neuroinvasive Viral Infection.
Authors: Daniels BP, Oberst A Abstract Neuroinvasive viral diseases are a considerable and growing burden on global public health. Despite this, these infections remain poorly understood, and the molecular mechanisms that govern protective versus pathological neuroinflammatory responses to infection are a matter of intense investigation. Recent evidence suggests that necroptosis, an immunogenic form of programmed cell death, may contribute to the pathogenesis of viral encephalitis. However, the receptor-interacting protein (RIP) kinases that coordinate necroptosis, RIPK1 and RIPK3, also appear to have unexpected, c...
Source: Current Topics in Microbiology and Immunology - April 9, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

α- and β-1,3-Glucan Synthesis and Remodeling.
α- and β-1,3-Glucan Synthesis and Remodeling. Curr Top Microbiol Immunol. 2020 Mar 20;: Authors: Wagener J, Striegler K, Wagener N Abstract Glucans are characteristic and major constituents of fungal cell walls. Depending on the species, different glucan polysaccharides can be found. These differ in the linkage of the D-glucose monomers which can be either in α- or β-conformation and form 1,3, 1,4 or 1,6 O-glycosidic bonds. The linkages and polymer lengths define the physical properties of the glucan macromolecules, which may form a scaffold for other cell wall structures and infl...
Source: Current Topics in Microbiology and Immunology - March 22, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

PAMPs of the Fungal Cell Wall and Mammalian PRRs.
Authors: Hatinguais R, Willment JA, Brown GD Abstract Fungi are opportunistic pathogens that infect immunocompromised patients and are responsible for an estimated 1.5 million deaths every year. The antifungal innate immune response is mediated through the recognition of pathogen-associated molecular patterns (PAMPs) by the host's pattern recognition receptors (PRRs). PRRs are immune receptors that ensure the internalisation and the killing of fungal pathogens. They also mount the inflammatory response, which contributes to initiate and polarise the adaptive response, controlled by lymphocytes. Both the innate and ...
Source: Current Topics in Microbiology and Immunology - March 19, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Exopolysaccharides and Biofilms.
Authors: Le Mauff F Abstract During infection, many fungal pathogens form biofilms within tissues or on biomedical devices. The growth of fungi within biofilms increases dramatically their resistance to both immune defences and antifungal therapies. In the last twenty years, studies have begun to shed light on many of the steps involved in biofilm synthesis and composition, revealing new antifungal strategies. This chapter will focus on the biofilm exopolysaccharides produced by A. fumigatus and C. albicans, the two main causes of human fungal infections. We will review the current state of our understanding of the...
Source: Current Topics in Microbiology and Immunology - February 21, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

C-Type Lectin Receptors in Phagocytosis.
Authors: Li K, Underhill DM Abstract C-type lectin receptors (CLRs) are a family of transmembrane proteins having at least one C-type lectin-like domain (CTLD) on the cell surface and either a short intracellular signaling tail or a transmembrane domain that facilitates interaction with a second protein, often the Fc receptor common gamma chain (FcRγ), that mediates signaling. Many CLRs directly recognize microbial cell walls and influence innate immunity by activating inflammatory and antimicrobial responses in phagocytes. In this review, we examine the contributions of certain CLRs to activation and regulat...
Source: Current Topics in Microbiology and Immunology - February 17, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

C-type Lectins in Immunity to Lung Pathogens.
Authors: Raymond BBA, Neyrolles O, Rombouts Y Abstract The respiratory tract is tasked with responding to a constant and vast influx of foreign agents. It acts as an important first line of defense in the innate immune system and as such plays a crucial role in preventing the entry of invading pathogens. While physical barriers like the mucociliary escalator exert their effects through the clearance of these pathogens, diverse and dynamic cellular mechanisms exist for the activation of the innate immune response through the recognition of pathogen-associated molecular patterns (PAMPs). These PAMPs are recognized by...
Source: Current Topics in Microbiology and Immunology - February 17, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Manipulation of Host Cell Death Pathways by Herpes Simplex Virus.
Authors: He S, Han J Abstract Herpes simplex virus (HSV)-1 and HSV-2 are ubiquitous human pathogens that infect keratinized epithelial surfaces and establish lifelong latent infection in sensory neurons of the peripheral nervous system. HSV-1 causes oral cold sores, and HSV-2 causes genital lesions characterized by recurrence at the site of the initial infection. In multicellular organisms, cell death plays a pivotal role in host defense by eliminating pathogen-infected cells. Apoptosis and necrosis are readily distinguished types of cell death. Apoptosis, the main form of programmed cell death, depends on the...
Source: Current Topics in Microbiology and Immunology - February 17, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Control of Actin and Calcium for Chitin Synthase Delivery to the Hyphal Tip of Aspergillus.
Authors: Takeshita N Abstract Filamentous fungi are covered by a cell wall consisting mainly of chitin and glucan. The synthesis of chitin, a β-1,4-linked homopolymer of N-acetylglucosamine, is essential for hyphal morphogenesis. Fungal chitin synthases are integral membrane proteins that have been classified into seven classes. ChsB, a class III chitin synthase, is known to play a key role in hyphal tip growth and has been used here as a model to understand the cell biology of cell wall biosynthesis in Aspergillus nidulans. Chitin synthases are transported on secretory vesicles to the plasma membrane for new ...
Source: Current Topics in Microbiology and Immunology - January 26, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Sensing Tissue Damage by Myeloid C-Type Lectin Receptors.
Authors: Del Fresno C, Cueto FJ, Sancho D Abstract After both sterile and infectious insults, damage is inflicted on tissues leading to accidental or programmed cell death. In addition, events of programmed cell death also take place under homeostatic conditions, such as in embryo development or in the turnover of hematopoietic cells. Mammalian tissues are seeded with myeloid immune cells, which harbor a plethora of receptors that allow the detection of cell death, modulating immune responses. The myeloid C-type lectin receptors (CLRs) are one of the most prominent families of receptors involved in tailoring immuni...
Source: Current Topics in Microbiology and Immunology - January 26, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Role of iBALT in Respiratory Immunity.
Authors: Silva-Sanchez A, Randall TD Abstract Pulmonary respiration inevitably exposes the mucosal surface of the lung to potentially noxious stimuli, including pathogens, allergens, and particulates, each of which can trigger pulmonary damage and inflammation. As inflammation resolves, B and T lymphocytes often aggregate around large bronchi to form inducible Bronchus-Associated Lymphoid Tissue (iBALT). iBALT formation can be initiated by a diverse array of molecular pathways that converge on the activation and differentiation of chemokine-expressing stromal cells that serve as the scaffolding for iBALT and facili...
Source: Current Topics in Microbiology and Immunology - January 26, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Structures of Type III Secretion System Needle Filaments.
Authors: Habenstein B, El Mammeri N, Tolchard J, Lamon G, Tawani A, Berbon M, Loquet A Abstract Among the Gram-negative bacterial secretion systems, type III secretion systems (T3SS) possess a unique extracellular molecular apparatus called the needle. This macromolecular protein assembly is a nanometre-size filament formed by the helical arrangement of hundreds of copies of a single, small protein, which is highly conserved between T3SSs from animal to plant bacterial pathogens. The needle filament forms a hollow tube with a channel ~20 Å in diameter that serves as a conduit for proteins secreted...
Source: Current Topics in Microbiology and Immunology - January 26, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Small Molecule Inhibitors Targeting Chikungunya Virus.
Authors: Haese N, Powers J, Streblow DN Abstract Chikungunya virus (CHIKV) infection in humans is rarely fatal but is often associated with chronic joint and muscle pain. Chronic CHIKV disease is highly debilitating and is associated with viral persistence. To date, there are no approved vaccines or therapeutics to prevent or treat CHIKV infections once they are established. Current palliative treatments aim to reduce joint inflammation and pain associated with acute and chronic CHIKV disease. Development of novel therapeutics that reduces viral loads should positively impact virus inflammatory disease and improve ...
Source: Current Topics in Microbiology and Immunology - January 26, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

ZBP1/DAI-Dependent Cell Death Pathways in Influenza A Virus Immunity and Pathogenesis.
Authors: Thomas PG, Shubina M, Balachandran S Abstract Influenza A viruses (IAV) are members of the Orthomyxoviridae family of negative-sense RNA viruses. The greatest diversity of IAV strains is found in aquatic birds, but a subset of strains infects other avian as well as mammalian species, including humans. In aquatic birds, infection is largely restricted to the gastrointestinal tract and spread is through feces, while in humans and other mammals, respiratory epithelial cells are the primary sites supporting productive replication and transmission. IAV triggers the death of most cell types in which it replicate...
Source: Current Topics in Microbiology and Immunology - January 25, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Hydrophobin Rodlets on the Fungal Cell Wall.
Authors: Ball SR, Kwan AH, Sunde M Abstract The conidia of airborne fungi are protected by a hydrophobic protein layer that coats the cell wall polysaccharides and renders the spores resistant to wetting and desiccation. A similar layer is presented on the outer surface of the aerial hyphae of some fungi. This layer serves multiple purposes, including facilitating spore dispersal, mediating the growth of hyphae into the air from moist environments, aiding host interactions in symbiotic relationships and increasing infectivity in pathogenic fungi. The layer consists of tightly packed, fibrillar structures termed &qu...
Source: Current Topics in Microbiology and Immunology - December 27, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Synthetic Oligosaccharides Mimicking Fungal Cell Wall Polysaccharides.
Authors: Krylov VB, Nifantiev NE Abstract The cell wall of pathogenic fungi is highly important for the development of fungal infections and is the first cellular component to interact with the host immune system. The fungal cell wall is mainly built up of different polysaccharides representing ligands for pattern recognition receptors (PRRs) on immune cells and antibodies. Purified fungal polysaccharides are not easily available; in addition, they are structurally heterogenic and have wide molecular weight distribution that limits the possibility to use natural polysaccharides to assess the structure of their acti...
Source: Current Topics in Microbiology and Immunology - December 27, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Cell Wall-Modifying Antifungal Drugs.
Authors: Perlin DS Abstract Antifungal therapy is a critical component of patient management for invasive fungal diseases. Yet, therapeutic choices are limited as only a few drug classes are available to treat systemic disease, and some infecting strains are resistant to one or more drug classes. The ideal antifungal inhibits a fungal-specific essential target not present in human cells to avoid off-target toxicities. The fungal cell wall is an ideal drug target because its integrity is critical to cell survival and a majority of biosynthetic enzymes and wall components is unique to fungi. Among currently approved ...
Source: Current Topics in Microbiology and Immunology - December 27, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Pyroptosis in Antiviral Immunity.
Authors: Kuriakose T, Kanneganti TD Abstract Pyroptosis is a form of lytic, programmed cell death that functions as an innate immune effector mechanism to facilitate host defense against pathogenic microorganisms, including viruses. This type of proinflammatory cell death is orchestrated by proteolytic activation of human or mouse caspase-1, mouse caspase-11 and human caspase-4 and caspase-5 in response to infectious and inflammatory stimuli. Induction of pyroptosis requires either a canonical inflammasome responsible for caspase-1 activation or a noncanonical complex composed of caspase-11 in mice or caspase-4 or ...
Source: Current Topics in Microbiology and Immunology - December 27, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Glucanases and Chitinases.
Authors: Roncero C, Vázquez de Aldana CR Abstract In many yeast and fungi, β-(1,3)-glucan and chitin are essential components of the cell wall, an important structure that surrounds cells and which is responsible for their mechanical protection and necessary for maintaining the cellular shape. In addition, the cell wall is a dynamic structure that needs to be remodelled along with the different phases of the fungal life cycle or in response to extracellular stimuli. Since β-(1,3)-glucan and chitin perform a central structural role in the assembly of the cell wall, it has been postulated that β...
Source: Current Topics in Microbiology and Immunology - December 7, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Mitochondrial Control of Fungal Cell Walls: Models and Relevance in Fungal Pathogens.
Authors: Koch B, Traven A Abstract Proper structure and function of the fungal cell wall are controlled by metabolic processes, as well as an interplay between a range of cellular organelles. Somewhat surprisingly, mitochondrial function has been shown to be important for proper cell wall biogenesis and integrity. Mitochondria also play a role in the susceptibility of fungi to cell wall-targeting drugs. This is true in a range of fungal species, including important human fungal pathogens. The biochemical mechanisms that explain the roles of mitochondria in cell wall biology have remained elusive, but studies to dat...
Source: Current Topics in Microbiology and Immunology - December 7, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Chitin: A "Hidden Figure" in the Fungal Cell Wall.
Chitin: A "Hidden Figure" in the Fungal Cell Wall. Curr Top Microbiol Immunol. 2019 Dec 06;: Authors: Brown HE, Esher SK, Alspaugh JA Abstract Chitin and chitosan are two related polysaccharides that provide important structural stability to fungal cell walls. Often embedded deeply within the cell wall structure, these molecules anchor other components at the cell surface. Chitin-directed organization of the cell wall layers allows the fungal cell to effectively monitor and interact with the external environment. For fungal pathogens, this interaction includes maintaining cellular strategies ...
Source: Current Topics in Microbiology and Immunology - December 7, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Impact of the Environment upon the Candida albicans Cell Wall and Resultant Effects upon Immune Surveillance.
Authors: Childers DS, Avelar GM, Bain JM, Larcombe DE, Pradhan A, Budge S, Heaney H, Brown AJP Abstract The fungal cell wall is an essential organelle that maintains cellular morphology and protects the fungus from environmental insults. For fungal pathogens such as Candida albicans, it provides a degree of protection against attack by host immune defences. However, the cell wall also presents key epitopes that trigger host immunity and attractive targets for antifungal drugs. Rather than being a rigid shield, it has become clear that the fungal cell wall is an elastic organelle that permits rapid changes in cell v...
Source: Current Topics in Microbiology and Immunology - November 30, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Structural Aspects of Carbohydrate Recognition Mechanisms of C-Type Lectins.
Authors: Nagae M, Yamaguchi Y Abstract Carbohydrate recognition is an essential function occurring in all living organisms. Lectins are carbohydrate-binding proteins and are classified into several families. In mammals, Ca2+-dependent C-type lectins, such as β-galactoside-binding galectin and sialic acid-binding siglec, play crucial roles in the immune response and homeostasis. C-type lectins are abundant and diverse in animals. Their immunological activities include lymphocyte homing, pathogen recognition, and clearance of apoptotic bodies. C-type lectin domains are composed of 110-130 amino acid residues wit...
Source: Current Topics in Microbiology and Immunology - November 30, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Priorities for Public-Private Cooperation to Mitigate Risk and Impact of Global Catastrophic Biological Risks.
Authors: Morhard R Abstract By definition, Global Catastrophic Biological Risks (GCBRs) are "beyond the collective capability of national and international governments and the private sector to control". Implicit in this definition is that no single country, sector, or entity can effectively mitigate risk and impact of GCBRs and that doing so requires public-private cooperation. This short commentary offers five trends suggesting that conditions for cooperation are favorable, along with three gaps to be addressed, and five high-level recommendations to strengthen public-private cooperation to mitigate ris...
Source: Current Topics in Microbiology and Immunology - November 2, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

The Structure of the Type III Secretion System Needle Complex.
Authors: Miletic S, Goessweiner-Mohr N, Marlovits TC Abstract The type III secretion system (T3SS) is an essential virulence factor of many pathogenic bacterial species including Salmonella, Yersinia, Shigella and enteropathogenic Escherichia coli (EPEC). It is an intricate molecular machine that spans the bacterial membranes and injects effector proteins into target host cells, enabling bacterial infection. The T3SS needle complex comprises of proteinaceous rings supporting a needle filament which extends out into the extracellular environment. It serves as the central conduit for translocating effector proteins. ...
Source: Current Topics in Microbiology and Immunology - November 2, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Viral Forecasting, Pathogen Cataloging, and Disease Ecosystem Mapping: Measuring Returns on Investments.
Authors: Fair J, Fair J Abstract Infectious disease emergence into humans from animals or the environment occurs primarily due to genetic changes in the microbe through mutation or re-assortment making it either more transmissible or virulent or through a change in the disease "ecosystem". Research into infectious disease emergence can be grouped into different strategic approaches. One strategic approach is to study a specific or model disease system to understand the ecology of an infectious disease and how is transmitted and propagated through the environment and different hosts and then extrapolate th...
Source: Current Topics in Microbiology and Immunology - October 28, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Does Biotechnology Pose New Catastrophic Risks?
Authors: DiEuliis D, Ellington AD, Gronvall GK, Imperiale MJ Abstract Advances in biotechnology in the twenty-first century, fueled in large part by the field of synthetic biology, have greatly accelerated capabilities to manipulate and re-program bacteria, viruses, and other organisms. These genetic engineering capabilities are driving innovation and progress in drug manufacturing, bioremediation, and tissue engineering, as well as biosecurity preparedness. However, biotechnology is largely dual use, holding the potential of misuse for deliberate harm along with positive applications; defenses against those threat...
Source: Current Topics in Microbiology and Immunology - August 31, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Characteristics of Microbes Most Likely to Cause Pandemics and Global Catastrophes.
Authors: Adalja AA, Watson M, Toner ES, Cicero A, Inglesby TV Abstract Predicting which pathogen will confer the highest global catastrophic biological risk (GCBR) of a pandemic is a difficult task. Many approaches are retrospective and premised on prior pandemics; however, such an approach may fail to appreciate novel threats that do not have exact historical precedent. In this paper, based on a study and project we undertook, a new paradigm for pandemic preparedness is presented. This paradigm seeks to root pandemic risk in actual attributes possessed by specific classes of microbial organisms and leads to specif...
Source: Current Topics in Microbiology and Immunology - August 31, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Chikungunya Virus Vaccines: Platforms, Progress, and Challenges.
Authors: DeFilippis VR Abstract Chikungunya is a clinically and economically important arbovirus that has spread globally in the twenty-first century. While uncommonly fatal, infection with the virus can lead to incapacitating arthralgia that can persist for months to years. The adverse impacts of viral spread are most severe in developing low- and middle-income countries in which medical infrastructure is insufficient and manual labor is an economic driver. Unfortunately, no prophylactic or therapeutic treatments are approved for human use to combat the virus. Historically, vaccination has proven to be the most ef...
Source: Current Topics in Microbiology and Immunology - July 26, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Correction to: Human Organotypic Models for Anti-infective Research.
Authors: Hendriks A, Cruz AR, Soldaini E, Manetti AGO, Bagnoli F Abstract ∎∎∎. PMID: 31321556 [PubMed - as supplied by publisher] (Source: Current Topics in Microbiology and Immunology)
Source: Current Topics in Microbiology and Immunology - July 21, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Enhancing Situational Awareness to Prevent Infectious Disease Outbreaks from Becoming Catastrophic.
Authors: Lipsitch M, Santillana M Abstract Catastrophic epidemics, if they occur, will very likely start from localized and far smaller (non-catastrophic) outbreaks that grow into much greater threats. One key bulwark against this outcome is the ability of governments and the health sector more generally to make informed decisions about control measures based on accurate understanding of the current and future extent of the outbreak. Situation reporting is the activity of periodically summarizing the state of the outbreak in a (usually) public way. We delineate key classes of decisions whose quality depends on high...
Source: Current Topics in Microbiology and Immunology - July 14, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

The Role of Melanin in Fungal Pathogenesis for Animal Hosts.
Authors: Smith DFQ, Casadevall A Abstract Melanins are a class of pigments that are ubiquitous throughout biology. They play incredibly diverse and important roles ranging from radiation protection to immune defense, camouflage, and virulence. Fungi have evolved to use melanin to be able to persist in the environment and within organisms. Fungal melanins are often located within the cell well and are able to neutralize reactive oxygen species and other radicals, defend against UV radiation, bind and sequester non-specific peptides and compounds, and produce a physical barrier that defends the cell. For this reason,...
Source: Current Topics in Microbiology and Immunology - July 8, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Diversity and Evolution of Type III Secreted Effectors: A Case Study of Three Families.
Authors: Bastedo DP, Lo T, Laflamme B, Desveaux D, Guttman DS Abstract A broad range of Gram-negative bacteria employ a type III secretion system (T3SS) to deliver virulence proteins termed type III secreted effectors directly into the cytoplasm of eukaryotic host cells. While effectors can contribute to the colonization of eukaryotic hosts by bacterial symbionts and pathogens, they can also elicit host immune responses that restrict bacterial growth. These opposing selective pressures have shaped the evolution of effector families and may be responsible for their incredible diversity in biochemical function, mecha...
Source: Current Topics in Microbiology and Immunology - June 28, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Assembly and Post-assembly Turnover and Dynamics in the Type III Secretion System.
This article aims to give an overview on the assembly and post-assembly dynamics of the T3SS, with a focus on emerging general concepts and adaptations of the general assembly pathway. PMID: 31218503 [PubMed - as supplied by publisher] (Source: Current Topics in Microbiology and Immunology)
Source: Current Topics in Microbiology and Immunology - June 22, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Artemisinin-Resistant Malaria as a Global Catastrophic Biological Threat.
Authors: Ricotta E, Kwan J Abstract The global spread of artemisinin resistance brings with it the threat of incurable malaria. Already, this disease threatens over 219 million lives per year and causes 5-6% losses in GDP in endemic areas, even with current advances in prevention and treatment. This chapter discusses the currently tenuous position we are in globally, and the impact that could be seen if artemisinin treatment is lost, whether due to the unchecked spread of K13 mutations or poor global investment in treatment and prevention advances. Artemisinin is the backbone of current ACT treatment programs and s...
Source: Current Topics in Microbiology and Immunology - June 22, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Transcriptional and Post-transcriptional Regulatory Mechanisms Controlling Type III Secretion.
Authors: Volk M, Vollmer I, Heroven AK, Dersch P Abstract Type III secretion systems (T3SSs) are utilized by numerous Gram-negative bacteria to efficiently interact with host cells and manipulate their function. Appropriate expression of type III secretion genes is achieved through the integration of multiple control elements and regulatory pathways that ultimately coordinate the activity of a central transcriptional activator usually belonging to the AraC/XylS family. Although several regulatory elements are conserved between different species and families, each pathogen uses a unique set of control factors and me...
Source: Current Topics in Microbiology and Immunology - June 22, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Export Mechanisms and Energy Transduction in Type-III Secretion Machines.
Authors: Renault TT, Guse A, Erhardt M Abstract The remarkably complex architecture and organization of bacterial nanomachines originally raised the enigma to how they are assembled in a coordinated manner. Over the years, the assembly processes of the flagellum and evolutionary-related injectisome complexes have been deciphered and were shown to rely on a conserved protein secretion machine: the type-III secretion system. In this book chapter, we demonstrate how individually evolved mechanisms cooperate in highly versatile and robust secretion machinery to export and assemble the building blocks of those nanomachi...
Source: Current Topics in Microbiology and Immunology - June 22, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

The Tip Complex: From Host Cell Sensing to Translocon Formation.
Authors: Picking WD, Barta ML Abstract Type III secretion systems are used by some Gram-negative bacteria to inject effector proteins into targeted eukaryotic cells for the benefit of the bacterium. The type III secretion injectisome is a complex nanomachine comprised of four main substructures including a cytoplasmic sorting platform, an envelope-spanning basal body, an extracellular needle and an exposed needle tip complex. Upon contact with a host cell, secretion is induced, resulting in the formation of a translocon pore in the host membrane. Translocon formation completes the conduit needed for effector secret...
Source: Current Topics in Microbiology and Immunology - June 22, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Flagellar Hook/Needle Length Control and Secretion Control in Type III Secretion Systems.
Authors: Aizawa SI Abstract The flagellum is a motile organ, and the needle complex is a type III secretion apparatus for pathogenesis. There are more similarities than differences between the two structures at the molecular level. Here I focus on the hook and the needle and discuss their length control mechanism. The hook is a substructure of the flagellum and the needle is a part of the needle complex. Both structures are tubular structures that have a central channel for protein secretion. Their lengths are controlled by an intriguing mechanism involving a ruler protein and a switchable gate of the protein secre...
Source: Current Topics in Microbiology and Immunology - June 12, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

The Type III Secretion System Sorting Platform.
Authors: Lara-Tejero M Abstract A central feature of type III protein secretion machines is their ability to engage their substrates in a hierarchical and organized fashion. The hierarchy in the secretion process is first observed during the assembly of the type III secretion injectisome when the secretion machine exclusively engages proteins required for building the needle complex substructure (early substrates). After completion of the needle complex, the secretion system loads the proteins that will form the needle tip substructure as well as the protein translocases (middle substrates), which upon contact with...
Source: Current Topics in Microbiology and Immunology - June 12, 2019 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research