Polymeric Nanoparticle-Based Vaccine Adjuvants and Delivery Vehicles.
Authors: Grego EA, Siddoway AC, Uz M, Liu L, Christiansen JC, Ross KA, Kelly SM, Mallapragada SK, Wannemuehler MJ, Narasimhan B Abstract As vaccine formulations have progressed from including live or attenuated strains of pathogenic components for enhanced safety, developing new adjuvants to more effectively generate adaptive immune responses has become necessary. In this context, polymeric nanoparticles have emerged as a promising platform with multiple advantages, including the dual capability of adjuvant and delivery vehicle, administration via multiple routes, induction of rapid and long-lived immunity, greater...
Source: Current Topics in Microbiology and Immunology - November 11, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Protein and Peptide Nanocluster Vaccines.
Authors: Chang TZ, Champion JA Abstract Recombinant protein- and peptide-based vaccines can deliver large amounts of specific antigens for tailored immune responses. One class of these are protein and peptide nanoclusters (PNCs), which are made entirely from the crosslinked antigen. PNCs leverage the inherent immunogenicity of nanoparticulate antigens while minimizing the use of excipients normally used to create them. In this chapter, we discuss PNC fabrication methods, immunostimulatory properties of nanoclusters observed in vitro and in vivo, and protective benefits of PNC vaccines against influenza and cancer m...
Source: Current Topics in Microbiology and Immunology - November 11, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Liposome Formulations as Adjuvants for Vaccines.
Authors: Rao M, Peachman KK, Alving CR Abstract Development of liposome-based formulations as vaccine adjuvants has been intimately associated with, and dependent on, and informed by, a fundamental understanding of biochemical and biophysical properties of liposomes themselves. The Walter Reed Army Institute of Research (WRAIR) has a fifty-year history of experience of basic research on liposomes; and development of liposomes as drug carriers; and development of liposomes as adjuvant formulations for vaccines. Uptake of liposomes by phagocytic cells in vitro has served as an excellent model for studying the intrace...
Source: Current Topics in Microbiology and Immunology - November 11, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Cell Killing by Reovirus: Mechanisms and Consequences.
Authors: McNamara A, Roebke K, Danthi P Abstract Infection of host cells by mammalian reovirus in culture or in tissues of infected animals results in cell death. Cell death of infected neurons and myocytes contributes to the pathogenesis of reovirus-induced encephalitis and myocarditis in a newborn mouse model. Thus, reovirus-induced cell death has been used to investigate the basis of viral disease. Depending on the cell type, infection of host cells by reovirus results in one of two forms of cell death-apoptosis and necroptosis. In addition to the obvious differences in how these two forms of cell death are exec...
Source: Current Topics in Microbiology and Immunology - September 30, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Signaling C-Type Lectin Receptors in Antifungal Immunity.
Authors: Höft MA, Hoving JC, Brown GD Abstract We are all exposed to fungal organisms daily, and although many of these organisms are not harmful, billions of people a year contract a fungal infection. Most of these infections are not fatal and can be cleared by the host immune response. However, due to an increase in high-risk populations, the global fungal burden has increased, with more than 1.5 million deaths per year caused by invasive fungal infections. The fungal cell wall is an important surface for interacting with the host immune system as it contains pathogen-associated molecular patterns (PAMPs) wh...
Source: Current Topics in Microbiology and Immunology - September 17, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Human Gastrointestinal Organoid Models for Studying Microbial Disease and Cancer.
Authors: Chakrabarti J, Dua-Awereh MB, Holokai L, Zavros Y Abstract One of the major discoveries in stem cell research in the past decade embraces the development of "organs in a dish," also known as "organoids." Organoids are three-dimensional cellular structures derived from primary stem cells of different organ-specific cell types which are capable of self-renewal and maintenance of the parental lineages. Researchers have developed in vitro organoid models to mimic in vivo host-microbial interactions and disease. In this review, we focus on the use of gastrointestinal organoids as models of m...
Source: Current Topics in Microbiology and Immunology - September 6, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Advances in Development of mRNA-Based Therapeutics.
Authors: Huang L, Zhang L, Li W, Li S, Wen J, Li H, Liu Z Abstract Recently, mRNA-based therapeutics have been greatly boosted since the development of novel technologies of both mRNA synthesis and delivery system. Promising results were showed in both preclinical and clinical studies in the field of cancer vaccine, tumor immunotherapy, infectious disease prevention and protein replacement therapy. Recent advancements in clinical trials also encouraged scientists to attempt new applications of mRNA therapy such as gene editing and cell programming. These studies bring mRNA therapeutics closer to real-world applicat...
Source: Current Topics in Microbiology and Immunology - July 21, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Broadly Neutralizing Antibodies to Highly Antigenically Variable Viruses as Templates for Vaccine Design.
Authors: Pauthner MG, Hangartner L Abstract Development of vaccines to highly variable viruses such as Human Immunodeficiency Virus and influenza A viruses faces multiple challenges. In this article, these challenges are described and reverse vaccinology approaches to generate universal vaccines against both pathogens are laid out and compared. PMID: 32648034 [PubMed - as supplied by publisher] (Source: Current Topics in Microbiology and Immunology)
Source: Current Topics in Microbiology and Immunology - July 11, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Regulatory Considerations on the Development of mRNA Vaccines.
Authors: Naik R, Peden K Abstract Developing traditional viral vaccines for infectious diseases usually takes years, as these are usually produced either by chemical inactivation of the virus or attenuation of the pathogen, processes that can take considerable time to validate and also require the live pathogen. With the advent of nucleic-acid vaccines (DNA and mRNA), the time to vaccine design and production is considerably shortened, since once the platform has been established, all that is required is the sequence of the antigen gene, its synthesis and insertion into an appropriate expression vector; importantly...
Source: Current Topics in Microbiology and Immunology - July 10, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Human Three-Dimensional Models for Studying Skin Pathogens.
Authors: Boero E, Mnich ME, Manetti AGO, Soldaini E, Grimaldi L, Bagnoli F Abstract Skin is the most exposed surface of the human body, separating the microbe-rich external environment, from the sterile inner part. When skin is breached or its homeostasis is perturbed, bacterial, fungal and viral pathogens can cause local infections or use the skin as an entry site to spread to other organs. In the last decades, it has become clear that skin provides niches for permanent microbial colonization, and it actively interacts with microorganisms. This crosstalk promotes skin homeostasis and immune maturation, preventing ...
Source: Current Topics in Microbiology and Immunology - July 1, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Basics of Inducible Lymphoid Organs.
Authors: Ruddle NH Abstract Tertiary lymphoid organs (TLOs), also known as inducible lymphoid organs, tertiary lymphoid structures, tertiary lymphoid tissues, or ectopic lymphoid organs are accumulations of cells in chronic inflammation that have been observed in most tissues in autoimmunity, infection, and cancer in mouse and man. They share many properties with secondary lymphoid organs (SLOs), particularly lymph nodes, with regard to cellular composition, function, and regulation. TLOs include T and B cells, dendritic cells, follicular dendritic cells, and many other stromal cells, and high endothelial venules (...
Source: Current Topics in Microbiology and Immunology - June 28, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Formulation and Delivery Technologies for mRNA Vaccines.
Authors: Zeng C, Zhang C, Walker PG, Dong Y Abstract mRNA vaccines have become a versatile technology for the prevention of infectious diseases and the treatment of cancers. In the vaccination process, mRNA formulation and delivery strategies facilitate effective expression and presentation of antigens, and immune stimulation. mRNA vaccines have been delivered in various formats: encapsulation by delivery carriers, such as lipid nanoparticles, polymers, peptides, free mRNA in solution, and ex vivo through dendritic cells. Appropriate delivery materials and formulation methods often boost the vaccine efficacy which ...
Source: Current Topics in Microbiology and Immunology - June 4, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Artificial Construction of Immune Tissues/Organoids and Their Application for Immunological Intervention.
Authors: Kobayashi Y, Watanabe T Abstract Human-type lymphoid tissue organoids, which stably function in our body for a certain period of time or longer, may have a great potential as immune-stimulatory or immune-regulatory devices and could be utilized in the future for the treatment of various diseases such as cancer, severe infection, autoimmunity and congenital as well as acquired immunodeficiency resulting from severe infections or aging. In this review, we discuss about rationality and trials of the synthesis of immunologically functional lymphoid tissue organoids mainly in mouse. We have been recently trying...
Source: Current Topics in Microbiology and Immunology - June 4, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Tertiary Lymphoid Organs in Rheumatoid Arthritis.
Authors: Rivellese F, Pontarini E, Pitzalis C Abstract Rheumatoid Arthritis (RA) is a chronic systemic autoimmune disease. RA mainly affects the joints, with inflammation of the synovial membrane, characterized by hyperplasia, neo-angiogenesis, and immune cell infiltration that drives local inflammation and, if untreated, can lead to joint destruction and disability. In parallel to the well-known clinical heterogeneity, the underlying synovitis can also be significantly heterogeneous. In particular, in about 40% of patients with RA, synovitis is characterized by a dense lymphocytic infiltrate that can acquire the f...
Source: Current Topics in Microbiology and Immunology - June 4, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

Memory Lymphocyte Clusters in Genital Immunity: Role of Tissue-Resident Memory T Cells (TRM).
Authors: Iijima N Abstract Development of front-line defenses in genital tissues is important to inhibit viral/bacterial replication and to eliminate sexually transmitted diseases. In this chapter, we discuss the cellular composition, location, and function of memory lymphocyte clusters deployed in mucosal tissues and compare them with those in secondary lymphoid organs and tertiary lymphoid structures. PMID: 32468205 [PubMed - as supplied by publisher] (Source: Current Topics in Microbiology and Immunology)
Source: Current Topics in Microbiology and Immunology - May 31, 2020 Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research

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