751
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Schorey JS, Harding CV. Extracellular vesicles and infectious diseases: new complexity to an old story. J Clin Invest 2016; 126:1181-9. [PMID: 27035809 DOI: 10.1172/jci81132] [Citation(s) in RCA: 157] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Exosomes and other extracellular microvesicles (ExMVs) have important functions in intercellular communication and regulation. During the course of infection, these vesicles can convey pathogen molecules that serve as antigens or agonists of innate immune receptors to induce host defense and immunity, or that serve as regulators of host defense and mediators of immune evasion. These molecules may include proteins, nucleic acids, lipids, and carbohydrates. Pathogen molecules may be disseminated by incorporation into vesicles that are created and shed by host cells, or they may be incorporated into vesicles shed from microbial cells. Involvement of ExMVs in the induction of immunity and host defense is widespread among many pathogens, whereas their involvement in immune evasion mechanisms is prominent among pathogens that establish chronic infection and is found in some that cause acute infection. Because of their immunogenicity and enrichment of pathogen molecules, exosomes may also have potential in vaccine preparations and as diagnostic markers. Additionally, the ability of exosomes to deliver molecules to recipient cells raises the possibility of their use for drug/therapy delivery. Thus, ExMVs play a major role in the pathogenesis of infection and provide exciting potential for the development of novel diagnostic and therapeutic approaches.
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752
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Flynn AD, Yin H. Lipid-Targeting Peptide Probes for Extracellular Vesicles. J Cell Physiol 2016; 231:2327-32. [PMID: 26909741 DOI: 10.1002/jcp.25354] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 02/19/2016] [Indexed: 12/13/2022]
Abstract
Extracellular vesicles released from cells are under intense investigation for their roles in cell-cell communication and cancer progression. However, individual vesicles have been difficult to probe as their small size renders them invisible by conventional light microscopy. However, as a consequence of their small size these vesicles possess highly curved lipid membranes that offer an unconventional target for curvature-sensing probes. In this article, we present a strategy for using peptide-based biosensors to detect highly curved membranes and the negatively charged membrane lipid phosphatidylserine, we delineate several assays used to validate curvature- and lipid-targeting mechanisms, and we explore potential applications in probing extracellular vesicles released from sources such as apoptotic cells, cancer cells, or activated platelets. J. Cell. Physiol. 231: 2327-2332, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Aaron D Flynn
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado.,BioFrontiers Institute, University of Colorado, Boulder, Colorado
| | - Hang Yin
- BioFrontiers Institute, University of Colorado, Boulder, Colorado.,Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado
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753
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McCotter SW, Horianopoulos LC, Kronstad JW. Regulation of the fungal secretome. Curr Genet 2016; 62:533-45. [DOI: 10.1007/s00294-016-0578-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Revised: 02/04/2016] [Accepted: 02/06/2016] [Indexed: 02/07/2023]
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754
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Klahn P, Brönstrup M. New Structural Templates for Clinically Validated and Novel Targets in Antimicrobial Drug Research and Development. Curr Top Microbiol Immunol 2016; 398:365-417. [PMID: 27704270 DOI: 10.1007/82_2016_501] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The development of bacterial resistance against current antibiotic drugs necessitates a continuous renewal of the arsenal of efficacious drugs. This imperative has not been met by the output of antibiotic research and development of the past decades for various reasons, including the declining efforts of large pharma companies in this area. Moreover, the majority of novel antibiotics are chemical derivatives of existing structures that represent mostly step innovations, implying that the available chemical space may be exhausted. This review negates this impression by showcasing recent achievements in lead finding and optimization of antibiotics that have novel or unexplored chemical structures. Not surprisingly, many of the novel structural templates like teixobactins, lysocin, griselimycin, or the albicidin/cystobactamid pair were discovered from natural sources. Additional compounds were obtained from the screening of synthetic libraries and chemical synthesis, including the gyrase-inhibiting NTBI's and spiropyrimidinetrione, the tarocin and targocil inhibitors of wall teichoic acid synthesis, or the boronates and diazabicyclo[3.2.1]octane as novel β-lactamase inhibitors. A motif that is common to most clinically validated antibiotics is that they address hotspots in complex biosynthetic machineries, whose functioning is essential for the bacterial cell. Therefore, an introduction to the biological targets-cell wall synthesis, topoisomerases, the DNA sliding clamp, and membrane-bound electron transport-is given for each of the leads presented here.
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Affiliation(s)
- Philipp Klahn
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany.
| | - Mark Brönstrup
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany.
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755
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Protection against Experimental Cryptococcosis following Vaccination with Glucan Particles Containing Cryptococcus Alkaline Extracts. mBio 2015; 6:e01905-15. [PMID: 26695631 PMCID: PMC4701832 DOI: 10.1128/mbio.01905-15] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
A vaccine capable of protecting at-risk persons against infections due to Cryptococcus neoformans and Cryptococcus gattii could reduce the substantial global burden of human cryptococcosis. Vaccine development has been hampered though, by lack of knowledge as to which antigens are immunoprotective and the need for an effective vaccine delivery system. We made alkaline extracts from mutant cryptococcal strains that lacked capsule or chitosan. The extracts were then packaged into glucan particles (GPs), which are purified Saccharomyces cerevisiae cell walls composed primarily of β-1,3-glucans. Subcutaneous vaccination with the GP-based vaccines provided significant protection against subsequent pulmonary infection with highly virulent strains of C. neoformans and C. gattii. The alkaline extract derived from the acapsular strain was analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS), and the most abundant proteins were identified. Separation of the alkaline extract by size exclusion chromatography revealed fractions that conferred protection when loaded in GP-based vaccines. Robust Th1- and Th17-biased CD4+ T cell recall responses were observed in the lungs of vaccinated and infected mice. Thus, our preclinical studies have indicated promising cryptococcal vaccine candidates in alkaline extracts delivered in GPs. Ongoing studies are directed at identifying the individual components of the extracts that confer protection and thus would be promising candidates for a human vaccine. The encapsulated yeast Cryptococcus neoformans and its closely related sister species, Cryptococcus gattii, are major causes of morbidity and mortality, particularly in immunocompromised persons. This study reports on the preclinical development of vaccines to protect at-risk populations from cryptococcosis. Antigens were extracted from Cryptococcus by treatment with an alkaline solution. The extracted antigens were then packaged into glucan particles, which are hollow yeast cell walls composed mainly of β-glucans. The glucan particle-based vaccines elicited robust T cell immune responses and protected mice from otherwise-lethal challenge with virulent strains of C. neoformans and C. gattii. The technology used for antigen extraction and subsequent loading into the glucan particle delivery system is relatively simple and can be applied to vaccine development against other pathogens.
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756
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Liévin-Le Moal V, Loiseau PM. Leishmania hijacking of the macrophage intracellular compartments. FEBS J 2015; 283:598-607. [PMID: 26588037 DOI: 10.1111/febs.13601] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 11/08/2015] [Accepted: 11/13/2015] [Indexed: 12/15/2022]
Abstract
Leishmania spp., transmitted to humans by the bite of the sandfly vector, are responsible for the three major forms of leishmaniasis, cutaneous, diffuse mucocutaneous and visceral. Leishmania spp. interact with membrane receptors of neutrophils and macrophages. In macrophages, the parasite is internalized within a parasitophorous vacuole and engages in a particular intracellular lifestyle in which the flagellated, motile Leishmania promastigote metacyclic form differentiates into non-motile, metacyclic amastigote form. This phenomenon is induced by Leishmania-triggered events leading to the fusion of the parasitophorous vacuole with vesicular members of the host cell endocytic pathway including recycling endosomes, late endosomes and the endoplasmic reticulum. Maturation of the parasitophorous vacuole leads to the intracellular proliferation of the Leishmania amastigote forms by acquisition of host cell nutrients while escaping host defense responses.
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Affiliation(s)
- Vanessa Liévin-Le Moal
- Anti-Parasitic Chemotherapy, Faculté de Pharmacie, CNRS, UMR 8076 BioCIS, Châtenay-Malabry, France.,Université Paris-Sud, Orsay, France.,Faculté de Pharmacie, Laboratory of Excellence in Research on Medication and Innovative Therapeutics (LabEx LERMIT), Châtenay-Malabry, France
| | - Philippe M Loiseau
- Anti-Parasitic Chemotherapy, Faculté de Pharmacie, CNRS, UMR 8076 BioCIS, Châtenay-Malabry, France.,Université Paris-Sud, Orsay, France.,Faculté de Pharmacie, Laboratory of Excellence in Research on Medication and Innovative Therapeutics (LabEx LERMIT), Châtenay-Malabry, France
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757
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Rodrigues ML, Godinho RMC, Zamith-Miranda D, Nimrichter L. Traveling into Outer Space: Unanswered Questions about Fungal Extracellular Vesicles. PLoS Pathog 2015; 11:e1005240. [PMID: 26633018 PMCID: PMC4669077 DOI: 10.1371/journal.ppat.1005240] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Marcio L Rodrigues
- Fundação Oswaldo Cruz (Fiocruz), Centro de Desenvolvimento Tecnológico em Saúde (CDTS), Rio de Janeiro, RJ, Brazil.,Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, RJ, Brazil
| | - Rodrigo M C Godinho
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, RJ, Brazil
| | - Daniel Zamith-Miranda
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, RJ, Brazil
| | - Leonardo Nimrichter
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, RJ, Brazil
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758
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Kabani M, Melki R. More than just trash bins? Potential roles for extracellular vesicles in the vertical and horizontal transmission of yeast prions. Curr Genet 2015; 62:265-70. [PMID: 26553335 PMCID: PMC4826420 DOI: 10.1007/s00294-015-0534-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 10/28/2015] [Accepted: 10/31/2015] [Indexed: 01/05/2023]
Abstract
In the yeast Saccharomyces cerevisiae, an ensemble of structurally and functionally diverse cytoplasmic proteins has the ability to form self-perpetuating protein aggregates (e.g. prions) which are the vectors of heritable non-Mendelian phenotypic traits. Whether harboring these prions is deleterious—akin to mammalian degenerative disorders—or beneficial—as epigenetic modifiers of gene expression—for yeasts has been intensely debated and strong arguments were made in support of both views. We recently reported that the yeast prion protein Sup35p is exported via extracellular vesicles (EV), both in its soluble and aggregated infectious states. Herein, we discuss the possible implications of this observation and propose several hypotheses regarding the roles of EV in both vertical and horizontal propagation of ‘good’ and ‘bad’ yeast prions.
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Affiliation(s)
- Mehdi Kabani
- Centre National de la Recherche Scientifique (CNRS), Paris-Saclay Institute of Neuroscience, Université Paris-Saclay, Bât. 32-33, Avenue de la Terrasse, 91190, Gif-sur-Yvette, France.
| | - Ronald Melki
- Centre National de la Recherche Scientifique (CNRS), Paris-Saclay Institute of Neuroscience, Université Paris-Saclay, Bât. 32-33, Avenue de la Terrasse, 91190, Gif-sur-Yvette, France.
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759
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Schwechheimer C, Kuehn MJ. Outer-membrane vesicles from Gram-negative bacteria: biogenesis and functions. Nat Rev Microbiol 2015; 13:605-19. [PMID: 26373371 PMCID: PMC5308417 DOI: 10.1038/nrmicro3525] [Citation(s) in RCA: 1106] [Impact Index Per Article: 122.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Outer-membrane vesicles (OMVs) are spherical buds of the outer membrane filled with periplasmic content and are commonly produced by Gram-negative bacteria. The production of OMVs allows bacteria to interact with their environment, and OMVs have been found to mediate diverse functions, including promoting pathogenesis, enabling bacterial survival during stress conditions and regulating microbial interactions within bacterial communities. Additionally, because of this functional versatility, researchers have begun to explore OMVs as a platform for bioengineering applications. In this Review, we discuss recent advances in the study of OMVs, focusing on new insights into the mechanisms of biogenesis and the functions of these vesicles.
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Affiliation(s)
- Carmen Schwechheimer
- Department of Biochemistry, Box 3711, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Meta J Kuehn
- Department of Biochemistry, Box 3711, Duke University Medical Center, Durham, North Carolina 27710, USA
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