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Rossi SA, García-Barbazán I, Chamorro-Herrero I, Taborda CP, Zaragoza Ó, Zambrano A. Use of 2D minilungs from human embryonic stem cells to study the interaction of Cryptococcus neoformans with the respiratory tract. Microbes Infect 2024; 26:105260. [PMID: 37981028 DOI: 10.1016/j.micinf.2023.105260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 11/09/2023] [Accepted: 11/16/2023] [Indexed: 11/21/2023]
Abstract
Organoids can meet the needs between the use of cell culture and in vivo work, bringing together aspects of multicellular tissues, providing a more similar in vitro system for the study of various components, including host-interactions with pathogens and drug response. Organoids are structures that resemble organs in vivo, originating from pluripotent stem cells (PSCs) or adult stem cells (ASCs). There is great interest in deepening the understanding of the use of this technology to produce information about fungal infections and their treatments. This work aims the use 2D human lung organoid derived from human embryonic stem cells (hESCs), to investigate Cryptococcus neoformans-host interactions. C. neoformans is an opportunistic fungus acquired by inhalation that causes systemic mycosis mainly in immunocompromised individuals. Our work highlights the suitability of human minilungs for the study of C. neoformans infection (adhesion, invasion and replication), the interaction with the surfactant and induction of the host's alveolar pro-inflammatory response.
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Affiliation(s)
- Suélen Andreia Rossi
- Biotechnology of Stem Cells and Organoids, Chronic Disease Program, Carlos III Health Institute, Madrid, Spain; Department of Microbiology, Biomedical Sciences Institute, University of São Paulo (USP), São Paulo, Brazil; Mycology Reference Laboratory, National Centre for Microbiology, Carlos III Health Institute, Madrid, Spain
| | - Irene García-Barbazán
- Mycology Reference Laboratory, National Centre for Microbiology, Carlos III Health Institute, Madrid, Spain
| | - Irene Chamorro-Herrero
- Biotechnology of Stem Cells and Organoids, Chronic Disease Program, Carlos III Health Institute, Madrid, Spain
| | - Carlos Pelleschi Taborda
- Department of Microbiology, Biomedical Sciences Institute, University of São Paulo (USP), São Paulo, Brazil; Tropical Medicine Institute, Department of Dermatology, Faculty of Medicine, University of São Paulo, São Paulo 05403-000, Brazil.
| | - Óscar Zaragoza
- Mycology Reference Laboratory, National Centre for Microbiology, Carlos III Health Institute, Madrid, Spain; Center for Biomedical Research in Network in Infectious Diseases (CIBERINFEC, Carlos III Health Institute, CB21/13/00105), Madrid, Spain.
| | - Alberto Zambrano
- Biotechnology of Stem Cells and Organoids, Chronic Disease Program, Carlos III Health Institute, Madrid, Spain.
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2
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Sonnberger J, Kasper L, Lange T, Brunke S, Hube B. "We've got to get out"-Strategies of human pathogenic fungi to escape from phagocytes. Mol Microbiol 2024; 121:341-358. [PMID: 37800630 DOI: 10.1111/mmi.15149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/08/2023] [Accepted: 08/16/2023] [Indexed: 10/07/2023]
Abstract
Human fungal pathogens are a deadly and underappreciated risk to global health that most severely affect immunocompromised individuals. A virulence attribute shared by some of the most clinically relevant fungal species is their ability to survive inside macrophages and escape from these immune cells. In this review, we discuss the mechanisms behind intracellular survival and elaborate how escape is mediated by lytic and non-lytic pathways as well as strategies to induce programmed host cell death. We also discuss persistence as an alternative to rapid host cell exit. In the end, we address the consequences of fungal escape for the host immune response and provide future perspectives for research and development of targeted therapies.
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Affiliation(s)
- Johannes Sonnberger
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, Jena, Germany
| | - Lydia Kasper
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, Jena, Germany
| | - Theresa Lange
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, Jena, Germany
| | - Sascha Brunke
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, Jena, Germany
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, Jena, Germany
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
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3
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Campuzano A, Hung CY, Wormley FL. Detection and Quantification of Cryptococcus Uptake by Phagocytic Cells Using Imaging Flow Cytometry. Methods Mol Biol 2024; 2775:195-209. [PMID: 38758319 DOI: 10.1007/978-1-0716-3722-7_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
Cryptococcus neoformans, the predominant etiological agent of cryptococcosis, is an encapsulated fungal pathogen found ubiquitously in the environment that causes pneumonia and life-threatening infections of the central nervous system. Following inhalation of yeasts or desiccated basidiospores into the lung alveoli, resident pulmonary phagocytic cells aid in the identification and eradication of Cryptococcus yeast through their arsenal of pattern recognition receptors (PRRs). PRRs recognize conserved pathogen-associated molecular patterns (PAMPs), such as branched mannans, β-glucans, and chitins that are the major components of the fungal cell wall. However, the key receptors/ligand interactions required for cryptococcal recognition and eventual fungal clearance have yet to be elucidated. Here we present an imaging flow cytometer (IFC) method that offers a novel quantitative cellular imaging and population statistics tool to accurately measure phagocytosis of fungal cells. It has the capacity to measure two distinct steps of phagocytosis: association/attachment and internalization in a high-throughput and quantitative manner that is difficult to achieve with other technologies. Results from these IFC studies allow for the potential to identify PRRs required for recognition, uptake, and subsequent activation of cytokine production, as well as other effector cell responses required for fungal clearance.
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Affiliation(s)
- Althea Campuzano
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX, USA
- South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX, USA
| | - Chiung-Yu Hung
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX, USA
- South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX, USA
| | - Floyd L Wormley
- South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX, USA.
- Department of Biology, Texas Christian University, Fort Worth, TX, USA.
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4
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Berguson HP, Caulfield LW, Price MS. Influence of Pathogen Carbon Metabolism on Interactions With Host Immunity. Front Cell Infect Microbiol 2022; 12:861405. [PMID: 35372116 PMCID: PMC8968422 DOI: 10.3389/fcimb.2022.861405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 02/24/2022] [Indexed: 11/22/2022] Open
Abstract
Cryptococcus neoformans is a ubiquitous opportunistic fungal pathogen typically causing disease in immunocompromised individuals and is globally responsible for about 15% of AIDS-related deaths annually. C. neoformans first causes pulmonary infection in the host and then disseminates to the brain, causing meningoencephalitis. The yeast must obtain and metabolize carbon within the host in order to survive in the central nervous system and cause disease. Communication between pathogen and host involves recognition of multiple carbon-containing compounds on the yeast surface: polysaccharide capsule, fungal cell wall, and glycosylated proteins comprising the major immune modulators. The structure and function of polysaccharide capsule has been studied for the past 70 years, emphasizing its role in virulence. While protected by the capsule, fungal cell wall has likewise been a focus of study for several decades for its role in cell integrity and host recognition. Associated with both of these major structures are glycosylated proteins, which exhibit known immunomodulatory effects. While many studies have investigated the role of carbon metabolism on virulence and survival within the host, the precise mechanism(s) affecting host-pathogen communication remain ill-defined. This review summarizes the current knowledge on mutants in carbon metabolism and their effect on the host immune response that leads to changes in pathogen recognition and virulence. Understanding these critical interactions will provide fresh perspectives on potential treatments and the natural history of cryptococcal disease.
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Affiliation(s)
- Hannah P. Berguson
- Department of Anatomical Sciences, Liberty University College of Osteopathic Medicine, Lynchburg, VA, United States
| | - Lauren W. Caulfield
- Department of Biology and Chemistry, Liberty University, Lynchburg, VA, United States
| | - Michael S. Price
- Department of Molecular and Cellular Sciences, Liberty University College of Osteopathic Medicine, Lynchburg, VA, United States
- Department of Medicine, Duke University School of Medicine, Durham, NC, United States
- *Correspondence: Michael S. Price,
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5
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Wang Q, Wang Q, Zhao Z, Fan J, Qin L, Alexander DB, Tsuda H, Zhao D, Xu J. Surfactant Proteins A/D-CD14 on Alveolar Macrophages Is a Common Pathway Associated With Phagocytosis of Nanomaterials and Cytokine Production. Front Immunol 2021; 12:758941. [PMID: 34777371 PMCID: PMC8578846 DOI: 10.3389/fimmu.2021.758941] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 10/07/2021] [Indexed: 12/12/2022] Open
Abstract
Alveolar macrophages are responsible for clearance of airborne dust and pathogens. How they recognize and phagocytose a variety of engineered nanomaterials (ENMs) with different properties is an important issue for safety assessment of ENMs. Surfactant-associated proteins, specifically existing in the pulmonary surfactant, are important opsonins for phagocytosis of airborne microorganisms. The purposes of the current study are to understand whether opsonization of ENMs by surfactant-associated proteins promotes phagocytosis of ENMs and cytokine production, and to determine whether a common pathway for phagocytosis of ENMs with different properties exists. For these purposes, four ENMs, MWCNT-7, TiO2, SiO2, and fullerene C60, with different shapes, sizes, chemical compositions, and surface reactivities, were chosen for this study. Short-term pulmonary exposure to MWCNT-7, TiO2, SiO2, and C60 induced inflammation in the rat lung, and most of the administered ENMs were phagocytosed by alveolar macrophages. The ENMs were phagocytosed by isolated primary alveolar macrophages (PAMs) in vitro, and phagocytosis was enhanced by rat bronchioalveolar lavage fluid (BALF), suggesting that proteins in the BALF were associated with phagocytosis. Analysis of proteins bound to the 4 ENMs by LC/MS indicated that surfactant-associated proteins A and D (SP-A, SP-D) were common binding proteins for all the 4 ENMs. Both BALF and SP-A, but not SP-D, enhanced TNF-α production by MWCNT-7 treated PAMs; BALF, SP-A, and SP-D increased IL-1β production in TiO2 and SiO2 treated PAMs; and BALF, SP-A, and SP-D enhanced IL-6 production in C60 treated PAMs. Knockdown of CD14, a receptor for SP-A/D, significantly reduced phagocytosis of ENMs and SP-A-enhanced cytokine production by PAMs. These results indicate that SP-A/D can opsonize all the test ENMs and enhance phagocytosis of the ENMs by alveolar macrophages through CD14, suggesting that SP-A/D-CD14 is a common pathway mediating phagocytosis of ENMs. Cytokine production induced by ENMs, however, is dependent on the type of ENM that is phagocytosed. Our results demonstrate a dual role for surfactant proteins as opsonins for both microbes and for inhaled dusts and fibers, including ENMs, allowing macrophages to recognize and remove the vast majority of these particles, thereby, greatly lessening their toxicity in the lung.
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Affiliation(s)
- Qiqi Wang
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China.,Department of Clinical Laboratory, Anhui General Hospital of Chinese People's Armed Police Forces, Hefei, China
| | - Qiong Wang
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Ziyue Zhao
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Jingbo Fan
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital, Anhui Medical University, Hefei, China
| | - Linghan Qin
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - David B Alexander
- Laboratory of Nanotoxicology Project, Nagoya City University, Nagoya, Japan
| | - Hiroyuki Tsuda
- Laboratory of Nanotoxicology Project, Nagoya City University, Nagoya, Japan
| | - Dahai Zhao
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital, Anhui Medical University, Hefei, China
| | - Jiegou Xu
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China.,Laboratory of Nanotoxicology Project, Nagoya City University, Nagoya, Japan
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Dellière S, Sze Wah Wong S, Aimanianda V. Soluble mediators in anti-fungal immunity. Curr Opin Microbiol 2020; 58:24-31. [PMID: 32604018 DOI: 10.1016/j.mib.2020.05.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/11/2020] [Accepted: 05/13/2020] [Indexed: 02/07/2023]
Abstract
Although soluble mediators of our innate immune system have a substantial impact on invading microbes, their role against fungal pathogens has been underexplored. Constituting the humoral immunity, soluble mediators comprise the complement system, collectins, acute-phase proteins, antibodies and antimicrobial peptides. These components can prevent fungal infection either by directly interacting with invading microbes, leading to their aggregation (microbistatic), destruction (microbicidal) or linking them to cellular immunity. The composition of soluble-mediator varies with human body-fluids, resulting in different antifungal mechanisms. Moreover, cellular immune system deploys both oxidative and non-oxidative mechanisms to destroy extracellular or internalized fungal pathogens; however, cellular immune activation is mainly influenced as well as regulated by soluble mediators. This review outlines the antifungal mechanism employed, directly or indirectly, by soluble mediators, and in response, the evading strategies of the fungal pathogens.
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Affiliation(s)
- Sarah Dellière
- Institut Pasteur, Molecular Mycology Unit, UMR2000, CNRS, Paris, France; Parasitology-Mycoloy Laboratory, Groupe Hospitalier Saint-Louis-Lariboisière-Fernand-Widal, Assistance Publique-Hôpitaux de Paris, Université de Paris, Paris, France
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7
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Madan T, Kishore U. Surfactant Protein D Recognizes Multiple Fungal Ligands: A Key Step to Initiate and Intensify the Anti-fungal Host Defense. Front Cell Infect Microbiol 2020; 10:229. [PMID: 32547959 PMCID: PMC7272678 DOI: 10.3389/fcimb.2020.00229] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 04/23/2020] [Indexed: 12/11/2022] Open
Abstract
With limited therapeutic options and associated severe adverse effects, fungal infections are a serious threat to human health. Innate immune response mediated by pattern recognition proteins is integral to host defense against fungi. A soluble pattern recognition protein, Surfactant protein D (SP-D), plays an important role in immune surveillance to detect and eliminate human pathogens. SP-D exerts its immunomodulatory activity via direct interaction with several receptors on the epithelial cells lining the mucosal tracts, as well as on innate and adaptive immune cells. Being a C-type lectin, SP-D shows calcium- and sugar-dependent interactions with several glycosylated ligands present on fungal cell walls. The interactome includes cell wall polysaccharides such as 1,3-β-D-glucan, 1,6-β-D-glucan, Galactosaminogalactan Galactomannan, Glucuronoxylomannan, Mannoprotein 1, and glycosylated proteins such as gp45, gp55, major surface glycoprotein complex (gpA). Recently, binding of a recombinant fragment of human SP-D to melanin on the dormant conidia of Aspergillus fumigatus was demonstrated that was not inhibited by sugars, suggesting a likely protein-protein interaction. Interactions of the ligands on the fungal spores with the oligomeric forms of full-length SP-D resulted in formation of spore-aggregates, increased uptake by phagocytes and rapid clearance besides a direct fungicidal effect against C. albicans. Exogenous administration of SP-D showed significant therapeutic potential in murine models of allergic and invasive mycoses. Altered susceptibility of SP-D gene-deficient mice to various fungal infections emphasized relevance of SP-D as an important sentinel of anti-fungal immunity. Levels of SP-D in the serum or lung lavage were significantly altered in the murine models and patients of fungal infections and allergies. Here, we review the cell wall ligands of clinically relevant fungal pathogens and allergens that are recognized by SP-D and their impact on the host defense. Elucidation of the molecular interactions between innate immune humoral such as SP-D and fungal pathogens would facilitate the development of novel therapeutic interventions.
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Affiliation(s)
- Taruna Madan
- Department of Innate Immunity, ICMR-National Institute for Research in Reproductive Health, Mumbai, India
| | - Uday Kishore
- Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
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8
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Zhang J, Tan SB, Guo ZG. CD47 decline in pancreatic islet cells promotes macrophage-mediated phagocytosis in type I diabetes. World J Diabetes 2020; 11:239-251. [PMID: 32547698 PMCID: PMC7284019 DOI: 10.4239/wjd.v11.i6.239] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 03/30/2020] [Accepted: 04/19/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Type I diabetes (T1D) is characterized by insulin loss caused by inflammatory cells that excessively infiltrate and destroy the pancreas, resulting in dysregulation of tissue homeostasis, mechanobiological properties, and the immune response. The streptozotocin (STZ)-induced mouse model exhibits multiple features of human T1D and enables mechanistic analysis of disease progression. However, the relationship between the mechanochemical signaling regulation of STZ-induced T1D and macrophage migration and phagocytosis is unclear.
AIM To study the mechanochemical regulation of STZ-induced macrophage response on pancreatic beta islet cells to gain a clearer understanding of T1D.
METHODS We performed experiments using different methods. We stimulated isolated pancreatic beta islet cells with STZ and then tested the macrophage migration and phagocytosis.
RESULTS In this study, we discovered that the integrin-associated surface factor CD47 played a critical role in immune defense in the STZ-induced T1D model by preventing pancreatic beta islet inflammation. In comparison with healthy mice, STZ-treated mice showed decreased levels of CD47 on islet cells and reduced interaction of CD47 with signal regulatory protein α (SIRPα), which negatively regulates macrophage-mediated phagocytosis. This resulted in weakened islet cell immune defense and promoted macrophage migration and phagocytosis of target inflammatory cells. Moreover, lipopolysaccharide-activated human acute monocytic leukemia THP-1 cells also exhibited enhanced phagocytosis in the STZ-treated islets, and the aggressive attack of the inflammatory islets correlated with impaired CD47-SIRPα interactions. In addition, CD47 overexpression rescued the pre-labeled targeted cells.
CONCLUSION This study indicates that CD47 deficiency promotes the migration and phagocytosis of macrophages and provides mechanistic insights into T1D by associating the interactions between membrane structures and inflammatory disease progression.
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Affiliation(s)
- Jing Zhang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210097, Jiangsu Province, China
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, United States
| | - Su-Bee Tan
- National Key Laboratory for Biochemistry, College of Life Sciences, Nanjing University, Nanjing 210093, Jiangsu Province, China
| | - Zhi-Gang Guo
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210097, Jiangsu Province, China
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Alkwai H, Aboelnaga SM, Hussain RA, Khatoon F. SURFACTANT PROTEIN D LEVELS WITH OBESITY AND TYPE 2 DIABETES MELLITUS. GOMAL JOURNAL OF MEDICAL SCIENCES 2020. [DOI: 10.46903/gjms/18.01.2080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Surfactant protein D (SP-D) is an important component of pulmonary innate immunity. It is mainly produced by type 2 alveolar and bronchial epithelial cells, but is also found in extra pulmonary tissues and blood. It acts as a primary host defense against inhaled microorganisms. It also enhances adaptive immunity by activating T cells. SP-D deficiency can lead to upper and lower respiratory tract infections.
Obesity has reached global epidemic proportions in both adults and children and is associated with numerous co-morbidities and insulin resistance. Type 2 diabetes & obesity are highly associated with recurrent pulmonary & extra pulmonary infections.
The primary objective of this study was to determine the association of serum surfactant protein D levels with obesity and type 2 diabetes mellitus.
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10
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Murugaiah V, Tsolaki AG, Kishore U. Collectins: Innate Immune Pattern Recognition Molecules. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1204:75-127. [PMID: 32152944 PMCID: PMC7120701 DOI: 10.1007/978-981-15-1580-4_4] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Collectins are collagen-containing C-type (calcium-dependent) lectins which are important pathogen pattern recognising innate immune molecules. Their primary structure is characterised by an N-terminal, triple-helical collagenous region made up of Gly-X-Y repeats, an a-helical coiled-coil trimerising neck region, and a C-terminal C-type lectin or carbohydrate recognition domain (CRD). Further oligomerisation of this primary structure can give rise to more complex and multimeric structures that can be seen under electron microscope. Collectins can be found in serum as well as in a range of tissues at the mucosal surfaces. Mannanbinding lectin can activate the complement system while other members of the collectin family are extremely versatile in recognising a diverse range of pathogens via their CRDs and bring about effector functions designed at the clearance of invading pathogens. These mechanisms include opsonisation, enhancement of phagocytosis, triggering superoxidative burst and nitric oxide production. Collectins can also potentiate the adaptive immune response via antigen presenting cells such as macrophages and dendritic cells through modulation of cytokines and chemokines, thus they can act as a link between innate and adaptive immunity. This chapter describes the structure-function relationships of collectins, their diverse functions, and their interaction with viruses, bacteria, fungi and parasites.
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Affiliation(s)
- Valarmathy Murugaiah
- College of Health and Life Sciences, Brunel University London, London, UB8 3PH, UK
| | - Anthony G Tsolaki
- College of Health and Life Sciences, Brunel University London, London, UB8 3PH, UK
| | - Uday Kishore
- College of Health and Life Sciences, Brunel University London, London, UB8 3PH, UK.
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11
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Lopes JP, Stylianou M, Backman E, Holmberg S, Ekoff M, Nilsson G, Urban CF. Cryptococcus neoformans Induces MCP-1 Release and Delays the Death of Human Mast Cells. Front Cell Infect Microbiol 2019; 9:289. [PMID: 31456952 PMCID: PMC6700240 DOI: 10.3389/fcimb.2019.00289] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 07/26/2019] [Indexed: 01/09/2023] Open
Abstract
Cryptococcosis, caused by the basidiomycete Cryptococcus neoformans, is a life-threatening disease affecting approximately one million people per year worldwide. Infection can occur when C. neoformans cells are inhaled by immunocompromised people. In order to establish infection, the yeast must bypass recognition and clearance by immune cells guarding the tissue. Using in vitro infections, we characterized the role of mast cells (MCs) in cryptococcosis. We found that MCs recognize C. neoformans and release inflammatory mediators such as tryptase and cytokines. From the latter group MCs released mainly CCL-2/MCP-1, a strong chemoattractant for monocytic cells. We demonstrated that supernatants of infected MCs recruit monocytes but not neutrophils. During infection with C. neoformans, MCs have a limited ability to kill the yeast depending on the serotype. C. neoformans, in turn, modulates the lifespan of MCs both, by presence of its polysaccharide capsule and by secreting soluble modulators. Taken together, MCs might have important contributions to fungal clearance during early stages of cryptocococis where these cells regulate recruitment of monocytes to mucosal tissues.
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Affiliation(s)
- José Pedro Lopes
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden.,Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden.,Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - Marios Stylianou
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden.,Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden.,Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - Emelie Backman
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden.,Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden.,Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - Sandra Holmberg
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden.,Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden.,Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - Maria Ekoff
- Immunology and Allergy Division, Department of Medicine Solna, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Gunnar Nilsson
- Immunology and Allergy Division, Department of Medicine Solna, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Constantin F Urban
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden.,Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden.,Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
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12
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Abstract
Respiratory fungal infection is a severe clinical problem, especially in patients with compromised immune functions. Aspergillus, Cryptococcus, Pneumocystis, and endemic fungi are major pulmonary fungal pathogens that are able to result in life-threatening invasive diseases. Growing data being reported have indicated that multiple cells and molecules orchestrate the host's response to a fungal infection in the lung. Upon fungal challenge, innate myeloid cells including macrophages, dendritic cells (DC), and recruited neutrophils establish the first line of defense through the phagocytosis and secretion of cytokines. Natural killer cells control the fungal expansion in the lung via the direct and indirect killing of invading organisms. Adaptive immune cells including Th1 and Th17 cells confer anti-fungal activity by producing their signature cytokines, interferon-γ, and IL-17. In addition, lung epithelial cells (LEC) also participate in the resistance against fungal infection by internalization, inflammatory cytokine production, or antimicrobial peptide secretion. In the host cells mentioned above, various molecules with distinct functions modulate the immune defense signaling: Pattern recognition receptors (PRRs) such as dectin-1 expressed on the cell surface are involved in fungal recognition; adaptor proteins such as MyD88 and TRAF6 are required for transduction of signals to the nucleus for transcriptional regulation; inflammasomes also play crucial roles in the host's defense against a fungal infection in the lung. Furthermore, transcriptional factors modulate the transcriptions of a series of genes, especially those encoding cytokines and chemokines, which are predominant regulators in the infectious microenvironment, mediating the cellular and molecular immune responses against a fungal infection in the lung.
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Affiliation(s)
- Zhi Li
- The Joint Center for Infection and Immunity, Guangzhou Women and Children's Medical Center, Guangzhou Institute of Pediatrics, Guangzhou, China
- The Joint Center for Infection and Immunity, Institute Pasteur of Shanghai, Chinese Academy of Science, Shanghai, China
| | - Gen Lu
- The Joint Center for Infection and Immunity, Guangzhou Women and Children's Medical Center, Guangzhou Institute of Pediatrics, Guangzhou, China
| | - Guangxun Meng
- The Joint Center for Infection and Immunity, Institute Pasteur of Shanghai, Chinese Academy of Science, Shanghai, China
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13
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Chang AL, Hole CR, Doering TL. An Automated Assay to Measure Phagocytosis of Cryptococcus neoformans. ACTA ACUST UNITED AC 2019; 53:e79. [PMID: 30802005 DOI: 10.1002/cpmc.79] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cryptococcus neoformans is an opportunistic fungal pathogen that causes meningoencephalitis, which kills 200,000 individuals worldwide each year. It is ubiquitous in the environment and is first inhaled into the lungs of the host, where it is taken up by phagocytes. The interaction of these fungal cells with host phagocytes, therefore, is a critical step in the pathogenesis of this disease. One characteristic of this initial step in host-pathogen interactions is the avidity with which fungal cells are taken up by phagocytes, described by the phagocytic index. In this chapter, we detail a high-throughput method of directly assessing the phagocytic index of fungal cells using an imaging-based paradigm. By automating image collection and processing, this method permits rapid assessment of this critical host interaction. © 2019 by John Wiley & Sons, Inc.
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14
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Childers DS, Avelar GM, Bain JM, Larcombe DE, Pradhan A, Budge S, Heaney H, Brown AJP. Impact of the Environment upon the Candida albicans Cell Wall and Resultant Effects upon Immune Surveillance. Curr Top Microbiol Immunol 2019; 425:297-330. [PMID: 31781866 DOI: 10.1007/82_2019_182] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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 volume and the transit of large liposomal particles such as extracellular vesicles. The fungal cell wall is also flexible in that it adapts to local environmental inputs, thereby enhancing the fitness of the fungus in these microenvironments. Recent evidence indicates that this cell wall adaptation affects host-fungus interactions by altering the exposure of major cell wall epitopes that are recognised by innate immune cells. Therefore, we discuss the impact of environmental adaptation upon fungal cell wall structure, and how this affects immune recognition, focussing on C. albicans and drawing parallels with other fungal pathogens.
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Affiliation(s)
- Delma S Childers
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Gabriela M Avelar
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Judith M Bain
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Daniel E Larcombe
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
- Medical Research Council Centre for Medical Mycology, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
| | - Arnab Pradhan
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
- Medical Research Council Centre for Medical Mycology, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
| | - Susan Budge
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Helen Heaney
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Alistair J P Brown
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
- Medical Research Council Centre for Medical Mycology, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK.
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15
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Goyal S, Castrillón-Betancur JC, Klaile E, Slevogt H. The Interaction of Human Pathogenic Fungi With C-Type Lectin Receptors. Front Immunol 2018; 9:1261. [PMID: 29915598 PMCID: PMC5994417 DOI: 10.3389/fimmu.2018.01261] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 05/18/2018] [Indexed: 01/19/2023] Open
Abstract
Fungi, usually present as commensals, are a major cause of opportunistic infections in immunocompromised patients. Such infections, if not diagnosed or treated properly, can prove fatal. However, in most cases healthy individuals are able to avert the fungal attacks by mounting proper antifungal immune responses. Among the pattern recognition receptors (PRRs), C-type lectin receptors (CLRs) are the major players in antifungal immunity. CLRs can recognize carbohydrate ligands, such as β-glucans and mannans, which are mainly found on fungal cell surfaces. They induce proinflammatory immune reactions, including phagocytosis, oxidative burst, cytokine, and chemokine production from innate effector cells, as well as activation of adaptive immunity via Th17 responses. CLRs such as Dectin-1, Dectin-2, Mincle, mannose receptor (MR), and DC-SIGN can recognize many disease-causing fungi and also collaborate with each other as well as other PRRs in mounting a fungi-specific immune response. Mutations in these receptors affect the host response and have been linked to a higher risk in contracting fungal infections. This review focuses on how CLRs on various immune cells orchestrate the antifungal response and on the contribution of single nucleotide polymorphisms in these receptors toward the risk of developing such infections.
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Affiliation(s)
- Surabhi Goyal
- Institute for Microbiology and Hygiene, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Septomics Research Center, Jena University Hospital, Jena, Germany
| | - Juan Camilo Castrillón-Betancur
- Septomics Research Center, Jena University Hospital, Jena, Germany.,International Leibniz Research School for Microbial and Biomolecular Interactions, Leibniz Institute for Natural Product Research and Infection Biology/Hans Knöll Institute, Jena, Germany
| | - Esther Klaile
- Septomics Research Center, Jena University Hospital, Jena, Germany
| | - Hortense Slevogt
- Septomics Research Center, Jena University Hospital, Jena, Germany
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16
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17
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Sorensen GL. Surfactant Protein D in Respiratory and Non-Respiratory Diseases. Front Med (Lausanne) 2018; 5:18. [PMID: 29473039 PMCID: PMC5809447 DOI: 10.3389/fmed.2018.00018] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 01/19/2018] [Indexed: 12/16/2022] Open
Abstract
Surfactant protein D (SP-D) is a multimeric collectin that is involved in innate immune defense and expressed in pulmonary, as well as non-pulmonary, epithelia. SP-D exerts antimicrobial effects and dampens inflammation through direct microbial interactions and modulation of host cell responses via a series of cellular receptors. However, low protein concentrations, genetic variation, biochemical modification, and proteolytic breakdown can induce decomposition of multimeric SP-D into low-molecular weight forms, which may induce pro-inflammatory SP-D signaling. Multimeric SP-D can decompose into trimeric SP-D, and this process, and total SP-D levels, are partly determined by variation within the SP-D gene, SFTPD. SP-D has been implicated in the development of respiratory diseases including respiratory distress syndrome, bronchopulmonary dysplasia, allergic asthma, and chronic obstructive pulmonary disease. Disease-induced breakdown or modifications of SP-D facilitate its systemic leakage from the lung, and circulatory SP-D is a promising biomarker for lung injury. Moreover, studies in preclinical animal models have demonstrated that local pulmonary treatment with recombinant SP-D is beneficial in these diseases. In recent years, SP-D has been shown to exert antimicrobial and anti-inflammatory effects in various non-pulmonary organs and to have effects on lipid metabolism and pro-inflammatory effects in vessel walls, which enhance the risk of atherosclerosis. A common SFTPD polymorphism is associated with atherosclerosis and diabetes, and SP-D has been associated with metabolic disorders because of its effects in the endothelium and adipocytes and its obesity-dampening properties. This review summarizes and discusses the reported genetic associations of SP-D with disease and the clinical utility of circulating SP-D for respiratory disease prognosis. Moreover, basic research on the mechanistic links between SP-D and respiratory, cardiovascular, and metabolic diseases is summarized. Perspectives on the development of SP-D therapy are addressed.
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Affiliation(s)
- Grith L Sorensen
- Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
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18
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Ordonez SR, Veldhuizen EJA, van Eijk M, Haagsman HP. Role of Soluble Innate Effector Molecules in Pulmonary Defense against Fungal Pathogens. Front Microbiol 2017; 8:2098. [PMID: 29163395 PMCID: PMC5671533 DOI: 10.3389/fmicb.2017.02098] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 10/12/2017] [Indexed: 12/21/2022] Open
Abstract
Fungal infections of the lung are life-threatening but rarely occur in healthy, immunocompetent individuals, indicating efficient clearance by pulmonary defense mechanisms. Upon inhalation, fungi will first encounter the airway surface liquid which contains several soluble effector molecules that form the first barrier of defense against fungal infections. These include host defense peptides, like LL-37 and defensins that can neutralize fungi by direct killing of the pathogen, and collectins, such as surfactant protein A and D, that can aggregate fungi and stimulate phagocytosis. In addition, these molecules have immunomodulatory activities which can aid in fungal clearance from the lung. However, existing observations are based on in vitro studies which do not reflect the complexity of the lung and its airway surface liquid. Ionic strength, pH, and the presence of mucus can have strong detrimental effects on antifungal activity, while the potential synergistic interplay between soluble effector molecules is largely unknown. In this review, we describe the current knowledge on soluble effector molecules that contribute to antifungal activity, the importance of environmental factors and discuss the future directions required to understand the innate antifungal defense in the lung.
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Affiliation(s)
- Soledad R Ordonez
- Division of Molecular Host Defence, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Edwin J A Veldhuizen
- Division of Molecular Host Defence, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Martin van Eijk
- Division of Molecular Host Defence, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Henk P Haagsman
- Division of Molecular Host Defence, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
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19
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Taylor-Smith LM. Cryptococcus-Epithelial Interactions. J Fungi (Basel) 2017; 3:jof3040053. [PMID: 29371569 PMCID: PMC5753155 DOI: 10.3390/jof3040053] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 09/28/2017] [Accepted: 09/30/2017] [Indexed: 12/12/2022] Open
Abstract
The fungal pathogen, Cryptococcus neoformans, causes devastating levels of morbidity and mortality. Infections with this fungus tend to be predominantly in immunocompromised individuals, such as those with HIV. Infections initiate with inhalation of cryptococcal cells and entry of the pathogen into the lungs. The bronchial epithelial cells of the upper airway and the alveolar epithelial cells of the lower airway are likely to be the first host cells that Cryptococcus engage with. Thus the interaction of cryptococci and the respiratory epithelia will be the focus of this review. C. neoformans has been shown to adhere to respiratory epithelial cells, although if the role of the capsule is in aiding or hindering this adhesion is debatable. The epithelia are also able to react to cryptococci with the release of cytokines and chemokines to start the immune response to this invading pathogen. The activity of surfactant components that line this mucosal barrier towards Cryptococcus and the metabolic and transcriptional reaction of cryptococci when encountering epithelial cells will also be discussed.
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Affiliation(s)
- Leanne M Taylor-Smith
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, West Midlands, UK.
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20
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Abstract
Cryptococcus species are encapsulated fungi found in the environment that predominantly cause disease in immunocompromised hosts after inhalation into the lungs. Even with contemporary antifungal regimens, patients with cryptococcosis continue to have high morbidity and mortality rates. The development of more effective therapies may depend on our understanding of the cellular and molecular mechanisms by which the host promotes sterilizing immunity against the fungus. This review will highlight our current knowledge of how Cryptococcus, primarily the species C. neoformans, is sensed by the mammalian host and how subsequent signaling pathways direct the anti-cryptococcal response by effector cells of the innate immune system.
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Affiliation(s)
- Lena J Heung
- Infectious Diseases Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
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21
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Heyen L, Müller U, Siegemund S, Schulze B, Protschka M, Alber G, Piehler D. Lung epithelium is the major source of IL-33 and is regulated by IL-33-dependent and IL-33-independent mechanisms in pulmonary cryptococcosis. Pathog Dis 2016; 74:ftw086. [DOI: 10.1093/femspd/ftw086] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2016] [Indexed: 01/08/2023] Open
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22
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Carreto-Binaghi LE, Aliouat EM, Taylor ML. Surfactant proteins, SP-A and SP-D, in respiratory fungal infections: their role in the inflammatory response. Respir Res 2016; 17:66. [PMID: 27250970 PMCID: PMC4888672 DOI: 10.1186/s12931-016-0385-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 05/25/2016] [Indexed: 12/20/2022] Open
Abstract
Pulmonary surfactant is a complex fluid that comprises phospholipids and four proteins (SP-A, SP-B, SP-C, and SP-D) with different biological functions. SP-B, SP-C, and SP-D are essential for the lungs’ surface tension function and for the organization, stability and metabolism of lung parenchyma. SP-A and SP-D, which are also known as pulmonary collectins, have an important function in the host’s lung immune response; they act as opsonins for different pathogens via a C-terminal carbohydrate recognition domain and enhance the attachment to phagocytic cells or show their own microbicidal activity by increasing the cellular membrane permeability. Interactions between the pulmonary collectins and bacteria or viruses have been extensively studied, but this is not the same for fungal pathogens. SP-A and SP-D bind glucan and mannose residues from fungal cell wall, but there is still a lack of information on their binding to other fungal carbohydrate residues. In addition, both their relation with immune cells for the clearance of these pathogens and the role of surfactant proteins’ regulation during respiratory fungal infections remain unknown. Here we highlight the relevant findings associated with SP-A and SP-D in those respiratory mycoses where the fungal infective propagules reach the lungs by the airways.
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Affiliation(s)
- Laura Elena Carreto-Binaghi
- Laboratorio de Inmunología de Hongos, Unidad de Micología, Departamento de Microbiología-Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM); Circuito Interior, Ciudad Universitaria, Av. Universidad 3000, México, D.F., 04510, Mexico
| | - El Moukhtar Aliouat
- Laboratoire Biologie et Diversité des Pathogènes Eucaryotes Emergents, CIIL Institut Pasteur de Lille, Bâtiment Guérin, 1 rue du Professeur Calmette, Lille, France
| | - Maria Lucia Taylor
- Laboratorio de Inmunología de Hongos, Unidad de Micología, Departamento de Microbiología-Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM); Circuito Interior, Ciudad Universitaria, Av. Universidad 3000, México, D.F., 04510, Mexico.
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23
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DeLeon-Rodriguez CM, Casadevall A. Cryptococcus neoformans: Tripping on Acid in the Phagolysosome. Front Microbiol 2016; 7:164. [PMID: 26925039 PMCID: PMC4756110 DOI: 10.3389/fmicb.2016.00164] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 02/01/2016] [Indexed: 01/10/2023] Open
Abstract
Cryptococcus neoformans (Cn) is a basidiomycetous pathogenic yeast that is a frequent cause of meningoencephalitis in immunocompromised individuals. Cn is a facultative intracellular pathogen in mammals, insects and amoeba. Cn infection occurs after inhalation of spores or desiccated cells from the environment. After inhalation Cn localizes to the lungs where it can be phagocytosed by alveolar macrophages. Cn is surrounded by a polysaccharide capsule that helps the fungus survive in vivo by interfering with phagocytosis, quenching free radical bursts and shedding polysaccharides that negatively modulates the immune system. After phagocytosis, Cn resides within the phagosome that matures to become a phagolysosome, a process that results in the acidification of the phagolysosomal lumen. Cn replicates at a higher rate inside macrophages than in the extracellular environment, possibly as a result that the phagosomal pH is near that optimal for growth. Cn increases the phagolysosomal pH and modulates the dynamics of Rab GTPases interaction with the phagolysosome. Chemical manipulation of the phagolysosomal pH with drugs can result in direct and indirect killing of Cn and reduced non-lytic exocytosis. Phagolysosomal membrane damage after Cn infection occurs both in vivo and in vitro, and is required for Cn growth and survival. Macrophage treatment with IFN-γ reduces the phagolysosomal damage and increases intracellular killing of Cn. Studies on mice and humans show that treatment with IFN-γ can improve host control of the disease. However, the mechanism by which Cn mediates phagolysosomal membrane damage remains unknown but likely candidates are phospholipases and mechanical damage from an enlarging capsule. Here we review Cn intracellular interaction with a particular emphasis on phagosomal interactions and develop the notion that the extent of damage of the phagosomal membrane is a key determinant of the outcome of the Cn-macrophage interaction.
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Affiliation(s)
| | - Arturo Casadevall
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, BronxNY, USA; Department of Molecular Microbiology and Immunology, Johns Hopkins University School of Public Health, BaltimoreMD, USA
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24
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Jiang Z, Zhu L. Update on molecular mechanisms of corticosteroid resistance in chronic obstructive pulmonary disease. Pulm Pharmacol Ther 2016; 37:1-8. [PMID: 26805715 DOI: 10.1016/j.pupt.2016.01.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 01/14/2016] [Accepted: 01/20/2016] [Indexed: 12/24/2022]
Abstract
Chronic obstructive pulmonary disease (COPD) is an inflammatory and irreversible pulmonary disorder that is characterized by inflammation and airway destruction. In recent years, COPD has become a global epidemic due to increased air pollution and exposure to cigarette smoke. Current therapeutics using bronchiodialator and anti-inflammatory corticosteroids are most widely used for all patients with persistent COPD, but these approaches are disappointing due to limited improvement in symptom control and survival rate. More importantly, a certain number of COPD patients are resistant to the corticosteroid treatment and their symptoms worsen. Therefore, more effective anti-inflammatory drugs and combinational treatment are required. Understanding of the underlying molecular and immunological mechanisms is critical to developing new therapeutics. Lung inflammation and the released pro-inflammatory cytokines affect glucocorticoid receptor (GR), histone deacetylase 2 (HDAC2) and surfactant protein D (SP-D) activities in many cell types. Macrophages, neutrophils, airway epithelial cells and lymphocytes are involved in the induction of corticosteroid resistance. This review updated the recent advances in molecular and immunological mechanisms of steroid resistance among patients and animal models with COPD. Meanwhile we discussed novel therapeutic approaches in controlling lung inflammation and improving corticosteroid sensitivity among the steroid resistant patients with COPD.
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Affiliation(s)
- Zhilong Jiang
- Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, 180 Feng Lin Road, Shanghai 200032, China.
| | - Lei Zhu
- Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, 180 Feng Lin Road, Shanghai 200032, China.
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25
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Zhang M, Sun D, Shi M. Dancing cheek to cheek: Cryptococcus neoformans and phagocytes. SPRINGERPLUS 2015; 4:410. [PMID: 26266081 PMCID: PMC4531118 DOI: 10.1186/s40064-015-1192-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 07/29/2015] [Indexed: 01/04/2023]
Abstract
Meningoencephalitis caused by Cryptococcus neoformans (Cn) has become one of the leading causes of mortality in AIDS patients. Understanding the interactions between Cn and phagocytes is fundamental in exploring the pathogenicity of cryptococcal meningoencephalitis. Cn may be extracellular or contained in the monocytes, macrophages, neutrophils, dendritic cells and even endothelial cells. The internalized Cn may proliferate inside the host cells, or cause the lysis of host cells, or leave the host cells via non-lytic exocytosis, or even hijack the host cells (Trojan horse) for the brain dissemination, which are regulated by microbe factors and also immune molecules. Coexistence of protective and deleterious roles of phagocytes in the progression of cryptococcosis warrant further investigation.
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Affiliation(s)
- Mingshun Zhang
- Division of Immunology, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD USA ; Department of Immunology, Nanjing Medical University, Nanjing, Jiangsu China
| | - Donglei Sun
- Division of Immunology, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD USA
| | - Meiqing Shi
- Division of Immunology, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD USA
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26
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Heteroresistance to Itraconazole Alters the Morphology and Increases the Virulence of Cryptococcus gattii. Antimicrob Agents Chemother 2015; 59:4600-9. [PMID: 26014951 DOI: 10.1128/aac.00466-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 05/14/2015] [Indexed: 12/22/2022] Open
Abstract
Cryptococcus gattii is the main etiological agent of cryptococcosis in immunocompetent individuals. The triazole drug itraconazole is one of the antifungals used to treat patients with cryptococcosis. Heteroresistance is an adaptive mechanism to counteract the stress of increasing drug concentrations, and it can enhance the ability of a microorganism to survive under antifungal pressure. In this study, we evaluated the ability of 11 C. gattii strains to develop itraconazole heteroresistance. Heteroresistant clones were analyzed for drug susceptibility, alterations in cell diameter, capsule properties, and virulence in a murine model. Heteroresistance to itraconazole was intrinsic in all of the strains analyzed, reduced both the capsule size and the cell diameter, induced molecular heterogeneity at the chromosomal level, changed the negatively charged cells, reduced ergosterol content, and improved the antioxidant system. A positive correlation between surface/volume ratio of original cells and the level of heteroresistance to itraconazole (LHI) was observed in addition to a negative correlation between capsule size of heteroresistant clones and LHI. Moreover, heteroresistance to itraconazole increased the engulfment of C. gattii by macrophages and augmented fungal proliferation inside these cells, which probably accounted for the reduced survival of the mice infected with the heteroresistant clones and the higher fungal burden in lungs and brain. Our results indicate that heteroresistance to itraconazole is intrinsic and increases the virulence of C. gattii. This phenomenon may represent an additional mechanism that contributes to relapses of cryptococcosis in patients during itraconazole therapy.
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27
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Ledford JG, Addison KJ, Foster MW, Que LG. Eosinophil-associated lung diseases. A cry for surfactant proteins A and D help? Am J Respir Cell Mol Biol 2015; 51:604-14. [PMID: 24960334 DOI: 10.1165/rcmb.2014-0095tr] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Surfactant proteins (SP)-A and SP-D (SP-A/-D) play important roles in numerous eosinophil-dominated diseases, including asthma, allergic bronchopulmonary aspergillosis, and allergic rhinitis. In these settings, SP-A/-D have been shown to modulate eosinophil chemotaxis, inhibit eosinophil mediator release, and mediate macrophage clearance of apoptotic eosinophils. Dysregulation of SP-A/-D function in eosinophil-dominated diseases is also not uncommon. Alterations in serum SP-A/-D levels are associated with disease severity in allergic rhinitis and chronic obstructive pulmonary disease. Furthermore, oligimerization of SP-A/-D, necessary for their proper function, can be perturbed by reactive nitrogen species, which are increased in eosinophilic disease. In this review, we highlight the associations of eosinophilic lung diseases with SP-A and SP-D levels and functions.
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Affiliation(s)
- Julie G Ledford
- 1 Department of Medicine, Division of Pulmonary, Allergy and Critical Care, and
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28
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Gibson JF, Johnston SA. Immunity to Cryptococcus neoformans and C. gattii during cryptococcosis. Fungal Genet Biol 2014; 78:76-86. [PMID: 25498576 PMCID: PMC4503824 DOI: 10.1016/j.fgb.2014.11.006] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Revised: 11/25/2014] [Accepted: 11/29/2014] [Indexed: 10/25/2022]
Abstract
The vast majority of infection with cryptococcal species occurs with Cryptococcus neoformans in the severely immunocompromised. A significant exception to this is the infections of those with apparently normal immune systems by Cryptococcus gattii. Susceptibility to cryptococcosis can be broadly categorised as a defect in adaptive immune responses, especially in T cell immunity. However, innate immune cells such as macrophages play a key role and are likely the primary effector cell in the killing and ultimate clearance of cryptococcal infection. In this review we discuss the current state of our understanding of how the immune system responds to cryptococcal infection in health and disease, with reference to the work communicated at the 9th International Conference on Cryptococcus and Cryptococcosis (ICCC9). We have focussed on cell mediated responses, particularly early in infection, but with the aim of presenting a broad overview of our understanding of immunity to cryptococcal infection, highlighting some recent advances and offering some perspectives on future directions.
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Affiliation(s)
- Josie F Gibson
- Department of Infection and Immunity, Medical School, University of Sheffield, S10 2RX, UK; Bateson Centre, Department of Biomedical Sciences, University of Sheffield, S10 2TN, UK
| | - Simon A Johnston
- Department of Infection and Immunity, Medical School, University of Sheffield, S10 2RX, UK; Bateson Centre, Department of Biomedical Sciences, University of Sheffield, S10 2TN, UK.
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29
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Dectin-2 deficiency promotes Th2 response and mucin production in the lungs after pulmonary infection with Cryptococcus neoformans. Infect Immun 2014; 83:671-81. [PMID: 25422263 DOI: 10.1128/iai.02835-14] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dectin-2 is a C-type lectin receptor that recognizes high mannose polysaccharides. Cryptococcus neoformans, a yeast-form fungal pathogen, is rich in polysaccharides in its cell wall and capsule. In the present study, we analyzed the role of Dectin-2 in the host defense against C. neoformans infection. In Dectin-2 gene-disrupted (knockout) (Dectin-2KO) mice, the clearance of this fungus and the inflammatory response, as shown by histological analysis and accumulation of leukocytes in infected lungs, were comparable to those in wild-type (WT) mice. The production of type 2 helper T (Th2) cytokines in lungs was higher in Dectin-2KO mice than in WT mice after infection, whereas there was no difference in the levels of production of Th1, Th17, and proinflammatory cytokines between these mice. Mucin production was significantly increased in Dectin-2KO mice, and this increase was reversed by administration of anti-interleukin 4 (IL-4) monoclonal antibody (MAb). The levels of expression of β1-defensin, cathelicidin, surfactant protein A (Sp-A), and Sp-D in infected lungs were comparable between these mice. In in vitro experiments, IL-12p40 and tumor necrosis factor alpha (TNF-α) production and expression of CD86 and major histocompatibility complex (MHC) class II by bone marrow-derived dendritic cells and alveolar macrophages were completely abrogated in Dectin-2KO mice. Finally, the disrupted lysates of C. neoformans, but not of whole yeast cells, activated Dectin-2-triggered signaling in an assay with nuclear factor of activated T cells (NFAT)-green fluorescent protein (GFP) reporter cells expressing this receptor. These results suggest that Dectin-2 may oppose the Th2 response and IL-4-dependent mucin production in the lungs after infection with C. neoformans, and it may not be required for the production of Th1, Th17, and proinflammatory cytokines or for clearance of this fungal pathogen.
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30
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Grimm MJ, D'Auria AC, Segal BH. Assessing anti-fungal activity of isolated alveolar macrophages by confocal microscopy. J Vis Exp 2014. [PMID: 25045941 DOI: 10.3791/51678] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The lung is an interface where host cells are routinely exposed to microbes and microbial products. Alveolar macrophages are the first-line phagocytic cells that encounter inhaled fungi and other microbes. Macrophages and other immune cells recognize Aspergillus motifs by pathogen recognition receptors and initiate downstream inflammatory responses. The phagocyte NADPH oxidase generates reactive oxygen intermediates (ROIs) and is critical for host defense. Although NADPH oxidase is critical for neutrophil-mediated host defense1-3, the importance of NADPH oxidase in macrophages is not well defined. The goal of this study was to delineate the specific role of NADPH oxidase in macrophages in mediating host defense against A. fumigatus. We found that NADPH oxidase in alveolar macrophages controls the growth of phagocytosed A. fumigatus spores4. Here, we describe a method for assessing the ability of mouse alveolar macrophages (AMs) to control the growth of phagocytosed Aspergillus spores (conidia). Alveolar macrophages are stained in vivo and ten days later isolated from mice by bronchoalveolar lavage (BAL). Macrophages are plated onto glass coverslips, then seeded with green fluorescent protein (GFP)-expressing A. fumigatus spores. At specified times, cells are fixed and the number of intact macrophages with phagocytosed spores is assessed by confocal microscopy.
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Affiliation(s)
| | | | - Brahm H Segal
- Department of Medicine, School of Medicine and Biomedical Sciences, University of Buffalo;
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Moliva JI, Rajaram MVS, Sidiki S, Sasindran SJ, Guirado E, Pan XJ, Wang SH, Ross P, Lafuse WP, Schlesinger LS, Turner J, Torrelles JB. Molecular composition of the alveolar lining fluid in the aging lung. AGE (DORDRECHT, NETHERLANDS) 2014; 36:9633. [PMID: 24584696 PMCID: PMC4082594 DOI: 10.1007/s11357-014-9633-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 02/14/2014] [Indexed: 06/01/2023]
Abstract
As we age, there is an increased risk for the development of pulmonary diseases, including infections, but few studies have considered changes in lung surfactant and components of the innate immune system as contributing factors to the increased susceptibility of the elderly to succumb to infections. We and others have demonstrated that human alveolar lining fluid (ALF) components, such as surfactant protein (SP)-A, SP-D, complement protein C3, and alveolar hydrolases, play a significant innate immune role in controlling microbial infections. However, there is a lack of information regarding the effect of increasing age on the level and function of ALF components in the lung. Here we addressed this gap in knowledge by determining the levels of ALF components in the aging lung that are important in controlling infection. Our findings demonstrate that pro-inflammatory cytokines, surfactant proteins and lipids, and complement components are significantly altered in the aged lung in both mice and humans. Further, we show that the aging lung is a relatively oxidized environment. Our study provides new information on how the pulmonary environment in old age can potentially modify mucosal immune responses, thereby impacting pulmonary infections and other pulmonary diseases in the elderly population.
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Affiliation(s)
- Juan I. Moliva
- />Center for Microbial Interface Biology, The Ohio State University, Columbus, OH USA
| | - Murugesan V. S. Rajaram
- />Center for Microbial Interface Biology, The Ohio State University, Columbus, OH USA
- />Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH USA
| | - Sabeen Sidiki
- />Center for Microbial Interface Biology, The Ohio State University, Columbus, OH USA
| | - Smitha J. Sasindran
- />Center for Microbial Interface Biology, The Ohio State University, Columbus, OH USA
| | - Evelyn Guirado
- />Center for Microbial Interface Biology, The Ohio State University, Columbus, OH USA
| | - Xueliang Jeff Pan
- />Center for Biostatistics, The Ohio State University, Columbus, OH USA
| | - Shu-Hua Wang
- />Center for Microbial Interface Biology, The Ohio State University, Columbus, OH USA
- />Division of Infectious Diseases, Department of Internal Medicine, The Ohio State University, Columbus, OH USA
| | - Patrick Ross
- />Division of Thoracic Surgery, Department of Surgery, The Ohio State University, Columbus, OH USA
| | - William P. Lafuse
- />Center for Microbial Interface Biology, The Ohio State University, Columbus, OH USA
- />Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH USA
| | - Larry S. Schlesinger
- />Center for Microbial Interface Biology, The Ohio State University, Columbus, OH USA
- />Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH USA
| | - Joanne Turner
- />Center for Microbial Interface Biology, The Ohio State University, Columbus, OH USA
- />Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH USA
| | - Jordi B. Torrelles
- />Center for Microbial Interface Biology, The Ohio State University, Columbus, OH USA
- />Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH USA
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Impact of surfactant protein D, interleukin-5, and eosinophilia on Cryptococcosis. Infect Immun 2013; 82:683-93. [PMID: 24478083 DOI: 10.1128/iai.00855-13] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Cryptococcus neoformans is an opportunistic fungal pathogen that initiates infection following inhalation. As a result, the pulmonary immune response provides a first line of defense against C. neoformans. Surfactant protein D (SP-D) is an important regulator of pulmonary immune responses and is typically host protective against bacterial and viral respiratory infections. However, SP-D is not protective against C. neoformans. This is evidenced by previous work from our laboratory demonstrating that SP-D-deficient mice infected with C. neoformans have a lower fungal burden and live longer than wild-type (WT) control animals. We hypothesized that SP-D alters susceptibility to C. neoformans by dysregulating the innate pulmonary immune response following infection. Thus, inflammatory cells and cytokines were compared in the bronchoalveolar lavage fluid from WT and SP-D(-/-) mice after C. neoformans infection. Postinfection, mice lacking SP-D have reduced eosinophil infiltration and interleukin-5 (IL-5) in lung lavage fluid. To further explore the interplay of SP-D, eosinophils, and IL-5, mice expressing altered levels of eosinophils and/or IL-5 were infected with C. neoformans to assess the role of these innate immune mediators. IL-5-overexpressing mice have increased pulmonary eosinophilia and are more susceptible to C. neoformans infection than WT mice. Furthermore, susceptibility of SP-D(-/-) mice to C. neoformans infection could be restored to the level of WT mice by increasing IL-5 and eosinophils by crossing the IL-5-overexpressing mice with SP-D(-/-) mice. Together, these studies support the conclusion that SP-D increases susceptibility to C. neoformans infection by promoting C. neoformans-driven pulmonary IL-5 and eosinophil infiltration.
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Springer DJ, Saini D, Byrnes EJ, Heitman J, Frothingham R. Development of an aerosol model of Cryptococcus reveals humidity as an important factor affecting the viability of Cryptococcus during aerosolization. PLoS One 2013; 8:e69804. [PMID: 23894542 PMCID: PMC3720958 DOI: 10.1371/journal.pone.0069804] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 06/12/2013] [Indexed: 12/14/2022] Open
Abstract
Cryptococcus is an emerging global health threat that is annually responsible for over 1,000,000 infections and one third of all AIDS patient deaths. There is an ongoing outbreak of cryptococcosis in the western United States and Canada. Cryptococcosis is a disease resulting from the inhalation of the infectious propagules from the environment. The current and most frequently used animal infection models initiate infection via liquid suspension through intranasal instillation or intravenous injection. These models do not replicate the typically dry nature of aerosol exposure and may hinder our ability to decipher the initial events that lead to clearance or the establishment of infection. We have established a standardized aerosol model of murine infection for the human fungal pathogen Cryptococcus. Aerosolized cells were generated utilizing a Collison nebulizer in a whole-body Madison Chamber at different humidity conditions. The aerosols inside the chamber were sampled using a BioSampler to determine viable aerosol concentration and spray factor (ratio of viable aerosol concentration to total inoculum concentration). We have effectively delivered yeast and yeast-spore mixtures to the lungs of mice and observed the establishment of disease. We observed that growth conditions prior to exposure and humidity within the Madison Chamber during exposure can alter Cryptococcus survival and dose retained in mice.
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Affiliation(s)
- Deborah J Springer
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA.
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Johnston SA, May RC. Cryptococcusinteractions with macrophages: evasion and manipulation of the phagosome by a fungal pathogen. Cell Microbiol 2012; 15:403-11. [DOI: 10.1111/cmi.12067] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 10/28/2012] [Accepted: 10/29/2012] [Indexed: 01/19/2023]
Affiliation(s)
| | - Robin C. May
- Institute of Microbiology and Infection; School of Biosciences; University of Birmingham; Birmingham; B15 2TT; UK
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Cryptococcus neoformans phosphoinositide-dependent kinase 1 (PDK1) ortholog is required for stress tolerance and survival in murine phagocytes. EUKARYOTIC CELL 2012; 12:12-22. [PMID: 23087368 DOI: 10.1128/ec.00235-12] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cryptococcus neoformans PKH2-01 and PKH2-02 are orthologous to mammalian PDK1 kinase genes. Although orthologs of these kinases have been extensively studied in S. cerevisiae, little is known about their function in pathogenic fungi. In this study, we show that PKH2-02 but not PKH2-01 is required for C. neoformans to tolerate cell wall, oxidative, nitrosative, and antifungal drug stress. Deletion of PKH2-02 leads to decreased basal levels of Pkc1 activity and, consequently, reduced activation of the cell wall integrity mitogen-activated protein kinase (MAPK) pathway in response to cell wall, oxidative, and nitrosative stress. PKH2-02 function also is required for tolerance of fluconazole and amphotericin B, two important drugs for the treatment of cryptococcosis. Furthermore, OSU-03012, an inhibitor of human PDK1, is synergistic and fungicidal in combination with fluconazole. Using a Galleria mellonella model of low-temperature cryptococcosis, we found that PKH2-02 is also required for virulence in a temperature-independent manner. Consistent with the hypersensitivity of the pkh2-02Δ mutant to oxidative and nitrosative stress, this mutant shows decreased survival in murine phagocytes compared to that of wild-type (WT) cells. In addition, we show that deletion of PKH2-02 affects the interaction between C. neoformans and phagocytes by decreasing its ability to suppress production of tumor necrosis factor alpha (TNF-α) and reactive oxygen species. Taken together, our studies demonstrate that Pkh2-02-mediated signaling in C. neoformans is crucial for stress tolerance, host-pathogen interactions, and both temperature-dependent and -independent virulence.
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Nayak A, Dodagatta-Marri E, Tsolaki AG, Kishore U. An Insight into the Diverse Roles of Surfactant Proteins, SP-A and SP-D in Innate and Adaptive Immunity. Front Immunol 2012; 3:131. [PMID: 22701116 PMCID: PMC3369187 DOI: 10.3389/fimmu.2012.00131] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Accepted: 05/07/2012] [Indexed: 01/20/2023] Open
Abstract
Surfactant proteins SP-A and SP-D are hydrophilic, collagen-containing calcium-dependent lectins, which appear to have a range of innate immune functions at pulmonary as well as extrapulmonary sites. These proteins bind to target ligands on pathogens, allergens, and apoptotic cells, via C-terminal homotrimeric carbohydrate recognition domains, while the collagen region brings about the effector functions via its interaction with cell surface receptors. SP-A and SP-D deal with various pathogens, using a range of innate immune mechanisms such as agglutination/aggregation, enhancement of phagocytosis, and killing mechanisms by phagocytic cells and direct growth inhibition. SP-A and SP-D have also been shown to be involved in the control of pulmonary inflammation including allergy and asthma. Emerging evidence suggest that SP-A and SP-D are capable of linking innate immunity with adaptive immunity that includes modulation of dendritic cell function and helper T cell polarization. This review enumerates immunological properties of SP-A and SP-D inside and outside lungs and discusses their importance in human health and disease.
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Affiliation(s)
- Annapurna Nayak
- Centre for Infection, Immunity and Disease Mechanisms, School of Health Sciences and Social Care, Brunel University London, UK
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Abstract
Concurrent with the global escalation of the AIDS pandemic, cryptococcal infections are increasing and are of significant medical importance. Furthermore, Cryptococcus neoformans has become a primary human pathogen, causing infection in seemingly healthy individuals. Although numerous studies have elucidated the virulence properties of C. neoformans, less is understood regarding lung host immune factors during early stages of fungal infection. Based on our previous studies documenting that pulmonary surfactant protein D (SP-D) protects C. neoformans cells against macrophage-mediated defense mechanisms in vitro (S. Geunes-Boyer et al., Infect. Immun. 77:2783-2794, 2009), we postulated that SP-D would facilitate fungal infection in vivo. To test this hypothesis, we examined the role of SP-D in response to C. neoformans using SP-D⁻/⁻ mice. Here, we demonstrate that mice lacking SP-D were partially protected during C. neoformans infection; they displayed a longer mean time to death and decreased fungal burden at several time points postinfection than wild-type mice. This effect was reversed by the administration of exogenous SP-D. Furthermore, we show that SP-D bound to the surface of the yeast cells and protected the pathogenic microbes against macrophage-mediated defense mechanisms and hydrogen peroxide (H₂O₂)-induced oxidative stress in vitro and in vivo. These findings indicate that C. neoformans is capable of coopting host SP-D to increase host susceptibility to the yeast. This study establishes a new paradigm for the role played by SP-D during host responses to C. neoformans and consequently imparts insight into potential future preventive and/or treatment strategies for cryptococcosis.
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Abstract
The pathogenic fungus Cryptococcus neoformans exhibits a striking propensity to cause central nervous system (CNS) disease in people with HIV/AIDS. Given that cryptococcal infections are generally initiated by pulmonary colonization, dissemination requires that the fungus withstand phagocytic killing, cross the alveolar-capillary interface in the lung, survive in the circulatory system and breach the blood-brain barrier. We know little about the molecular mechanisms underlying dissemination, but there is a rapidly growing list of mutants that fail to cause CNS disease. These mutants reveal a remarkable diversity of functions and therefore illustrate the complexity of the cryptococcal-host interaction. The challenge now is to extend the analysis of these mutants to acquire a detailed understanding of each step in dissemination.
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Abstract
The interaction of pathogenic Cryptococcus species with their various hosts is somewhat unique compared to other fungal pathogens such as Aspergillus fumigatus and Candida albicans. Cryptococcus shares an intimate association with host immune cells, leading to enhanced intracellular growth. Furthermore, unlike most other fungal pathogens, the signs and symptoms of cryptococcal disease are typically self-inflicted by the host during the host's attempt to clear this invader from sensitive organ systems such as the central nervous system. In this review, we will summarize the story of host-Cryptococcus interactions to date and explore strategies to exploit the current knowledge for treatment of cryptococcal infections.
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Affiliation(s)
- Michael S Price
- Department of Medicine, Duke University Medical Center, Research Drive, Durham, NC 27710, USA
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Aono Y, Ledford JG, Mukherjee S, Ogawa H, Nishioka Y, Sone S, Beers MF, Noble PW, Wright JR. Surfactant protein-D regulates effector cell function and fibrotic lung remodeling in response to bleomycin injury. Am J Respir Crit Care Med 2011; 185:525-36. [PMID: 22198976 DOI: 10.1164/rccm.201103-0561oc] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
RATIONALE Surfactant protein (SP)-D and SP-A have been implicated in immunomodulation in the lung. It has been reported that patients with idiopathic pulmonary fibrosis (IPF) often have elevated serum levels of SP-A and SP-D, although their role in the disease is not known. OBJECTIVES The goal of this study was to test the hypothesis that SP-D plays an important role in lung fibrosis using a mouse model of fibrosis induced by bleomycin (BLM). METHODS Triple transgenic inducible SP-D mice (iSP-D mice), in which rat SP-D is expressed in response to doxycycline (Dox) treatment, were administered BLM (100 U/kg) or saline subcutaneously using miniosmotic pumps. MEASUREMENTS AND MAIN RESULTS BLM-treated iSP-D mice off Dox (SP-D off) had increased lung fibrosis compared with mice on Dox (SP-D on). SP-D deficiency also increased macrophage-dominant cell infiltration and the expression of profibrotic cytokines (transforming growth factor [TGF]-β1, platelet-derived growth factor-AA). Alveolar macrophages isolated from BLM-treated iSP-D mice off Dox (SP-D off) secreted more TGF-β1. Fibrocytes, which are bone marrow-derived mesenchymal progenitor cells, were increased to a greater extent in the lungs of the BLM-treated iSP-D mice off Dox (SP-D off). Fibrocytes isolated from BLM-treated iSP-D mice off Dox (SP-D off) expressed more of the profibrotic cytokine TGF-β1 and more CXCR4, a chemokine receptor that is important in fibrocyte migration into the lungs. Exogenous SP-D administered intratracheally attenuated BLM-induced lung fibrosis in SP-D(-/-) mice. CONCLUSIONS These data suggest that alveolar SP-D regulates numbers of macrophages and fibrocytes in the lungs, profibrotic cytokine expression, and fibrotic lung remodeling in response to BLM injury.
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Affiliation(s)
- Yoshinori Aono
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA
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Abstract
Cryptococcosis is a life-threatening fungal disease that infects around one million people each year. Establishment and progression of disease involves a complex interplay between the fungus and a diverse range of host cell types. Over recent years, numerous cellular, tissue, and animal models have been exploited to probe this host-pathogen interaction. Here we review the range of experimental models that are available for cryptococcosis research and compare the relative advantages and limitations of the different systems.
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Qin QM, Luo J, Lin X, Pei J, Li L, Ficht TA, de Figueiredo P. Functional analysis of host factors that mediate the intracellular lifestyle of Cryptococcus neoformans. PLoS Pathog 2011; 7:e1002078. [PMID: 21698225 PMCID: PMC3116820 DOI: 10.1371/journal.ppat.1002078] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Accepted: 04/07/2011] [Indexed: 11/18/2022] Open
Abstract
Cryptococcus neoformans (Cn), the major causative agent of human fungal meningoencephalitis, replicates within phagolysosomes of infected host cells. Despite more than a half-century of investigation into host-Cn interactions, host factors that mediate infection by this fungal pathogen remain obscure. Here, we describe the development of a system that employs Drosophila S2 cells and RNA interference (RNAi) to define and characterize Cn host factors. The system recapitulated salient aspects of fungal interactions with mammalian cells, including phagocytosis, intracellular trafficking, replication, cell-to-cell spread and escape of the pathogen from host cells. Fifty-seven evolutionarily conserved host factors were identified using this system, including 29 factors that had not been previously implicated in mediating fungal pathogenesis. Subsequent analysis indicated that Cn exploits host actin cytoskeletal elements, cell surface signaling molecules, and vesicle-mediated transport proteins to establish a replicative niche. Several host molecules known to be associated with autophagy (Atg), including Atg2, Atg5, Atg9 and Pi3K59F (a class III PI3-kinase) were also uncovered in our screen. Small interfering RNA (siRNA) mediated depletion of these autophagy proteins in murine RAW264.7 macrophages demonstrated their requirement during Cn infection, thereby validating findings obtained using the Drosophila S2 cell system. Immunofluorescence confocal microscopy analyses demonstrated that Atg5, LC3, Atg9a were recruited to the vicinity of Cn containing vacuoles (CnCvs) in the early stages of Cn infection. Pharmacological inhibition of autophagy and/or PI3-kinase activity further demonstrated a requirement for autophagy associated host proteins in supporting infection of mammalian cells by Cn. Finally, systematic trafficking studies indicated that CnCVs associated with Atg proteins, including Atg5, Atg9a and LC3, during trafficking to a terminal intracellular compartment that was decorated with the lysosomal markers LAMP-1 and cathepsin D. Our findings validate the utility of the Drosophila S2 cell system as a functional genomic platform for identifying and characterizing host factors that mediate fungal intracellular replication. Our results also support a model in which host Atg proteins mediate Cn intracellular trafficking and replication.
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Affiliation(s)
- Qing-Ming Qin
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, United States of America
- Borlaug Advanced Research Center, Texas A&M University, College Station, Texas, United States of America
- * E-mail: (QMQ); (PdF)
| | - Jijing Luo
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, United States of America
| | - Xiaorong Lin
- Department of Biology, Texas A&M University, College Station, Texas, United States of America
| | - Jianwu Pei
- Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas, United States of America
| | - Lei Li
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, United States of America
- Borlaug Advanced Research Center, Texas A&M University, College Station, Texas, United States of America
| | - Thomas A. Ficht
- Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas, United States of America
| | - Paul de Figueiredo
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas, United States of America
- Borlaug Advanced Research Center, Texas A&M University, College Station, Texas, United States of America
- Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas, United States of America
- * E-mail: (QMQ); (PdF)
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Liu Y, Mei J, Gonzales L, Yang G, Dai N, Wang P, Zhang P, Favara M, Malcolm KC, Guttentag S, Worthen GS. IL-17A and TNF-α exert synergistic effects on expression of CXCL5 by alveolar type II cells in vivo and in vitro. THE JOURNAL OF IMMUNOLOGY 2011; 186:3197-205. [PMID: 21282514 DOI: 10.4049/jimmunol.1002016] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
CXCL5, a member of the CXC family of chemokines, contributes to neutrophil recruitment during lung inflammation, but its regulation is poorly understood. Because the T cell-derived cytokine IL-17A enhances host defense by triggering production of chemokines, particularly in combination with TNF-α, we hypothesized that IL-17A would enhance TNF-α-induced expression of CXCL5. Intratracheal coadministration of IL-17A and TNF-α in mice induced production of CXCL1, CXCL2, and CXCL5, which was associated with increased neutrophil influx in the lung at 8 and 24 h. The synergistic effects of TNF-α and IL17A were greatly attenuated in Cxcl5(-/-) mice at 24 h, but not 8 h, after exposure, a time when CXCL5 expression was at its peak in wild-type mice. Bone marrow chimeras produced using Cxcl5(-/-) donors and recipients demonstrated that lung-resident cells were the source of CXCL5. Using differentiated alveolar epithelial type II (ATII) cells derived from human fetal lung, we found that IL-17A enhanced TNF-α-induced CXCL5 transcription and stabilized TNF-α-induced CXCL5 transcripts. Whereas expression of CXCL5 required activation of NF-κB, IL-17A did not increase TNF-α-induced NF-κB activation. Apical costimulation of IL-17A and TNF-α provoked apical secretion of CXCL5 by human ATII cells in a transwell system, whereas basolateral costimulation led to both apical and basolateral secretion of CXCL5. The observation that human ATII cells secrete CXCL5 in a polarized fashion may represent a mechanism to recruit neutrophils in host defense in a fashion that discriminates the site of initial injury.
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Affiliation(s)
- Yuhong Liu
- Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, PA 19014, USA
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Automated analysis of cryptococcal macrophage parasitism using GFP-tagged cryptococci. PLoS One 2010; 5:e15968. [PMID: 21209844 PMCID: PMC3013146 DOI: 10.1371/journal.pone.0015968] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Accepted: 12/06/2010] [Indexed: 01/01/2023] Open
Abstract
The human fungal pathogens Cryptococcus neoformans and C. gattii cause life-threatening infections of the central nervous system. One of the major characteristics of cryptococcal disease is the ability of the pathogen to parasitise upon phagocytic immune effector cells, a phenomenon that correlates strongly with virulence in rodent models of infection. Despite the importance of phagocyte/Cryptococcus interactions to disease progression, current methods for assaying virulence in the macrophage system are both time consuming and low throughput. Here, we introduce the first stable and fully characterised GFP–expressing derivatives of two widely used cryptococcal strains: C. neoformans serotype A type strain H99 and C. gattii serotype B type strain R265. Both strains show unaltered responses to environmental and host stress conditions and no deficiency in virulence in the macrophage model system. In addition, we report the development of a method to effectively and rapidly investigate macrophage parasitism by flow cytometry, a technique that preserves the accuracy of current approaches but offers a four-fold improvement in speed.
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Olszewski MA, Zhang Y, Huffnagle GB. Mechanisms of cryptococcal virulence and persistence. Future Microbiol 2010; 5:1269-88. [PMID: 20722603 DOI: 10.2217/fmb.10.93] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cryptococcus neoformans is an environmental yeast that is a leading cause of fatal mycosis in AIDS patients and a major cause of meningoencephalitis and CNS-related mortality around the globe. Although C. neoformans infection is mostly a manifestation of immune deficiency, up to 25% of cases reported in the USA occur in patients without recognizable immune defects, indicating that C. neoformans can develop mechanisms that allow it to evade immune defenses and persist in noncompromised hosts. This article discusses mechanisms and routes of infection and the most important elements of host response as well as the mechanisms that promote cryptococcal survival within the host. Metabolic adaptation to physiological host conditions and the mechanisms limiting immune recognition, interfering with phagocytosis and extending intracellular survival of C. neoformans are highlighted. We describe the mechanisms by which C. neoformans can alter adaptive host responses, especially cell-mediated immunity, which is required for clearance of this microbe. We also review cryptococcal strategies of survival in the CNS and briefly discuss adaptations developing in response to medical treatment.
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Affiliation(s)
- Michal A Olszewski
- Ann Arbor Veterans Administration Health System (11R), 2215 Fuller Road, Ann Arbor, MI 48105, USA.
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Geunes-Boyer S, Heitman J, Wright JR, Steinbach WJ. Surfactant protein D binding to Aspergillus fumigatus hyphae is calcineurin-sensitive. Med Mycol 2010; 48:580-8. [PMID: 20141481 DOI: 10.3109/13693780903401682] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Surfactant protein D (SP-D) plays a central role in pulmonary innate immune responses to microbes and allergens, often enhancing clearance of inhaled material. Although SP-D functions during bacterial and viral infections are well established, much less is known about its possible roles during invasive fungal infections. Aspergillus fumigatus is a prominent fungal pathogen in immunocompromised individuals, and can cause allergic or invasive aspergillosis. SP-D has been shown to be protective against both of these disease modalities. The moieties present on the fungal surface responsible for SP-D binding remain largely unclear, although cell wall 1,3-beta-D-glucan is bound by SP-D in other fungal species. There is little information regarding the interaction of SP-D with A. fumigatus hyphae which are responsible for the invasive form of disease. Here, we show that SP-D binding to A. fumigatus hyphae is sensitive to the activity of the calcium-activated protein phosphatase calcineurin. Deletion of the catalytic subunit calcineurin A (DeltacnaA) or pharmacologic inhibition of calcineurin through FK506 abrogated SP-D binding. In contrast, SP-D binding to Cruptococcus neoformans was calcineurin-independent. Pharmacologic inhibition of A. fumigatus cell wall components by caspofungin (inhibits 1,3-beta-D-glucan synthesis) and nikkomycin Z (inhibits chitin synthesis) increased SP-D binding to the wild-type strain. In contrast, SP-D binding increased in the DeltacnaA strain only after nikkomycin Z treatment. We conclude that SP-D binding to A. fumigatus hyphae is calcineurin-sensitive, presumably as a consequence of calcineurin's role in regulating production of key cell wall binding partners, such as 1,3-beta-D-glucan. Elucidation of the interaction between lung innate immune factors and A. fumigatus could lead to the development of novel therapeutic interventions.
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Affiliation(s)
- Scarlett Geunes-Boyer
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
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Cryptococcus neoformans histone acetyltransferase Gcn5 regulates fungal adaptation to the host. EUKARYOTIC CELL 2010; 9:1193-202. [PMID: 20581290 DOI: 10.1128/ec.00098-10] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cryptococcus neoformans is an environmental fungus and an opportunistic human pathogen. Previous studies have demonstrated major alterations in its transcriptional profile as this microorganism enters the hostile environment of the human host. To assess the role of chromatin remodeling in host-induced transcriptional responses, we identified the C. neoformans Gcn5 histone acetyltransferase and demonstrated its function by complementation studies of Saccharomyces cerevisiae. The C. neoformans gcn5Delta mutant strain has defects in high-temperature growth and capsule attachment to the cell surface, in addition to increased sensitivity to FK506 and oxidative stress. Treatment of wild-type cells with the histone acetyltransferase inhibitor garcinol mimics cellular effects of the gcn5Delta mutation. Gcn5 regulates the expression of many genes that are important in responding to the specific environmental conditions encountered by C. neoformans inside the host. Accordingly, the gcn5Delta mutant is avirulent in animal models of cryptococcosis. Our study demonstrates the importance of chromatin remodeling by the conserved histone acetyltransferase Gcn5 in regulating the expression of specific genes that allow C. neoformans to respond appropriately to the human host.
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Schleh C, Erpenbeck VJ, Winkler C, Lauenstein HD, Nassimi M, Braun A, Krug N, Hohlfeld JM. Allergen particle binding by human primary bronchial epithelial cells is modulated by surfactant protein D. Respir Res 2010; 11:83. [PMID: 20569420 PMCID: PMC2898774 DOI: 10.1186/1465-9921-11-83] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Accepted: 06/22/2010] [Indexed: 12/25/2022] Open
Abstract
Background Allergen-containing subpollen particles (SPP) are released from whole plant pollen upon contact with water or even high humidity. Because of their size SPP can preferentially reach the lower airways where they come into contact with surfactant protein (SP)-D. Our previous work demonstrated that SP-D increases the uptake of SPP by alveolar macrophages. In the present study, we investigated the uptake of SPP in human primary epithelial cells and the potential modulation by SP-D. The patho-physiological consequence was evaluated by measurement of pro-inflammatory mediators. Methods SPP were isolated from timothy grass and subsequently fluorescently labelled. Human primary bronchial epithelial cells were incubated with SPP or polystyrene particles (PP) in the presence and absence of surfactant protein D. In addition, different sizes and surface charges of the PP were studied. Particle uptake was evaluated by flow cytometry and confocal microscopy. Soluble mediators were measured by enzyme linked immunosorbent assay or bead array. Results SPP were taken up by primary epithelial cells in a dose dependent manner. This uptake was coincided with secretion of Interleukin (IL)-8. SP-D increased the fraction of bronchial epithelial cells that bound SPP but not the fraction of cells that internalized SPP. SPP-induced secretion of IL-8 was further increased by SP-D. PP were bound and internalized by epithelial cells but this was not modulated by SP-D. Conclusions Epithelial cells bind and internalize SPP and PP which leads to increased IL-8 secretion. SP-D promotes attachment of SPP to epithelial cells and may thus be involved in the inflammatory response to inhaled allergen.
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Affiliation(s)
- Carsten Schleh
- Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover, Germany
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Seider K, Heyken A, Lüttich A, Miramón P, Hube B. Interaction of pathogenic yeasts with phagocytes: survival, persistence and escape. Curr Opin Microbiol 2010; 13:392-400. [PMID: 20627672 DOI: 10.1016/j.mib.2010.05.001] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 05/05/2010] [Accepted: 05/06/2010] [Indexed: 10/19/2022]
Abstract
Pathogenic yeasts, either from the environment or the normal flora, have to face phagocytic cells that constitute the first line of defence during infection. In order to evade or counteract attack by phagocytes, pathogenic yeasts have acquired a repertoire of strategies to survive, colonize and infect the host. In this review we focus on the interaction of yeasts, such as Candida, Histoplasma or Cryptococcus species, with macrophages or neutrophils. We discuss strategies used by these fungi to prevent phagocytosis or to counteract phagocytic activities. We go on to describe the strategies that permit intracellular survival within phagocytes and that may eventually lead to damage of and escape from the phagocyte.
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Affiliation(s)
- Katja Seider
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute Jena (HKI), Jena, Germany
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