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Jia LJ, González K, Orasch T, Schmidt F, Brakhage AA. Manipulation of host phagocytosis by fungal pathogens and therapeutic opportunities. Nat Microbiol 2024; 9:2216-2231. [PMID: 39187614 DOI: 10.1038/s41564-024-01780-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 07/09/2024] [Indexed: 08/28/2024]
Abstract
An important host defence mechanism against pathogens is intracellular killing, which is achieved through phagocytosis, a cellular process for engulfing and neutralizing extracellular particles. Phagocytosis results in the formation of matured phagolysosomes, which are specialized compartments that provide a hostile environment and are considered the end point of the degradative pathway. However, all fungal pathogens studied to date have developed strategies to manipulate phagosomal function directly and also indirectly by redirecting phagosomes from the degradative pathway to a non-degradative pathway with the expulsion and even transfer of pathogens between cells. Here, using the major human fungal pathogens Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans and Histoplasma capsulatum as examples, we discuss the processes involved in host phagosome-fungal pathogen interactions, with a focus on fungal evasion strategies. We also discuss recent approaches to targeting intraphagosomal pathogens, including the redirection of phagosomes towards degradative pathways for fungal pathogen eradication.
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Affiliation(s)
- Lei-Jie Jia
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (Leibniz-HKI), Jena, Germany.
- Junior Research Group Phagosome Biology and Engineering, Leibniz-HKI, Jena, Germany.
| | - Katherine González
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (Leibniz-HKI), Jena, Germany
| | - Thomas Orasch
- Transfer Group Anti-infectives, Leibniz-HKI, Jena, Germany
| | - Franziska Schmidt
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (Leibniz-HKI), Jena, Germany
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (Leibniz-HKI), Jena, Germany.
- Department of Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University, Jena, Germany.
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2
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Bertuzzi M, Howell GJ, Thomson DD, Fortune-Grant R, Möslinger A, Dancer P, Van Rhijn N, Motsi N, Codling A, Bignell EM. Epithelial uptake leads to fungal killing in vivo and is aberrant in COPD-derived epithelial cells. iScience 2024; 27:109939. [PMID: 38846001 PMCID: PMC11154633 DOI: 10.1016/j.isci.2024.109939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 12/07/2023] [Accepted: 05/06/2024] [Indexed: 06/09/2024] Open
Abstract
Hundreds of spores of Aspergillus fumigatus (Af) are inhaled daily by human beings, representing a constant, possibly fatal, threat to respiratory health. The small size of Af spores suggests that interactions with alveolar epithelial cells (AECs) are frequent; thus, we hypothesized that spore uptake by AECs is important for driving fungal killing and susceptibility to Aspergillus-related disease. Using single-cell approaches to measure spore uptake and its outcomes in vivo, we demonstrate that Af spores are internalized and killed by AECs during whole-animal infection. Moreover, comparative analysis of primary human AECs from healthy and chronic obstructive pulmonary disease (COPD) donors revealed significant alterations in the uptake and killing of spores in COPD-derived AECs. We conclude that AECs contribute to the killing of Af spores and that dysregulation of curative AEC responses in COPD may represent a driver of Aspergillus-related diseases.
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Affiliation(s)
- Margherita Bertuzzi
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Core Technology Facility, Grafton Street, Manchester M13 9NT, UK
| | - Gareth J. Howell
- Flow Cytometry Core Facility, Faculty of Biology, Medicine and Health, Core Technology Facility, Grafton Street, Manchester M13 9NT, UK
| | - Darren D. Thomson
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Core Technology Facility, Grafton Street, Manchester M13 9NT, UK
| | - Rachael Fortune-Grant
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Core Technology Facility, Grafton Street, Manchester M13 9NT, UK
| | - Anna Möslinger
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Core Technology Facility, Grafton Street, Manchester M13 9NT, UK
| | - Patrick Dancer
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Core Technology Facility, Grafton Street, Manchester M13 9NT, UK
| | - Norman Van Rhijn
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Core Technology Facility, Grafton Street, Manchester M13 9NT, UK
| | - Natasha Motsi
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Core Technology Facility, Grafton Street, Manchester M13 9NT, UK
| | - Alice Codling
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Core Technology Facility, Grafton Street, Manchester M13 9NT, UK
| | - Elaine M. Bignell
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Core Technology Facility, Grafton Street, Manchester M13 9NT, UK
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3
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Lax C, Nicolás FE, Navarro E, Garre V. Molecular mechanisms that govern infection and antifungal resistance in Mucorales. Microbiol Mol Biol Rev 2024; 88:e0018822. [PMID: 38445820 PMCID: PMC10966947 DOI: 10.1128/mmbr.00188-22] [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] [Indexed: 03/07/2024] Open
Abstract
SUMMARYThe World Health Organization has established a fungal priority pathogens list that includes species critical or highly important to human health. Among them is the order Mucorales, a fungal group comprising at least 39 species responsible for the life-threatening infection known as mucormycosis. Despite the continuous rise in cases and the poor prognosis due to innate resistance to most antifungal drugs used in the clinic, Mucorales has received limited attention, partly because of the difficulties in performing genetic manipulations. The COVID-19 pandemic has further escalated cases, with some patients experiencing the COVID-19-associated mucormycosis, highlighting the urgent need to increase knowledge about these fungi. This review addresses significant challenges in treating the disease, including delayed and poor diagnosis, the lack of accurate global incidence estimation, and the limited treatment options. Furthermore, it focuses on the most recent discoveries regarding the mechanisms and genes involved in the development of the disease, antifungal resistance, and the host defense response. Substantial advancements have been made in identifying key fungal genes responsible for invasion and tissue damage, host receptors exploited by the fungus to invade tissues, and mechanisms of antifungal resistance. This knowledge is expected to pave the way for the development of new antifungals to combat mucormycosis. In addition, we anticipate significant progress in characterizing Mucorales biology, particularly the mechanisms involved in pathogenesis and antifungal resistance, with the possibilities offered by CRISPR-Cas9 technology for genetic manipulation of the previously intractable Mucorales species.
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Affiliation(s)
- Carlos Lax
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Murcia, Spain
| | - Francisco E. Nicolás
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Murcia, Spain
| | - Eusebio Navarro
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Murcia, Spain
| | - Victoriano Garre
- Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Murcia, Spain
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4
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Shang S, He D, Liu C, Bao X, Han S, Wang L. TRAF3 gene regulates macrophage migration and activation by lung epithelial cells infected with Aspergillus fumigatus. Microbiol Spectr 2024; 12:e0269923. [PMID: 38018974 PMCID: PMC10783100 DOI: 10.1128/spectrum.02699-23] [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: 06/29/2023] [Accepted: 10/21/2023] [Indexed: 11/30/2023] Open
Abstract
IMPORTANCE Aspergillus fumigatus can infect immunocompromised individuals and cause chronic and fatal invasive fungal infections. A better understanding of the molecular mechanisms of A. fumigatus-host interactions may provide new references for disease treatment. In this study, we demonstrated that the TRAF3 gene plays an important role in the early infection of A. fumigatus by regulating the resistance of lung epithelial cells to A. fumigatus. Macrophages are the most abundant innate immune cells in the alveoli; however, few studies have reported on the interactions between lung epithelial cells and macrophages in response to A. fumigatus invasion. In our study, it was demonstrated that the TRAF3 gene reduces migration to macrophages and cytokine production by negatively regulating lung epithelial cell adhesion and internalization of A. fumigatus spores. Together, our results provide new insights into lung epithelial cell-macrophage interactions during A. fumigatus infection.
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Affiliation(s)
- Shumi Shang
- Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Zoonosis Research, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, China
| | - Dan He
- Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Zoonosis Research, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, China
| | - Cong Liu
- Department of Dermatology, First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Xinyuan Bao
- Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Zoonosis Research, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, China
| | - Shuaishuai Han
- Beijing ZhongKai TianCheng Bio-technology Co. Ltd., Beijing, China
| | - Li Wang
- Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Zoonosis Research, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, China
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Thakur R, Shishodia SK, Sharma A, Chauhan A, Kaur S, Shankar J. Accelerating the understanding of Aspergillus terreus: Epidemiology, physiology, immunology and advances. CURRENT RESEARCH IN MICROBIAL SCIENCES 2024; 6:100220. [PMID: 38303967 PMCID: PMC10831165 DOI: 10.1016/j.crmicr.2024.100220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2024] Open
Abstract
Aspergillus species encompass a variety of infections, ranging from invasive aspergillosis to allergic conditions, contingent upon the immune status of the host. In this spectrum, Aspergillus terreus stands out due to its emergence as a notable pathogen and its intrinsic resistance to amphotericin-B. The significance of Aspergillus-associated infections has witnessed a marked increase in the past few decades, particularly with the increasing number of immunocompromised individuals. The exploration of epidemiology, morphological transitions, immunopathology, and novel treatment approaches such as new antifungal drugs (PC945, olorofim) and combinational therapy using antifungal drugs and phytochemicals (Phytochemicals: quercetin, shikonin, artemisinin), also using immunotherapies to modulate immune response has resulted in better outcomes. Furthermore, in the context COVID-19 era and its aftermath, fungal infections have emerged as a substantial challenge for both immunocompromised and immunocompetent individuals. This is attributed to the use of immune-suppressing therapies during COVID-19 infections and the increase in transplant cases. Consequently, this review aims to provide an updated overview encompassing the epidemiology, germination events, immunopathology, and novel drug treatment strategies against Aspergillus terreus-associated infections.
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Affiliation(s)
- Raman Thakur
- Department of Medical Laboratory Science, Lovely Professional University, Jalandhar, Punjab, India
| | | | - Ananya Sharma
- Genomic Laboratory, Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat Solan, Himachal Pradesh, India
| | - Arjun Chauhan
- Department of Biotechnology, Institute of Applied Sciences and Humanities, GLA University, Mathura, Uttar Pradesh, India
| | - Sumanpreet Kaur
- Department of Medical Laboratory Science, Lovely Professional University, Jalandhar, Punjab, India
| | - Jata Shankar
- Genomic Laboratory, Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat Solan, Himachal Pradesh, India
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Ghosh S, Humera Khathun AH, Athulya GS, Vignesh P, Mathan L, Mudaraddi N, Narendran S, Lalitha P, Venkatesh Prajna N. Host cell-type and pathogen-specific immunomodulatory functions of macrophage migration inhibitory factor (MIF) in infectious keratitis. Exp Eye Res 2023; 236:109669. [PMID: 37774962 DOI: 10.1016/j.exer.2023.109669] [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: 05/27/2023] [Revised: 09/11/2023] [Accepted: 09/27/2023] [Indexed: 10/01/2023]
Abstract
Therapeutic management of inflammation in infectious keratitis (IK) requires new strategy and targets for selective immunomodulation. Targeting host cell-type specific inflammatory responses might be a viable strategy to curtail unnecessary inflammation and reduce tissue damage without affecting pathogen clearance. This study explores the possibility of pathogen and host cell-type dependent differences in the inflammatory pathways relevant in the pathogenesis of IK. Human corneal epithelial cell line (HCEC) and phorbol 12-myristate-13 acetate (PMA) differentiated THP-1 macrophage line were infected with either Aspergillus flavus conidia or Acanthamoeba castellanii trophozoites and the elicited inflammatory responses were studied in terms of gene expression and secretion of proinflammatory factors interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α) and an upstream inflammatory regulator and mediator protein-the Macrophage Migration Inhibitory Factor (MIF). Given the pleotropic mode of MIF function in diverse cell types relevant in many human diseases, we tested if MIF driven responses to infection is different in HCECs and THP-1 macrophages by studying its expression, secretion and involvement in inflammation by siRNA mediated knockdown. We also examined IK patient tear samples for MIF levels. Infection with A. flavus or A. castellanii induced IL-8 and TNF-α responses in HCECs and THP-1 macrophages but to different levels. Our preliminary human data showed that the level of secreted MIF protein was elevated in IK patient tear, however, MIF secretion by the two cell types were strikingly different in-vitro, under both normal and infected conditions. We found that HCECs released MIF constitutively, which was significantly inhibited with infection, whereas THP-1 macrophages were stimulated to release MIF during infection. MIF gene expression remained largely unaffected by infection in both the cell lines. Although MIF in HCECs appeared to be intracellularly captured during infection, MIF knockdown in HCECs associated with a partial reduction of the IL-8 and TNF-α expression produced by either of the pathogens, suggesting a pro-inflammatory role for MIF in HCECs, independent of its canonical cytokine like function. In contrast, MIF knockdown in THP-1 macrophages accompanied a dramatic increase in IL-8 and TNF-α expression during A. castellanii infection, while the responses to A. flavus infection remained unchanged. These data imply a host cell-type and pathogen specific distinction in the MIF- related inflammatory signaling and MIF as a potential selective immunomodulatory target in infectious keratitis.
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Affiliation(s)
- Swagata Ghosh
- Department of Microbiology, Aravind Medical Research Foundation, Madurai, India.
| | - A H Humera Khathun
- Department of Microbiology, Aravind Medical Research Foundation, Madurai, India
| | - G S Athulya
- Department of Microbiology, Aravind Medical Research Foundation, Madurai, India
| | - P Vignesh
- Department of Microbiology, Aravind Medical Research Foundation, Madurai, India
| | - L Mathan
- Department of Proteomics, Aravind Medical Research Foundation, Madurai, India
| | - Ninad Mudaraddi
- Department of Cornea and Refractive Surgery, Aravind Eye Hospital, Madurai, India
| | - Siddharth Narendran
- Department of Microbiology, Aravind Medical Research Foundation, Madurai, India; Aravind Eye Hospital, Coimbatore, India
| | - Prajna Lalitha
- Department of Ocular Microbiology, Aravind Eye Hospital, Madurai, India
| | - N Venkatesh Prajna
- Department of Cornea and Refractive Surgery, Aravind Eye Hospital, Madurai, India
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7
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Liu H, Lin J, Phan QT, Gravelat FN, Sheppard DC, Filler SG. Use of a human small airway epithelial cell line to study the interactions of Aspergillus fumigatus with pulmonary epithelial cells. mSphere 2023; 8:e0031423. [PMID: 37578262 PMCID: PMC10597448 DOI: 10.1128/msphere.00314-23] [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: 06/12/2023] [Accepted: 06/12/2023] [Indexed: 08/15/2023] Open
Abstract
During the initiation of invasive aspergillosis, inhaled Aspergillus fumigatus conidia are deposited on the epithelial cells lining the bronchi, terminal bronchioles, and alveoli. While the interactions of A. fumigatus with bronchial and type II alveolar cell lines have been investigated in vitro, little is known about the interactions of this fungus with terminal bronchiolar epithelial cells. Using the HSAEC1-KT human small airway epithelial (HSAE) cell line, we developed an in vitro model to study the interaction of two strains of A. fumigatus with these cells. We then compared the interactions of A. fumigatus with the A549 type II alveolar epithelial cell line and the HSAE cell line. We found that A. fumigatus conidia were poorly endocytosed by A549 cells, but avidly endocytosed by HSAE cells. A. fumigatus germlings invaded both cell types by induced endocytosis, but not by active penetration. A549 cell endocytosis of A. fumigatus was independent of fungal viability, more dependent on host microfilaments than microtubules, and induced by A. fumigatus CalA interacting with host cell integrin α5β1. By contrast, HSAE cell endocytosis required fungal viability, was more dependent on microtubules than microfilaments, and did not require CalA or integrin α5β1. HSAE cells were more susceptible than A549 cells to damage caused by direct contact with killed A. fumigatus germlings and by secreted fungal products. In response to A. fumigatus infection, A549 cells secreted a broader profile of cytokines and chemokines than HSAE cells. Taken together, these results demonstrate that studies of HSAE cells provide complementary data to A549 cells and thus represent a useful model for probing the interactions of A. fumigatus with bronchiolar epithelial cells in vitro. Importance During the initiation of invasive aspergillosis, Aspergillus fumigatus interacts with the epithelial cells that line the airways and alveoli. Previous studies of A. fumigatus-epithelial cell interactions in vitro used either large airway epithelial cell lines or the A549 type II alveolar epithelial cell line; the interactions of fungi with terminal bronchiolar epithelial cells were not investigated. Using the TERT-immortalized human small airway epithelial HSAEC1-KT (HSAE) cell line, we developed an in vitro model of the interactions of A. fumigatus with bronchiolar epithelial cells. We discovered that A. fumigatus invades and damages A549 and HSAE cell lines by distinct mechanisms. Also, the proinflammatory responses of the cell lines to A. fumigatus are different. These results provide insight into how A. fumigatus interacts with different types of epithelial cells during invasive aspergillosis and demonstrate that HSAE cells are useful in vitro model for investigating the interactions of this fungus with bronchiolar epithelial cells.
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Affiliation(s)
- Hong Liu
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Jianfeng Lin
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Quynh T. Phan
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Fabrice N. Gravelat
- Department of Medicine, Infectious Diseases, and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Donald C. Sheppard
- Department of Medicine, Infectious Diseases, and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Scott G. Filler
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
- David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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8
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Liu H, Lin J, Phan QT, Gravelat FN, Sheppard DC, Filler SG. Use of a human small airway epithelial cell line to study the interactions of Aspergillus fumigatus with pulmonary epithelial cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.18.537379. [PMID: 37131584 PMCID: PMC10153395 DOI: 10.1101/2023.04.18.537379] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
During the initiation of invasive aspergillosis, inhaled Aspergillus fumigatus conidia are deposited on the epithelial cells lining the bronchi, terminal bronchioles, and alveoli. While the interactions of A. fumigatus with bronchial and type II alveolar cell lines have been investigated in vitro , little is known about the interactions of this fungus with terminal bronchiolar epithelial cells. We compared the interactions of A. fumigatus with the A549 type II alveolar epithelial cell line and the HSAEC1-KT human small airway epithelial (HSAE) cell line. We found that A. fumigatus conidia were poorly endocytosed by A549 cells, but avidly endocytosed by HSAE cells. A. fumigatus germlings invaded both cell types by induced endocytosis, but not by active penetration. A549 cell endocytosis of A. fumigatus was independent of fungal viability, more dependent on host microfilaments than microtubules, and induced by A. fumigatus CalA interacting with host cell integrin α5β1. By contrast, HSAE cell endocytosis required fungal viability, was more dependent on microtubules than microfilaments, and did not require CalA or integrin α5β1. HSAE cells were more susceptible than A549 cells to damage caused by direct contact with killed A. fumigatus germlings and by secreted fungal products. In response to A. fumigatus infection, A549 cells secreted a broader profile of cytokines and chemokines than HSAE cells. Taken together, these results demonstrate that studies of HSAE cells provide complementary data to A549 cells and thus represent a useful model for probing the interactions of A. fumigatus with bronchiolar epithelial cells in vitro . Importance During the initiation of invasive aspergillosis, Aspergillus fumigatus invades, damages, and stimulates the epithelial cells that line the airways and alveoli. Previous studies of A. fumigatus - epithelial cell interactions in vitro have used either large airway epithelial cell lines or the A549 type II alveolar epithelial cell line. The interactions of fungi with terminal bronchiolar epithelial cells have not been investigated. Here, we compared the interactions of A. fumigatus with A549 cells and the Tert-immortalized human small airway epithelial HSAEC1-KT (HSAE) cell line. We discovered that A. fumigatus invades and damages these two cell lines by distinct mechanisms. Also, the proinflammatory responses of the cell lines to A. fumigatus are different. These results provide insight into how A. fumigatus interacts with different types of epithelial cells during invasive aspergillosis and demonstrate that HSAE cells are useful in vitro model for investigating the interactions of this fungus with bronchiolar epithelial cells.
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9
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Jia LJ, Rafiq M, Radosa L, Hortschansky P, Cunha C, Cseresnyés Z, Krüger T, Schmidt F, Heinekamp T, Straßburger M, Löffler B, Doenst T, Lacerda JF, Campos A, Figge MT, Carvalho A, Kniemeyer O, Brakhage AA. Aspergillus fumigatus hijacks human p11 to redirect fungal-containing phagosomes to non-degradative pathway. Cell Host Microbe 2023; 31:373-388.e10. [PMID: 36893734 PMCID: PMC10016320 DOI: 10.1016/j.chom.2023.02.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 11/28/2022] [Accepted: 02/03/2023] [Indexed: 03/10/2023]
Abstract
The decision whether endosomes enter the degradative or recycling pathway in mammalian cells is of fundamental importance for pathogen killing, and its malfunctioning has pathological consequences. We discovered that human p11 is a critical factor for this decision. The HscA protein present on the conidial surface of the human-pathogenic fungus Aspergillus fumigatus anchors p11 on conidia-containing phagosomes (PSs), excludes the PS maturation mediator Rab7, and triggers binding of exocytosis mediators Rab11 and Sec15. This reprogramming redirects PSs to the non-degradative pathway, allowing A. fumigatus to escape cells by outgrowth and expulsion as well as transfer of conidia between cells. The clinical relevance is supported by the identification of a single nucleotide polymorphism in the non-coding region of the S100A10 (p11) gene that affects mRNA and protein expression in response to A. fumigatus and is associated with protection against invasive pulmonary aspergillosis. These findings reveal the role of p11 in mediating fungal PS evasion.
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Affiliation(s)
- Lei-Jie Jia
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), 07745 Jena, Germany
| | - Muhammad Rafiq
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), 07745 Jena, Germany; Institute of Microbiology, Friedrich Schiller University, 07745 Jena, Germany
| | - Lukáš Radosa
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), 07745 Jena, Germany
| | - Peter Hortschansky
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), 07745 Jena, Germany
| | - Cristina Cunha
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | | | - Thomas Krüger
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), 07745 Jena, Germany
| | - Franziska Schmidt
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), 07745 Jena, Germany
| | - Thorsten Heinekamp
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), 07745 Jena, Germany
| | | | - Bettina Löffler
- Institute of Medical Microbiology, Jena University Hospital, 07747 Jena, Germany
| | - Torsten Doenst
- Klinik für Herz- und Thoraxchirurgie, Jena University Hospital, 07747 Jena, Germany
| | - João F Lacerda
- Serviço de Hematologia e Transplantação de Medula, Hospital de Santa Maria, 1649-035 Lisboa, Portugal; Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - António Campos
- Serviço de Transplantação de Medula Óssea, Instituto Português de Oncologia do Porto, 4200-072 Porto, Portugal
| | - Marc Thilo Figge
- Institute of Microbiology, Friedrich Schiller University, 07745 Jena, Germany; Research Group Applied Systems Biology, Leibniz-HKI, Jena, Germany
| | - Agostinho Carvalho
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Olaf Kniemeyer
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), 07745 Jena, Germany
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), 07745 Jena, Germany; Institute of Microbiology, Friedrich Schiller University, 07745 Jena, Germany.
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10
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Abstract
The respiratory tree maintains sterilizing immunity against human fungal pathogens. Humans inhale ubiquitous filamentous molds and geographically restricted dimorphic fungal pathogens that form small airborne conidia. In addition, pathogenic yeasts, exemplified by encapsulated Cryptococcus species, and Pneumocystis pose significant fungal threats to the lung. Classically, fungal pneumonia occurs in immune compromised individuals, specifically in patients with HIV/AIDS, in patients with hematologic malignancies, in organ transplant recipients, and in patients treated with corticosteroids and targeted biologics that impair fungal immune surveillance in the lung. The emergence of fungal co-infections during severe influenza and COVID-19 underscores the impairment of fungus-specific host defense pathways in the lung by respiratory viruses and by medical therapies to treat viral infections. Beyond life-threatening invasive syndromes, fungal antigen exposure can exacerbate allergenic disease in the lung. In this review, we discuss emerging principles of lung-specific antifungal immunity, integrate the contributions and cooperation of lung epithelial, innate immune, and adaptive immune cells to mucosal barrier immunity, and highlight the pathogenesis of fungal-associated allergenic disease. Improved understanding of fungus-specific immunity in the respiratory tree has paved the way to develop improved diagnostic, pre-emptive, therapeutic, and vaccine approaches for fungal diseases of the lung.
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Affiliation(s)
- Lena J Heung
- Division of Infectious Diseases, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA; Research Division of Immunology, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA; Women's Guild Lung Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Darin L Wiesner
- Center for Immunity and Inflammation, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, NJ, USA
| | - Keyi Wang
- Center for Immunity and Inflammation, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, NJ, USA
| | - Amariliz Rivera
- Center for Immunity and Inflammation, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, NJ, USA
| | - Tobias M Hohl
- Infectious Disease Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
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11
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Woodring T, Deepe GS, Levitz SM, Wuethrich M, Klein BS. They shall not grow mold: Soldiers of innate and adaptive immunity to fungi. Semin Immunol 2023; 65:101673. [PMID: 36459927 PMCID: PMC10311222 DOI: 10.1016/j.smim.2022.101673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Indexed: 11/30/2022]
Abstract
Fungi are ubiquitous commensals, seasoned predators, and important agents of emerging infectious diseases [1 ]. The immune system assumes the essential responsibility for responding intelligently to the presence of known and novel fungi to maintain host health. In this Review, we describe the immune responses to pathogenic fungi and the varied array of fungal agents confronting the vertebrate host within the broader context of fungal and animal evolution. We provide an overview of the mechanistic details of innate and adaptive antifungal immune responses, as well as ways in which these basic mechanisms support the development of vaccines and immunotherapies.
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Affiliation(s)
- Therese Woodring
- Departments of Pediatrics, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI, USA
| | - George S Deepe
- Department of Medicine, Division of Infectious Diseases, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Stuart M Levitz
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Marcel Wuethrich
- Departments of Pediatrics, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI, USA
| | - Bruce S Klein
- Departments of Pediatrics, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI, USA; Departments of Internal Medicine, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI, USA; Departments of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison WI, USA.
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12
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Rahman S, van Rhijn N, Papastamoulis P, Thomson DD, Carter Z, Fortune-Grant R, Rattray M, Bromley MJ, Bignell E. Distinct Cohorts of Aspergillus fumigatus Transcription Factors Are Required for Epithelial Damage Occurring via Contact- or Soluble Effector-Mediated Mechanisms. Front Cell Infect Microbiol 2022; 12:907519. [PMID: 35982778 PMCID: PMC9379863 DOI: 10.3389/fcimb.2022.907519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 05/18/2022] [Indexed: 11/16/2022] Open
Abstract
Damage to the lung epithelium is a unifying feature of disease caused by the saprophytic fungus Aspergillus fumigatus. However, the mechanistic basis and the regulatory control of such damage is poorly characterized. Previous studies have identified A. fumigatus mediated pathogenesis as occurring at early (≤ 16 hours) or late (>16 hours) phases of the fungal interaction with epithelial cells, and respectively involve direct contact with the host cell or the action of soluble factors produced by mature fungal hyphae. Both early and late phases of epithelial damage have been shown to be subject to genetic regulation by the pH-responsive transcription factor PacC. This study sought to determine whether other transcriptional regulators play a role in modulating epithelial damage. In particular, whether the early and late phases of epithelial damage are governed by same or distinct regulators. Furthermore, whether processes such as spore uptake and hyphal adhesion, that have previously been documented to promote epithelial damage, are governed by the same cohorts of epithelial regulators. Using 479 strains from the recently constructed library of A. fumigatus transcription factor null mutants, two high-throughput screens assessing epithelial cell detachment and epithelial cell lysis were conducted. A total of 17 transcription factor mutants were found to exhibit reproducible deficits in epithelial damage causation. Of these, 10 mutants were defective in causing early phase damage via epithelial detachment and 8 mutants were defective in causing late phase damage via epithelial lysis. Remarkably only one transcription factor, PacC, was required for causation of both phases of epithelial damage. The 17 mutants exhibited varied and often unique phenotypic profiles with respect to fitness, epithelial adhesion, cell wall defects, and rates of spore uptake by epithelial cells. Strikingly, 9 out of 10 mutants deficient in causing early phase damage also exhibited reduced rates of hyphal extension, and culture supernatants of 7 out of 8 mutants deficient in late phase damage were significantly less cytotoxic. Our study delivers the first high-level overview of A. fumigatus regulatory genes governing lung epithelial damage, suggesting highly coordinated genetic orchestration of host-damaging activities that govern epithelial damage in both space and time.
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Affiliation(s)
- Sayema Rahman
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Norman van Rhijn
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | | | - Darren D Thomson
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- MRC Centre for Medical Mycology, University of Exeter, Exeter, United Kingdom
| | - Zorana Carter
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Rachael Fortune-Grant
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Magnus Rattray
- Division of Informatics, School of Heath Sciences, University of Manchester, Manchester, United Kingdom
| | - Michael John Bromley
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Elaine Bignell
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- MRC Centre for Medical Mycology, University of Exeter, Exeter, United Kingdom
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13
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Verburg K, van Neer J, Duca M, de Cock H. Novel Treatment Approach for Aspergilloses by Targeting Germination. J Fungi (Basel) 2022; 8:758. [PMID: 35893126 PMCID: PMC9331470 DOI: 10.3390/jof8080758] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/03/2022] [Accepted: 07/19/2022] [Indexed: 12/24/2022] Open
Abstract
Germination of conidia is an essential process within the Aspergillus life cycle and plays a major role during the infection of hosts. Conidia are able to avoid detection by the majority of leukocytes when dormant. Germination can cause severe health problems, specifically in immunocompromised people. Aspergillosis is most often caused by Aspergillus fumigatus (A. fumigatus) and affects neutropenic patients, as well as people with cystic fibrosis (CF). These patients are often unable to effectively detect and clear the conidia or hyphae and can develop chronic non-invasive and/or invasive infections or allergic inflammatory responses. Current treatments with (tri)azoles can be very effective to combat a variety of fungal infections. However, resistance against current azoles has emerged and has been increasing since 1998. As a consequence, patients infected with resistant A. fumigatus have a reported mortality rate of 88% to 100%. Especially with the growing number of patients that harbor azole-resistant Aspergilli, novel antifungals could provide an alternative. Aspergilloses differ in defining characteristics, but germination of conidia is one of the few common denominators. By specifically targeting conidial germination with novel antifungals, early intervention might be possible. In this review, we propose several morphotypes to disrupt conidial germination, as well as potential targets. Hopefully, new antifungals against such targets could contribute to disturbing the ability of Aspergilli to germinate and grow, resulting in a decreased fungal burden on patients.
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Affiliation(s)
- Kim Verburg
- Molecular Microbiology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands; (K.V.); (J.v.N.)
| | - Jacq van Neer
- Molecular Microbiology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands; (K.V.); (J.v.N.)
| | - Margherita Duca
- Department of Chemical Biology & Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CG Utrecht, The Netherlands;
| | - Hans de Cock
- Molecular Microbiology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands; (K.V.); (J.v.N.)
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14
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Matthaiou EI, Chiu W, Conrad C, Hsu J. Macrophage Lysosomal Alkalinization Drives Invasive Aspergillosis in a Mouse Cystic Fibrosis Model of Airway Transplantation. J Fungi (Basel) 2022; 8:751. [PMID: 35887506 PMCID: PMC9321820 DOI: 10.3390/jof8070751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 07/05/2022] [Accepted: 07/08/2022] [Indexed: 01/25/2023] Open
Abstract
Cystic fibrosis (CF) lung transplant recipients (LTRs) exhibit a disproportionately high rate of life-threatening invasive aspergillosis (IA). Loss of the cystic fibrosis transmembrane conductance regulator (CFTR-/-) in macrophages (mφs) has been associated with lyosomal alkalinization. We hypothesize that this alkalinization would persist in the iron-laden post-transplant microenvironment increasing the risk of IA. To investigate our hypothesis, we developed a murine CF orthotopic tracheal transplant (OTT) model. Iron levels were detected by immunofluorescence staining and colorimetric assays. Aspergillus fumigatus (Af) invasion was evaluated by Grocott methenamine silver staining. Phagocytosis and killing of Af conidia were examined by flow cytometry and confocal microscopy. pH and lysosomal acidification were measured by LysoSensorTM and LysotrackerTM, respectively. Af was more invasive in the CF airway transplant recipient compared to the WT recipient (p < 0.05). CFTR-/- mφs were alkaline at baseline, a characteristic that was increased with iron-overload. These CFTR-/- mφs were unable to phagocytose and kill Af conidia (p < 0.001). Poly(lactic-co-glycolic acid) (PLGA) nanoparticles acidified lysosomes, restoring the CFTR-/- mφs’ ability to clear conidia. Our results suggest that CFTR-/- mφs’ alkalinization interacts with the iron-loaded transplant microenvironment, decreasing the CF-mφs’ ability to kill Af conidia, which may explain the increased risk of IA. Therapeutic pH modulation after transplantation could decrease the risk of IA.
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Affiliation(s)
- Efthymia Iliana Matthaiou
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Stanford University School of Medicine, Stanford, CA 94304, USA; (E.I.M.); (W.C.)
| | - Wayland Chiu
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Stanford University School of Medicine, Stanford, CA 94304, USA; (E.I.M.); (W.C.)
- Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Carol Conrad
- Department of Pediatrics, Pulmonary Medicine, Stanford University School of Medicine, Stanford, CA 94304, USA;
| | - Joe Hsu
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Stanford University School of Medicine, Stanford, CA 94304, USA; (E.I.M.); (W.C.)
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15
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Michels K, Solomon AL, Scindia Y, Sordo Vieira L, Goddard Y, Whitten S, Vaulont S, Burdick MD, Atkinson C, Laubenbacher R, Mehrad B. Aspergillus Utilizes Extracellular Heme as an Iron Source During Invasive Pneumonia, Driving Infection Severity. J Infect Dis 2022; 225:1811-1821. [PMID: 35267014 PMCID: PMC9113461 DOI: 10.1093/infdis/jiac079] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 03/01/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Depriving microbes of iron is critical to host defense. Hemeproteins, the largest source of iron within vertebrates, are abundant in infected tissues in aspergillosis due to hemorrhage, but Aspergillus species have been thought to lack heme import mechanisms. We hypothesized that heme provides iron to Aspergillus during invasive pneumonia, thereby worsening the outcomes of the infection. METHODS We assessed the effect of heme on fungal phenotype in various in vitro conditions and in a neutropenic mouse model of invasive pulmonary aspergillosis. RESULTS In mice with neutropenic invasive aspergillosis, we found a progressive and compartmentalized increase in lung heme iron. Fungal cells cultured under low iron conditions took up heme, resulting in increased fungal iron content, resolution of iron starvation, increased conidiation, and enhanced resistance to oxidative stress. Intrapulmonary administration of heme to mice with neutropenic invasive aspergillosis resulted in markedly increased lung fungal burden, lung injury, and mortality, whereas administration of heme analogs or heme with killed Aspergillus did not. Finally, infection caused by fungal germlings cultured in the presence of heme resulted in a more severe infection. CONCLUSIONS Invasive aspergillosis induces local hemolysis in infected tissues, thereby supplying heme iron to the fungus, leading to lethal infection.
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Affiliation(s)
- Kathryn Michels
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
| | - Angelica L Solomon
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of Florida, Gainesville, Florida, USA
| | - Yogesh Scindia
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of Florida, Gainesville, Florida, USA
| | - Luis Sordo Vieira
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of Florida, Gainesville, Florida, USA
| | - Yana Goddard
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of Florida, Gainesville, Florida, USA
| | - Spencer Whitten
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of Florida, Gainesville, Florida, USA
| | - Sophie Vaulont
- Université de Paris, INSERM U1016, Institut Cochin, Paris, France
| | - Marie D Burdick
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of Florida, Gainesville, Florida, USA
| | - Carl Atkinson
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of Florida, Gainesville, Florida, USA
| | - Reinhard Laubenbacher
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of Florida, Gainesville, Florida, USA
| | - Borna Mehrad
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of Florida, Gainesville, Florida, USA
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16
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Ortiz SC, Pennington K, Thomson DD, Bertuzzi M. Novel Insights into Aspergillus fumigatus Pathogenesis and Host Response from State-of-the-Art Imaging of Host-Pathogen Interactions during Infection. J Fungi (Basel) 2022; 8:264. [PMID: 35330266 PMCID: PMC8954776 DOI: 10.3390/jof8030264] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 02/21/2022] [Accepted: 03/01/2022] [Indexed: 12/03/2022] Open
Abstract
Aspergillus fumigatus spores initiate more than 3,000,000 chronic and 300,000 invasive diseases annually, worldwide. Depending on the immune status of the host, inhalation of these spores can lead to a broad spectrum of disease, including invasive aspergillosis, which carries a 50% mortality rate overall; however, this mortality rate increases substantially if the infection is caused by azole-resistant strains or diagnosis is delayed or missed. Increasing resistance to existing antifungal treatments is becoming a major concern; for example, resistance to azoles (the first-line available oral drug against Aspergillus species) has risen by 40% since 2006. Despite high morbidity and mortality, the lack of an in-depth understanding of A. fumigatus pathogenesis and host response has hampered the development of novel therapeutic strategies for the clinical management of fungal infections. Recent advances in sample preparation, infection models and imaging techniques applied in vivo have addressed important gaps in fungal research, whilst questioning existing paradigms. This review highlights the successes and further potential of these recent technologies in understanding the host-pathogen interactions that lead to aspergillosis.
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Affiliation(s)
- Sébastien C Ortiz
- Manchester Academic Health Science Centre, Core Technology Facility, Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Grafton Street, Manchester M13 9NT, UK
| | - Katie Pennington
- Manchester Academic Health Science Centre, Core Technology Facility, Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Grafton Street, Manchester M13 9NT, UK
| | - Darren D Thomson
- Medical Research Council Centre for Medical Mycology, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK
| | - Margherita Bertuzzi
- Manchester Academic Health Science Centre, Core Technology Facility, Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Grafton Street, Manchester M13 9NT, UK
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17
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Arunachalam D, Ramanathan SM, Menon A, Madhav L, Ramaswamy G, Namperumalsamy VP, Prajna L, Kuppamuthu D. Expression of immune response genes in human corneal epithelial cells interacting with Aspergillus flavus conidia. BMC Genomics 2022; 23:5. [PMID: 34983375 PMCID: PMC8728928 DOI: 10.1186/s12864-021-08218-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 11/18/2021] [Indexed: 12/19/2022] Open
Abstract
Background Aspergillus flavus, one of the causative agents of human fungal keratitis, can be phagocytosed by human corneal epithelial (HCE) cells and the conidia containing phagosomes mature into phagolysosomes. But the immunological responses of human corneal epithelial cells interacting with A. flavus are not clear. In this study, we report the expression of immune response related genes of HCE cells exposed to A. flavus spores using targeted transcriptomics. Methods Human corneal epithelial cell line and primary cultures were grown in a six-well plate and used for coculture experiments. Internalization of the conidia was confirmed by immunofluorescence microscopy of the colocalized endosomal markers CD71 and LAMP1. Total RNA was isolated, and the quantity and quality of the isolated RNA were assessed using Qubit and Bioanalyzer. NanoString nCounter platform was used for the analysis of mRNA abundance using the Human Immunology panel. R-package and nSolver software were used for data analysis. KEGG and FunRich 3.1.3 tools were used to analyze the differentially expressed genes. Results Different morphotypes of conidia were observed after 6 h of coculture with human corneal epithelial cells and found to be internalized by epithelial cells. NanoString profiling showed more than 20 differentially expressed genes in immortalized human corneal epithelial cell line and more than ten differentially expressed genes in primary corneal epithelial cells. Distinct set of genes were altered in their expression in cell line and primary corneal epithelial cells. KEGG pathway analysis revealed that genes associated with TNF signaling, NF-KB signaling, and Th17 signaling were up-regulated, and genes associated with chemokine signaling and B cell receptor signaling were down regulated. FunRich pathway analysis showed that pathways such as CDC42 signaling, PI3K signaling, and Arf6 trafficking events were activated by the clinical isolates CI1123 and CI1698 in both type of cells. Conclusions Combining the transcript analysis data from cell lines and primary cultures, we showed the up regulation of immune defense genes in A. flavus infected cells. At the same time, chemokine signaling and B cell signaling pathways are downregulated. The variability in the expression levels in the immortalized cell line and the primary cultures is likely due to the variable epigenetic reprogramming in the immortalized cells and primary cultures in the absence of any changes in the genome. It highlights the importance of using both cell types in host-pathogen interaction studies. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-08218-5.
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Affiliation(s)
- Divya Arunachalam
- Proteomics Department, Aravind Medical Research Foundation, Dr. G. Venkataswamy Eye Research Institute, Aravind Eye Care System, Madurai, Tamil Nadu, India.,Department of Biotechnology, Alagappa University, Karaikudi, Tamil Nadu, India
| | - Shruthi Mahalakshmi Ramanathan
- Proteomics Department, Aravind Medical Research Foundation, Dr. G. Venkataswamy Eye Research Institute, Aravind Eye Care System, Madurai, Tamil Nadu, India
| | - Athul Menon
- Theracues Innovations Private Limited, Bangalore, India, Karnataka
| | - Lekshmi Madhav
- Theracues Innovations Private Limited, Bangalore, India, Karnataka
| | | | | | - Lalitha Prajna
- Department of Ocular Microbiology, Aravind Eye Hospital, Aravind Eye Care System, Madurai, Tamil Nadu, India
| | - Dharmalingam Kuppamuthu
- Proteomics Department, Aravind Medical Research Foundation, Dr. G. Venkataswamy Eye Research Institute, Aravind Eye Care System, Madurai, Tamil Nadu, India. .,Department of Biotechnology, Alagappa University, Karaikudi, Tamil Nadu, India. .,Aravind Medical Research Foundation, Dr. G.Venkataswamy Eye Research Institute, Aravind Eye Care System, No.1 Anna Nagar, Madurai, Tamil Nadu, India.
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18
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Ouyang H, Zhang Y, Zhou H, Ma Y, Li R, Yang J, Wang X, Jin C. Deficiency of GPI Glycan Modification by Ethanolamine Phosphate Results in Increased Adhesion and Immune Resistance of Aspergillus fumigatus. Front Cell Infect Microbiol 2021; 11:780959. [PMID: 34956933 PMCID: PMC8695850 DOI: 10.3389/fcimb.2021.780959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 11/18/2021] [Indexed: 11/13/2022] Open
Abstract
Glycosylphosphatidylinositol (GPI)-anchored proteins play important roles in maintaining the function of the cell wall and participating in pathogenic processes. The addition and removal of phosphoethanolamine (EtN-P) on the second mannose residue in the GPI anchor are vital for maturation and sorting of GPI-anchored proteins. Previously, we have shown that deletion of the gpi7, the gene that encodes an EtN-P transferase responsible for the addition of EtN-P to the second mannose residue of the GPI anchor, leads to the mislocalization of GPI-anchored proteins, abnormal polarity, reduced conidiation, and fast germination in Aspergillus fumigatus. In this report, the adherence and virulence of the A. fumigatus gpi7 deletion mutant were further investigated. The germinating conidia of the mutant exhibited an increased adhesion and a higher exposure of cell wall polysaccharides. Although the virulence was not affected, an increased adherence and a stronger inflammation response of the mutant were documented in an immunocompromised mouse model. An in vitro assay confirmed that the Δgpi7 mutant induced a stronger immune response and was more resistant to killing. Our findings, for the first time, demonstrate that in A. fumigatus, GPI anchoring is required for proper organization of the conidial cell wall. The lack of Gpi7 leads to fast germination, stronger immune response, and resistance to macrophage killing.
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Affiliation(s)
- Haomiao Ouyang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yi Zhang
- Department of Dermatology and Venerology, Peking University First Hospital, Beijing, China.,Research Center for Medical Mycology, Peking University, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Peking University First Hospital, Beijing, China.,National Clinical Research Center for Skin and Immune Diseases, Peking University First Hospital, Beijing, China
| | - Hui Zhou
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yubo Ma
- Department of Dermatology and Venerology, Peking University First Hospital, Beijing, China.,Research Center for Medical Mycology, Peking University, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Peking University First Hospital, Beijing, China.,National Clinical Research Center for Skin and Immune Diseases, Peking University First Hospital, Beijing, China
| | - Ruoyu Li
- Department of Dermatology and Venerology, Peking University First Hospital, Beijing, China.,Research Center for Medical Mycology, Peking University, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Peking University First Hospital, Beijing, China.,National Clinical Research Center for Skin and Immune Diseases, Peking University First Hospital, Beijing, China
| | - Jinghua Yang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xiaowen Wang
- Department of Dermatology and Venerology, Peking University First Hospital, Beijing, China.,Research Center for Medical Mycology, Peking University, Beijing, China.,Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Peking University First Hospital, Beijing, China.,National Clinical Research Center for Skin and Immune Diseases, Peking University First Hospital, Beijing, China
| | - Cheng Jin
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
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19
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Ewald J, Rivieccio F, Radosa L, Schuster S, Brakhage AA, Kaleta C. Dynamic optimization reveals alveolar epithelial cells as key mediators of host defense in invasive aspergillosis. PLoS Comput Biol 2021; 17:e1009645. [PMID: 34898608 PMCID: PMC8699926 DOI: 10.1371/journal.pcbi.1009645] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 12/23/2021] [Accepted: 11/15/2021] [Indexed: 11/18/2022] Open
Abstract
Aspergillus fumigatus is an important human fungal pathogen and its conidia are constantly inhaled by humans. In immunocompromised individuals, conidia can grow out as hyphae that damage lung epithelium. The resulting invasive aspergillosis is associated with devastating mortality rates. Since infection is a race between the innate immune system and the outgrowth of A. fumigatus conidia, we use dynamic optimization to obtain insight into the recruitment and depletion of alveolar macrophages and neutrophils. Using this model, we obtain key insights into major determinants of infection outcome on host and pathogen side. On the pathogen side, we predict in silico and confirm in vitro that germination speed is an important virulence trait of fungal pathogens due to the vulnerability of conidia against host defense. On the host side, we found that epithelial cells, which have been underappreciated, play a role in fungal clearance and are potent mediators of cytokine release. Both predictions were confirmed by in vitro experiments on established cell lines as well as primary lung cells. Further, our model affirms the importance of neutrophils in invasive aspergillosis and underlines that the role of macrophages remains elusive. We expect that our model will contribute to improvement of treatment protocols by focusing on the critical components of immune response to fungi but also fungal virulence traits.
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Affiliation(s)
- Jan Ewald
- Department of Bioinformatics, Friedrich Schiller University Jena, Jena, Germany.,Center for Scalable Data Analytics and Artificial Intelligence (ScaDS.AI), University of Leipzig, Leipzig, Germany
| | - Flora Rivieccio
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Jena, Germany.,Department of Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Lukáš Radosa
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Jena, Germany
| | - Stefan Schuster
- Department of Bioinformatics, Friedrich Schiller University Jena, Jena, Germany
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Jena, Germany.,Department of Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Christoph Kaleta
- Research Group Medical Systems Biology, Institute of Experimental Medicine, Kiel University, Kiel, Germany
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20
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Ghosh A, Sarkar A, Paul P, Patel P. The rise in cases of mucormycosis, candidiasis and aspergillosis amidst COVID19. FUNGAL BIOL REV 2021; 38:67-91. [PMID: 34548877 PMCID: PMC8445778 DOI: 10.1016/j.fbr.2021.09.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 09/05/2021] [Accepted: 09/08/2021] [Indexed: 12/15/2022]
Abstract
The Coronavirus outbreak globally has changed the medical system and also led to a shortage of medical facilities in both developing and underdeveloped countries. The COVID19 disease, being novel in nature along with high infectivity and frequent mutational rate, has been termed to be fatal across the globe. The advent of infection by SARS-CoV-2 has brought a myriad of secondary complications and comorbidities resulting in additional challenges to the health care system induced by novel therapeutic procedures. The emerging variant with respect to the Indian subcontinent and the associated genetic mutations have worsened the situation at hand. Proper clinical management along with epidemiological studies and clinical presentations in scientific studies and trials is necessary in order to combat the simultaneous waves of emerging strains. This article summarizes three of the major fungal outbreaks in India namely mucormycosis, candidiasis and aspergillosis, and elaborates their subtypes, pathogenesis, symptoms and treatment and detection techniques. A detail of future therapeutics under consideration are also elaborated along with a general hypothesis on how COVID19 is related to immunological advances leading to major widespread fungal infection in the country. The factors that contribute in promoting virus proliferation and invasive fungal infections include cell-mediated immunity, associated immunocompromised conditions and treatment protocols that slows down immune mechanisms. To better comprehend a fungal or bacterial outbreak, it is very important to conduct audits mediated through multicenter national and state research teams for recognizing patterns and studying current cases of fungal infection in both healthy and comorbid groups of COVID19 patients.
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Affiliation(s)
- Asmita Ghosh
- Department of Biotechnology, Heritage Institute of Technology, Kolkata 700107, West Bengal, India
| | - Anusua Sarkar
- Department of Biotechnology, Heritage Institute of Technology, Kolkata 700107, West Bengal, India
| | - Pubali Paul
- Department of Biotechnology, Heritage Institute of Technology, Kolkata 700107, West Bengal, India
| | - Parth Patel
- H. K. College of Pharmacy, Jogeshwari West, Mumbai 400102, Maharashtra, India
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21
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Schiefermeier-Mach N, Perkhofer S, Heinrich L, Haller T. Stimulation of surfactant exocytosis in primary alveolar type II cells by A. fumigatus. Med Mycol 2021; 59:168-179. [PMID: 32459847 DOI: 10.1093/mmy/myaa042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 04/06/2020] [Accepted: 04/30/2020] [Indexed: 02/06/2023] Open
Abstract
Aspergillus fumigatus is an opportunistic fungal pathogen with small airborne spores (conidia) that may escape clearance by upper airways and directly impact the alveolar epithelium. Consequently, innate alveolar defense mechanisms are being activated, including professional phagocytosis by alveolar macrophages, recruitment of circulating neutrophils and probably enhanced secretion of pulmonary surfactant by the alveolar type II (AT II) cells. However, no data are available in support of the latter hypothesis. We therefore used a coculture model of GFP-Aspergillus conidia with primary rat AT II cells and studied fungal growth, cellular Ca2+ homeostasis, and pulmonary surfactant exocytosis by live cell video microscopy. We observed all stages of fungal development, including reversible attachment, binding and internalization of conidia as well as conidial swelling, formation of germ tubes and outgrowth of hyphae. In contrast to resting conidia, which did not provoke immediate cellular effects, metabolically active conidia, fungal cellular extracts (CE) and fungal culture filtrates (CF) prepared from swollen conidia caused a Ca2+-independent exocytosis. Ca2+ signals of greatly varying delays, durations and amplitudes were observed by applying CE or CF obtained from hyphae of A. fumigatus, suggesting compounds secreted by filamentous A. fumigatus that severely interfere with AT II cell Ca2+ homeostasis. The mechanisms underlying the stimulatory effects, with respect to exocytosis and Ca2+ signaling, are unclear and need to be identified.
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Affiliation(s)
| | - Susanne Perkhofer
- FH Gesundheit, Health University of Applied Sciences Tyrol, Innrain 98, A-6020 Innsbruck, Austria
| | - Lea Heinrich
- FH Gesundheit, Health University of Applied Sciences Tyrol, Innrain 98, A-6020 Innsbruck, Austria.,Department of Physiology and Medical Physics, Institute of Physiology, Medical University of Innsbruck, Schöpfstrasse 41, A-6020 Innsbruck, Austria
| | - Thomas Haller
- Department of Physiology and Medical Physics, Institute of Physiology, Medical University of Innsbruck, Schöpfstrasse 41, A-6020 Innsbruck, Austria
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22
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Rowley J, Namvar S, Gago S, Labram B, Bowyer P, Richardson MD, Herrick SE. Differential Proinflammatory Responses to Aspergillus fumigatus by Airway Epithelial Cells In Vitro Are Protease Dependent. J Fungi (Basel) 2021; 7:468. [PMID: 34200666 PMCID: PMC8228831 DOI: 10.3390/jof7060468] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/29/2021] [Accepted: 06/03/2021] [Indexed: 12/05/2022] Open
Abstract
Aspergillus fumigatus is an important human respiratory mould pathogen. In addition to a barrier function, airway epithelium elicits a robust defence against inhaled A. fumigatus by initiating an immune response. The manner by which A. fumigatus initiates this response and the reasons for the immunological heterogeneity with different isolates are unclear. Both direct fungal cell wall-epithelial cell interaction and secretion of soluble proteases have been proposed as possible mechanisms. Our aim was to determine the contribution of fungal proteases to the induction of epithelial IL-6 and IL-8 in response to different A. fumigatus isolates. Airway epithelial cells were exposed to conidia from a low or high protease-producing strain of A. fumigatus, and IL-6 and IL-8 gene expression and protein production were quantified. The role of proteases in cytokine production was further determined using specific protease inhibitors. The proinflammatory cytokine response correlated with conidia germination and hyphal extension. IL-8 induction was significantly reduced in the presence of matrix metalloprotease or cysteine protease inhibitors. With a high protease-producing strain of A. fumigatus, IL-6 release was metalloprotease dependent. Dectin-1 antagonism also inhibited the production of both cytokines. In conclusion, A. fumigatus-secreted proteases mediate a proinflammatory response by airway epithelial cells in a strain-dependent manner.
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Affiliation(s)
- Jessica Rowley
- School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester and Manchester Academic Health Science Centre, Manchester M13 9PT, UK; (J.R.); (S.N.); (S.G.); (B.L.); (P.B.); (M.D.R.)
| | - Sara Namvar
- School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester and Manchester Academic Health Science Centre, Manchester M13 9PT, UK; (J.R.); (S.N.); (S.G.); (B.L.); (P.B.); (M.D.R.)
- School of Science, Engineering and Environment, University of Salford, Salford M5 4WT, UK
| | - Sara Gago
- School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester and Manchester Academic Health Science Centre, Manchester M13 9PT, UK; (J.R.); (S.N.); (S.G.); (B.L.); (P.B.); (M.D.R.)
- Manchester Fungal Infection Group, Division of Infection, Immunity and Respiratory Medicine, University of Manchester, Manchester M13 9NT, UK
- NIHR Manchester Biomedical Research Centre, Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, Manchester M23 9LT, UK
| | - Briony Labram
- School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester and Manchester Academic Health Science Centre, Manchester M13 9PT, UK; (J.R.); (S.N.); (S.G.); (B.L.); (P.B.); (M.D.R.)
| | - Paul Bowyer
- School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester and Manchester Academic Health Science Centre, Manchester M13 9PT, UK; (J.R.); (S.N.); (S.G.); (B.L.); (P.B.); (M.D.R.)
- Manchester Fungal Infection Group, Division of Infection, Immunity and Respiratory Medicine, University of Manchester, Manchester M13 9NT, UK
| | - Malcolm D. Richardson
- School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester and Manchester Academic Health Science Centre, Manchester M13 9PT, UK; (J.R.); (S.N.); (S.G.); (B.L.); (P.B.); (M.D.R.)
- Manchester Fungal Infection Group, Division of Infection, Immunity and Respiratory Medicine, University of Manchester, Manchester M13 9NT, UK
- NIHR Manchester Biomedical Research Centre, Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, Manchester M23 9LT, UK
- Mycology Reference Centre, ECMM Excellence Centre of Medical Mycology, Manchester University NHS Foundation Trust, Manchester M23 9LT, UK
| | - Sarah E. Herrick
- School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester and Manchester Academic Health Science Centre, Manchester M13 9PT, UK; (J.R.); (S.N.); (S.G.); (B.L.); (P.B.); (M.D.R.)
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23
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Evaluation of Stable LifeAct-mRuby2- and LAMP1-NeonGreen Expressing A549 Cell Lines for Investigation of Aspergillus fumigatus Interaction with Pulmonary Cells. Int J Mol Sci 2021; 22:ijms22115965. [PMID: 34073107 PMCID: PMC8198894 DOI: 10.3390/ijms22115965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 05/29/2021] [Indexed: 11/20/2022] Open
Abstract
Inhaled Aspergillus fumigatus spores can be internalized by alveolar type II cells. Cell lines stably expressing fluorescently labeled components of endocytic pathway enable investigations of intracellular organization during conidia internalization and measurement of the process kinetics. The goal of this report was to evaluate the methodological appliance of cell lines for studying fungal conidia internalization. We have generated A549 cell lines stably expressing fluorescently labeled actin (LifeAct-mRuby2) and late endosomal protein (LAMP1-NeonGreen) following an evaluation of cell-pathogen interactions in live and fixed cells. Our data show that the LAMP1-NeonGreen cell line can be used to visualize conidia co-localization with LAMP1 in live and fixed cells. However, caution is necessary when using LifeAct-mRuby2-cell lines as it may affect the conidia internalization dynamics.
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24
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Human Corneal Epithelial Cells Internalize Aspergillus flavus Spores by Actin-Mediated Endocytosis. Infect Immun 2021; 89:IAI.00794-20. [PMID: 33753415 DOI: 10.1128/iai.00794-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 03/03/2021] [Indexed: 01/09/2023] Open
Abstract
Human corneal epithelial (HCE) cells play a significant role in the innate immune response by secreting cytokines and antimicrobial peptides when they encounter fungal pathogens. But the detailed mechanism of attachment and engulfment of the fungal conidia by HCE cells is not well understood. Here, we show the phagocytosis of Aspergillus flavus conidia by RCB2280 cells and primary HCE cultures using confocal microscopy and proteomic analysis of conidium-containing phagosomes. Phalloidin staining showed actin polymerization, leading to an actin ring around engulfed conidia. Cytochalasin D inhibited the actin-mediated endocytosis of the conidia. Immunolabeling of the early endosomal markers CD71 and early endosomal antigen (EEA1) and the late endosomal markers lysosome-associated membrane protein 1 (LAMP1), Rab7, and cathepsin G showed that endosomal proteins were recruited to the site of conidia and showed maturation of the conidium-containing phagosomes. Lysotracker red DND 99 labeling showed the acidification of the phagosomes containing conidia. Phagosome-specific proteome analysis confirmed the recruitment of various phagosomal and endosomal proteins to the conidium-containing phagosomes. These results show that the ocular surface epithelium contributes actively to antifungal defense by the phagocytosis of invading fungal conidia.
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25
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Warner EF, Bohálová N, Brázda V, Waller ZAE, Bidula S. Analysis of putative quadruplex-forming sequences in fungal genomes: novel antifungal targets? Microb Genom 2021; 7:000570. [PMID: 33956596 PMCID: PMC8209732 DOI: 10.1099/mgen.0.000570] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/26/2021] [Indexed: 12/26/2022] Open
Abstract
Fungal infections cause >1 million deaths annually and the emergence of antifungal resistance has prompted the exploration for novel antifungal targets. Quadruplexes are four-stranded nucleic acid secondary structures, which can regulate processes such as transcription, translation, replication and recombination. They are also found in genes linked to virulence in microbes, and ligands that bind to quadruplexes can eliminate drug-resistant pathogens. Using a computational approach, we quantified putative quadruplex-forming sequences (PQS) in 1359 genomes across the fungal kingdom and explored their presence in genes related to virulence, drug resistance and biological processes associated with pathogenicity in Aspergillus fumigatus. Here we present the largest analysis of PQS in fungi and identify significant heterogeneity of these sequences throughout phyla, genera and species. PQS were genetically conserved in Aspergillus spp. and frequently pathogenic species appeared to contain fewer PQS than their lesser/non-pathogenic counterparts. GO-term analysis identified that PQS-containing genes were involved in processes linked with virulence such as zinc ion binding, the biosynthesis of secondary metabolites and regulation of transcription in A. fumigatus. Although the genome frequency of PQS was lower in A. fumigatus, PQS could be found enriched in genes involved in virulence, and genes upregulated during germination and hypoxia. Moreover, PQS were found in genes involved in drug resistance. Quadruplexes could have important roles within fungal biology and virulence, but their roles require further elucidation.
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Affiliation(s)
- Emily F. Warner
- School of Clinical Medicine, University of Cambridge, Cambridge, UK
- Present address: Ikarovec Limited, Norwich Research Park Innovation Centre, Norwich, UK
| | - Natália Bohálová
- Institute of Biophysics of the Czech Academy of Sciences, Brno, Czechia
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czechia
| | - Václav Brázda
- Institute of Biophysics of the Czech Academy of Sciences, Brno, Czechia
| | | | - Stefan Bidula
- School of Biological Sciences, University of East Anglia, Norwich, UK
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26
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F. Q. Smith D, Casadevall A. Fungal immunity and pathogenesis in mammals versus the invertebrate model organism Galleria mellonella. Pathog Dis 2021; 79:ftab013. [PMID: 33544836 PMCID: PMC7981337 DOI: 10.1093/femspd/ftab013] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 02/03/2021] [Indexed: 02/07/2023] Open
Abstract
In recent decades, Galleria mellonella (Lepidoptera: Pyralidae) have emerged as a model system to explore experimental aspects of fungal pathogenesis. The benefits of the G. mellonella model include being faster, cheaper, higher throughput and easier compared with vertebrate models. Additionally, as invertebrates, their use is subject to fewer ethical and regulatory issues. However, for G. mellonella models to provide meaningful insight into fungal pathogenesis, the G. mellonella-fungal interactions must be comparable to mammalian-fungal interactions. Indeed, as discussed in the review, studies suggest that G. mellonella and mammalian immune systems share many similarities, and fungal virulence factors show conserved functions in both hosts. While the moth model has opened novel research areas, many comparisons are superficial and leave large gaps of knowledge that need to be addressed concerning specific mechanisms underlying G. mellonella-fungal interactions. Closing these gaps in understanding will strengthen G. mellonella as a model for fungal virulence in the upcoming years. In this review, we provide comprehensive comparisons between fungal pathogenesis in mammals and G. mellonella from immunological and virulence perspectives. When information on an antifungal immune component is unknown in G. mellonella, we include findings from other well-studied Lepidoptera. We hope that by outlining this information available in related species, we highlight areas of needed research and provide a framework for understanding G. mellonella immunity and fungal interactions.
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Affiliation(s)
- Daniel F. Q. Smith
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Arturo Casadevall
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
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27
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Bertuzzi M, Howell GJ. Single-Cell Analysis of Fungal Uptake in Cultured Airway Epithelial Cells Using Differential Fluorescent Staining and Imaging Flow Cytometry. Methods Mol Biol 2021; 2260:83-109. [PMID: 33405032 DOI: 10.1007/978-1-0716-1182-1_6] [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] [Indexed: 03/09/2023]
Abstract
The respiratory epithelium is the initial point of host contact for inhaled particles, leading to orchestrated, but highly heterogeneous, responses. Human airway epithelial cells (AECs) play a crucial role in host defense by promoting uptake and killing of inhaled microorganisms and concomitant cytokine production in order to recruit professional phagocytes to the site of infection. However, inhaled pathogens can also reside and replicate intracellularly to evade host immune defenses or circulating antimicrobial drugs, ultimately causing apoptosis or cell death of the infected AECs. Imaging flow cytometry (IFC) combines flow cytometry, fluorescent microscopy, and advanced data-processing algorithms to dissect the heterogeneity of the interaction of AECs and inhaled microorganisms and its outcomes at the single-cell level. Here, we describe a novel single-cell approach based on differential fluorescent staining and state-of-the-art IFC to identify, quantify, and analyze individual host-pathogen complexes from cultured AECs infected with spores of the major human fungal pathogen Aspergillus fumigatus.
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Affiliation(s)
- Margherita Bertuzzi
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, Core Technology Facility Building, The University of Manchester, Manchester, UK.
- Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK.
| | - Gareth J Howell
- Flow Cytometry Core Facility, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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28
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Seidel C, Moreno-Velásquez SD, Ben-Ghazzi N, Gago S, Read ND, Bowyer P. Phagolysosomal Survival Enables Non-lytic Hyphal Escape and Ramification Through Lung Epithelium During Aspergillus fumigatus Infection. Front Microbiol 2020; 11:1955. [PMID: 32973709 PMCID: PMC7468521 DOI: 10.3389/fmicb.2020.01955] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 07/24/2020] [Indexed: 12/20/2022] Open
Abstract
Aspergillus fumigatus is the most important mould pathogen in immunosuppressed patients. Suboptimal clearance of inhaled spores results in the colonisation of the lung airways by invasive hyphae. The first point of contact between A. fumigatus and the host is the lung epithelium. In vitro and ex vivo studies have characterised critical aspects of the interaction of invasive hyphae on the surface of epithelial cells. However, the cellular interplay between internalised A. fumigatus and the lung epithelium remains largely unexplored. Here, we use high-resolution live-cell confocal microscopy, 3D rendered imaging and transmission electron microscopy to define the development of A. fumigatus after lung epithelium internalisation in vitro. Germination, morphology and growth of A. fumigatus were significantly impaired upon internalisation by alveolar (A549) and bronchial (16HBE) lung epithelial cells compared to those growing on the host surface. Internalised spores and germlings were surrounded by the host phagolysosome membrane. Sixty per cent of the phagosomes containing germlings were not acidified at 24 h post infection allowing hyphal development. During escape, the phagolysosomal membrane was not ruptured but likely fused to host plasma membrane allowing hyphal exit from the intact host cell in an non-lytic Manner. Subsequently, escaping hyphae elongated between or through adjacent epithelial lung cells without penetration of the host cytoplasm. Hyphal tips penetrating new epithelial cells were surrounded by the recipient cell plasma membrane. Altogether, our results suggest cells of lung epithelium survive fungal penetration because the phagolysosomal and plasma membranes are never breached and that conversely, fungal spores survive due to phagosome maturation failure. Consequently, fungal hyphae can grow through the epithelial cell layer without directly damaging the host. These processes likely prevent the activation of downstream immune responses alongside limiting the access of professional phagocytes to the invading fungal hypha. Further research is needed to investigate if these events also occur during penetration of fungi in endothelial cells, fibroblasts and other cell types.
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Affiliation(s)
- Constanze Seidel
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Core Technology Facility, Manchester, United Kingdom
| | - Sergio D Moreno-Velásquez
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Core Technology Facility, Manchester, United Kingdom
| | - Nagwa Ben-Ghazzi
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Core Technology Facility, Manchester, United Kingdom
| | - Sara Gago
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Core Technology Facility, Manchester, United Kingdom
| | - Nick D Read
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Core Technology Facility, Manchester, United Kingdom
| | - Paul Bowyer
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Core Technology Facility, Manchester, United Kingdom
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29
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Bigot J, Guillot L, Guitard J, Ruffin M, Corvol H, Balloy V, Hennequin C. Bronchial Epithelial Cells on the Front Line to Fight Lung Infection-Causing Aspergillus fumigatus. Front Immunol 2020; 11:1041. [PMID: 32528481 PMCID: PMC7257779 DOI: 10.3389/fimmu.2020.01041] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 04/30/2020] [Indexed: 12/18/2022] Open
Abstract
Aspergillus fumigatus is an environmental filamentous fungus that can be pathogenic for humans, wherein it is responsible for a large variety of clinical forms ranging from allergic diseases to life-threatening disseminated infections. The contamination occurs by inhalation of conidia present in the air, and the first encounter of this fungus in the human host is most likely with the bronchial epithelial cells. Although alveolar macrophages have been widely studied in the Aspergillus–lung interaction, increasing evidence suggests that bronchial epithelium plays a key role in responding to the fungus. This review focuses on the innate immune response of the bronchial epithelial cells against A. fumigatus, the predominant pathogenic species. We have also detailed the molecular interactants and the effects of the different modes of interaction between these cells and the fungus.
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Affiliation(s)
- Jeanne Bigot
- Sorbonne Université, Inserm, Centre de Recherche Saint-Antoine, CRSA, AP-HP, Hôpital Saint-Antoine, Service de Parasitologie-Mycologie, Paris, France
| | - Loïc Guillot
- Sorbonne Université, Inserm, Centre de Recherche Saint-Antoine, Paris, France
| | - Juliette Guitard
- Sorbonne Université, Inserm, Centre de Recherche Saint-Antoine, CRSA, AP-HP, Hôpital Saint-Antoine, Service de Parasitologie-Mycologie, Paris, France
| | - Manon Ruffin
- Sorbonne Université, Inserm, Centre de Recherche Saint-Antoine, Paris, France
| | - Harriet Corvol
- Sorbonne Université, Inserm, Centre de Recherche Saint-Antoine, CRSA, AP-HP, Hôpital Trousseau, Service de Pneumologie Pédiatrique, Paris, France
| | - Viviane Balloy
- Sorbonne Université, Inserm, Centre de Recherche Saint-Antoine, Paris, France
| | - Christophe Hennequin
- Sorbonne Université, Inserm, Centre de Recherche Saint-Antoine, CRSA, AP-HP, Hôpital Saint-Antoine, Service de Parasitologie-Mycologie, Paris, France
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30
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Ahmad KS, Gul P. Fungicide isopyrazam degradative response toward extrinsically added fungal and bacterial strains. J Basic Microbiol 2020; 60:484-493. [PMID: 32314411 DOI: 10.1002/jobm.201900687] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/25/2020] [Accepted: 03/28/2020] [Indexed: 12/20/2022]
Abstract
The current research is a pioneer in the evaluation of isopyrazam biodegradation, which has been performed utilizing soil-isolated microbes. Biodisintegrative assays of pure fungal strains, namely Aspergillus flavus (AF), Penicillium chrysogenum (PC), Aspergillus niger (AN), Aspergillus terreus (AT), and Aspergillus fumigatus (AFu), and bacterial strains, namely Xanthomonas axonopodis (XA) and Pseudomonas syringae (PS), were utilized. Initial isopyrazam concentration (10 mg/L) was prepared with an individual microbial suspension and monitored for 35 days. Isopyrazam biotransformation was analyzed quantitatively and qualitatively by UV-visible spectrophotometery and gas chromatography-mass spectroscopy. P. syringae (R2 = 0.90) and X. axonopodis (R2 = 0.88) displayed maximal potential to metabolize the fungicide (86% and 80%, respectively) while forming intermediate metabolites, including 3-difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic acid ((S)-9-hydroxy-9-isopropyl-1,2,3,4-tetrahydro-1,4-methanonaphthalen-5-yl)-amide, 3-difluoromethyl-1H-pyrazole-4-carboxylic acid, and 3-difluoromethyl-1-methyl-1H-pyrazole-4-amide. Isopyrazam degradation by all strains, AT, PC, AFu, AN, AF, XA, and PS, was found to be 11%, 18%, 21%, 21%, 18%, 30%, 80%, and 86%, respectively, after 35 days, elucidating the effectiveness of all the utilized strains in degrading isopyrazam at varying rates. The descending order of half-lives (days) obtained is as follows: AT (56.8) > PC (44.7) > AFu (40.7) > AN (39.6) > AF (32.6) > XA (28.1) > PS (21) days. Current research can influence imperative and significant environment-friendly bioremedial strategies for xenobiotic eradication from the ecological compartments.
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Affiliation(s)
- Khuram Shahzad Ahmad
- Department of Environmental Sciences, Fatima Jinnah Women University, Rawalpindi, Pakistan
| | - Palwasha Gul
- Department of Environmental Sciences, Fatima Jinnah Women University, Rawalpindi, Pakistan
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31
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Aspergillus fumigatus Cell Wall Promotes Apical Airway Epithelial Recruitment of Human Neutrophils. Infect Immun 2020; 88:IAI.00813-19. [PMID: 31767773 DOI: 10.1128/iai.00813-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 11/19/2019] [Indexed: 02/06/2023] Open
Abstract
Aspergillus fumigatus is a ubiquitous fungal pathogen capable of causing multiple pulmonary diseases, including invasive aspergillosis, chronic necrotizing aspergillosis, fungal colonization, and allergic bronchopulmonary aspergillosis. Intact mucociliary barrier function and early airway neutrophil responses are critical for clearing fungal conidia from the host airways prior to establishing disease. Following inhalation, Aspergillus conidia deposit in the small airways, where they are likely to make their initial host encounter with epithelial cells. Challenges in airway infection models have limited the ability to explore early steps in the interactions between A. fumigatus and the human airway epithelium. Here, we use inverted air-liquid interface cultures to demonstrate that the human airway epithelium responds to apical stimulation by A. fumigatus to promote the transepithelial migration of neutrophils from the basolateral membrane surface to the apical airway surface. Promoting epithelial transmigration with Aspergillus required prolonged exposure with live resting conidia. Swollen conidia did not expedite epithelial transmigration. Using A. fumigatus strains containing deletions of genes for cell wall components, we identified that deletion of the hydrophobic rodlet layer or dihydroxynaphthalene-melanin in the conidial cell wall amplified the epithelial transmigration of neutrophils, using primary human airway epithelium. Ultimately, we show that an as-yet-unidentified nonsecreted cell wall protein is required to promote the early epithelial transmigration of human neutrophils into the airspace in response to A. fumigatus Together, these data provide critical insight into the initial epithelial host response to Aspergillus.
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Margalit A, Kavanagh K, Carolan JC. Characterization of the Proteomic Response of A549 Cells Following Sequential Exposure to Aspergillus fumigatus and Pseudomonas aeruginosa. J Proteome Res 2020; 19:279-291. [PMID: 31693381 DOI: 10.1021/acs.jproteome.9b00520] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Aspergillus fumigatus and Pseudomonas aeruginosa are the most prevalent fungal and bacterial pathogens associated with cystic-fibrosis-related infections, respectively. P. aeruginosa eventually predominates as the primary pathogen, though it is unknown why this is the case. Label-free quantitative proteomics was employed to investigate the cellular response of the alveolar epithelial cell line, A549, to coexposure of A. fumigatus and P. aeruginosa. These studies revealed a significant increase in the rate of P. aeruginosa proliferation where A. fumigatus was present. Shotgun proteomics performed on A549 cells exposed to either A. fumigatus or P. aeruginosa or to A. fumigatus and P. aeruginosa sequentially revealed distinct changes to the host cell proteome in response to either or both pathogens. While key signatures of infection were retained among all pathogen-exposed groups, including changes in mitochondrial activity and energy output, the relative abundance of proteins associated with endocytosis, phagosomes, and lysosomes was decreased in sequentially exposed cells compared to cells exposed to either pathogen. Our findings indicate that A. fumigatus renders A549 cells unable to internalize bacteria, thus providing an environment in which P. aeruginosa can proliferate. This research provides novel insights into the whole-cell proteomic response of A549 cells to A. fumigatus and P. aeruginosa and highlights distinct differences in the proteome following sequential exposure to both pathogens, which may explain why P. aeruginosa can predominate.
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Affiliation(s)
- Anatte Margalit
- Department of Biology , Maynooth University , Maynooth, Co. Kildare W23F2H6 , Ireland
| | - Kevin Kavanagh
- Department of Biology , Maynooth University , Maynooth, Co. Kildare W23F2H6 , Ireland
| | - James C Carolan
- Department of Biology , Maynooth University , Maynooth, Co. Kildare W23F2H6 , Ireland
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Fungal Infections and ABPA. Respir Med 2020. [DOI: 10.1007/978-3-030-42382-7_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Abstract
Aspergillus fumigatus is a saprotrophic fungus; its primary habitat is the soil. In its ecological niche, the fungus has learned how to adapt and proliferate in hostile environments. This capacity has helped the fungus to resist and survive against human host defenses and, further, to be responsible for one of the most devastating lung infections in terms of morbidity and mortality. In this review, we will provide (i) a description of the biological cycle of A. fumigatus; (ii) a historical perspective of the spectrum of aspergillus disease and the current epidemiological status of these infections; (iii) an analysis of the modes of immune response against Aspergillus in immunocompetent and immunocompromised patients; (iv) an understanding of the pathways responsible for fungal virulence and their host molecular targets, with a specific focus on the cell wall; (v) the current status of the diagnosis of different clinical syndromes; and (vi) an overview of the available antifungal armamentarium and the therapeutic strategies in the clinical context. In addition, the emergence of new concepts, such as nutritional immunity and the integration and rewiring of multiple fungal metabolic activities occurring during lung invasion, has helped us to redefine the opportunistic pathogenesis of A. fumigatus.
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Affiliation(s)
- Jean-Paul Latgé
- School of Medicine, University of Crete, Heraklion, Crete, Greece
| | - Georgios Chamilos
- School of Medicine, University of Crete, Heraklion, Crete, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Heraklion, Crete, Greece
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Zhang C, Chen F, Liu X, Han X, Hu Y, Su X, Chen Y, Sun Y, Han L. Gliotoxin Induces Cofilin Phosphorylation to Promote Actin Cytoskeleton Dynamics and Internalization of Aspergillus fumigatus Into Type II Human Pneumocyte Cells. Front Microbiol 2019; 10:1345. [PMID: 31275272 PMCID: PMC6591310 DOI: 10.3389/fmicb.2019.01345] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 05/29/2019] [Indexed: 01/27/2023] Open
Abstract
Aspergillus fumigatus is able to internalize into lung epithelial cells to escape from immune attack for further dissemination. We previously reported that gliotoxin, a major mycotoxin of A. fumigatus, promotes this internalization; however, the mechanism remained unclear. Here, we report that gliotoxin is able to induce cofilin phosphorylation in A549 type II human pneumocytes. Either too high or too low a level of cofilin phosphorylation blocked the gliotoxin-induced actin cytoskeleton rearrangement and A. fumigatus internalization. LIM domain kinase 1 (LIMK1) and its upstream small GTPases (Cdc42 and RhoA, but not Rac1) predominantly mediated the gliotoxin-induced cofilin phosphorylation and A. fumigatus internalization. Simultaneously, gliotoxin significantly stimulated an increase in cAMP; however, adding an antagonist of PKA did not block gliotoxin-induced A. fumigatus internalization. In vivo, exogenous gliotoxin helped gliotoxin synthesis deficient strain gliPΔ invade into the lung tissue and the lung fungal burden increased markedly in immunosuppressed mice. In conclusion, these data revealed a novel role of gliotoxin in inducing cofilin phosphorylation mostly through the Cdc42/RhoA-LIMK1 signaling pathway to promote actin cytoskeleton rearrangement and internalization of A. fumigatus into type II human pneumocytes.
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Affiliation(s)
- Changjian Zhang
- Chinese PLA Center for Disease Control and Prevention, Beijing, China.,Academy of Military Medical Sciences, Beijing, China
| | - Fangyan Chen
- Chinese PLA Center for Disease Control and Prevention, Beijing, China
| | - Xiaoyu Liu
- Chinese PLA Center for Disease Control and Prevention, Beijing, China.,Academy of Military Medical Sciences, Beijing, China
| | - Xuelin Han
- Chinese PLA Center for Disease Control and Prevention, Beijing, China
| | - Yingsong Hu
- Chinese PLA Center for Disease Control and Prevention, Beijing, China
| | - Xueting Su
- Chinese PLA Center for Disease Control and Prevention, Beijing, China
| | - Yong Chen
- Chinese PLA Center for Disease Control and Prevention, Beijing, China
| | - Yansong Sun
- Academy of Military Medical Sciences, Beijing, China
| | - Li Han
- Chinese PLA Center for Disease Control and Prevention, Beijing, China
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Silva P, Fernandes C, Barros L, Ferreira ICFR, Pereira L, Gonçalves T. The antifungal activity of extracts of Osmundea pinnatifida, an edible seaweed, indicates its usage as a safe environmental fungicide or as a food additive preventing post-harvest fungal food contamination. Food Funct 2019; 9:6187-6195. [PMID: 30457140 DOI: 10.1039/c8fo01797b] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In the present work, we explored the antifungal activity of the wild edible seaweed Osmundea pinnatifida (Rhodophyta) collected from the Portuguese coast, which is used as a food seasoning in Scotland, Ireland and Portugal. We performed a sequential extraction of the seaweed components with methanol, dichloromethane and n-hexane. These extracts showed an antifungal activity against Alternaria infectoria and Aspergillus fumigatus. The n-hexane fraction of the seaweed inhibited the sporulation of Alternaria infectoria at 30 μg mL-1 and induced a statistically significant (P < 0.001) decrease in β-glucan content. Furthermore, liquid cultures of Aspergillus fumigatus supplemented with 10 μg mL-1 of the n-hexane fraction showed abnormal conidiophores, completely devoid of phialides and conidia associated with a decrease of 18.3% in the chitin content (P < 0.01). The n-hexane fraction analysis by GC-MS revealed that it includes palmitic acid (29.6%), phytol isomer 1 (12.8%), oleic acid (9.6%), stearic acid (6.2%) and d-(-)-tagatofuranose (4.1%), among other compounds present at lower concentrations. The present study reveals Osmundea pinnatifida as a promising source of biologically active compounds inhibiting fungal growth and conidiation, the main dispersal mechanism of filamentous fungi as Aspergillus fumigatus and Alternaria alternata, revealing its utility both as an environmental fungicide against fungal diseases and as a food preservative against fungal post-harvest food contamination.
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Affiliation(s)
- Paulo Silva
- MARE - Marine and Environmental Sciences Centre/IMAR - Institute of Marine Research, Department of Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal
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Mirkov I, Popov Aleksandrov A, Lazovic B, Glamoclija J, Kataranovski M. Usefulness of animal models of aspergillosis in studying immunity against Aspergillus infections. J Mycol Med 2019; 29:84-96. [DOI: 10.1016/j.mycmed.2019.01.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 11/28/2018] [Accepted: 01/14/2019] [Indexed: 01/08/2023]
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Westman J, Hube B, Fairn GD. Integrity under stress: Host membrane remodelling and damage by fungal pathogens. Cell Microbiol 2019; 21:e13016. [DOI: 10.1111/cmi.13016] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 01/30/2019] [Accepted: 02/05/2019] [Indexed: 12/28/2022]
Affiliation(s)
- Johannes Westman
- Program in Cell Biology The Hospital for Sick Children Toronto Ontario Canada
| | - Bernhard Hube
- Department Microbial Pathogenicity Mechanisms Hans Knoell Institute Jena Germany
- Institute of Microbiology Microbial Pathogenicity Friedrich Schiller University Jena Germany
| | - Gregory D. Fairn
- Keenan Research Centre for Biomedical Sciences St. Michael's Hospital Toronto Ontario Canada
- Department of Surgery University of Toronto Toronto Ontario Canada
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Bertuzzi M, Hayes GE, Bignell EM. Microbial uptake by the respiratory epithelium: outcomes for host and pathogen. FEMS Microbiol Rev 2019; 43:145-161. [PMID: 30657899 PMCID: PMC6435450 DOI: 10.1093/femsre/fuy045] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 01/17/2019] [Indexed: 12/21/2022] Open
Abstract
Intracellular occupancy of the respiratory epithelium is a useful pathogenic strategy facilitating microbial replication and evasion of professional phagocytes or circulating antimicrobial drugs. A less appreciated but growing body of evidence indicates that the airway epithelium also plays a crucial role in host defence against inhaled pathogens, by promoting ingestion and quelling of microorganisms, processes that become subverted to favour pathogen activities and promote respiratory disease. To achieve a deeper understanding of beneficial and deleterious activities of respiratory epithelia during antimicrobial defence, we have comprehensively surveyed all current knowledge on airway epithelial uptake of bacterial and fungal pathogens. We find that microbial uptake by airway epithelial cells (AECs) is a common feature of respiratory host-microbe interactions whose stepwise execution, and impacts upon the host, vary by pathogen. Amidst the diversity of underlying mechanisms and disease outcomes, we identify four key infection scenarios and use best-characterised host-pathogen interactions as prototypical examples of each. The emergent view is one in which effi-ciency of AEC-mediated pathogen clearance correlates directly with severity of disease outcome, therefore highlighting an important unmet need to broaden our understanding of the antimicrobial properties of respiratory epithelia and associated drivers of pathogen entry and intracellular fate.
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Affiliation(s)
- Margherita Bertuzzi
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health. The University of Manchester, Manchester Academic Health Science Centre, Core Technology Facility, Grafton Street, Manchester M13 9NT, UK
- Lydia Becker Institute of Immunology and Inflammation, Biology, Medicine and Health. The University of Manchester, Manchester Academic Health Science Centre
| | - Gemma E Hayes
- Northern Devon Healthcare NHS Trust, North Devon District Hospital, Raleigh Park, Barnstaple EX31 4JB, UK
| | - Elaine M Bignell
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health. The University of Manchester, Manchester Academic Health Science Centre, Core Technology Facility, Grafton Street, Manchester M13 9NT, UK
- Lydia Becker Institute of Immunology and Inflammation, Biology, Medicine and Health. The University of Manchester, Manchester Academic Health Science Centre
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40
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Abstract
Patients with suppressed immunity are at the highest risk for hospital-acquired infections. Among these, invasive candidiasis is the most prevalent systemic fungal nosocomial infection. Over recent decades, the combined prevalence of non-albicans Candida species outranked Candida albicans infections in several geographical regions worldwide, highlighting the need to understand their pathobiology in order to develop effective treatment and to prevent future outbreaks. Candida parapsilosis is the second or third most frequently isolated Candida species from patients. Besides being highly prevalent, its biology differs markedly from that of C. albicans, which may be associated with C. parapsilosis' increased incidence. Differences in virulence, regulatory and antifungal drug resistance mechanisms, and the patient groups at risk indicate that conclusions drawn from C. albicans pathobiology cannot be simply extrapolated to C. parapsilosis Such species-specific characteristics may also influence their recognition and elimination by the host and the efficacy of antifungal drugs. Due to the availability of high-throughput, state-of-the-art experimental tools and molecular genetic methods adapted to C. parapsilosis, genome and transcriptome studies are now available that greatly contribute to our understanding of what makes this species a threat. In this review, we summarize 10 years of findings on C. parapsilosis pathogenesis, including the species' genetic properties, transcriptome studies, host responses, and molecular mechanisms of virulence. Antifungal susceptibility studies and clinician perspectives are discussed. We also present regional incidence reports in order to provide an updated worldwide epidemiology summary.
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Culibrk L, Croft CA, Toor A, Yang SJ, Singhera GK, Dorscheid DR, Moore MM, Tebbutt SJ. Phagocytosis of Aspergillus fumigatus by Human Bronchial Epithelial Cells Is Mediated by the Arp2/3 Complex and WIPF2. Front Cell Infect Microbiol 2019; 9:16. [PMID: 30792969 PMCID: PMC6375057 DOI: 10.3389/fcimb.2019.00016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 01/17/2019] [Indexed: 12/01/2022] Open
Abstract
Aspergillus fumigatus is an opportunistic fungal pathogen capable of causing severe infection in humans. One of the limitations in our understanding of how A. fumigatus causes infection concerns the initial stages of infection, notably the initial interaction between inhaled spores or conidia and the human airway. Using publicly-available datasets, we identified the Arp2/3 complex and the WAS-Interacting Protein Family Member 2 WIPF2 as being potentially responsible for internalization of conidia by airway epithelial cells. Using a cell culture model, we demonstrate that RNAi-mediated knockdown of WIPF2 significantly reduces internalization of conidia into airway epithelial cells. Furthermore, we demonstrate that inhibition of Arp2/3 by a small molecule inhibitor causes similar effects. Using super-resolution fluorescence microscopy, we demonstrate that WIPF2 is transiently localized to the site of bound conidia. Overall, we demonstrate the active role of the Arp2/3 complex and WIPF2 in mediating the internalization of A. fumigatus conidia into human airway epithelial cells.
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Affiliation(s)
- Luka Culibrk
- Centre for Heart Lung Innovation, University of British Columbia and St. Paul's Hospital, Vancouver, BC, Canada
| | - Carys A Croft
- Centre for Heart Lung Innovation, University of British Columbia and St. Paul's Hospital, Vancouver, BC, Canada
| | - Amreen Toor
- Centre for Heart Lung Innovation, University of British Columbia and St. Paul's Hospital, Vancouver, BC, Canada.,Department of Graduate Studies, Experimental Medicine, University of British Columbia, Vancouver, BC, Canada
| | - S Jasemine Yang
- Centre for Heart Lung Innovation, University of British Columbia and St. Paul's Hospital, Vancouver, BC, Canada.,Department of Graduate Studies, Experimental Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Gurpreet K Singhera
- Centre for Heart Lung Innovation, University of British Columbia and St. Paul's Hospital, Vancouver, BC, Canada.,Divison of Respiratory Medicine, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Delbert R Dorscheid
- Centre for Heart Lung Innovation, University of British Columbia and St. Paul's Hospital, Vancouver, BC, Canada.,Divison of Respiratory Medicine, Department of Medicine, University of British Columbia, Vancouver, BC, Canada.,Divison of Critical Care Medicine, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Margo M Moore
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Scott J Tebbutt
- Centre for Heart Lung Innovation, University of British Columbia and St. Paul's Hospital, Vancouver, BC, Canada.,Divison of Respiratory Medicine, Department of Medicine, University of British Columbia, Vancouver, BC, Canada.,Prevention of Organ Failure Centre of Excellence, Vancouver, BC, Canada
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Endocytic Markers Associated with the Internalization and Processing of Aspergillus fumigatus Conidia by BEAS-2B Cells. mSphere 2019; 4:4/1/e00663-18. [PMID: 30728282 PMCID: PMC6365614 DOI: 10.1128/msphere.00663-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Conidia from the fungus Aspergillus fumigatus are notorious for their ability to stay airborne. This characteristic is believed to allow conidia to penetrate into the cleanest environments. Several hundred conidia are thought to be inhaled each day by a given individual and then expelled by mucociliary clearance. Given that airway epithelial cells make up a significant portion of the pulmonary-air interface, we set out to determine the percentage of conidia that are actually internalized after initial contact with airway epithelial cells. We determined this through an in vitro assay using an immortalized bronchial airway epithelial cell line known as BEAS-2B. Our results suggest a small fraction of conidia are internalized by BEAS-2B cells, while the majority stay adherent to the surface of cells or are washed away during sample processing. Internalization of conidia was observed at 6 h postchallenge and not prior. Our data also indicate conidia are rendered metabolically inactive within 3 h of challenge, suggesting BEAS-2B cells process a large number of conidia without internalization in this early time frame. We have also identified several host endocytosis markers that localize around internalized conidia as well as contribute to the processing of conidia. Understanding how these host endocytosis markers affect the processing of internal and/or external conidia may provide a novel avenue for therapeutic development. Aspergillus fumigatus is a ubiquitous mold that produces small airborne conidia capable of traversing deep into the respiratory system. Recognition, processing, and clearance of A. fumigatus conidia by bronchial airway epithelial cells are thought to be relevant to host defense and immune signaling. Using z-stack confocal microscopy, we observed that only 10 to 20% of adherent conidia from the AF293 clinical isolate are internalized by BEAS-2B cells 6 h postchallenge and not prior. Similar percentages of internalization were observed for the CEA10 clinical isolate. A large subset of both AF293 and CEA10 conidia are rendered metabolically inactive without internalization at 3 h postchallenge by BEAS-2B cells. A significantly larger percentage of CEA10 conidia are metabolically active at 9 and 12 h postchallenge in comparison to the AF293 isolate, demonstrating heterogeneity among clinical isolates. We identified 7 host markers (caveolin, flotillin-2, RAB5C, RAB8B, RAB7A, 2xFYVE, and FAPP1) that consistently localized around internalized conidia 9 h postchallenge. Transient gene silencing of RAB5C, PIK3C3, and flotillin-2 resulted in a larger population of metabolically active conidia. Our findings emphasize the abundance of both host phosphatidylinositol 3-phosphate (PI3P) and PI4P around internalized conidia, as well as the importance of class III PI3P kinase for conidial processing. Therapeutic development focused on RAB5C-, PIK3C3-, and flotillin-2-mediated pathways may provide novel opportunities to modulate conidial processing and internalization. Determination of how contacted, external conidia are processed by airway epithelial cells may also provide a novel avenue to generate host-targeted therapeutics. IMPORTANCE Conidia from the fungus Aspergillus fumigatus are notorious for their ability to stay airborne. This characteristic is believed to allow conidia to penetrate into the cleanest environments. Several hundred conidia are thought to be inhaled each day by a given individual and then expelled by mucociliary clearance. Given that airway epithelial cells make up a significant portion of the pulmonary-air interface, we set out to determine the percentage of conidia that are actually internalized after initial contact with airway epithelial cells. We determined this through an in vitro assay using an immortalized bronchial airway epithelial cell line known as BEAS-2B. Our results suggest a small fraction of conidia are internalized by BEAS-2B cells, while the majority stay adherent to the surface of cells or are washed away during sample processing. Internalization of conidia was observed at 6 h postchallenge and not prior. Our data also indicate conidia are rendered metabolically inactive within 3 h of challenge, suggesting BEAS-2B cells process a large number of conidia without internalization in this early time frame. We have also identified several host endocytosis markers that localize around internalized conidia as well as contribute to the processing of conidia. Understanding how these host endocytosis markers affect the processing of internal and/or external conidia may provide a novel avenue for therapeutic development.
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Toor A, Culibrk L, Singhera GK, Moon KM, Prudova A, Foster LJ, Moore MM, Dorscheid DR, Tebbutt SJ. Transcriptomic and proteomic host response to Aspergillus fumigatus conidia in an air-liquid interface model of human bronchial epithelium. PLoS One 2018; 13:e0209652. [PMID: 30589860 PMCID: PMC6307744 DOI: 10.1371/journal.pone.0209652] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 12/10/2018] [Indexed: 12/31/2022] Open
Abstract
Aspergillus fumigatus (A. fumigatus) is a wide-spread fungus that is a potent allergen in hypersensitive individuals but also an opportunistic pathogen in immunocompromised patients. It reproduces asexually by releasing airborne conidiospores (conidia). Upon inhalation, fungal conidia are capable of reaching the airway epithelial cells (AECs) in bronchial and alveolar tissues. Previous studies have predominantly used submerged monolayer cultures for studying this host-pathogen interaction; however, these cultures do not recapitulate the mucocililary differentiation phenotype of the in vivo epithelium in the respiratory tract. Thus, the aim of this study was to use well-differentiated primary human bronchial epithelial cells (HBECs) grown at the air-liquid interface (ALI) to determine their transcriptomic and proteomic responses following interaction with A. fumigatus conidia. We visualized conidial interaction with HBECs using confocal laser scanning microscopy (CLSM), and applied NanoString nCounter and shotgun proteomics to assess gene expression changes in the human cells upon interaction with A. fumigatus conidia. Western blot analysis was used to assess the expression of top three differentially expressed proteins, CALR, SET and NUCB2. CLSM showed that, unlike submerged monolayer cultures, well-differentiated ALI cultures of primary HBECs were estimated to internalize less than 1% of bound conidia. Nevertheless, transcriptomic and proteomic analyses revealed numerous differentially expressed host genes; these were enriched for pathways including apoptosis/autophagy, translation, unfolded protein response and cell cycle (up-regulated); complement and coagulation pathways, iron homeostasis, nonsense mediated decay and rRNA binding (down-regulated). CALR and SET were confirmed to be up-regulated in ALI cultures of primary HBECs upon exposure to A. fumigatus via western blot analysis. Therefore, using transcriptomics and proteomics approaches, ALI models recapitulating the bronchial epithelial barrier in the conductive zone of the respiratory tract can provide novel insights to the molecular response of bronchial epithelial cells upon exposure to A. fumigatus conidia.
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Affiliation(s)
- Amreen Toor
- Experimental Medicine, University of British Columbia, Vancouver, Canada
- Centre for Heart Lung Innovation, University of British Columbia and St. Paul’s Hospital, Vancouver, Canada
| | - Luka Culibrk
- Centre for Heart Lung Innovation, University of British Columbia and St. Paul’s Hospital, Vancouver, Canada
| | - Gurpreet K. Singhera
- Centre for Heart Lung Innovation, University of British Columbia and St. Paul’s Hospital, Vancouver, Canada
| | - Kyung-Mee Moon
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Anna Prudova
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Leonard J. Foster
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Margo M. Moore
- Department of Biological Sciences, Simon Fraser University, Burnaby, Canada
| | - Delbert R. Dorscheid
- Centre for Heart Lung Innovation, University of British Columbia and St. Paul’s Hospital, Vancouver, Canada
- Department of Medicine, Division of Respiratory Medicine, University of British Columbia, Vancouver, Canada
| | - Scott J. Tebbutt
- Centre for Heart Lung Innovation, University of British Columbia and St. Paul’s Hospital, Vancouver, Canada
- Department of Medicine, Division of Respiratory Medicine, University of British Columbia, Vancouver, Canada
- Prevention of Organ Failure (PROOF) Centre of Excellence, Vancouver, Canada
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Richard N, Marti L, Varrot A, Guillot L, Guitard J, Hennequin C, Imberty A, Corvol H, Chignard M, Balloy V. Human Bronchial Epithelial Cells Inhibit Aspergillus fumigatus Germination of Extracellular Conidia via FleA Recognition. Sci Rep 2018; 8:15699. [PMID: 30356167 PMCID: PMC6200801 DOI: 10.1038/s41598-018-33902-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 10/06/2018] [Indexed: 12/27/2022] Open
Abstract
Aspergillus fumigatus is an environmental filamentous fungus that may act as an opportunistic pathogen causing a variety of diseases, including asthma or allergic bronchopulmonary aspergillosis, and infection, ranging from asymptomatic colonization to invasive pulmonary form, especially in immunocompromised patients. This fungus is characterized by different morphotypes including conidia which are the infective propagules able to germinate into hyphae. Due to their small size (2–3 µm), conidia released in the air can reach the lower respiratory tract. The objective of this study was to characterize the interactions between conidia and bronchial epithelial cells. To this end, we studied the role of bronchial epithelial cells, i.e., the BEAS-2B cell line and human primary cells, in conidial germination of a laboratory strain and three clinical strains of A. fumigatus. Microscopic observations and galactomannan measurements demonstrated that contact between epithelial cells and conidia leads to the inhibition of conidia germination. We demonstrated that this fungistatic process is not associated with the release of any soluble components nor internalization by the epithelial cells. We highlight that this antifungal process involves the phosphoinositide 3-kinase pathway on the host cellular side and the lectin FleA on the fungal side. Collectively, our results show that bronchial epithelial cells attenuate fungal virulence by inhibiting germination of extracellular conidia, thus preventing the morphological change from conidia to filaments, which is responsible for tissue invasion.
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Affiliation(s)
- Nicolas Richard
- Sorbonne Université, UPMC Univ. Paris 06, Inserm, Centre de Recherche Saint-Antoine Paris, Paris, France
| | - Léa Marti
- Sorbonne Université, UPMC Univ. Paris 06, Inserm, Centre de Recherche Saint-Antoine Paris, Paris, France
| | - Annabelle Varrot
- Université Grenoble Alpes, CNRS, CERMAV, 38000, Grenoble, France
| | - Loïc Guillot
- Sorbonne Université, UPMC Univ. Paris 06, Inserm, Centre de Recherche Saint-Antoine Paris, Paris, France
| | - Juliette Guitard
- Sorbonne Université, UPMC Univ. Paris 06, Inserm, Centre de Recherche Saint-Antoine Paris, Paris, France.,Service de Parasitologie-Mycologie, Hôpital St Antoine, AP-HP, Paris, France
| | - Christophe Hennequin
- Sorbonne Université, UPMC Univ. Paris 06, Inserm, Centre de Recherche Saint-Antoine Paris, Paris, France.,Service de Parasitologie-Mycologie, Hôpital St Antoine, AP-HP, Paris, France
| | - Anne Imberty
- Université Grenoble Alpes, CNRS, CERMAV, 38000, Grenoble, France
| | - Harriet Corvol
- Sorbonne Université, UPMC Univ. Paris 06, Inserm, Centre de Recherche Saint-Antoine Paris, Paris, France.,Pneumologie Pédiatrique, AP-HP, Hôpital Trousseau, Paris, France
| | - Michel Chignard
- Sorbonne Université, UPMC Univ. Paris 06, Inserm, Centre de Recherche Saint-Antoine Paris, Paris, France
| | - Viviane Balloy
- Sorbonne Université, UPMC Univ. Paris 06, Inserm, Centre de Recherche Saint-Antoine Paris, Paris, France.
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45
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Gago S, Overton NLD, Ben-Ghazzi N, Novak-Frazer L, Read ND, Denning DW, Bowyer P. Lung colonization by Aspergillus fumigatus is controlled by ZNF77. Nat Commun 2018; 9:3835. [PMID: 30237437 PMCID: PMC6147781 DOI: 10.1038/s41467-018-06148-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 07/27/2018] [Indexed: 01/21/2023] Open
Abstract
Aspergillus fumigatus is a critical pathogen of humans. Exposure to A. fumigatus conidia occurs frequently but is normally cleared from the respiratory airways. In contrast, individuals with respiratory diseases are often highly colonized by fungi. Here, we use genome-edited epithelial cells to show that the genetic variant rs35699176 in ZNF77 causes loss of integrity of the bronchial epithelium and increases levels of extracellular matrix proteins. These changes promote A. fumigatus conidial adhesion, germination and growth. RNA-seq and LC/MS-MS analysis reveal rs35699176 upregulates vesicle trafficking leading to an increment of adhesion proteins. These changes make cells carrying rs35699176 more receptive to A. fumigatus in the early stages of infection. Moreover, patients with fungal asthma carrying rs35699176+/- have higher A. fumigatus loads in their respiratory airway. Our results indicate ZNF77 as a key controller of Aspergillus colonization and suggest its utility as a risk-marker for patient stratification.
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Affiliation(s)
- Sara Gago
- Manchester Fungal Infection Group, Division of Infection, Immunity and Respiratory Medicine, University of Manchester, CTF Building, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Nicola L D Overton
- Manchester Fungal Infection Group, Division of Infection, Immunity and Respiratory Medicine, University of Manchester, CTF Building, 46 Grafton Street, Manchester, M13 9NT, UK.,Clinical & Experimental Pharmacology Group, CRUK Manchester Institute, University of Manchester, Manchester, M20 4GJ, UK
| | - Nagwa Ben-Ghazzi
- Manchester Fungal Infection Group, Division of Infection, Immunity and Respiratory Medicine, University of Manchester, CTF Building, 46 Grafton Street, Manchester, M13 9NT, UK
| | - Lilyann Novak-Frazer
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Manchester Academic Health Science Centre, The University of Manchester and University Hospital of South Manchester NHS Foundation Trust, Manchester, M23 9LT, UK.,Mycology Reference Centre, ECMM Excellence Centre of Medical Mycology, Manchester University NHS Foundation Trust, Manchester, M23 9LT, UK
| | - Nick D Read
- Manchester Fungal Infection Group, Division of Infection, Immunity and Respiratory Medicine, University of Manchester, CTF Building, 46 Grafton Street, Manchester, M13 9NT, UK
| | - David W Denning
- National Aspergillosis Centre, Manchester Academic Health Science Centre, University Hospital of South Manchester NHS Foundation Trust, Manchester, M23 9LT, UK
| | - Paul Bowyer
- Manchester Fungal Infection Group, Division of Infection, Immunity and Respiratory Medicine, University of Manchester, CTF Building, 46 Grafton Street, Manchester, M13 9NT, UK.
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46
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Validation of a simplified in vitro Transwell ® model of the alveolar surface to assess host immunity induced by different morphotypes of Aspergillus fumigatus. Int J Med Microbiol 2018; 308:1009-1017. [PMID: 30197238 DOI: 10.1016/j.ijmm.2018.09.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 08/08/2018] [Accepted: 09/02/2018] [Indexed: 12/21/2022] Open
Abstract
Interactions between fungal pathogens such as Aspergillus fumigatus with host alveolar epithelium and innate immune cells are crucial in the defense against opportunistic fungal infections. In this study a simplified Transwell® system with a confluent layer of A549 cells acted as a model for the alveolar surface. A. fumigatus and dendritic cells were added to simulate the spatial and cellular complexity in the alveolus. Fungal growth into the lower chamber was validated by galactomannan assays. Addition of moDCs to the upper chamber led to a reduced GM signal and fungal growth, indicating moDC antifungal activity. Minimal cell death was documented by analyses of lactate dehydrogenase concentrations and pro-apoptotic gene expression. Measurement of trans-epithelial dextran blue movement confirmed tightness of the epithelial barrier even in presence of A. fumigatus. Cytokine measurements in supernatants from both chambers of the Transwell® system documented distinct response patterns during early and late stages of epithelial invasion, with A549 cells appearing to make a minimal contribution to cytokine release. Concentrations of cytokines in the lower chamber varied distinctly from the upper chamber, depending on the molecular weight of the cytokines. Low inter-assay variability of fungal biomarkers and cytokines was confirmed, highlighting that in vitro models closely mimicking conditions in the human lung can facilitate reproducible measurement of the dynamics of cytokine release and fungal penetration of host epithelia.
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Feldman MB, Vyas JM, Mansour MK. It takes a village: Phagocytes play a central role in fungal immunity. Semin Cell Dev Biol 2018; 89:16-23. [PMID: 29727727 DOI: 10.1016/j.semcdb.2018.04.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Accepted: 04/24/2018] [Indexed: 12/12/2022]
Abstract
Phagocytosis is an essential step in the innate immune response to invasive fungal infections. This process is carried out by a proverbial "village" of professional phagocytic cells, which have evolved efficient machinery to recognize and ingest pathogens, namely macrophages, neutrophils and dendritic cells. These innate immune cells drive early cytokine production, fungicidal activity, antigen presentation and activation of the adaptive immune system. Despite the development of antifungal agents with potent activity, the biological activity of professional phagocytic innate immune cells has proven indispensable in protecting a host from invasive fungal infections. Additionally, an emerging body of evidence suggests non-professional phagocytes, such as airway epithelial cells, carry out phagocytosis and may play a critical role in the elimination of fungal pathogens. Here, we review recent advances of phagocytosis by both professional and non-professional phagocytes in response to fungal pathogens, with a focus on invasive aspergillosis as a model disease.
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Affiliation(s)
- Michael B Feldman
- Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Jatin M Vyas
- Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114 USA; Harvard Medical School, Boston, MA 02115, USA
| | - Michael K Mansour
- Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114 USA; Harvard Medical School, Boston, MA 02115, USA.
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48
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Wang T, Zhang T, Meng T, Li Y, Chen L, Yang Q, Dong H, Lei J, Chen L, Dong Y. A strategy for designing voriconazole dosage regimens to prevent invasive pulmonary aspergillosis based on a cellular pharmacokinetics/pharmacodynamics model. J Transl Med 2018; 16:157. [PMID: 29880050 PMCID: PMC5992762 DOI: 10.1186/s12967-018-1533-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Accepted: 06/01/2018] [Indexed: 12/26/2022] Open
Abstract
Background Invasive pulmonary aspergillosis (IPA) is a life-threatening disease in immunosuppressed patients. Voriconazole is commonly used to prevent and treat IPA in the clinic, but the optimal prophylactic antifungal regimen is unknown. The objective of this study was to clarify the mechanism underlying how voriconazole prevents IPA based on a target cellular pharmacokinetics/pharmacodynamics model, with the aim of identifying a way to design an optimal prophylactic antifungal regimen. Methods A nystatin assay was used to establish a target-cells model for A. fumigatus infection. An inhibitory effect sigmoid Emax model was developed to explore the cellular PK/PD breakpoint, and Monte Carlo simulation was used to design the prophylactic antifungal regimen. Results The intracellular activity of voriconazole in the target cells varied with its concentration, with the minimum inhibitory concentration (MIC) being an important determinant. For A. fumigatus strains AF293 and AF26, voriconazole decreased the intracellular inoculum by 0.79 and 0.84 lg cfu, respectively. The inhibitory effect sigmoid Emax model showed that 84.01% of the intracellular inoculum was suppressed by voriconazole within 24 h, and that a PK/PD value of 35.53 for the extracellular voriconazole concentration divided by MIC was associated with a 50% suppression of intracellular A. fumigatus. The Monte Carlo simulation results showed that the oral administration of at least 200 mg of voriconazole twice daily was yielded estimated the cumulative fraction of response value of 91.48%. Concentration of voriconazole in the pulmonary epithelial lining fluid and the plasma of > 17.77 and > 1.55 mg/L, respectively, would ensure the PK/PD > 35.53 for voriconazole against most isolates of A. fumigatus and may will be benefit to prevent IPA in clinical applications. Conclusions This study used a target cellular pharmacokinetics/pharmacodynamics model to reveal a potential mechanism underlying how voriconazole prevents IPA and has provided a method for designing voriconazole prophylactic antifungal regimen in immunosuppressed patients.
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Affiliation(s)
- Taotao Wang
- Department of Pharmacy, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China
| | - Tao Zhang
- Department of Pharmacy, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China
| | - Ti Meng
- Department of Pharmacy, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China
| | - Ying Li
- Department of Pharmacy, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China
| | - Lu Chen
- Department of Pharmacy, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China
| | - Qianting Yang
- Department of Pharmacy, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China
| | - Haiyan Dong
- Department of Pharmacy, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China
| | - Jin'e Lei
- Department of Laboratory, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China
| | - Limei Chen
- Department of Hematology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China
| | - Yalin Dong
- Department of Pharmacy, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China.
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Fernandes J, Hamidi F, Leborgne R, Beau R, Castier Y, Mordant P, Boukkerou A, Latgé JP, Pretolani M. Penetration of the Human Pulmonary Epithelium by Aspergillus fumigatus Hyphae. J Infect Dis 2018; 218:1306-1313. [DOI: 10.1093/infdis/jiy298] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 05/23/2018] [Indexed: 12/12/2022] Open
Affiliation(s)
- Julien Fernandes
- INSERM UMR1152, Physiopathologie et Epidémiologie des Maladies Respiratoires, Paris, France
- Université Paris Diderot, Sorbonne Paris-Cité, Faculté de Médecine, site Bichat, France
- Laboratory of Excellence INFLAMEX, Université Sorbonne Paris-Cité, France
- Département Hospitalo-Universitaire FIRE, Paris, France
| | - Fatima Hamidi
- INSERM UMR1152, Physiopathologie et Epidémiologie des Maladies Respiratoires, Paris, France
- Université Paris Diderot, Sorbonne Paris-Cité, Faculté de Médecine, site Bichat, France
- Laboratory of Excellence INFLAMEX, Université Sorbonne Paris-Cité, France
- Département Hospitalo-Universitaire FIRE, Paris, France
| | - Remi Leborgne
- ImagoSeine Electron Microscopy Facility, Institut Jacques Monod, Centre National de la Recherche Scientifique UMR 7592, Université Paris Diderot, Sorbonne Paris-Cité, France
| | - Remi Beau
- Unité des Aspergillus, Institut Pasteur, Paris, France
| | - Yves Castier
- INSERM UMR1152, Physiopathologie et Epidémiologie des Maladies Respiratoires, Paris, France
- Université Paris Diderot, Sorbonne Paris-Cité, Faculté de Médecine, site Bichat, France
- Laboratory of Excellence INFLAMEX, Université Sorbonne Paris-Cité, France
- Département Hospitalo-Universitaire FIRE, Paris, France
- Service de Chirurgie Thoracique, Groupement Hospitalier Universitaire Nord Bichat-Claude Bernard, Assistance Publique des Hopitaux de Paris, France
| | - Pierre Mordant
- INSERM UMR1152, Physiopathologie et Epidémiologie des Maladies Respiratoires, Paris, France
- Université Paris Diderot, Sorbonne Paris-Cité, Faculté de Médecine, site Bichat, France
- Laboratory of Excellence INFLAMEX, Université Sorbonne Paris-Cité, France
- Département Hospitalo-Universitaire FIRE, Paris, France
- Service de Chirurgie Thoracique, Groupement Hospitalier Universitaire Nord Bichat-Claude Bernard, Assistance Publique des Hopitaux de Paris, France
| | - Amira Boukkerou
- INSERM UMR1152, Physiopathologie et Epidémiologie des Maladies Respiratoires, Paris, France
- Université Paris Diderot, Sorbonne Paris-Cité, Faculté de Médecine, site Bichat, France
- Laboratory of Excellence INFLAMEX, Université Sorbonne Paris-Cité, France
- Département Hospitalo-Universitaire FIRE, Paris, France
| | | | - Marina Pretolani
- INSERM UMR1152, Physiopathologie et Epidémiologie des Maladies Respiratoires, Paris, France
- Université Paris Diderot, Sorbonne Paris-Cité, Faculté de Médecine, site Bichat, France
- Laboratory of Excellence INFLAMEX, Université Sorbonne Paris-Cité, France
- Département Hospitalo-Universitaire FIRE, Paris, France
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50
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Nesbitt JR, Steves EY, Schonhofer CR, Cait A, Manku SS, Yeung JHF, Bennet AJ, McNagny KM, Choy JC, Hughes MR, Moore MM. The Aspergillus fumigatus Sialidase (Kdnase) Contributes to Cell Wall Integrity and Virulence in Amphotericin B-Treated Mice. Front Microbiol 2018; 8:2706. [PMID: 29403452 PMCID: PMC5778107 DOI: 10.3389/fmicb.2017.02706] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 12/29/2017] [Indexed: 12/02/2022] Open
Abstract
Aspergillus fumigatus is a filamentous fungus that can cause a life-threatening invasive pulmonary aspergillosis (IPA) in immunocompromised individuals. We previously characterized an exo-sialidase from A. fumigatus that prefers the sialic acid substrate, 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid (Kdn); hence it is a Kdnase. Sialidases are known virulence factors in other pathogens; therefore, the goal of our study was to evaluate the importance of Kdnase in A. fumigatus. A kdnase knockout strain (Δkdnase) was unable to grow on medium containing Kdn and displayed reduced growth and abnormal morphology. Δkdnase was more sensitive than wild type to hyperosmotic conditions and the antifungal agent, amphotericin B. In contrast, Δkdnase had increased resistance to nikkomycin, Congo Red and Calcofluor White indicating activation of compensatory cell wall chitin deposition. Increased cell wall thickness and chitin content in Δkdnase were confirmed by electron and immunofluorescence microscopy. In a neutropenic mouse model of invasive aspergillosis, the Δkdnase strain had attenuated virulence and a significantly lower lung fungal burden but only in animals that received liposomal amphotericin B after spore exposure. Macrophage numbers were almost twofold higher in lung sections from mice that received the Δkdnase strain, possibly related to higher survival of macrophages that internalized the Δkdnase conidia. Thus, A. fumigatus Kdnase is important for fungal cell wall integrity and virulence, and because Kdnase is not present in the host, it may represent a potential target for the development of novel antifungal agents.
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Affiliation(s)
- Jason R Nesbitt
- Department of Biological Sciences and the Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Elizabeth Y Steves
- Department of Biological Sciences and the Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Cole R Schonhofer
- Department of Biological Sciences and the Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Alissa Cait
- Biomedical Research Centre, The University of British Columbia, Vancouver, BC, Canada
| | - Sukhbir S Manku
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Juliana H F Yeung
- Department of Biological Sciences and the Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Andrew J Bennet
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Kelly M McNagny
- Biomedical Research Centre, The University of British Columbia, Vancouver, BC, Canada
| | - Jonathan C Choy
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Michael R Hughes
- Biomedical Research Centre, The University of British Columbia, Vancouver, BC, Canada
| | - Margo M Moore
- Department of Biological Sciences and the Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
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