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Gandhi P, Hebert B, Yun A, Bradley J, Moldoveanu B. Histoplasmosis around the world: A global perspective on the presentation, virulence factors, and treatment of histoplasmosis. Am J Med Sci 2024; 368:287-299. [PMID: 38885929 DOI: 10.1016/j.amjms.2024.06.011] [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: 10/31/2023] [Revised: 04/29/2024] [Accepted: 06/12/2024] [Indexed: 06/20/2024]
Abstract
Histoplasmosis is a systemic infection caused by an endemic dimorphic fungus, Histoplasma capsulatum. Though prevalent in the eastern United States of America, near the Ohio and Mississippi River Valleys, the evidence underlying the global prevalence of histoplasmosis, especially in immunocompromised populations, is underappreciated. This article highlights the global epidemiology, risk factors, microbiology and pathophysiological characteristics, pulmonary and extrapulmonary manifestations, prevention measures, radiographic patterns, diagnostic techniques, and antifungal treatment approaches for Histoplasma capsulatum.
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Affiliation(s)
- Pooja Gandhi
- Division of General Internal Medicine, University of Louisville, Louisville, Kentucky, USA
| | - Brandon Hebert
- Division of General Internal Medicine, University of Louisville, Louisville, Kentucky, USA
| | - Angelica Yun
- Division of General Internal Medicine, University of Louisville, Louisville, Kentucky, USA
| | - James Bradley
- Division of Pulmonary, Critical Care Medicine, and Sleep Disorders, University of Louisville, Louisville, Kentucky, USA.
| | - Bogdan Moldoveanu
- Division of Pulmonary, Critical Care Medicine, and Sleep Disorders, University of Louisville, Louisville, Kentucky, USA
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2
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Sepúlveda VE, Goldman WE, Matute DR. Genotypic diversity, virulence, and molecular genetic tools in Histoplasma. Microbiol Mol Biol Rev 2024; 88:e0007623. [PMID: 38819148 PMCID: PMC11332355 DOI: 10.1128/mmbr.00076-23] [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] [Indexed: 06/01/2024] Open
Abstract
SUMMARYHistoplasmosis is arguably the most common fungal respiratory infection worldwide, with hundreds of thousands of new infections occurring annually in the United States alone. The infection can progress in the lung or disseminate to visceral organs and can be difficult to treat with antifungal drugs. Histoplasma, the causative agent of the disease, is a pathogenic fungus that causes life-threatening lung infections and is globally distributed. The fungus has the ability to germinate from conidia into either hyphal (mold) or yeast form, depending on the environmental temperature. This transition also regulates virulence. Histoplasma and histoplasmosis have been classified as being of emergent importance, and in 2022, the World Health Organization included Histoplasma as 1 of the 19 most concerning human fungal pathogens. In this review, we synthesize the current understanding of the ecological niche, evolutionary history, and virulence strategies of Histoplasma. We also describe general patterns of the symptomatology and epidemiology of histoplasmosis. We underscore areas where research is sorely needed and highlight research avenues that have been productive.
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Affiliation(s)
- Victoria E. Sepúlveda
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - William E. Goldman
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Daniel R. Matute
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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3
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Sonnberger J, Kasper L, Lange T, Brunke S, Hube B. "We've got to get out"-Strategies of human pathogenic fungi to escape from phagocytes. Mol Microbiol 2024; 121:341-358. [PMID: 37800630 DOI: 10.1111/mmi.15149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/08/2023] [Accepted: 08/16/2023] [Indexed: 10/07/2023]
Abstract
Human fungal pathogens are a deadly and underappreciated risk to global health that most severely affect immunocompromised individuals. A virulence attribute shared by some of the most clinically relevant fungal species is their ability to survive inside macrophages and escape from these immune cells. In this review, we discuss the mechanisms behind intracellular survival and elaborate how escape is mediated by lytic and non-lytic pathways as well as strategies to induce programmed host cell death. We also discuss persistence as an alternative to rapid host cell exit. In the end, we address the consequences of fungal escape for the host immune response and provide future perspectives for research and development of targeted therapies.
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Affiliation(s)
- Johannes Sonnberger
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, Jena, Germany
| | - Lydia Kasper
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, Jena, Germany
| | - Theresa Lange
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, Jena, Germany
| | - Sascha Brunke
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, Jena, Germany
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, Jena, Germany
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
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4
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Mejía SP, Marques RDC, Landfester K, Orozco J, Mailänder V. Effect of Protein Corona on the Specificity and Efficacy of Nanobioconjugates to Treat Intracellular Infections. Macromol Biosci 2024; 24:e2300197. [PMID: 37639236 DOI: 10.1002/mabi.202300197] [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: 05/06/2023] [Revised: 07/20/2023] [Indexed: 08/29/2023]
Abstract
Encapsulating drugs into functionalized nanoparticles (NPs) is an alternative to reach the specific therapeutic target with lower doses. However, when the NPs are in contact with physiological media, proteins adsorb on their surfaces, forming a protein corona (PC) biomolecular layer, acquiring a distinct biological identity that alters their interactions with cells. Itraconazole (ITZ), an antifungal agent, is encapsulated into PEGylated and/or functionalized NPs with high specificity for macrophages. It is evaluated how the PC impacts their cell uptake and antifungal effect. The minimum inhibitory concentration and colony-forming unit assays demonstrate that encapsulated ITZ into poly(ethylene glycol) (PEG) NPs improves the antifungal effect compared with NPs lacking PEGylation. The improvement can be related to the synergistic effect of the encapsulated ITZ and NPs composition and the reduction of PC formation in PEG NPs. Functionalized NPs with anti-F4/80 and anti-MARCO antibodies, or mannose without PEG and treated with PC, show an improved uptake but, in the presence of PEG, significantly reduce the endocytosis, dominating the stealth effect from PEG. Therefore, the PC plays a crucial role in the nanosystem uptake and antifungal effects, which suggests the need for in vivo model studies to evaluate the effect of PC in the specificity and biodistribution.
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Affiliation(s)
- Susana P Mejía
- Max Planck Tandem Group in Nanobioengineering, Institute of Chemistry, Faculty of Natural and Exact Sciences, University of Antioquia, Complejo Ruta N, Calle 67 No 52-20, Medellin, 050010, Colombia
- Max Planck Institute for Polymer Research, 55128, Mainz, Germany
| | | | | | - Jahir Orozco
- Max Planck Tandem Group in Nanobioengineering, Institute of Chemistry, Faculty of Natural and Exact Sciences, University of Antioquia, Complejo Ruta N, Calle 67 No 52-20, Medellin, 050010, Colombia
| | - Volker Mailänder
- Max Planck Institute for Polymer Research, 55128, Mainz, Germany
- Dermatology Clinic, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeck str. 1, 55131, Mainz, Germany
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Marques PH, Tiwari S, Felice AG, Jaiswal AK, Aburjaile FF, Azevedo V, Silva-Vergara ML, Ferreira-Paim K, Soares SDC, Fonseca FM. Design of a Multi-Epitope Vaccine against Histoplasma capsulatum through Immunoinformatics Approaches. J Fungi (Basel) 2024; 10:43. [PMID: 38248954 PMCID: PMC10817582 DOI: 10.3390/jof10010043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 12/20/2023] [Accepted: 12/28/2023] [Indexed: 01/23/2024] Open
Abstract
Histoplasmosis is a widespread systemic disease caused by Histoplasma capsulatum, prevalent in the Americas. Despite its significant morbidity and mortality rates, no vaccines are currently available. Previously, five vaccine targets and specific epitopes for H. capsulatum were identified. Immunoinformatics has emerged as a novel approach for determining the main immunogenic components of antigens through in silico methods. Therefore, we predicted the main helper and cytotoxic T lymphocytes and B-cell epitopes for these targets to create a potential multi-epitope vaccine known as HistoVAC-TSFM. A total of 38 epitopes were found: 23 common to CTL and B-cell responses, 11 linked to HTL and B cells, and 4 previously validated epitopes associated with the B subunit of cholera toxin, a potent adjuvant. In silico evaluations confirmed the stability, non-toxicity, non-allergenicity, and non-homology of these vaccines with the host. Notably, the vaccine exhibited the potential to trigger both innate and adaptive immune responses, likely involving the TLR4 pathway, as supported by 3D modeling and molecular docking. The designed HistoVAC-TSFM appears promising against Histoplasma, with the ability to induce important cytokines, such as IFN-γ, TNF-α, IL17, and IL6. Future studies could be carried out to test the vaccine's efficacy in in vivo models.
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Affiliation(s)
- Pedro Henrique Marques
- Postgraduate Interunits Program in Bioinformatics, Federal University of Minas Gerais, Belo Horizonte 31270-901, Brazil; (P.H.M.); (A.K.J.)
- Department of Preventive Veterinary, Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, Brazil;
| | - Sandeep Tiwari
- Institute of Biology, Federal University of Bahia, Salvador 40170-115, Brazil;
- Institute of Health Sciences, Federal University of Bahia, Salvador 40170-115, Brazil
| | - Andrei Giacchetto Felice
- Department of Microbiology, Immunology and Parasitology, Federal University of Triangulo Mineiro, Uberaba 38015-050, Brazil; (A.G.F.); (S.d.C.S.)
| | - Arun Kumar Jaiswal
- Postgraduate Interunits Program in Bioinformatics, Federal University of Minas Gerais, Belo Horizonte 31270-901, Brazil; (P.H.M.); (A.K.J.)
| | - Flávia Figueira Aburjaile
- Department of Preventive Veterinary, Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-901, Brazil;
| | - Vasco Azevedo
- Department of Genetics, Ecology and Evolution, Federal University of Minas Gerais, Belo Horizonte 31270-901, Brazil;
| | - Mario León Silva-Vergara
- Department of Infectious Diseases, Federal University of Triangulo Mineiro, Uberaba 38025-440, Brazil;
| | - Kennio Ferreira-Paim
- Department of Microbiology, Immunology and Parasitology, Federal University of Triangulo Mineiro, Uberaba 38015-050, Brazil; (A.G.F.); (S.d.C.S.)
| | - Siomar de Castro Soares
- Department of Microbiology, Immunology and Parasitology, Federal University of Triangulo Mineiro, Uberaba 38015-050, Brazil; (A.G.F.); (S.d.C.S.)
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Wijaya M, Surja SS, Adawiyah R, Hariadi A, Setianingrum F, Rozaliyani A, Burhan E, Tugiran M, Sjam R, Denning DW, Wahyuningsih R. Histoplasma antigen detection in unconfirmed pulmonary tuberculosis and cross-reactivity with Aspergillus antigen in patients and in food in Jakarta, Indonesia. Mycoses 2024; 67:e13670. [PMID: 37897135 DOI: 10.1111/myc.13670] [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: 08/22/2023] [Revised: 10/23/2023] [Accepted: 10/26/2023] [Indexed: 10/29/2023]
Abstract
PURPOSE H. capsulatum is endemic in Indonesia, but the value of Histoplasma antigen detection has not been studied. PATIENTS AND METHODS Histoplasma galactomannan (GM) ELISA was applied to sera of patients with unproven pulmonary tuberculosis (TB) and patients with a positive Aspergillus GM. Both Histoplasma and Aspergillus GM tests were performed to determine any possible cross-reaction with certain foods. RESULTS Fourteen of 122 (11.5%) sera of patients with newly diagnosed clinical TB were positive for Histoplasma GM. The positivity rate in the serum of patients 5-6 and 12 months after TB diagnosis was 3.8% and 3.5%, respectively. Of 88 positive Aspergillus GM sera, 63 (71.6%) were also positive for Histoplasma GM. All tested foods were positive for Aspergillus GM, while 65% of foods were positive for Histoplasma GM. CONCLUSION Galactomannan is widespread in sera and food in Jakarta, possibly related to food consumption. Histoplasma and Aspergillus antigen detection for the diagnosis will require additional means of confirming the diagnosis; negative tests may be more helpful for ruling out invasive histoplasmosis and aspergillosis.
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Affiliation(s)
- Meiliyana Wijaya
- Study Program of Clinical Parasitology, Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Department of Parasitology, School of Medicine and Health Sciences, Atma Jaya Catholic University of Indonesia, Jakarta, Indonesia
| | - Sem Samuel Surja
- Department of Parasitology, School of Medicine and Health Sciences, Atma Jaya Catholic University of Indonesia, Jakarta, Indonesia
| | - Robiatul Adawiyah
- Study Program of Clinical Parasitology, Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Indonesia Pulmonary Mycoses Centre (IPMC), Faculty of Medicine Universitas Indonesia and Persahabatan National Respiratory Referral Hospital, Jakarta, Indonesia
- Master's Programme in Biomedical Sciences, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Infectious Diseases and Immunology Research Center (IDIRC), Indonesian Medical Education and Research Institute (IMERI), Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
| | - Ariananda Hariadi
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
| | - Findra Setianingrum
- Study Program of Clinical Parasitology, Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Indonesia Pulmonary Mycoses Centre (IPMC), Faculty of Medicine Universitas Indonesia and Persahabatan National Respiratory Referral Hospital, Jakarta, Indonesia
- Master's Programme in Biomedical Sciences, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
| | - Anna Rozaliyani
- Study Program of Clinical Parasitology, Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Indonesia Pulmonary Mycoses Centre (IPMC), Faculty of Medicine Universitas Indonesia and Persahabatan National Respiratory Referral Hospital, Jakarta, Indonesia
- Master's Programme in Biomedical Sciences, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
| | - Erlina Burhan
- Indonesia Pulmonary Mycoses Centre (IPMC), Faculty of Medicine Universitas Indonesia and Persahabatan National Respiratory Referral Hospital, Jakarta, Indonesia
- Department of Pulmonology and Respiratory Medicine, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Persahabatan National Respiratory Referral Hospital, Jakarta, Indonesia
| | - Mulyati Tugiran
- Study Program of Clinical Parasitology, Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Indonesia Pulmonary Mycoses Centre (IPMC), Faculty of Medicine Universitas Indonesia and Persahabatan National Respiratory Referral Hospital, Jakarta, Indonesia
- Master's Programme in Biomedical Sciences, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
| | - Ridhawati Sjam
- Study Program of Clinical Parasitology, Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Indonesia Pulmonary Mycoses Centre (IPMC), Faculty of Medicine Universitas Indonesia and Persahabatan National Respiratory Referral Hospital, Jakarta, Indonesia
- Master's Programme in Biomedical Sciences, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
| | - David W Denning
- Manchester Fungal Infection Group, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Retno Wahyuningsih
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Department of Parasitology, Faculty of Medicine, Universitas Kristen Indonesia, Jakarta, Indonesia
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Rappleye CA. Targeted gene deletions in the dimorphic fungal pathogen Histoplasma using an optimized episomal CRISPR/Cas9 system. mSphere 2023; 8:e0017823. [PMID: 37389430 PMCID: PMC10449496 DOI: 10.1128/msphere.00178-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 05/22/2023] [Indexed: 07/01/2023] Open
Abstract
The rapid development of CRISPR/CRISPR-associated (Cas) systems has revolutionized the ability to produce genetic mutations in a desired locus, particularly in organisms with low rates of homologous recombination. Histoplasma is an important respiratory and systemic fungal pathogen that has few reverse genetic options. We describe an optimized CRISPR/Cas system for the efficient generation of mutations in desired genes. The limited requirements for CRISPR/Cas, namely a gene-targeting guide RNA (gRNA) and expression of a Cas endonuclease, enabled both the gRNA and the Streptococcus pyogenes Cas9 gene to be expressed from a single episomal vector. The gRNAs are expressed from a strong Pol(II) promoter, a critical parameter for increasing the recovery of mutated genes, and processed into the mature gRNA by ribozymes in the mRNA. Expression of dual-tandem gRNAs facilitates the generation of gene deletions at a good frequency which can be detected by PCR-based screening of pooled isolates resulting in the isolation of marker-less deletion mutants. The CRISPR/Cas system is encoded on an episomal telomeric vector facilitating curing strains of the CRISPR/Cas vector upon generation of the mutant. We demonstrate the successful application of this CRISPR/Cas system in diverse Histoplasma species and applicable for multiple genes. The optimized system shows promise for accelerating reverse genetic studies in Histoplasma spp. IMPORTANCE The ability to eliminate gene product functions is central to understanding molecular mechanisms. In the fungal pathogen Histoplasma, methods to inactivate or deplete gene products are inefficient, which hampers progress in defining Histoplasma's virulence mechanisms. We describe an efficient CRISPR/Cas-based system for generating gene deletions in Histoplasma and show its validation on multiple genes with selectable and non-selectable phenotypes.
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Affiliation(s)
- Chad A. Rappleye
- Department of Microbiology, Ohio State University, Columbus, Ohio, USA
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8
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Comparative Genomics of Histoplasma capsulatum and Prediction of New Vaccines and Drug Targets. J Fungi (Basel) 2023; 9:jof9020193. [PMID: 36836308 PMCID: PMC9963733 DOI: 10.3390/jof9020193] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 01/18/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023] Open
Abstract
Histoplasma capsulatum is a thermodymorphic fungus that causes histoplasmosis, a systemic mycosis that presents different clinical manifestations, ranging from self-limiting to acute lung infection, chronic lung infection and disseminated infection. Usually, it affects severely immunocompromised patients although immunocompetent patients can also be infected. Currently, there are no vaccines to prevent histoplasmosis and the available antifungal treatment presents moderate to high toxicity. Additionally, there are few options of antifungal drugs. Thus, the aim of this study was to predict possible protein targets for the construction of potential vaccine candidates and predict potential drug targets against H. capsulatum. Whole genome sequences from four previously published H. capsulatum strains were analyzed and submitted to different bioinformatic approaches such as reverse vaccinology and subtractive genomics. A total of four proteins were characterized as good protein candidates (vaccine antigens) for vaccine development, three of which are membrane-bound and one is secreted. In addition, it was possible to predict four cytoplasmic proteins which were classified as good protein candidates and, through molecular docking performed for each identified target, we found four natural compounds that showed favorable interactions with our target proteins. Our study can help in the development of potential vaccines and new drugs that can change the current scenario of the treatment and prevention of histoplasmosis.
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9
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Brown AJP. Fungal resilience and host-pathogen interactions: Future perspectives and opportunities. Parasite Immunol 2023; 45:e12946. [PMID: 35962618 PMCID: PMC10078341 DOI: 10.1111/pim.12946] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 08/08/2022] [Accepted: 08/10/2022] [Indexed: 01/31/2023]
Abstract
We are constantly exposed to the threat of fungal infection. The outcome-clearance, commensalism or infection-depends largely on the ability of our innate immune defences to clear infecting fungal cells versus the success of the fungus in mounting compensatory adaptive responses. As each seeks to gain advantage during these skirmishes, the interactions between host and fungal pathogen are complex and dynamic. Nevertheless, simply compromising the physiological robustness of fungal pathogens reduces their ability to evade antifungal immunity, their virulence, and their tolerance against antifungal therapy. In this article I argue that this physiological robustness is based on a 'Resilience Network' which mechanistically links and controls fungal growth, metabolism, stress resistance and drug tolerance. The elasticity of this network probably underlies the phenotypic variability of fungal isolates and the heterogeneity of individual cells within clonal populations. Consequently, I suggest that the definition of the fungal Resilience Network represents an important goal for the future which offers the clear potential to reveal drug targets that compromise drug tolerance and synergise with current antifungal therapies.
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Affiliation(s)
- Alistair J P Brown
- Medical Research Council Centre for Medical Mycology at the University of Exeter, Exeter, UK
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10
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Rappleye CA. Antifungal Susceptibility Testing and Drug Discovery in the Dimorphic Fungus Histoplasma Capsulatum. Methods Mol Biol 2023; 2658:43-52. [PMID: 37024694 DOI: 10.1007/978-1-0716-3155-3_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
Abstract
The thermal dimorphism of the fungal pathogen Histoplasma is linked to its virulence in mammalian hosts. Mammalian body temperature triggers differentiation of the fungus into virulent yeasts which successfully infect host phagocytes. Accurate determination of antifungal susceptibility with relevance to infection requires that the tests be performed specifically using the yeast form, not the filamentous environmental form. However, traditional CLSI methodology for antifungal susceptibility testing of yeasts with Histoplasma is in adequate. We present optimized methodology for performing antifungal susceptibility assays on Histoplasma yeasts with an emphasis on quantitative yeast growth determination. Colorimetric and fluorometric assays for Histoplasma growth overcome challenges associated with quantifying some Histoplasma strains which grow as aggregates of yeasts. We also describe antifungal susceptibility testing of Histoplasma yeasts within macrophages to provide improved accuracy and better physiological relevance of antifungal susceptibility profiles.
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Affiliation(s)
- Chad A Rappleye
- Department of Microbiology, Ohio State University, Columbus, OH, USA.
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11
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Histoplasma capsulatum Activates Hematopoietic Stem Cells and Their Progenitors through a Mechanism Dependent on TLR2, TLR4, and Dectin-1. J Fungi (Basel) 2022; 8:jof8101108. [PMID: 36294673 PMCID: PMC9604687 DOI: 10.3390/jof8101108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/28/2022] [Accepted: 09/30/2022] [Indexed: 11/21/2022] Open
Abstract
Hematopoietic stem cells (HSCs), a multipotent and self-renewing population responsible for the generation and maintenance of blood cells, have been the subject of numerous investigations due to their therapeutic potential. It has been shown that these cells are able to interact with pathogens through the TLRs that they express on their surface, affecting the hematopoiesis process. However, the interaction between hematopoietic stem and progenitor cells (HSPC) with fungal pathogens such as Histoplasma capsulatum has not been studied. Therefore, the objective of the present study was to determine if the interaction of HSPCs with H. capsulatum yeasts affects the hematopoiesis, activation, or proliferation of these cells. The results indicate that HSPCs are able to adhere to and internalize H. capsulatum yeasts through a mechanism dependent on TLR2, TLR4, and Dectin-1; however, this process does not affect the survival of the fungus, and, on the contrary, such interaction induces a significant increase in the expression of IL-1β, IL-6, IL-10, IL-17, TNF-α, and TGF-β, as well as the immune mediators Arg-1 and iNOS. Moreover, H. capsulatum induces apoptosis and alters HSPC proliferation. These findings suggest that H. capsulatum directly modulates the immune response exerted by HPSC through PRRs, and this interaction could directly affect the process of hematopoiesis, a fact that could explain clinical manifestations such as anemia and pancytopenia in patients with severe histoplasmosis, especially in those with fungal spread to the bone marrow.
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12
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Valdez AF, Miranda DZ, Guimarães AJ, Nimrichter L, Nosanchuk JD. Pathogenicity & Virulence of Histoplasma capsulatum - a multifaceted organism adapted to intracellular environments. Virulence 2022; 13:1900-1919. [PMID: 36266777 DOI: 10.1080/21505594.2022.2137987] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Histoplasmosis is a systemic mycosis caused by the thermally dimorphic fungus Histoplasma capsulatum. Although healthy individuals can develop histoplasmosis, the disease is particularly life-threatening in immunocompromised patients, with a wide range of clinical manifestations depending on the inoculum and virulence of the infecting strain. In this review, we discuss the established virulence factors and pathogenesis traits that make H. capsulatum highly adapted to a wide variety of hosts, including mammals. Understanding and integrating these mechanisms is a key step towards devising new preventative and therapeutic interventions.
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Affiliation(s)
- Alessandro F Valdez
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Departamento de Microbiologia Geral, Rio de Janeiro, Brazil
| | - Daniel Zamith Miranda
- Departments of Medicine (Division of Infectious Diseases) and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Allan Jefferson Guimarães
- Universidade Federal Fluminense, Instituto Biomédico, Departamento de Microbiologia e Parasitologia - MIP, Niterói, Rio de Janeiro, Brazil
| | - Leonardo Nimrichter
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Departamento de Microbiologia Geral, Rio de Janeiro, Brazil
| | - Joshua D Nosanchuk
- Departments of Medicine (Division of Infectious Diseases) and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
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13
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Antifungal Encapsulated into Ligand-Functionalized Nanoparticles with High Specificity for Macrophages. Pharmaceutics 2022; 14:pharmaceutics14091932. [PMID: 36145686 PMCID: PMC9501281 DOI: 10.3390/pharmaceutics14091932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/31/2022] [Accepted: 09/02/2022] [Indexed: 12/28/2022] Open
Abstract
Infectious diseases caused by intracellular microorganisms such as Histoplasma capsulatum represent a significant challenge worldwide. Drug encapsulation into functionalized nanoparticles (NPs) is a valuable alternative to improving drug solubility and bioavailability, preventing undesirable interactions and drug degradation, and reaching the specific therapeutic target with lower doses. This work reports on Itraconazole (ITZ) encapsulated into core-shell-like polymeric NPs and functionalized with anti-F4/80 antibodies for their targeted and controlled release into macrophages. Uptake assay on co-culture showed significant differences between the uptake of functionalized and bare NPs, higher with functionalized NPs. In vitro assays showed that F4/80-NPs with 0.007 µg/mL of encapsulated ITZ eliminated the H. capsulatum fungus in co-culture with macrophages effectively compared to the bare NPs, without any cytotoxic effect on macrophages after 24 h interaction. Furthermore, encapsulated ITZ modulated the gene expression of anti and pro-inflammatory cytokines (IL-1, INF-Y, IL-6 and IL-10) on macrophages. Additionally, the anti-F4/80 antibody-coating enhanced natural and adequate antifungal response in the cells, exerting a synergistic effect that prevented the growth of the fungus at the intracellular level. Functionalized NPs can potentially improve macrophage-targeted therapy, increasing NPs endocytosis and intracellular drug concentration.
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Cohen A, Jeng EE, Voorhies M, Symington J, Ali N, Rodriguez RA, Bassik MC, Sil A. Genome-scale CRISPR screening reveals that C3aR signaling is critical for rapid capture of fungi by macrophages. PLoS Pathog 2022; 18:e1010237. [PMID: 36174103 PMCID: PMC9578593 DOI: 10.1371/journal.ppat.1010237] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 10/18/2022] [Accepted: 07/13/2022] [Indexed: 11/18/2022] Open
Abstract
The fungal pathogen Histoplasma capsulatum (Hc) invades, replicates within, and destroys macrophages. To interrogate the molecular mechanisms underlying this interaction, we conducted a host-directed CRISPR-Cas9 screen and identified 361 genes that modify macrophage susceptibility to Hc infection, greatly expanding our understanding of host gene networks targeted by Hc. We identified pathways that have not been previously implicated in Hc interaction with macrophages, including the ragulator complex (involved in nutrient stress sensing), glycosylation enzymes, protein degradation machinery, mitochondrial respiration genes, solute transporters, and the ER membrane complex (EMC). The highest scoring protective hits included the complement C3a receptor (C3aR), a G-protein coupled receptor (GPCR) that recognizes the complement fragment C3a. Although it is known that complement components react with the fungal surface, leading to opsonization and release of small peptide fragments such as C3a, a role for C3aR in macrophage interactions with fungi has not been elucidated. We demonstrated that whereas C3aR is dispensable for macrophage phagocytosis of bacteria and latex beads, it is critical for optimal macrophage capture of pathogenic fungi, including Hc, the ubiquitous fungal pathogen Candida albicans, and the causative agent of Valley Fever Coccidioides posadasii. We showed that C3aR localizes to the early phagosome during Hc infection where it coordinates the formation of actin-rich membrane protrusions that promote Hc capture. We also showed that the EMC promotes surface expression of C3aR, likely explaining its identification in our screen. Taken together, our results provide new insight into host processes that affect Hc-macrophage interactions and uncover a novel and specific role for C3aR in macrophage recognition of fungi.
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Affiliation(s)
- Allison Cohen
- University of California San Francisco, Department of Microbiology and Immunology, San Francisco, California, United States of America
| | - Edwin E. Jeng
- Stanford University, Department of Genetics, Palo Alto, California, United States of America
| | - Mark Voorhies
- University of California San Francisco, Department of Microbiology and Immunology, San Francisco, California, United States of America
| | - Jane Symington
- University of California San Francisco, Department of Microbiology and Immunology, San Francisco, California, United States of America
| | - Nebat Ali
- University of California San Francisco, Department of Microbiology and Immunology, San Francisco, California, United States of America
| | - Rosa A. Rodriguez
- University of California San Francisco, Department of Microbiology and Immunology, San Francisco, California, United States of America
| | - Michael C. Bassik
- Stanford University, Department of Genetics, Palo Alto, California, United States of America
| | - Anita Sil
- University of California San Francisco, Department of Microbiology and Immunology, San Francisco, California, United States of America
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Challenges in Serologic Diagnostics of Neglected Human Systemic Mycoses: An Overview on Characterization of New Targets. Pathogens 2022; 11:pathogens11050569. [PMID: 35631090 PMCID: PMC9143782 DOI: 10.3390/pathogens11050569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 04/18/2022] [Accepted: 04/21/2022] [Indexed: 12/04/2022] Open
Abstract
Systemic mycoses have been viewed as neglected diseases and they are responsible for deaths and disabilities around the world. Rapid, low-cost, simple, highly-specific and sensitive diagnostic tests are critical components of patient care, disease control and active surveillance. However, the diagnosis of fungal infections represents a great challenge because of the decline in the expertise needed for identifying fungi, and a reduced number of instruments and assays specific to fungal identification. Unfortunately, time of diagnosis is one of the most important risk factors for mortality rates from many of the systemic mycoses. In addition, phenotypic and biochemical identification methods are often time-consuming, which has created an increasing demand for new methods of fungal identification. In this review, we discuss the current context of the diagnosis of the main systemic mycoses and propose alternative approaches for the identification of new targets for fungal pathogens, which can help in the development of new diagnostic tests.
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16
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Considerations about the Geographic Distribution of Histoplasma Species. Appl Environ Microbiol 2022; 88:e0201021. [PMID: 35262368 DOI: 10.1128/aem.02010-21] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Histoplasmosis is a mycotic infection principally affecting pulmonary tissue; sometimes, histoplasmosis can progress into a systemic disease. This infection involves immunocompetent and immunosuppressed human and other mammalian hosts, depending on particular circumstances. Histoplasmosis infection has been documented worldwide. The infection is acquired by inhaling infective mycelial propagules of the dimorphic fungus Histoplasma capsulatum. New reports of clinical cases of histoplasmosis in extreme latitudes could be related to human social adaptations and climate changes in the world, which are creating new favorable environments for this fungus and for bats, its major natural reservoirs and dispersers. Histoplasma has been isolated from most continents, and it is considered a complex of cryptic species, consisting of various groups of isolates that differ genetically and correlate with a particular geographic distribution. Based on updated studies, Histoplasma taxonomy is adjusting to new genetic data. Here, we have suggested that Histoplasma has at least 14 phylogenetic species distributed worldwide and new genotypes that could be under deliberation. Histoplasma's geographic radiation began in South America millions of years ago when the continents were joined and the climate was favorable. For fungal spreading, the role of bats and some birds is crucial, although other natural factors could also participate.
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17
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Höft MA, Duvenage L, Hoving JC. Key thermally dimorphic fungal pathogens: shaping host immunity. Open Biol 2022; 12:210219. [PMID: 35259948 PMCID: PMC8905152 DOI: 10.1098/rsob.210219] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 02/09/2022] [Indexed: 01/09/2023] Open
Abstract
Exposure to fungal pathogens from the environment is inevitable and with the number of at-risk populations increasing, the prevalence of invasive fungal infection is on the rise. An interesting group of fungal organisms known as thermally dimorphic fungi predominantly infects immunocompromised individuals. These potential pathogens are intriguing in that they survive in the environment in one form, mycelial phase, but when entering the host, they are triggered by the change in temperature to switch to a new pathogenic form. Considering the growing prevalence of infection and the need for improved diagnostic and treatment approaches, studies identifying key components of fungal recognition and the innate immune response to these pathogens will significantly contribute to our understanding of disease progression. This review focuses on key endemic dimorphic fungal pathogens that significantly contribute to disease, including Histoplasma, Coccidioides and Talaromyces species. We briefly describe their prevalence, route of infection and clinical presentation. Importantly, we have reviewed the major fungal cell wall components of these dimorphic fungi, the host pattern recognition receptors responsible for recognition and important innate immune responses supporting adaptive immunity and fungal clearance or the failure thereof.
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Affiliation(s)
- Maxine A. Höft
- CMM AFRICA Medical Mycology Research Unit, Institute of Infectious Diseases and Molecular Medicine (IDM), University of Cape Town, Cape Town 7925, South Africa
- Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
- MRC Centre for Medical Mycology at the University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK
| | - Lucian Duvenage
- CMM AFRICA Medical Mycology Research Unit, Institute of Infectious Diseases and Molecular Medicine (IDM), University of Cape Town, Cape Town 7925, South Africa
- Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
- MRC Centre for Medical Mycology at the University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK
| | - J. Claire Hoving
- CMM AFRICA Medical Mycology Research Unit, Institute of Infectious Diseases and Molecular Medicine (IDM), University of Cape Town, Cape Town 7925, South Africa
- Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa
- MRC Centre for Medical Mycology at the University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK
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18
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Blancett LT, Runge KA, Reyes GM, Kennedy LA, Jackson SC, Scheuermann SE, Harmon MB, Williams JC, Shearer G. Deletion of the Stress Response Gene DDR48 from Histoplasma capsulatum Increases Sensitivity to Oxidative Stress, Increases Susceptibility to Antifungals, and Decreases Fitness in Macrophages. J Fungi (Basel) 2021; 7:981. [PMID: 34829268 PMCID: PMC8617954 DOI: 10.3390/jof7110981] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 11/21/2022] Open
Abstract
The stress response gene DDR48 has been characterized in Saccharomyces cerevisiae and Candida albicans to be involved in combating various cellular stressors, from oxidative agents to antifungal compounds. Surprisingly, the biological function of DDR48 has yet to be identified, though it is likely an important part of the stress response. To gain insight into its function, we characterized DDR48 in the dimorphic fungal pathogen Histoplasma capsulatum. Transcriptional analyses showed preferential expression of DDR48 in the mycelial phase. Induction of DDR48 in Histoplasma yeasts developed after treatment with various cellular stress compounds. We generated a ddr48∆ deletion mutant to further characterize DDR48 function. Loss of DDR48 alters the transcriptional profile of the oxidative stress response and membrane synthesis pathways. Treatment with ROS or antifungal compounds reduced survival of ddr48∆ yeasts compared to controls, consistent with an aberrant cellular stress response. In addition, we infected RAW 264.7 macrophages with DDR48-expressing and ddr48∆ yeasts and observed a 50% decrease in recovery of ddr48∆ yeasts compared to wild-type yeasts. Loss of DDR48 function results in numerous negative effects in Histoplasma yeasts, highlighting its role as a key player in the global sensing and response to cellular stress by fungi.
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Affiliation(s)
- Logan T. Blancett
- Center for Molecular and Cellular Biology, The University of Southern Mississippi, Hattiesburg, MS 39406, USA; (K.A.R.); (G.M.R.); (L.A.K.); (S.C.J.); (S.E.S.); (M.B.H.); (J.C.W.); (G.S.J.)
- Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Kauri A. Runge
- Center for Molecular and Cellular Biology, The University of Southern Mississippi, Hattiesburg, MS 39406, USA; (K.A.R.); (G.M.R.); (L.A.K.); (S.C.J.); (S.E.S.); (M.B.H.); (J.C.W.); (G.S.J.)
- ThruPore Technologies, Inc., New Castle, DE 19720, USA
| | - Gabriella M. Reyes
- Center for Molecular and Cellular Biology, The University of Southern Mississippi, Hattiesburg, MS 39406, USA; (K.A.R.); (G.M.R.); (L.A.K.); (S.C.J.); (S.E.S.); (M.B.H.); (J.C.W.); (G.S.J.)
| | - Lauren A. Kennedy
- Center for Molecular and Cellular Biology, The University of Southern Mississippi, Hattiesburg, MS 39406, USA; (K.A.R.); (G.M.R.); (L.A.K.); (S.C.J.); (S.E.S.); (M.B.H.); (J.C.W.); (G.S.J.)
- Department of Cell and Molecular Biology, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Sydney C. Jackson
- Center for Molecular and Cellular Biology, The University of Southern Mississippi, Hattiesburg, MS 39406, USA; (K.A.R.); (G.M.R.); (L.A.K.); (S.C.J.); (S.E.S.); (M.B.H.); (J.C.W.); (G.S.J.)
| | - Sarah E. Scheuermann
- Center for Molecular and Cellular Biology, The University of Southern Mississippi, Hattiesburg, MS 39406, USA; (K.A.R.); (G.M.R.); (L.A.K.); (S.C.J.); (S.E.S.); (M.B.H.); (J.C.W.); (G.S.J.)
- Mississippi INBRE Research Scholars Program, Mississippi INBRE, The University of Southern Mississippi, Hattiesburg, MS 39406, USA
- High Containment Research Performance Core, Tulane National Primate Research Center, Covington, LA 70433, USA
| | - Mallory B. Harmon
- Center for Molecular and Cellular Biology, The University of Southern Mississippi, Hattiesburg, MS 39406, USA; (K.A.R.); (G.M.R.); (L.A.K.); (S.C.J.); (S.E.S.); (M.B.H.); (J.C.W.); (G.S.J.)
- Mississippi INBRE Research Scholars Program, Mississippi INBRE, The University of Southern Mississippi, Hattiesburg, MS 39406, USA
| | - Jamease C. Williams
- Center for Molecular and Cellular Biology, The University of Southern Mississippi, Hattiesburg, MS 39406, USA; (K.A.R.); (G.M.R.); (L.A.K.); (S.C.J.); (S.E.S.); (M.B.H.); (J.C.W.); (G.S.J.)
- Mississippi INBRE Research Scholars Program, Mississippi INBRE, The University of Southern Mississippi, Hattiesburg, MS 39406, USA
| | - Glenmore Shearer
- Center for Molecular and Cellular Biology, The University of Southern Mississippi, Hattiesburg, MS 39406, USA; (K.A.R.); (G.M.R.); (L.A.K.); (S.C.J.); (S.E.S.); (M.B.H.); (J.C.W.); (G.S.J.)
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Last A, Maurer M, S. Mosig A, S. Gresnigt M, Hube B. In vitro infection models to study fungal-host interactions. FEMS Microbiol Rev 2021; 45:fuab005. [PMID: 33524102 PMCID: PMC8498566 DOI: 10.1093/femsre/fuab005] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 01/14/2021] [Indexed: 12/14/2022] Open
Abstract
Fungal infections (mycoses) affect over a billion people per year. Approximately, two million of these infections are life-threatening, especially for patients with a compromised immune system. Fungi of the genera Aspergillus, Candida, Histoplasma and Cryptococcus are opportunistic pathogens that contribute to a substantial number of mycoses. To optimize the diagnosis and treatment of mycoses, we need to understand the complex fungal-host interplay during pathogenesis, the fungal attributes causing virulence and how the host resists infection via immunological defenses. In vitro models can be used to mimic fungal infections of various tissues and organs and the corresponding immune responses at near-physiological conditions. Furthermore, models can include fungal interactions with the host-microbiota to mimic the in vivo situation on skin and mucosal surfaces. This article reviews currently used in vitro models of fungal infections ranging from cell monolayers to microfluidic 3D organ-on-chip (OOC) platforms. We also discuss how OOC models can expand the toolbox for investigating interactions of fungi and their human hosts in the future.
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Affiliation(s)
- Antonia Last
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology—Hans Knoell Institute, Beutenbergstrasse 11a, 07745, Jena, Germany
| | - Michelle Maurer
- Center for Sepsis Control and Care (CSCC), Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany
- Institute of Biochemistry II, Jena University Hospital, Nonnenplan 2,07743, Jena, Germany
| | - Alexander S. Mosig
- Center for Sepsis Control and Care (CSCC), Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany
- Institute of Biochemistry II, Jena University Hospital, Nonnenplan 2,07743, Jena, Germany
| | - Mark S. Gresnigt
- Junior Research Group Adaptive Pathogenicity Strategies, Leibniz Institute for Natural Product Research and Infection Biology—Hans Knoell Institute, Beutenbergstrasse 11a, 07745, Jena, Germany
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology—Hans Knoell Institute, Beutenbergstrasse 11a, 07745, Jena, Germany
- Institute of Microbiology, Friedrich Schiller University, Neugasse 24, 07743, Jena, Germany
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Alcantara C, Almeida BR, Barros BCSC, Orikaza CM, Toledo MS, Suzuki E. Histoplasma capsulatum chemotypes I and II induce IL-8 secretion in lung epithelial cells in distinct manners. Med Mycol 2021; 58:1169-1177. [PMID: 32119085 DOI: 10.1093/mmy/myaa006] [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: 11/24/2019] [Revised: 01/30/2020] [Accepted: 02/05/2020] [Indexed: 12/19/2022] Open
Abstract
The cell wall is one of the most important structures of pathogenic fungi, enabling initial interaction with the host and consequent modulation of immunological responses. Over the years, some researchers have shown that cell wall components of Histoplasma capsulatum vary among fungal isolates, and one of the major differences is the presence or absence of α-(1,3)-glucan, classifying wild-type fungi as chemotypes II or I, respectively. The present work shows that an isolate of H. capsulatum chemotype I induced lower levels of interleukin (IL)-8 secretion by the lung epithelial cell line A549, when compared to chemotype II yeasts. Thus, we expected that the absence of α-glucan in spontaneous variant yeasts, which were isolated from chemotype II cultures, would modify IL-8 secretion by A549 cells, but surprisingly, these fungi promoted similar levels of IL-8 secretion as their wild-type counterpart. Furthermore, when using a specific inhibitor for Syk activation, we observed that this inhibitor reduced IL-8 levels in A549 cell cultures infected with wild type chemotype I fungi. This inhibitor failed to reduce this cytokine levels in A549 cell cultures infected with chemotype II and their spontaneous variant yeasts, which also do not present α-glucan on their surface. The importance of SFKs and PKC δ in this event was also analyzed. Our results show that different isolates of H. capsulatum modulate distinct cell signaling pathways to promote cytokine secretion in host epithelial cells, emphasizing the existence of various mechanisms for Histoplasma pathogenicity.
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Affiliation(s)
- Cristiane Alcantara
- Department of Microbiology, Immunology, and Parasitology, Escola Paulista de Medicina - Universidade Federal de São Paulo, São Paulo - SP, Brazil
| | - Bruna Rocha Almeida
- Department of Microbiology, Immunology, and Parasitology, Escola Paulista de Medicina - Universidade Federal de São Paulo, São Paulo - SP, Brazil
| | - Bianca Carla Silva Campitelli Barros
- Department of Microbiology, Immunology, and Parasitology, Escola Paulista de Medicina - Universidade Federal de São Paulo, São Paulo - SP, Brazil
| | - Cristina Mary Orikaza
- Department of Microbiology, Immunology, and Parasitology, Escola Paulista de Medicina - Universidade Federal de São Paulo, São Paulo - SP, Brazil
| | - Marcos Sergio Toledo
- Department of Biochemistry, Escola Paulista de Medicina - Universidade Federal de São Paulo, São Paulo - SP, Brazil
| | - Erika Suzuki
- Department of Microbiology, Immunology, and Parasitology, Escola Paulista de Medicina - Universidade Federal de São Paulo, São Paulo - SP, Brazil
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Yang D, Shen LX, Chen RF, Fu Y, Xu HY, Zhang LN, Liu DH. The Effect of Talaromyces marneffei Infection on CD86 Expression in THP-1 Cells. Infect Drug Resist 2021; 14:651-660. [PMID: 33642869 PMCID: PMC7903953 DOI: 10.2147/idr.s297160] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 01/31/2021] [Indexed: 12/11/2022] Open
Abstract
Background Talaromyces marneffei (T. marneffei) is a destructive opportunistic dimorphic fungal which can cause lethiferous Talaromycosis, but the clearance of T. marneffei mainly depends on the innate immune response. Objective To investigate whether T. marneffei can inhibit the expression of CD86 in THP-1 cells after infection and discuss the potential mechanisms. Methods Western blot and immunoelectron microscopy were used to detect the CD86 expression on T. marneffei cultured on BHI medium at 37°C. Western blot, enzyme-linked immunoassay and immunofluorescence were used to detect the change of CD86 expression on macrophages incubating with T. marneffei. Enzyme-linked immunoassay was used to detect the content of CD86 in supernatant in the co-culture system. Immunohistochemistry and immunoelectron microscopy were used to detect the expression of CD86 on T. marneffei incubating with macrophages. Results T. marneffei did not express CD86 when cultured separately at 37°C detected by Western blot and immunoelectron microscopy, but it did express CD86 when incubated with macrophages detected by immunohistochemistry and immunoelectron microscopy. The CD86 expression of macrophages significantly decreased at 72 hours when infected with T. marneffei while the content of CD86 in supernatant significantly increased at 72 hours compared with the control group which were detected by Western blot, enzyme-linked immunoassay and immunofluorescence. Conclusion 1) After T. marneffei infection, CD86 expression on THP-1 decreased, and with the progression of infection, insufficient polarization of M1 macrophages gradually appeared; 2) T. marneffei may adsorb or uptake CD86 in supernatant produced by macrophages during the contact with THP-1 cells, thus leading to the consumption of CD86 in macrophages.
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Affiliation(s)
- Di Yang
- Department of Dermatology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, People's Republic of China
| | - Lin-Xia Shen
- Department of Dermatology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, People's Republic of China.,Department of Dermatology and Venereology, Huashan Hospital, Fudan University, Shanghai, 200040, People's Republic of China
| | - Ri-Feng Chen
- Department of Dermatology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, People's Republic of China
| | - Yu Fu
- Department of Dermatology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, People's Republic of China
| | - Hong-Yan Xu
- Department of Dermatology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, People's Republic of China
| | - Li-Na Zhang
- Department of Dermatology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, People's Republic of China
| | - Dong-Hua Liu
- Department of Dermatology, The First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, People's Republic of China.,Guangxi Key Laboratory of AIDS Prevention and Treatment, School of Public Health, Nanning, 530021, People's Republic of China
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22
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Baranov MV, Kumar M, Sacanna S, Thutupalli S, van den Bogaart G. Modulation of Immune Responses by Particle Size and Shape. Front Immunol 2021; 11:607945. [PMID: 33679696 PMCID: PMC7927956 DOI: 10.3389/fimmu.2020.607945] [Citation(s) in RCA: 104] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 12/23/2020] [Indexed: 12/12/2022] Open
Abstract
The immune system has to cope with a wide range of irregularly shaped pathogens that can actively move (e.g., by flagella) and also dynamically remodel their shape (e.g., transition from yeast-shaped to hyphal fungi). The goal of this review is to draw general conclusions of how the size and geometry of a pathogen affect its uptake and processing by phagocytes of the immune system. We compared both theoretical and experimental studies with different cells, model particles, and pathogenic microbes (particularly fungi) showing that particle size, shape, rigidity, and surface roughness are important parameters for cellular uptake and subsequent immune responses, particularly inflammasome activation and T cell activation. Understanding how the physical properties of particles affect immune responses can aid the design of better vaccines.
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Affiliation(s)
- Maksim V. Baranov
- Department of Molecular Immunology and Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Manoj Kumar
- Simons Center for the Study of Living Machines, National Centre for Biological Sciences, Tata Institute for Fundamental Research, Bangalore, India
| | - Stefano Sacanna
- Molecular Design Institute, Department of Chemistry, New York University, New York, NY, United States
| | - Shashi Thutupalli
- Simons Center for the Study of Living Machines, National Centre for Biological Sciences, Tata Institute for Fundamental Research, Bangalore, India
- International Centre for Theoretical Sciences, Tata Institute for Fundamental Research, Bangalore, India
| | - Geert van den Bogaart
- Department of Molecular Immunology and Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
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Differential miRNA Expression in Human Macrophage-Like Cells Infected with Histoplasma capsulatum Yeasts Cultured in Planktonic and Biofilm Forms. J Fungi (Basel) 2021; 7:jof7010060. [PMID: 33477397 PMCID: PMC7830537 DOI: 10.3390/jof7010060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 11/19/2020] [Indexed: 12/14/2022] Open
Abstract
Histoplasma capsulatum affects healthy and immunocompromised individuals, sometimes causing a severe disease. This fungus has two morphotypes, the mycelial (infective) and the yeast (parasitic) phases. MicroRNAs (miRNAs) are small RNAs involved in the regulation of several cellular processes, and their differential expression has been associated with many disease states. To investigate miRNA expression in host cells during H. capsulatum infection, we studied the changes in the miRNA profiles of differentiated human macrophages infected with yeasts from two fungal strains with different virulence, EH-315 (high virulence) and 60I (low virulence) grown in planktonic cultures, and EH-315 grown in biofilm form. MiRNA profiles were evaluated by means of reverse transcription-quantitative polymerase chain reaction using a commercial human miRNome panel. The target genes of the differentially expressed miRNAs and their corresponding signaling pathways were predicted using bioinformatics analyses. Here, we confirmed biofilm structures were present in the EH-315 culture whose conditions facilitated producing insoluble exopolysaccharide and intracellular polysaccharides. In infected macrophages, bioinformatics analyses revealed especially increased (hsa-miR-99b-3p) or decreased (hsa-miR-342-3p) miRNAs expression levels in response to infection with biofilms or both growth forms of H. capsulatum yeasts, respectively. The results of miRNAs suggested that infection by H. capsulatum can affect important biological pathways of the host cell, targeting two genes: one encoding a protein that is important in the cortical cytoskeleton; the other, a protein involved in the formation of stress granules. Expressed miRNAs in the host’s response could be proposed as new therapeutic and/or diagnostic tools for histoplasmosis.
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Gonçalves DDS, Rodriguez de La Noval C, Ferreira MDS, Honorato L, Araújo GRDS, Frases S, Pizzini CV, Nosanchuk JD, Cordero RJB, Rodrigues ML, Peralta JM, Nimrichter L, Guimarães AJ. Histoplasma capsulatum Glycans From Distinct Genotypes Share Structural and Serological Similarities to Cryptococcus neoformans Glucuronoxylomannan. Front Cell Infect Microbiol 2021; 10:565571. [PMID: 33585262 PMCID: PMC7874066 DOI: 10.3389/fcimb.2020.565571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 11/17/2020] [Indexed: 11/20/2022] Open
Abstract
The cell wall is a ubiquitous structure in the fungal kingdom, with some features varying depending on the species. Additional external structures can be present, such as the capsule of Cryptococcus neoformans (Cn), its major virulence factor, mainly composed of glucuronoxylomannan (GXM), with anti-phagocytic and anti-inflammatory properties. The literature shows that other cryptococcal species and even more evolutionarily distant species, such as the Trichosporon asahii, T. mucoides, and Paracoccidioides brasiliensis can produce GXM-like polysaccharides displaying serological reactivity to GXM-specific monoclonal antibodies (mAbs), and these complex polysaccharides have similar composition and anti-phagocytic properties to cryptococcal GXM. Previously, we demonstrated that the fungus Histoplasma capsulatum (Hc) incorporates, surface/secreted GXM of Cn and the surface accumulation of the polysaccharide enhances Hc virulence in vitro and in vivo. In this work, we characterized the ability of Hc to produce cellular-attached (C-gly-Hc) and secreted (E-gly) glycans with reactivity to GXM mAbs. These C-gly-Hc are readily incorporated on the surface of acapsular Cn cap59; however, in contrast to Cn GXM, C-gly-Hc had no xylose and glucuronic acid in its composition. Mapping of recognized Cn GXM synthesis/export proteins confirmed the presence of orthologs in the Hc database. Evaluation of C-gly and E-gly of Hc from strains of distinct monophyletic clades showed serological reactivity to GXM mAbs, despite slight differences in their molecular dimensions. These C-gly-Hc and E-gly-Hc also reacted with sera of cryptococcosis patients. In turn, sera from histoplasmosis patients recognized Cn glycans, suggesting immunogenicity and the presence of cross-reacting antibodies. Additionally, C-gly-Hc and E-gly-Hc coated Cn cap59 were more resistant to phagocytosis and macrophage killing. C-gly-Hc and E-gly-Hc coated Cn cap59 were also able to kill larvae of Galleria mellonella. These GXM-like Hc glycans, as well as those produced by other pathogenic fungi, may also be important during host-pathogen interactions, and factors associated with their regulation are potentially important targets for the management of histoplasmosis.
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Affiliation(s)
- Diego de Souza Gonçalves
- Laboratório de Bioquímica e Imunologia das Micoses, Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Niterói, Brazil
- Pós-Graduação em Doenças Infecciosas e Parasitárias, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Claudia Rodriguez de La Noval
- Laboratório de Bioquímica e Imunologia das Micoses, Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Niterói, Brazil
- Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marina da Silva Ferreira
- Laboratório de Bioquímica e Imunologia das Micoses, Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Niterói, Brazil
- Departamento de Imunologia, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Leandro Honorato
- Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Glauber Ribeiro de Sousa Araújo
- Laboratório de Biofísica de Fungos, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Susana Frases
- Laboratório de Biofísica de Fungos, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Claudia Vera Pizzini
- Laboratório de Micologia, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Joshua D. Nosanchuk
- Department of Microbiology and Immunology and Division of infectious Diseases, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY, United States
| | - Radames J. B. Cordero
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Marcio L. Rodrigues
- Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (Fiocruz), Curitiba, Brazil
| | - José Mauro Peralta
- Departamento de Imunologia, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Leonardo Nimrichter
- Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Allan J. Guimarães
- Laboratório de Bioquímica e Imunologia das Micoses, Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Universidade Federal Fluminense, Niterói, Brazil
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Garcia-Effron G. Rezafungin-Mechanisms of Action, Susceptibility and Resistance: Similarities and Differences with the Other Echinocandins. J Fungi (Basel) 2020; 6:E262. [PMID: 33139650 PMCID: PMC7711656 DOI: 10.3390/jof6040262] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/19/2020] [Accepted: 10/22/2020] [Indexed: 12/20/2022] Open
Abstract
Rezafungin (formerly CD101) is a new β-glucan synthase inhibitor that is chemically related with anidulafungin. It is considered the first molecule of the new generation of long-acting echinocandins. It has several advantages over the already approved by the Food and Drug Administration (FDA) echinocandins as it has better tissue penetration, better pharmacokinetic/phamacodynamic (PK/PD) pharmacometrics, and a good safety profile. It is much more stable in solution than the older echinocandins, making it more flexible in terms of dosing, storage, and manufacturing. These properties would allow rezafungin to be administered once-weekly (intravenous) and to be potentially administered topically and subcutaneously. In addition, higher dose regimens were tested with no evidence of toxic effect. This will eventually prevent (or reduce) the selection of resistant strains. Rezafungin also has several similarities with older echinocandins as they share the same in vitro behavior (very similar Minimum Inhibitory Concentration required to inhibit the growth of 50% of the isolates (MIC50) and half enzyme maximal inhibitory concentration 50% (IC50)) and spectrum, the same target, and the same mechanisms of resistance. The selection of FKS mutants occurred at similar frequency for rezafungin than for anidulafungin and caspofungin. In this review, rezafungin mechanism of action, target, mechanism of resistance, and in vitro data are described in a comparative manner with the already approved echinocandins.
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Affiliation(s)
- Guillermo Garcia-Effron
- Laboratorio de Micología y Diagnóstico Molecular, Cátedra de Parasitología y Micología, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, C.P. 3000 Santa Fe, Argentina; or ; Tel.: +54-9342-4575209 (ext. 135)
- Consejo Nacional de Investigaciones Científicas y Tecnológicas, C.P. 3000 Santa Fe, Argentina
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Biodiverse Histoplasma Species Elicit Distinct Patterns of Pulmonary Inflammation following Sublethal Infection. mSphere 2020; 5:5/4/e00742-20. [PMID: 32848006 PMCID: PMC7449625 DOI: 10.1128/msphere.00742-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Acute pulmonary histoplasmosis in healthy individuals comprises most of the disease burden caused by the fungal pathogen Histoplasma. Fungal pneumonia is frequently delayed in diagnosis and treatment due to a prolonged period of quiescence early during infection. In this study, we used a murine respiratory model of histoplasmosis to investigate how different Histoplasma species modulate lung inflammation throughout the complete course of infection. We propose that a relatively low, sublethal inoculum is ideal to model acute pulmonary histoplasmosis in humans, primarily due to the quiescent stage of fungal growth that occurs in the lungs of mice prior to the initiation of inflammation. Our results reveal the unique course of lung immunity associated with divergent species of Histoplasma and imply that the progression of clinical disease is considerably more heterogeneous than previously recognized. Histoplasma is an endemic dimorphic fungus that can cause disease in healthy and immunocompromised individuals after the transition of inhaled spores into the facultative intracellular yeast form. There is substantial diversity among Histoplasma species, but it is not clear how this heterogeneity impacts the progression of pathology and cellular immune responses during acute respiratory infection, which represents the vast majority of histoplasmosis disease burden. After inoculating mice intranasally with a sublethal inoculum, we characterized the immune response to Histoplasma capsulatum (strain G186A) and Histoplasma ohiense (strain G217B) using comprehensive flow cytometric and single-cell analyses. Within 8 days after inoculation, H. ohiense induced a significantly higher infiltration of neutrophils and inflammatory monocytes into the lung compared to H. capsulatum. Microscopic analysis of infected lung tissue revealed that although the total number of fungi was similar within inflamed lung lesions, we observed different species-dependent intracellular yeast distribution patterns. Inoculation with gfp-expressing strains indicated that H. ohiense, but not H. capsulatum, was associated primarily with alveolar macrophages early after infection. Interestingly, we observed a significant reduction in the total number of alveolar macrophages 12 to 16 days after H. ohiense, but not H. capsulatum infection, despite similar intracellular growth dynamics within AMJ2-C11 alveolar macrophages in vitro. Together, our data suggest that H. ohiense, but not H. capsulatum, preferentially interacts with alveolar macrophages early after infection, which may lead to a different course of inflammation and resolution despite similar rates of fungal clearance. IMPORTANCE Acute pulmonary histoplasmosis in healthy individuals comprises most of the disease burden caused by the fungal pathogen Histoplasma. Fungal pneumonia is frequently delayed in diagnosis and treatment due to a prolonged period of quiescence early during infection. In this study, we used a murine respiratory model of histoplasmosis to investigate how different Histoplasma species modulate lung inflammation throughout the complete course of infection. We propose that a relatively low, sublethal inoculum is ideal to model acute pulmonary histoplasmosis in humans, primarily due to the quiescent stage of fungal growth that occurs in the lungs of mice prior to the initiation of inflammation. Our results reveal the unique course of lung immunity associated with divergent species of Histoplasma and imply that the progression of clinical disease is considerably more heterogeneous than previously recognized.
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Min K, Neiman AM, Konopka JB. Fungal Pathogens: Shape-Shifting Invaders. Trends Microbiol 2020; 28:922-933. [PMID: 32474010 DOI: 10.1016/j.tim.2020.05.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/24/2020] [Accepted: 05/05/2020] [Indexed: 12/11/2022]
Abstract
Fungal infections are on the rise due to new medical procedures that have increased the number of immune compromised patients, antibacterial antibiotics that disrupt the microbiome, and increased use of indwelling medical devices that provide sites for biofilm formation. Key to understanding the mechanisms of pathogenesis is to determine how fungal morphology impacts virulence strategies. For example, small budding cells use very different strategies to disseminate compared with long hyphal filaments. Furthermore, cell morphology must be monitored in the host, as many fungal pathogens change their shape to disseminate into new areas, acquire nutrients, and avoid attack by the immune system. This review describes the shape-shifting alterations in morphogenesis of human fungal pathogens and how they influence virulence strategies.
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Affiliation(s)
- Kyunghun Min
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, NY, USA
| | - Aaron M Neiman
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, USA
| | - James B Konopka
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, NY, USA.
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Chang CC, Levitz SM. Fungal immunology in clinical practice: Magical realism or practical reality? Med Mycol 2019; 57:S294-S306. [PMID: 31292656 DOI: 10.1093/mmy/myy165] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 12/21/2018] [Accepted: 01/28/2019] [Indexed: 12/15/2022] Open
Abstract
Invasive fungal infections (IFIs) occur predominantly in immunocompromised individuals but can also be seen in previously well persons. The human innate immune system recognizes key components of the fungal cell wall as foreign resulting in a myriad of signaling cascades. This triggers release of antifungal molecules as well as adaptive immune responses, which kill or at least contain the invading fungi. However, these defences may fail in hosts with primary or secondary immunodeficiencies resulting in IFIs. Knowledge of a patient's immune status enables the clinician to predict the fungal infections most likely to occur. Moreover, the occurrence of an opportunistic mycosis in a patient without known immunocompromise usually should prompt a search for an occult immune defect. A rapidly expanding number of primary and secondary immunodeficiencies associated with mycoses has been identified. An investigative approach to determining the nature of these immunodeficiencies is suggested to help guide clinicians encountering patients with IFI. Finally, promising adjunctive immunotherapy measures are currently being investigated in IFI.
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Affiliation(s)
- Christina C Chang
- Department of Infectious Diseases, Alfred Hospital and Monash University, Melbourne, Australia
| | - Stuart M Levitz
- Department of Medicine, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, Massachusetts, United States
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29
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Denham ST, Wambaugh MA, Brown JCS. How Environmental Fungi Cause a Range of Clinical Outcomes in Susceptible Hosts. J Mol Biol 2019; 431:2982-3009. [PMID: 31078554 PMCID: PMC6646061 DOI: 10.1016/j.jmb.2019.05.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/18/2019] [Accepted: 05/01/2019] [Indexed: 12/11/2022]
Abstract
Environmental fungi are globally ubiquitous and human exposure is near universal. However, relatively few fungal species are capable of infecting humans, and among fungi, few exposure events lead to severe systemic infections. Systemic infections have mortality rates of up to 90%, cost the US healthcare system $7.2 billion annually, and are typically associated with immunocompromised patients. Despite this reputation, exposure to environmental fungi results in a range of outcomes, from asymptomatic latent infections to severe systemic infection. Here we discuss different exposure outcomes for five major fungal pathogens: Aspergillus, Blastomyces, Coccidioides, Cryptococcus, and Histoplasma species. These fungi include a mold, a budding yeast, and thermal dimorphic fungi. All of these species must adapt to dramatically changing environments over the course of disease. These dynamic environments include the human lung, which is the first exposure site for these organisms. Fungi must defend themselves against host immune cells while germinating and growing, which risks further exposing microbe-associated molecular patterns to the host. We discuss immune evasion strategies during early infection, from disruption of host immune cells to major changes in fungal cell morphology.
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Affiliation(s)
- Steven T Denham
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Morgan A Wambaugh
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Jessica C S Brown
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.
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30
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Decote-Ricardo D, LaRocque-de-Freitas IF, Rocha JDB, Nascimento DO, Nunes MP, Morrot A, Freire-de-Lima L, Previato JO, Mendonça-Previato L, Freire-de-Lima CG. Immunomodulatory Role of Capsular Polysaccharides Constituents of Cryptococcus neoformans. Front Med (Lausanne) 2019; 6:129. [PMID: 31275938 PMCID: PMC6593061 DOI: 10.3389/fmed.2019.00129] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 05/24/2019] [Indexed: 12/13/2022] Open
Abstract
Cryptococcosis is a systemic fungal infection caused by Cryptococcus neoformans. In immunocompetent patients, cryptococcal infection is often confined to the lungs. In immunocompromised individuals, C. neoformans may cause life-threatening illness, either from novel exposure or through reactivation of a previously acquired latent infection. For example, cryptococcal meningitis is a severe clinical disease that can manifest in people that are immunocompromised due to AIDS. The major constituents of the Cryptococcus polysaccharide capsule, glucuronoxylomannan (GXM), and galactoxylomannan (GalXM), also known as glucuronoxylomanogalactan (GXMGal), are considered the primary virulence factors of Cryptococcus. Despite the predominance of GXM in the polysaccharide capsule, GalXM has more robust immunomodulatory effects on host cellular immunity. This review summarizes current knowledge regarding host-Crytococcus neoformans interactions and the role of capsular polysaccharides in host immunomodulation. Future studies will likely facilitate a better understanding of the mechanisms involved in antigenic recognition and host immune response to C. neoformans and lead to the development of new therapeutic pathways for cryptococcal infection.
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Affiliation(s)
- Debora Decote-Ricardo
- Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, Brazil
| | | | - Juliana Dutra B Rocha
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Danielle O Nascimento
- Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, Brazil.,Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marise P Nunes
- Laboratório de Imunoparasitologia, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
| | - Alexandre Morrot
- Laboratório de Imunoparasitologia, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil.,Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Leonardo Freire-de-Lima
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jose Osvaldo Previato
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lucia Mendonça-Previato
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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31
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Roth MT, Zamith-Miranda D, Nosanchuk JD. Immunization Strategies for the Control of Histoplasmosis. CURRENT TROPICAL MEDICINE REPORTS 2019; 6:35-41. [PMID: 31772912 PMCID: PMC6879175 DOI: 10.1007/s40475-019-00172-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Histoplasmosis is an infection caused by the dimorphic fungus Histoplasma capsulatum. Histoplasmosis is typically self-limited and presents asymptomatically in most people. Nevertheless, histoplasmosis can cause severe pulmonary disease and death. Histoplasmosis is increasingly found worldwide; however, it is best documented in the endemic region of the Mississippi river valley system in the Eastern part of the United States (US). Epidemiological studies from the US detailing the morbidity, mortality, and cost associated with histoplasmosis underscore the need to develop a vaccine. PURPOSE OF REVIEW This review will detail some of the major developments in potential vaccines against histoplasmosis, with particular emphasis on those that could be used to immunize immunocompromised hosts. Additionally, this review will highlight some non-traditional vaccine-like ideas for the prevention of diverse mycoses. RECENT FINDINGS Historically, immunization strategies against histoplasmosis have largely focused on identifying immunogenic proteins that confer protection in animal models. More recently, novel active, therapeutic, and immunomodulatory strategies have been explored as potential alternatives for those with various immune-deficiencies. SUMMARY The studies summarized in this review demonstrate that more research is needed to clarify the immunobiology, clinical role and efficacy of each candidate vaccine in the ever-expanding potential armamentarium against histoplasmosis.
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Affiliation(s)
- Maxwell T Roth
- Department of Medicine (Division of Infectious Diseases) and Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Daniel Zamith-Miranda
- Department of Medicine (Division of Infectious Diseases) and Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Joshua D Nosanchuk
- Department of Medicine (Division of Infectious Diseases) and Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
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