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Li X, Paccoud O, Chan KH, Yuen KY, Manchon R, Lanternier F, Slavin MA, van de Veerdonk FL, Bicanic T, Lortholary O. Cryptococcosis Associated With Biologic Therapy: A Narrative Review. Open Forum Infect Dis 2024; 11:ofae316. [PMID: 38947739 PMCID: PMC11212009 DOI: 10.1093/ofid/ofae316] [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: 03/05/2024] [Accepted: 06/17/2024] [Indexed: 07/02/2024] Open
Abstract
Cryptococcus is an opportunistic fungal pathogen that can cause disseminated infection with predominant central nervous system involvement in patients with compromised immunity. Biologics are increasingly used in the treatment of neoplasms and autoimmune/inflammatory conditions and the prevention of transplant rejection, which may affect human defense mechanisms against cryptococcosis. In this review, we comprehensively investigate the association between cryptococcosis and various biologics, highlighting their risks of infection, clinical manifestations, and clinical outcomes. Clinicians should remain vigilant for the risk of cryptococcosis in patients receiving biologics that affect the Th1/macrophage activation pathways, such as tumor necrosis factor α antagonists, Bruton tyrosine kinase inhibitors, fingolimod, JAK/STAT inhibitors (Janus kinase/signal transducer and activator of transcription), and monoclonal antibody against CD52. Other risk factors-such as age, underlying condition, and concurrent immunosuppressants, especially corticosteroids-should also be taken into account during risk stratification.
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Affiliation(s)
- Xin Li
- Department of Infectious Diseases and Tropical Medicine, Université Paris Cité, Necker-Enfants Malades University Hospital, Assistance Publique–Hôpitaux de Paris, IHU Imagine, Paris, France
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Olivier Paccoud
- Department of Infectious Diseases and Tropical Medicine, Université Paris Cité, Necker-Enfants Malades University Hospital, Assistance Publique–Hôpitaux de Paris, IHU Imagine, Paris, France
| | - Koon-Ho Chan
- Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Kwok-Yung Yuen
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Romain Manchon
- Department of Infectious Diseases and Tropical Medicine, Université Paris Cité, Necker-Enfants Malades University Hospital, Assistance Publique–Hôpitaux de Paris, IHU Imagine, Paris, France
| | - Fanny Lanternier
- Department of Infectious Diseases and Tropical Medicine, Université Paris Cité, Necker-Enfants Malades University Hospital, Assistance Publique–Hôpitaux de Paris, IHU Imagine, Paris, France
- Institut Pasteur, National Reference Center for Invasive Mycoses and Antifungals, Mycology Translational Research Group, Mycology Department, Université Paris Cité, Paris, France
| | - Monica A Slavin
- Department of Infectious Diseases, Peter MacCallum Cancer Centre, Melbourne, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
- Victorian Infectious Diseases Service, Royal Melbourne Hospital, Melbourne, Australia
| | - Frank L van de Veerdonk
- Department of Internal Medicine, Radboud Center for Infectious Diseases, Radboudumc, Nijmegen, the Netherlands
| | - Tihana Bicanic
- Institute of Infection and Immunity, St George's University of London, London, UK
| | - Olivier Lortholary
- Department of Infectious Diseases and Tropical Medicine, Université Paris Cité, Necker-Enfants Malades University Hospital, Assistance Publique–Hôpitaux de Paris, IHU Imagine, Paris, France
- Institut Pasteur, National Reference Center for Invasive Mycoses and Antifungals, Mycology Translational Research Group, Mycology Department, Université Paris Cité, Paris, France
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Tugume L, Ssebambulidde K, Kasibante J, Ellis J, Wake RM, Gakuru J, Lawrence DS, Abassi M, Rajasingham R, Meya DB, Boulware DR. Cryptococcal meningitis. Nat Rev Dis Primers 2023; 9:62. [PMID: 37945681 DOI: 10.1038/s41572-023-00472-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/09/2023] [Indexed: 11/12/2023]
Abstract
Cryptococcus neoformans and Cryptococcus gattii species complexes cause meningoencephalitis with high fatality rates and considerable morbidity, particularly in persons with deficient T cell-mediated immunity, most commonly affecting people living with HIV. Whereas the global incidence of HIV-associated cryptococcal meningitis (HIV-CM) has decreased over the past decade, cryptococcosis still accounts for one in five AIDS-related deaths globally due to the persistent burden of advanced HIV disease. Moreover, mortality remains high (~50%) in low-resource settings. The armamentarium to decrease cryptococcosis-associated mortality is expanding: cryptococcal antigen screening in the serum and pre-emptive azole therapy for cryptococcal antigenaemia are well established, whereas enhanced pre-emptive combination treatment regimens to improve survival of persons with cryptococcal antigenaemia are in clinical trials. Short courses (≤7 days) of amphotericin-based therapy combined with flucytosine are currently the preferred options for induction therapy of cryptococcal meningitis. Whether short-course induction regimens improve long-term morbidity such as depression, reduced neurocognitive performance and physical disability among survivors is the subject of further study. Here, we discuss underlying immunology, changing epidemiology, and updates on the management of cryptococcal meningitis with emphasis on HIV-associated disease.
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Affiliation(s)
- Lillian Tugume
- Infectious Diseases Institute, Makerere University, Kampala, Uganda.
| | - Kenneth Ssebambulidde
- Infectious Diseases Institute, Makerere University, Kampala, Uganda
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - John Kasibante
- Infectious Diseases Institute, Makerere University, Kampala, Uganda
| | - Jayne Ellis
- Infectious Diseases Institute, Makerere University, Kampala, Uganda
- Clinical Research Department, Faculty of Infectious and Tropical Diseases London School of Hygiene and Tropical Medicine, London, UK
| | - Rachel M Wake
- Institute for Infection and Immunity, St George's University of London, London, UK
| | - Jane Gakuru
- Infectious Diseases Institute, Makerere University, Kampala, Uganda
| | - David S Lawrence
- Clinical Research Department, Faculty of Infectious and Tropical Diseases London School of Hygiene and Tropical Medicine, London, UK
- Botswana Harvard AIDS Institute Partnership, Gaborone, Botswana
| | - Mahsa Abassi
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Radha Rajasingham
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - David B Meya
- Infectious Diseases Institute, Makerere University, Kampala, Uganda
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - David R Boulware
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA
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Kietrungruang K, Sookkree S, Sangboonruang S, Semakul N, Poomanee W, Kitidee K, Tragoolpua Y, Tragoolpua K. Ethanolic Extract Propolis-Loaded Niosomes Diminish Phospholipase B1, Biofilm Formation, and Intracellular Replication of Cryptococcus neoformans in Macrophages. Molecules 2023; 28:6224. [PMID: 37687052 PMCID: PMC10488685 DOI: 10.3390/molecules28176224] [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: 07/24/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
Secretory phospholipase B1 (PLB1) and biofilms act as microbial virulence factors and play an important role in pulmonary cryptococcosis. This study aims to formulate the ethanolic extract of propolis-loaded niosomes (Nio-EEP) and evaluate the biological activities occurring during PLB1 production and biofilm formation of Cryptococcus neoformans. Some physicochemical characterizations of niosomes include a mean diameter of 270 nm in a spherical shape, a zeta-potential of -10.54 ± 1.37 mV, and 88.13 ± 0.01% entrapment efficiency. Nio-EEP can release EEP in a sustained manner and retains consistent physicochemical properties for a month. Nio-EEP has the capability to permeate the cellular membranes of C. neoformans, causing a significant decrease in the mRNA expression level of PLB1. Interestingly, biofilm formation, biofilm thickness, and the expression level of biofilm-related genes (UGD1 and UXS1) were also significantly reduced. Pre-treating with Nio-EEP prior to yeast infection reduced the intracellular replication of C. neoformans in alveolar macrophages by 47%. In conclusion, Nio-EEP mediates as an anti-virulence agent to inhibit PLB1 and biofilm production for preventing fungal colonization on lung epithelial cells and also decreases the intracellular replication of phagocytosed cryptococci. This nano-based EEP delivery might be a potential therapeutic strategy in the prophylaxis and treatment of pulmonary cryptococcosis in the future.
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Affiliation(s)
- Kritapat Kietrungruang
- Division of Clinical Microbiology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand; (K.K.); (S.S.); (S.S.)
| | - Sanonthinee Sookkree
- Division of Clinical Microbiology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand; (K.K.); (S.S.); (S.S.)
| | - Sirikwan Sangboonruang
- Division of Clinical Microbiology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand; (K.K.); (S.S.); (S.S.)
| | - Natthawat Semakul
- Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand;
| | - Worrapan Poomanee
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, Chiang Mai University, Chiang Mai 50200, Thailand;
| | - Kuntida Kitidee
- Center for Research Innovation and Biomedical Informatics, Faculty of Medical Technology, Mahidol University, Salaya, Nakhon Pathom 73170, Thailand;
| | - Yingmanee Tragoolpua
- Natural Extracts and Innovative Products for Alternative Healthcare Research Group, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand;
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Khajornsak Tragoolpua
- Division of Clinical Microbiology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand; (K.K.); (S.S.); (S.S.)
- Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand;
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Lee HH, Carmichael DJ, Ríbeiro V, Parisi DN, Munzen ME, Charles-Niño CL, Hamed MF, Kaur E, Mishra A, Patel J, Rooklin RB, Sher A, Carrillo-Sepulveda MA, Eugenin EA, Dores MR, Martinez LR. Glucuronoxylomannan intranasal challenge prior to Cryptococcus neoformans pulmonary infection enhances cerebral cryptococcosis in rodents. PLoS Pathog 2023; 19:e1010941. [PMID: 37115795 PMCID: PMC10171644 DOI: 10.1371/journal.ppat.1010941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 05/10/2023] [Accepted: 04/17/2023] [Indexed: 04/29/2023] Open
Abstract
The encapsulated fungus Cryptococcus neoformans is the most common cause of fungal meningitis, with the highest rate of disease in patients with AIDS or immunosuppression. This microbe enters the human body via inhalation of infectious particles. C. neoformans capsular polysaccharide, in which the major component is glucuronoxylomannan (GXM), extensively accumulates in tissues and compromises host immune responses. C. neoformans travels from the lungs to the bloodstream and crosses to the brain via transcytosis, paracytosis, or inside of phagocytes using a "Trojan horse" mechanism. The fungus causes life-threatening meningoencephalitis with high mortality rates. Hence, we investigated the impact of intranasal exogenous GXM administration on C. neoformans infection in C57BL/6 mice. GXM enhances cryptococcal pulmonary infection and facilitates fungal systemic dissemination and brain invasion. Pre-challenge of GXM results in detection of the polysaccharide in lungs, serum, and surprisingly brain, the latter likely reached through the nasal cavity. GXM significantly alters endothelial cell tight junction protein expression in vivo, suggesting significant implications for the C. neoformans mechanisms of brain invasion. Using a microtiter transwell system, we showed that GXM disrupts the trans-endothelial electrical resistance, weakening human brain endothelial cell monolayers co-cultured with pericytes, supportive cells of blood vessels/capillaries found in the blood-brain barrier (BBB) to promote C. neoformans BBB penetration. Our findings should be considered in the development of therapeutics to combat the devastating complications of cryptococcosis that results in an estimated ~200,000 deaths worldwide each year.
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Affiliation(s)
- Hiu Ham Lee
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, New York, United States of America
| | - Dylan J Carmichael
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, New York, United States of America
| | - Victoria Ríbeiro
- Department of Neuroscience, Cell Biology, and Anatomy, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Dana N Parisi
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, New York, United States of America
- Department of Biomedical Sciences, Long Island University-Post, Brookville, New York, United States of America
| | - Melissa E Munzen
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, United States of America
| | - Claudia L Charles-Niño
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, United States of America
| | - Mohamed F Hamed
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, United States of America
- Department of Pathology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
| | - Ettiman Kaur
- Department of Biology, Hofstra University, Hempstead, New York, United States of America
| | - Ayush Mishra
- Department of Biology, Hofstra University, Hempstead, New York, United States of America
| | - Jiya Patel
- Department of Biology, Hofstra University, Hempstead, New York, United States of America
| | - Rikki B Rooklin
- Department of Biology, Hofstra University, Hempstead, New York, United States of America
| | - Amina Sher
- Department of Biology, Hofstra University, Hempstead, New York, United States of America
| | - Maria A Carrillo-Sepulveda
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, New York, United States of America
| | - Eliseo A Eugenin
- Department of Neuroscience, Cell Biology, and Anatomy, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Michael R Dores
- Department of Biology, Hofstra University, Hempstead, New York, United States of America
| | - Luis R Martinez
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, New York, United States of America
- Department of Biomedical Sciences, Long Island University-Post, Brookville, New York, United States of America
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- Center for Immunology and Transplantation, University of Florida, Gainesville, Florida, United States of America
- Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, Florida, United States of America
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5
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Abstract
Cryptococcosis is a disease caused by the pathogenic fungi Cryptococcus neoformans and Cryptococcus gattii, both environmental fungi that cause severe pneumonia and may even lead to cryptococcal meningoencephalitis. Although C. neoformans affects more fragile individuals, such as immunocompromised hosts through opportunistic infections, C. gattii causes a serious indiscriminate primary infection in immunocompetent individuals. Typically seen in tropical and subtropical environments, C. gattii has increased its endemic area over recent years, largely due to climatic factors that favor contagion in warmer climates. It is important to point out that not only C. gattii, but the Cryptococcus species complex produces a polysaccharidic capsule with immunomodulatory properties, enabling the pathogenic species of Cryptococccus to subvert the host immune response during the establishment of cryptococcosis, facilitating its dissemination in the infected organism. C. gattii causes a more severe and difficult-to-treat infection, with few antifungals eliciting an effective response during chronic treatment. Much of the immunopathology of this cryptococcosis is still poorly understood, with most studies focusing on cryptococcosis caused by the species C. neoformans. C. gattii became more important in the epidemiological scenario with the outbreaks in the Pacific Northwest of the United States, which resulted in phylogenetic studies of the virulent variant responsible for the severe infection in the region. Since then, the study of cryptococcosis caused by C. gattii has helped researchers understand the immunopathological aspects of different variants of this pathogen.
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Qian W, Wang W, Zhang J, Fu Y, Liu Q, Li X, Wang T, Zhang Q. Exploitation of the antifungal and antibiofilm activities of plumbagin against Cryptococcus neoformans. BIOFOULING 2022; 38:558-574. [PMID: 35818738 DOI: 10.1080/08927014.2022.2094260] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 06/02/2022] [Accepted: 06/11/2022] [Indexed: 06/15/2023]
Abstract
Cryptococcus neoformans is an important opportunistic fungal pathogen that causes various infections. Here, the antifungal and antibiofilm activities of plumbagin against C. neoformans and the underlying mechanisms were evaluated. The minimum inhibitory concentration (MIC) of plumbagin against C. neoformans H99 was 8 μg ml-1. Plumbagin disrupted the cell membrane integrity and reduced the metabolic activities of C. neoformans H99. C. neoformans H99 biofilm cells were damaged by plumbagin at a concentration of 64 μg ml-1, whereas 48-h mature biofilms were dispersed at a plumbagin concentration of 128 μg ml-1. Whole-transcriptome analysis of plumbagin-treated C. neoformans H99 in the biofilm and planktonic states identified differentially expressed genes enriched in several important cellular processes (cell membrane, ribosome biogenesis, fatty acid synthesis, melanin and capsule production). Notably, plumbagin damaged biofilm cells by downregulating FAS1 and FAS2 expression. Thus, plumbagin can be exploited as an antifungal agent to combat C. neoformans-related infections.
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Affiliation(s)
- Weidong Qian
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, PR China
| | - Wenjing Wang
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, PR China
| | - Jianing Zhang
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, PR China
| | - Yuting Fu
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, PR China
| | - Qiming Liu
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, PR China
| | - Xinchen Li
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, PR China
| | - Ting Wang
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, PR China
| | - Qian Zhang
- Department of Dermatology, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen, PR China
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Rathore SS, Sathiyamoorthy J, Lalitha C, Ramakrishnan J. A holistic review on Cryptococcus neoformans. Microb Pathog 2022; 166:105521. [DOI: 10.1016/j.micpath.2022.105521] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 04/06/2022] [Accepted: 04/06/2022] [Indexed: 12/21/2022]
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Gene, virulence and related regulatory mechanisms in Cryptococcus gattii. Acta Biochim Biophys Sin (Shanghai) 2022; 54:593-603. [PMID: 35593469 PMCID: PMC9828318 DOI: 10.3724/abbs.2022029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Cryptococcus gattii is a kind of basidiomycetous yeast, which grows in human and animal hosts. C. gattii has four distinct genomes, VGI/AFLP4, VGII/AFLP6, VGIII/AFLP5, and VGIV/AFLP7. The virulence of C. gattii is closely associated with genotype and related stress-signaling pathways, but the pathogenic mechanism of C. gattii has not been fully identified. With the development of genomics and transcriptomics, the relationship among genes, regulatory mechanisms, virulence, and treatment is gradually being recognized. In this review, to better understand how C. gattii causes disease and to characterize hypervirulent C. gattii strains, we summarize the current understanding of C. gattii genotypes, phenotypes, virulence, and the regulatory mechanisms.
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Strickland AB, Shi M. Mechanisms of fungal dissemination. Cell Mol Life Sci 2021; 78:3219-3238. [PMID: 33449153 PMCID: PMC8044058 DOI: 10.1007/s00018-020-03736-z] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 11/23/2020] [Accepted: 12/08/2020] [Indexed: 12/13/2022]
Abstract
Fungal infections are an increasing threat to global public health. There are more than six million fungal species worldwide, but less than 1% are known to infect humans. Most of these fungal infections are superficial, affecting the hair, skin and nails, but some species are capable of causing life-threatening diseases. The most common of these include Cryptococcus neoformans, Aspergillus fumigatus and Candida albicans. These fungi are typically innocuous and even constitute a part of the human microbiome, but if these pathogens disseminate throughout the body, they can cause fatal infections which account for more than one million deaths worldwide each year. Thus, systemic dissemination of fungi is a critical step in the development of these deadly infections. In this review, we discuss our current understanding of how fungi disseminate from the initial infection sites to the bloodstream, how immune cells eliminate fungi from circulation and how fungi leave the blood and enter distant organs, highlighting some recent advances and offering some perspectives on future directions.
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Affiliation(s)
- Ashley B Strickland
- Division of Immunology, Virginia-Maryland College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, MD, USA.
| | - Meiqing Shi
- Division of Immunology, Virginia-Maryland College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, MD, USA.
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Associations between Cryptococcus Genotypes, Phenotypes, and Clinical Parameters of Human Disease: A Review. J Fungi (Basel) 2021; 7:jof7040260. [PMID: 33808500 PMCID: PMC8067209 DOI: 10.3390/jof7040260] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 03/25/2021] [Accepted: 03/25/2021] [Indexed: 12/11/2022] Open
Abstract
The genus Cryptococcus contains two primary species complexes that are significant opportunistic human fungal pathogens: C. neoformans and C. gattii. In humans, cryptococcosis can manifest in many ways, but most often results in either pulmonary or central nervous system disease. Patients with cryptococcosis can display a variety of symptoms on a spectrum of severity because of the interaction between yeast and host. The bulk of our knowledge regarding Cryptococcus and the mechanisms of disease stem from in vitro experiments and in vivo animal models that make a fair attempt, but do not recapitulate the conditions inside the human host. To better understand the dynamics of initiation and progression in cryptococcal disease, it is important to study the genetic and phenotypic differences in the context of human infection to identify the human and fungal risk factors that contribute to pathogenesis and poor clinical outcomes. In this review, we summarize the current understanding of the different clinical presentations and health outcomes that are associated with pathogenicity and virulence of cryptococcal strains with respect to specific genotypes and phenotypes.
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Normile TG, Bryan AM, Del Poeta M. Animal Models of Cryptococcus neoformans in Identifying Immune Parameters Associated With Primary Infection and Reactivation of Latent Infection. Front Immunol 2020; 11:581750. [PMID: 33042164 PMCID: PMC7522366 DOI: 10.3389/fimmu.2020.581750] [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: 07/09/2020] [Accepted: 08/12/2020] [Indexed: 12/13/2022] Open
Abstract
Cryptococcus species are environmental fungal pathogens and the causative agents of cryptococcosis. Infection occurs upon inhalation of infectious particles, which proliferate in the lung causing a primary infection. From this primary lung infection, fungal cells can eventually disseminate to other organs, particularly the brain, causing lethal meningoencephalitis. However, in most cases, the primary infection resolves with the formation of a lung granuloma. Upon severe immunodeficiency, dormant cryptococcal cells will start proliferating in the lung granuloma and eventually will disseminate to the brain. Many investigators have sought to study the protective host immune response to this pathogen in search of host parameters that keep the proliferation of cryptococcal cells under control. The majority of the work assimilates research carried out using the primary infection animal model, mainly because a reactivation model has been available only very recently. This review will focus on anti-cryptococcal immunity in both the primary and reactivation models. An understanding of the differences in host immunity between the primary and reactivation models will help to define the key host parameters that control the infections and are important for the research and development of new therapeutic and vaccine strategies against cryptococcosis.
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Affiliation(s)
- Tyler G Normile
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, NY, United States
| | - Arielle M Bryan
- Ingenious Targeting Laboratory Incorporated, Ronkonkoma, NY, United States
| | - Maurizio Del Poeta
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, NY, United States.,Division of Infectious Diseases, School of Medicine, Stony Brook University, Stony Brook, NY, United States.,Veterans Administration Medical Center, Northport, NY, United States
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12
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Berry SB, Haack AJ, Theberge AB, Brighenti S, Svensson M. Host and Pathogen Communication in the Respiratory Tract: Mechanisms and Models of a Complex Signaling Microenvironment. Front Med (Lausanne) 2020; 7:537. [PMID: 33015094 PMCID: PMC7511576 DOI: 10.3389/fmed.2020.00537] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 07/29/2020] [Indexed: 01/15/2023] Open
Abstract
Chronic lung diseases are a leading cause of morbidity and mortality across the globe, encompassing a diverse range of conditions from infections with pathogenic microorganisms to underlying genetic disorders. The respiratory tract represents an active interface with the external environment having the primary immune function of resisting pathogen intrusion and maintaining homeostasis in response to the myriad of stimuli encountered within its microenvironment. To perform these vital functions and prevent lung disorders, a chemical and biological cross-talk occurs in the complex milieu of the lung that mediates and regulates the numerous cellular processes contributing to lung health. In this review, we will focus on the role of cross-talk in chronic lung infections, and discuss how different cell types and signaling pathways contribute to the chronicity of infection(s) and prevent effective immune clearance of pathogens. In the lung microenvironment, pathogens have developed the capacity to evade mucosal immunity using different mechanisms or virulence factors, leading to colonization and infection of the host; such mechanisms include the release of soluble and volatile factors, as well as contact dependent (juxtracrine) interactions. We explore the diverse modes of communication between the host and pathogen in the lung tissue milieu in the context of chronic lung infections. Lastly, we review current methods and approaches used to model and study these host-pathogen interactions in vitro, and the role of these technological platforms in advancing our knowledge about chronic lung diseases.
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Affiliation(s)
- Samuel B. Berry
- Department of Medicine, Center for Infectious Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
- Department of Chemistry, University of Washington, Seattle, WA, United States
| | - Amanda J. Haack
- Department of Chemistry, University of Washington, Seattle, WA, United States
| | | | - Susanna Brighenti
- Department of Medicine, Center for Infectious Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Mattias Svensson
- Department of Medicine, Center for Infectious Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
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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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Camacho E, Casadevall A. Cryptococcal Traits Mediating Adherence to Biotic and Abiotic Surfaces. J Fungi (Basel) 2018; 4:jof4030088. [PMID: 30060601 PMCID: PMC6162697 DOI: 10.3390/jof4030088] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 07/25/2018] [Accepted: 07/27/2018] [Indexed: 01/22/2023] Open
Abstract
Several species in the genus Cryptococcus are facultative intracellular pathogens capable of causing disease associated with high mortality and morbidity in humans. These fungi interact with other organisms in the soil, and these interactions may contribute to the development of adaptation mechanisms that function in virulence by promoting fungal survival in animal hosts. Fungal adhesion molecules, also known as adhesins, have been classically considered as cell-surface or secreted proteins that play critical roles in microbial pathogenesis or in biofilm formation as structural components. Pathogenic Cryptococcus spp. differ from other pathogenic yeasts in having a polysaccharide capsule that covers the cell wall surface and precludes interactions of those structures with host cell receptors. Hence, pathogenic Cryptococcus spp. use unconventional tools for surface attachment. In this essay, we review the unique traits and mechanisms favoring adhesion of Cryptococcus spp. to biotic and abiotic surfaces. Knowledge of the traits that mediate adherence could be exploited in the development of therapeutic, biomedical, and/or industrial products.
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Affiliation(s)
- Emma Camacho
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, 615 N Wolfe St Room E5132, Baltimore, MD 21205, USA.
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, 615 N Wolfe St Room E5132, Baltimore, MD 21205, USA.
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15
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Casadevall A, Coelho C, Alanio A. Mechanisms of Cryptococcus neoformans-Mediated Host Damage. Front Immunol 2018; 9:855. [PMID: 29760698 PMCID: PMC5936990 DOI: 10.3389/fimmu.2018.00855] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 04/06/2018] [Indexed: 01/22/2023] Open
Abstract
Cryptococcus neoformans is not usually considered a cytotoxic fungal pathogen but there is considerable evidence that this microbe can damage host cells and tissues. In this essay, we review the evidence that C. neoformans damages host cells and note that the mechanisms involved are diverse. We consider C. neoformans-mediated host damage at the molecular, cellular, tissue, and organism level. Direct mechanisms of cytotoxicity include lytic exocytosis, organelle dysfunction, phagolysosomal membrane damage, and cytoskeletal alterations. Cytotoxicity contributes to pathogenesis by interfering with immune effector cell function and disrupting endothelial barriers thus allowing dissemination. When C. neoformans-mediated and immune-mediated host damage is sufficient to affect homeostasis, cryptococcosis occurs at the organism level.
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Affiliation(s)
- Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, MD, United States
| | - Carolina Coelho
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, MD, United States
| | - Alexandre Alanio
- Department of Molecular Microbiology and Immunology, Johns Hopkins School of Public Health, Baltimore, MD, United States
- Institut Pasteur, Molecular Mycology Unit, CNRS UMR2000, Paris, France
- Laboratoire de Parasitologie-Mycologie, Hôpital Saint-Louis, Groupe Hospitalier Lariboisière, Saint-Louis, Fernand Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Université Paris Diderot, Sorbonne Paris Cité, Paris, France
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16
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Esher SK, Zaragoza O, Alspaugh JA. Cryptococcal pathogenic mechanisms: a dangerous trip from the environment to the brain. Mem Inst Oswaldo Cruz 2018; 113:e180057. [PMID: 29668825 PMCID: PMC5909089 DOI: 10.1590/0074-02760180057] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 03/08/2018] [Indexed: 12/16/2022] Open
Abstract
Cryptococcus neoformans is an opportunistic pathogenic yeast that causes serious infections, most commonly of the central nervous system (CNS). C. neoformans is mainly found in the environment and acquired by inhalation. It could be metaphorically imagined that cryptococcal disease is a "journey" for the microorganism that starts in the environment, where this yeast loads its suitcase with virulence traits. C. neoformans first encounters the infected mammalian host in the lungs, a site in which it must choose the right elements from its "virulence suitcase" to survive the pulmonary immune response. However, the lung is often only the first stop in this journey, and in some individuals the fungal trip continues to the brain. To enter the brain, C. neoformans must "open" the main barrier that protects this organ, the blood brain barrier (BBB). Once in the brain, C. neoformans expresses a distinct set of protective attributes that confers a strong neurotropism and the ability to cause brain colonisation. In summary, C. neoformans is a unique fungal pathogen as shown in its ability to survive in the face of multiple stress factors and to express virulence factors that contribute to the development of disease.
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Affiliation(s)
- Shannon K Esher
- Duke University School of Medicine, Department of Molecular Genetics and Microbiology, Department of Medicine, Durham, USA
| | - Oscar Zaragoza
- Instituto de Salud Carlos III, National Centre for Microbiology, Mycology Reference Laboratory, Madrid, Spain
| | - James Andrew Alspaugh
- Duke University School of Medicine, Department of Molecular Genetics and Microbiology, Department of Medicine, Durham, USA
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17
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Mechanisms of Pulmonary Escape and Dissemination by Cryptococcus neoformans. J Fungi (Basel) 2018; 4:jof4010025. [PMID: 29463005 PMCID: PMC5872328 DOI: 10.3390/jof4010025] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 02/09/2018] [Accepted: 02/16/2018] [Indexed: 12/15/2022] Open
Abstract
Cryptococcus neoformans is a common environmental saprophyte and human fungal pathogen that primarily causes disease in immunocompromised individuals. Similar to many environmentally acquired human fungal pathogens, C. neoformans initiates infection in the lungs. However, the main driver of mortality is invasive cryptococcosis leading to fungal meningitis. After C. neoformans gains a foothold in the lungs, a critical early step in invasion is transversal of the respiratory epithelium. In this review, we summarize current knowledge relating to pulmonary escape. We focus on fungal factors that allow C. neoformans to disseminate from the lungs via intracellular and extracellular routes.
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18
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Taylor-Smith LM. Cryptococcus-Epithelial Interactions. J Fungi (Basel) 2017; 3:jof3040053. [PMID: 29371569 PMCID: PMC5753155 DOI: 10.3390/jof3040053] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 09/28/2017] [Accepted: 09/30/2017] [Indexed: 12/12/2022] Open
Abstract
The fungal pathogen, Cryptococcus neoformans, causes devastating levels of morbidity and mortality. Infections with this fungus tend to be predominantly in immunocompromised individuals, such as those with HIV. Infections initiate with inhalation of cryptococcal cells and entry of the pathogen into the lungs. The bronchial epithelial cells of the upper airway and the alveolar epithelial cells of the lower airway are likely to be the first host cells that Cryptococcus engage with. Thus the interaction of cryptococci and the respiratory epithelia will be the focus of this review. C. neoformans has been shown to adhere to respiratory epithelial cells, although if the role of the capsule is in aiding or hindering this adhesion is debatable. The epithelia are also able to react to cryptococci with the release of cytokines and chemokines to start the immune response to this invading pathogen. The activity of surfactant components that line this mucosal barrier towards Cryptococcus and the metabolic and transcriptional reaction of cryptococci when encountering epithelial cells will also be discussed.
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Affiliation(s)
- Leanne M Taylor-Smith
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, West Midlands, UK.
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19
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Pritchard M, Jack A, Powell L, Sadh H, Rye P, Hill K, Thomas D. Alginate oligosaccharides modify hyphal infiltration ofCandida albicansin anin vitromodel of invasive human candidosis. J Appl Microbiol 2017. [DOI: 10.1111/jam.13516] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- M.F. Pritchard
- Advanced Therapies Group; Cardiff University School of Dentistry; College of Biomedical and Life Sciences; Cardiff UK
| | - A.A. Jack
- Advanced Therapies Group; Cardiff University School of Dentistry; College of Biomedical and Life Sciences; Cardiff UK
| | - L.C. Powell
- Advanced Therapies Group; Cardiff University School of Dentistry; College of Biomedical and Life Sciences; Cardiff UK
| | - H. Sadh
- Advanced Therapies Group; Cardiff University School of Dentistry; College of Biomedical and Life Sciences; Cardiff UK
| | | | - K.E. Hill
- Advanced Therapies Group; Cardiff University School of Dentistry; College of Biomedical and Life Sciences; Cardiff UK
| | - D.W. Thomas
- Advanced Therapies Group; Cardiff University School of Dentistry; College of Biomedical and Life Sciences; Cardiff UK
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20
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Steenwyk JL, Soghigian JS, Perfect JR, Gibbons JG. Copy number variation contributes to cryptic genetic variation in outbreak lineages of Cryptococcus gattii from the North American Pacific Northwest. BMC Genomics 2016; 17:700. [PMID: 27590805 PMCID: PMC5009542 DOI: 10.1186/s12864-016-3044-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 08/24/2016] [Indexed: 12/13/2022] Open
Abstract
Background Copy number variants (CNVs) are a class of structural variants (SVs) and are defined as fragments of DNA that are present at variable copy number in comparison with a reference genome. Recent advances in bioinformatics methodologies and sequencing technologies have enabled the high-resolution quantification of genome-wide CNVs. In pathogenic fungi SVs have been shown to alter gene expression, influence host specificity, and drive fungicide resistance, but little attention has focused specifically on CNVs. Using publicly available sequencing data, we identified 90 isolates across 212 Cryptococcus gattii genomes that belong to the VGII subgroups responsible for the recent deadly outbreaks in the North American Pacific Northwest. We generated CNV profiles for each sample to investigate the prevalence and function of CNV in C. gattii. Results We identified eight genetic clusters among publicly available Illumina whole genome sequence data from 212 C. gattii isolates through population structure analysis. Three clusters represent the VGIIa, VGIIb, and VGIIc subgroups from the North American Pacific Northwest. CNV was bioinformatically predicted and affected ~300–400 Kilobases (Kb) of the C. gattii VGII subgroup genomes. Sixty-seven loci, encompassing 58 genes, showed highly divergent patterns of copy number variation between VGII subgroups. Analysis of PFam domains within divergent CN variable genes revealed enrichment of protein domains associated with transport, cell wall organization and external encapsulating structure. Conclusions CNVs may contribute to pathological and phenotypic differences observed between the C. gattii VGIIa, VGIIb, and VGIIc subpopulations. Genes overlapping with population differentiated CNVs were enriched for several virulence related functional terms. These results uncover novel candidate genes to examine the genetic and functional underpinnings of C. gattii pathogenicity. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-3044-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jacob L Steenwyk
- Biology Department, Clark University, 950 Main Street, Worcester, MA, USA.,Current address: Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - John S Soghigian
- Biology Department, Clark University, 950 Main Street, Worcester, MA, USA.,Current address: Department of Environmental Sciences, The Connecticut Agricultural Experiment Station, New Haven, CT, USA
| | - John R Perfect
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | - John G Gibbons
- Biology Department, Clark University, 950 Main Street, Worcester, MA, USA.
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21
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Choo KK, Chong PP, Ho ASH, Yong PVC. The role of host microfilaments and microtubules during opsonin-independent interactions of Cryptococcus neoformans with mammalian lung cells. Eur J Clin Microbiol Infect Dis 2015; 34:2421-7. [PMID: 26463450 DOI: 10.1007/s10096-015-2497-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2015] [Accepted: 09/21/2015] [Indexed: 02/03/2023]
Abstract
The purpose of this investigation was to characterise the interactions of Cryptococcus neoformans with mammalian host alveolar epithelial cells and alveolar macrophages, with emphasis on the roles of the cryptococcal capsule and the host cell cytoskeletons. The adherence and internalisation of C. neoformans into mammalian lung cells and the roles of host cell cytoskeletons in host-pathogen interactions were studied using in vitro models coupled with a differential fluorescence assay, fluorescence staining, immunofluorescence and drug inhibition of actin and microtubule polymerisation. Under conditions devoid of opsonin and macrophage activation, C. neoformans has a high affinity towards MH-S alveolar macrophages, yet associated poorly to A549 alveolar epithelial cells. Acapsular C. neoformans adhered to and internalised into the mammalian cells more effectively compared to encapsulated cryptococci. Acapsular C. neoformans induced prominent actin reorganisation at the host-pathogen interface in MH-S alveolar macrophages, but minimally affected actin reorganisation in A549 alveolar epithelial cells. Acapsular C. neoformans also induced localisation of microtubules to internalised cryptococci in MH-S cells. Drug inhibition of actin and microtubule polymerisation both reduced the association of acapsular C. neoformans to alveolar macrophages. The current study visualises and confirms the interactions of C. neoformans with mammalian alveolar cells during the establishment of infection in the lungs. The acapsular form of C. neoformans effectively adhered to and internalised into alveolar macrophages by inducing localised actin reorganisation, relying on the host's actin and microtubule activities.
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Affiliation(s)
- K K Choo
- School of Biosciences, Taylor's University, Subang, Selangor, Malaysia
| | - P P Chong
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - A S H Ho
- School of Biosciences, Taylor's University, Subang, Selangor, Malaysia
| | - P V C Yong
- School of Biosciences, Taylor's University, Subang, Selangor, Malaysia.
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22
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Soares DA, Oliveira MB, Evangelista AF, Venancio EJ, Andrade RV, Felipe MSS, Petrofeza S. Phospholipase gene expression during Paracoccidioides brasiliensis morphological transition and infection. Mem Inst Oswaldo Cruz 2014; 108:808-11. [PMID: 24037207 PMCID: PMC3970691 DOI: 10.1590/0074-0276108062013021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 06/07/2013] [Indexed: 11/24/2022] Open
Abstract
Phospholipase is an important virulence factor for pathogenic fungi. In this
study, we demonstrate the following: (i) the Paracoccidioides
brasiliensis pld gene is preferentially expressed in mycelium
cells, (ii) the plb1 gene is mostly up-regulated by infection
after 6 h of co-infection of MH-S cells or during BALB/c mice
lung infection, (iii) during lung infection, plb1,
plc and pld gene expression are
significantly increased 6-48 h post-infection compared to 56 days after
infection, strongly suggesting that phospholipases play a role in the early
events of infection, but not during the chronic stages of pulmonary infection by
P. brasiliensis.
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Affiliation(s)
- Deyze Alencar Soares
- Instituto de Ciências Biológicas, Universidade Federal de Goiás, GoiâniaGO, Brasil
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23
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Kwon-Chung KJ, Fraser JA, Doering TL, Wang Z, Janbon G, Idnurm A, Bahn YS. Cryptococcus neoformans and Cryptococcus gattii, the etiologic agents of cryptococcosis. Cold Spring Harb Perspect Med 2014; 4:a019760. [PMID: 24985132 PMCID: PMC4066639 DOI: 10.1101/cshperspect.a019760] [Citation(s) in RCA: 312] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cryptococcus neoformans and Cryptococcus gattii are the two etiologic agents of cryptococcosis. They belong to the phylum Basidiomycota and can be readily distinguished from other pathogenic yeasts such as Candida by the presence of a polysaccharide capsule, formation of melanin, and urease activity, which all function as virulence determinants. Infection proceeds via inhalation and subsequent dissemination to the central nervous system to cause meningoencephalitis. The most common risk for cryptococcosis caused by C. neoformans is AIDS, whereas infections caused by C. gattii are more often reported in immunocompetent patients with undefined risk than in the immunocompromised. There have been many chapters, reviews, and books written on C. neoformans. The topics we focus on in this article include species description, pathogenesis, life cycle, capsule, and stress response, which serve to highlight the specializations in virulence that have occurred in this unique encapsulated melanin-forming yeast that causes global deaths estimated at more than 600,000 annually.
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Affiliation(s)
- Kyung J Kwon-Chung
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - James A Fraser
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Tamara L Doering
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Zhou Wang
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Guilhem Janbon
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, 75015 Paris, France
| | - Alexander Idnurm
- Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri, Kansas City, Missouri 64110
| | - Yong-Sun Bahn
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
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24
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25
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Coelho C, Bocca AL, Casadevall A. The intracellular life of Cryptococcus neoformans. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2013; 9:219-38. [PMID: 24050625 DOI: 10.1146/annurev-pathol-012513-104653] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cryptococcus neoformans is a fungal pathogen with worldwide distribution. Serological studies of human populations show a high prevalence of human infection, which rarely progresses to disease in immunocompetent hosts. However, decreased host immunity places individuals at high risk for cryptococcal disease. The disease can result from acute infection or reactivation of latent infection, in which yeasts within granulomas and host macrophages emerge to cause disease. In this review, we summarize what is known about the cellular recognition, ingestion, and killing of C. neoformans and discuss the unique and remarkable features of its intracellular life, including the proposed mechanisms for fungal persistence and killing in phagocytic cells.
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Affiliation(s)
- Carolina Coelho
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Yeshiva University, Bronx, New York 10461;
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26
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Silveira CP, Piffer AC, Kmetzsch L, Fonseca FL, Soares DA, Staats CC, Rodrigues ML, Schrank A, Vainstein MH. The heat shock protein (Hsp) 70 of Cryptococcus neoformans is associated with the fungal cell surface and influences the interaction between yeast and host cells. Fungal Genet Biol 2013; 60:53-63. [PMID: 23954835 DOI: 10.1016/j.fgb.2013.08.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 08/01/2013] [Accepted: 08/08/2013] [Indexed: 01/03/2023]
Abstract
The pathogenic yeast Cryptococcus neoformans secretes numerous proteins, such as heat shock proteins, by unconventional mechanisms during its interaction with host cells. Hsp70 is a conserved chaperone that plays important roles in various cellular processes, including the interaction of fungi with host immune cells. Here, we report that sera from individuals with cryptococcosis infection recognize a recombinant C. neoformans Hsp70 (Cn_rHsp70). Moreover, immunofluorescence assays using antibodies against Cn_rHsp70 revealed the localization of this protein at the cell surface mainly in association with the capsular network. We found that the addition of Cn_rHsp70 positively modulated the interaction of C. neoformans with human alveolar epithelial cells and decreased fungal killing by mouse macrophages, without affecting phagocytosis rates. Immunofluorescence analysis showed that there was a competitive association among the receptor, GXM and Cn_rHsp70, indicating that the Hsp70-binding sites in host cells appear to be shared by glucuronoxylomannan (GXM), the major capsular antigen in C. neoformans. Our observations suggest additional mechanisms by which Hsp70 influences the interaction of C. neoformans with host cells.
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Affiliation(s)
- Carolina P Silveira
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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27
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Springer DJ, Saini D, Byrnes EJ, Heitman J, Frothingham R. Development of an aerosol model of Cryptococcus reveals humidity as an important factor affecting the viability of Cryptococcus during aerosolization. PLoS One 2013; 8:e69804. [PMID: 23894542 PMCID: PMC3720958 DOI: 10.1371/journal.pone.0069804] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 06/12/2013] [Indexed: 12/14/2022] Open
Abstract
Cryptococcus is an emerging global health threat that is annually responsible for over 1,000,000 infections and one third of all AIDS patient deaths. There is an ongoing outbreak of cryptococcosis in the western United States and Canada. Cryptococcosis is a disease resulting from the inhalation of the infectious propagules from the environment. The current and most frequently used animal infection models initiate infection via liquid suspension through intranasal instillation or intravenous injection. These models do not replicate the typically dry nature of aerosol exposure and may hinder our ability to decipher the initial events that lead to clearance or the establishment of infection. We have established a standardized aerosol model of murine infection for the human fungal pathogen Cryptococcus. Aerosolized cells were generated utilizing a Collison nebulizer in a whole-body Madison Chamber at different humidity conditions. The aerosols inside the chamber were sampled using a BioSampler to determine viable aerosol concentration and spray factor (ratio of viable aerosol concentration to total inoculum concentration). We have effectively delivered yeast and yeast-spore mixtures to the lungs of mice and observed the establishment of disease. We observed that growth conditions prior to exposure and humidity within the Madison Chamber during exposure can alter Cryptococcus survival and dose retained in mice.
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Affiliation(s)
- Deborah J Springer
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA.
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28
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Sabiiti W, May RC. Mechanisms of infection by the human fungal pathogen Cryptococcus neoformans. Future Microbiol 2013; 7:1297-313. [PMID: 23075448 DOI: 10.2217/fmb.12.102] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Brain infection by the fungus Cryptococcus neoformans results in inflammation of the meninges and brain parenchyma, a condition known as meningoencephalitis. One million people are estimated to suffer cryptococcal meningitis globally and >60% of these cases die within 3 months of diagnosis. Humans are believed to contract infection by inhalation of spores or dried yeast cells, which subsequently colonize the lung tissue. In the lungs, cryptococci may be cleared by the lung phagocytes, stay latent, cause pulmonary infection and/or disseminate to other body parts, preferentially the brain, culminating in cryptococcal meningoencephalitis. In this review, we discuss the pathogenesis of C. neoformans from the environment to the brain, the current understanding of the mechanisms of cryptococcal transmission into the brain and cryptococcal meningitis. We also give an insight into future cryptococcosis research and the development of novel therapies.
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Affiliation(s)
- Wilber Sabiiti
- Infection & Immunity, Clinical Sciences Division, St Georges' University of London, London SW17 0RE, UK
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29
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Osherov N. Interaction of the pathogenic mold Aspergillus fumigatus with lung epithelial cells. Front Microbiol 2012; 3:346. [PMID: 23055997 PMCID: PMC3458433 DOI: 10.3389/fmicb.2012.00346] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Accepted: 09/08/2012] [Indexed: 02/02/2023] Open
Abstract
Aspergillus fumigatus is an opportunistic environmental mold that can cause severe allergic responses in atopic individuals and poses a life-threatening risk for severely immunocompromised patients. Infection is caused by inhalation of fungal spores (conidia) into the lungs. The initial point of contact between the fungus and the host is a monolayer of lung epithelial cells. Understanding how these cells react to fungal contact is crucial to elucidating the pathobiology of Aspergillus-related disease states. The experimental systems, both in vitro and in vivo, used to study these interactions, are described. Distinction is made between bronchial and alveolar epithelial cells. The experimental findings suggest that lung epithelial cells are more than just “innocent bystanders” or a purely physical barrier against infection. They can be better described as an active extension of our innate immune system, operating as a surveillance mechanism that can specifically identify fungal spores and activate an offensive response to block infection. This response includes the internalization of adherent conidia and the release of cytokines, antimicrobial peptides, and reactive oxygen species. In the case of allergy, lung epithelial cells can dampen an over-reactive immune response by releasing anti-inflammatory compounds such as kinurenine. This review summarizes our current knowledge regarding the interaction of A. fumigatus with lung epithelial cells. A better understanding of the interactions between A. fumigatus and lung epithelial cells has therapeutic implications, as stimulation or inhibition of the epithelial response may alter disease outcome.
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Affiliation(s)
- Nir Osherov
- Department of Clinical Microbiology and Immunology, Aspergillus and Antifungal Research Laboratory, Sackler School of Medicine, Tel-Aviv University Ramat-Aviv, Tel-Aviv, Israel
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Benton CS, Miller BH, Skwerer S, Suzuki O, Schultz LE, Cameron MD, Marron JS, Pletcher MT, Wiltshire T. Evaluating genetic markers and neurobiochemical analytes for fluoxetine response using a panel of mouse inbred strains. Psychopharmacology (Berl) 2012; 221:297-315. [PMID: 22113448 PMCID: PMC3337404 DOI: 10.1007/s00213-011-2574-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 11/03/2011] [Indexed: 02/03/2023]
Abstract
RATIONALE Identification of biomarkers that establish diagnosis or treatment response is critical to the advancement of research and management of patients with depression. OBJECTIVE Our goal was to identify biomarkers that can potentially assess fluoxetine response and risk to poor treatment outcome. METHODS We measured behavior, gene expression, and the levels of 36 neurobiochemical analytes across a panel of genetically diverse mouse inbred lines after chronic treatment with water or fluoxetine. RESULTS Glyoxylase 1 (GLO1) and guanine nucleotide-binding protein 1 (GNB1) mostly account for baseline anxiety-like and depressive-like behavior, indicating a common biological link between depression and anxiety. Fluoxetine-induced biochemical alterations discriminated positive responders, while baseline neurobiochemical differences differentiated negative responders (p < 0.006). Results show that glial fibrillary acidic protein, S100 beta protein, GLO1, and histone deacetylase 5 contributed most to fluoxetine response. These proteins are linked within a cellular growth/proliferation pathway, suggesting the involvement of cellular genesis in fluoxetine response. Furthermore, a candidate genetic locus that associates with baseline depressive-like behavior contains a gene that encodes for cellular proliferation/adhesion molecule (Cadm1), supporting a genetic basis for the role of neuro/gliogenesis in depression. CONCLUSION We provided a comprehensive analysis of behavioral, neurobiochemical, and transcriptome data across 30 mouse inbred strains that has not been accomplished before. We identified biomarkers that influence fluoxetine response, which, altogether, implicate the importance of cellular genesis in fluoxetine treatment. More broadly, this approach can be used to assess a wide range of drug response phenotypes that are challenging to address in human samples.
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Affiliation(s)
- Cristina S. Benton
- Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina at Chapel Hill, Genetic Medicine Building, 120 Mason Farm Road, Chapel Hill, NC 27599 USA
| | - Brooke H. Miller
- Department of Neuroscience, The Scripps Research Institute, Florida, Jupiter, FL USA
| | - Sean Skwerer
- Department of Statistics and Operations Research, University of North Carolina at Chapel Hill, Chapel Hill, NC USA
| | - Oscar Suzuki
- Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina at Chapel Hill, Genetic Medicine Building, 120 Mason Farm Road, Chapel Hill, NC 27599 USA
| | - Laura E. Schultz
- Department of Neuroscience, The Scripps Research Institute, Florida, Jupiter, FL USA
| | - Michael D. Cameron
- Department of Neuroscience, The Scripps Research Institute, Florida, Jupiter, FL USA
| | - J. S. Marron
- Department of Statistics and Operations Research, University of North Carolina at Chapel Hill, Chapel Hill, NC USA
| | - Mathew T. Pletcher
- Orphan and Genetic Diseases Research Unit, Pfizer Global Research and Development, 200 Cambridge Park Drive, Cambridge, MA 02140 USA
| | - Tim Wiltshire
- Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina at Chapel Hill, Genetic Medicine Building, 120 Mason Farm Road, Chapel Hill, NC 27599 USA
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Unravelling secretion in Cryptococcus neoformans: more than one way to skin a cat. Mycopathologia 2011; 173:407-18. [PMID: 21898146 DOI: 10.1007/s11046-011-9468-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 08/22/2011] [Indexed: 01/10/2023]
Abstract
Secretion pathways in fungi are essential for the maintenance of cell wall architecture and for the export of a number of virulence factors. In the fungal pathogen, Cryptococcus neoformans, much evidence supports the existence of more than one route taken by secreted molecules to reach the cell periphery and extracellular space, and a significant degree of crosstalk between conventional and non-conventional secretion routes. The need for such complexity may be due to differences in the nature of the exported cargo, the spatial and temporal requirements for constitutive and non-constitutive protein secretion, and/or as a means of compensating for the extra burden on the secretion machinery imposed by the elaboration of the polysaccharide capsule. This review focuses on the role of specific components of the C. neoformans secretion machinery in protein and/or polysaccharide export, including Sec4, Sec6, Sec14, Golgi reassembly and stacking protein and extracellular exosome-like vesicles. We also address what is known about traffic of the lipid, glucosylceramide, a target of therapeutic antibodies and an important regulator of C. neoformans pathogenicity, and the role of signalling pathways in the regulation of secretion.
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Dippe M, Ulbrich-Hofmann R. Phospholipid acylhydrolases trigger membrane degradation during fungal sporogenesis. Fungal Genet Biol 2011; 48:921-7. [DOI: 10.1016/j.fgb.2011.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2011] [Revised: 05/06/2011] [Accepted: 05/28/2011] [Indexed: 11/27/2022]
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Chayakulkeeree M, Johnston SA, Oei JB, Lev S, Williamson PR, Wilson CF, Zuo X, Leal AL, Vainstein MH, Meyer W, Sorrell TC, May RC, Djordjevic JT. SEC14 is a specific requirement for secretion of phospholipase B1 and pathogenicity of Cryptococcus neoformans. Mol Microbiol 2011; 80:1088-101. [PMID: 21453402 DOI: 10.1111/j.1365-2958.2011.07632.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Secreted phospholipase B1 (CnPlb1) is essential for dissemination of Cryptococcus neoformans to the central nervous system (CNS) yet essential components of its secretion machinery remain to be elucidated. Using gene deletion analysis we demonstrate that CnPlb1 secretion is dependent on the CnSEC14 product, CnSec14-1p. CnSec14-1p is a homologue of the phosphatidylinositol transfer protein ScSec14p, which is essential for secretion and viability in Saccharomyces cerevisiae. In contrast to CnPlb1, neither laccase 1-induced melanization within the cell wall nor capsule induction were negatively impacted in CnSEC14-1 deletion mutants (CnΔsec14-1 and CnΔsec14-1CnΔsfh5). Similar to the CnPLB1 deletion mutant (CnΔplb1), CnΔsec14-1 was hypovirulent in mice and did not disseminate to the CNS by day 14 post infection. Furthermore, macrophage expulsion of live CnΔsec14-1 and CnΔplb1 (vomocytosis) was reduced. Individual deletion of CnSEC14-2, a closely related CnSEC14-1 homologue, and CnSFH5, a distantly related SEC fourteen like homologue, did not abrogate CnPlb1 secretion or virulence. However, reconstitution of CnΔsec14-1 with CnSEC14-1 or CnSEC14-2 restored both phenotypes, consistent with functional genetic redundancy. We conclude that CnPlb1 secretion is SEC14-dependent and that C. neoformans preferentially exports virulence determinants to the cell periphery via distinct pathways. We also demonstrate that CnPlb1 secretion is essential for vomocytosis.
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Affiliation(s)
- Methee Chayakulkeeree
- Centre for Infectious Diseases and Microbiology, Sydney Medical School-Western, and Westmead Millennium Institute, University of Sydney at Westmead Hospital, Westmead 2145 NSW, Australia
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Desalermos A, Muhammed M, Glavis-Bloom J, Mylonakis E. Using C. elegans for antimicrobial drug discovery. Expert Opin Drug Discov 2011; 6:645-652. [PMID: 21686092 DOI: 10.1517/17460441.2011.573781] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION: The number of microorganism strains with resistance to known antimicrobials is increasing. Therefore, there is a high demand for new, non-toxic and efficient antimicrobial agents. Research with the microscopic nematode Caenorhabditis elegans can address this high demand for the discovery of new antimicrobial compounds. In particular, C. elegans can be used as a model host for in vivo drug discovery through high-throughput screens of chemical libraries. AREAS COVERED: This review introduces the use of substitute model hosts and especially C. elegans in the study of microbial pathogenesis. The authors also highlight recently published literature on the role of C. elegans in drug discovery and outline its use as a promising host with unique advantages in the discovery of new antimicrobial drugs. EXPERT OPINION: C. elegans can be used, as a model host, to research many diseases, including fungal infections and Alzheimer's disease. In addition, high-throughput techniques, for screening chemical libraries, can also be facilitated. Nevertheless, C. elegans and mammals have significant differences that both limit the use of the nematode in research and the degree by which results can be interpreted. That being said, the use of C. elegans in drug discovery still holds promise and the field continues to grow, with attempts to improve the methodology already underway.
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Affiliation(s)
- Athanasios Desalermos
- Division of Infectious Diseases, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA
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Djordjevic JT. Role of phospholipases in fungal fitness, pathogenicity, and drug development - lessons from cryptococcus neoformans. Front Microbiol 2010; 1:125. [PMID: 21687772 PMCID: PMC3109512 DOI: 10.3389/fmicb.2010.00125] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Accepted: 10/25/2010] [Indexed: 11/13/2022] Open
Abstract
Many pathogenic microbes, including many fungi, produce phospholipases which facilitate survival of the pathogen in vivo, invasion and dissemination throughout the host, expression of virulence traits and evasion of host immune defense mechanisms. These phospholipases are either secreted or produced intracellularly and act by physically disrupting host membranes, and/or by affecting fungal cell signaling and production of immunomodulatory effectors. Many of the secreted phospholipases acquire a glycosylphosphatidylinositol sorting motif to facilitate membrane and/or cell wall association and secretion. This review focuses primarily on the role of two members of the phospholipase enzyme family, phospholipase B (Plb) and phosphatidylinositol (PI)-specific phospholipase C (PI-C/Plc), in fungal pathogenesis and in particular, what has been learnt about their function from studies performed in the model pathogenic yeast, Cryptococcus neoformans. These studies have revealed how Plb has adapted to become an important part of the virulence repertoire of pathogenic fungi and how its secretion is regulated. They have also provided valuable insight into how the intracellular enzyme, Plc1, contributes to fungal fitness and pathogenicity – via a putative role in signal transduction pathways that regulate the production of stress-protecting pigments, polysaccharide capsule, cell wall integrity, and adaptation to growth at host temperature. Finally, this review will address the role fungal phospholipases have played in the development of a new class of antifungal drugs, which mimic their phospholipid substrates.
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Affiliation(s)
- Julianne Teresa Djordjevic
- Fungal Pathogenesis Laboratory, Centre for Infectious Diseases and Microbiology, Sydney Medical School-Western, Westmead Millennium Institute, University of Sydney at Westmead Hospital Westmead, NSW, Australia
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Rodrigues ML, Fonseca FL, Frases S, Casadevall A, Nimrichter L. The still obscure attributes of cryptococcal glucuronoxylomannan. Med Mycol 2010; 47:783-8. [PMID: 19343609 DOI: 10.3109/13693780902788621] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Glucuronoxylomannan (GXM) is the major capsular polysaccharide of Cryptococcus neoformans. It is essential for fungal virulence and causes a number of deleterious effects to host cells. During the last decades, most of the experimental models designed to study the roles of GXM during cryptococcal infection were based on the stimulation of animal cells. This most commonly involved macrophages or other effector cells, with polysaccharide fractions obtained by precipitation with cationic detergents. More recently, it has been demonstrated that GXM interferes with the physiological state of other target cells, such as the epithelium. In addition, recent studies indicate that the structure of the polysaccharide and, consequently, its functions vary according with the method used for its purification. This raises questions as to what is native GXM and the significance of prior studies. In this paper, we discuss some of the aspects of GXM that are still poorly explored in the current literature, including the relevance of the polysaccharide in the interaction of cryptococci with non-phagocytic cells and the relationship between its structure and biological activity.
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Affiliation(s)
- Marcio L Rodrigues
- Laboratório de Estudos Integrados em Bioquímica Microbiana, Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Brazil.
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Soares DA, de Andrade RV, Silva SS, Bocca AL, Soares Felipe SM, Petrofeza S. Extracellular Paracoccidioides brasiliensis phospholipase B involvement in alveolar macrophage interaction. BMC Microbiol 2010; 10:241. [PMID: 20843362 PMCID: PMC2949701 DOI: 10.1186/1471-2180-10-241] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Accepted: 09/15/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Phospholipase B (PLB) has been reported to be one of the virulence factors for human pathogenic fungi and has also been described as necessary for the early events in infection. Based on these data, we investigated the role of PLB in virulence and modulation of the alveolar pulmonary immune response during infection using an in-vitro model of host-pathogen interaction, i.e. Paracoccidioides brasiliensis yeast cells infecting alveolar macrophage (MH-S) cells. RESULTS The effect of PLB was analyzed using the specific inhibitor alexidine dihydrochloride (0.25 μM), and pulmonary surfactant (100 μg mL-1), during 6 hours of co-cultivation of P. brasiliensis and MH-S cells. Alexidine dihydrochloride inhibited PLB activity by 66% and significantly decreased the adhesion and internalization of yeast cells by MH-S cells. Genes involved in phagocytosis (trl2, cd14) and the inflammatory response (nfkb, tnf-α, il-1β) were down-regulated in the presence of this PLB inhibitor. In contrast, PLB activity and internalization of yeast cells significantly increased in the presence of pulmonary surfactant; under this condition, genes such as clec2 and the pro-inflammatory inhibitor (nkrf) were up-regulated. Also, the pulmonary surfactant did not alter cytokine production, while alexidine dihydrochloride decreased the levels of interleukin-10 (IL-10) and increased the levels of IL-12 and tumor necrosis factor-α (TNF-α). In addition, gene expression analysis of plb1, sod3 and icl1 suggests that P. brasiliensis gene re-programming is effective in facilitating adaptation to this inhospitable environment, which mimics the lung-environment interaction. CONCLUSION P. brasiliensis PLB activity is involved in the process of adhesion and internalization of yeast cells at the MH-S cell surface and may enhance virulence and subsequent down-regulation of macrophage activation.
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Affiliation(s)
- Deyze Alencar Soares
- Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
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Souza LKH, Souza Junior AH, Costa CR, Faganello J, Vainstein MH, Chagas ALB, Souza ACM, Silva MRR. Molecular typing and antifungal susceptibility of clinical and environmental Cryptococcus neoformans species complex isolates in Goiania, Brazil. Mycoses 2010; 53:62-7. [DOI: 10.1111/j.1439-0507.2008.01662.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Abstract
Cryptococcus neoformans and Cryptococcus gattii are the cause of life-threatening meningoencephalitis in immunocompromised and immunocompetent individuals respectively. The increasing incidence of cryptococcal infection as a result of the AIDS epidemic, the recent emergence of a hypervirulent cryptococcal strain in Canada and the fact that mortality from cryptococcal disease remains high have stimulated intensive research into this organism. Here we outline recent advances in our understanding of C. neoformans and C. gattii, including intraspecific complexity, virulence factors, and key signaling pathways. We discuss the molecular basis of cryptococcal virulence and the interaction between these pathogens and the host immune system. Finally, we discuss future challenges in the study and treatment of cryptococcosis.
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Affiliation(s)
- Hansong Ma
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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Chayakulkeeree M, Sorrell TC, Siafakas AR, Wilson CF, Pantarat N, Gerik KJ, Boadle R, Djordjevic JT. Role and mechanism of phosphatidylinositol-specific phospholipase C in survival and virulence of Cryptococcus neoformans. Mol Microbiol 2008; 69:809-26. [PMID: 18532984 DOI: 10.1111/j.1365-2958.2008.06310.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Phospholipase B1 (Plb1) is secreted after release from its glycosylphosphatidylinositol anchor and is implicated in initiation and dissemination of infection of the pathogenic fungus, Cryptococcus neoformans. To investigate the role of phosphatidylinositol-specific phospholipase C (PI-PLC) in Plb1 secretion, we identified two putative PI-PLC-encoding genes in C. neoformans var. grubii (PLC1 and PLC2), and created Deltaplc1 and Deltaplc2 deletion mutants. In Deltaplc1, which expressed less PI-PLC activity than wild type (WT), three major cryptococcal virulence traits, Plb1 secretion, melanin production and growth at host temperature (37 degrees C) were abolished and absence of Plb1 secretion coincided with Plb1 accumulation in plasma membranes. In addition, Deltaplc1 cell walls were defective, as indicated by cell clumping and irregular morphology, slower growth and an inability to activate mitogen-activated protein kinase (MAPK) in the presence of cell wall-perturbing agents. In contrast to Deltaplc2, which was as virulent as WT, Deltaplc1 was avirulent in mice and exhibited attenuated killing of Caenorhabditis elegans at 25 degrees C, demonstrating that mechanism(s) independent of the 37 degrees C growth defect contribute to the virulence composite. We conclude that Plc1 is a central regulator of cryptococcal virulence, acting through the protein kinase C/MAPK pathway, that it regulates release of Plb1 from the plasma membrane and is a candidate antifungal drug target.
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Affiliation(s)
- Methee Chayakulkeeree
- Centre for Infectious Diseases and Microbiology, ICPMR and Westmead Millennium Institute, University of Sydney at Westmead Hospital, NSW 2145, Australia
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Guillot L, Carroll SF, Badawy M, Qureshi ST. Cryptococcus neoformans induces IL-8 secretion and CXCL1 expression by human bronchial epithelial cells. Respir Res 2008; 9:9. [PMID: 18211687 PMCID: PMC2254606 DOI: 10.1186/1465-9921-9-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2007] [Accepted: 01/22/2008] [Indexed: 11/10/2022] Open
Abstract
Background Cryptococcus neoformans (C. neoformans) is a globally distributed fungal pathogen with the potential to cause serious disease, particularly among immune compromised hosts. Exposure to this organism is believed to occur by inhalation and may result in pneumonia and/or disseminated infection of the brain as well as other organs. Little is known about the role of airway epithelial cells in cryptococcal recognition or their ability to induce an inflammatory response. Methods Immortalized BEAS-2B bronchial epithelial cells and primary normal human bronchial epithelium (NHBE) were stimulated in vitro with encapsulated or acapsular C. neoformans cultivated at room temperature or 37°C. Activation of bronchial epithelial cells was characterized by analysis of inflammatory cytokine and chemokine expression, transcription factor activation, fungal-host cell association, and host cell damage. Results Viable C. neoformans is a strong activator of BEAS-2B cells, resulting in the production of the neutrophil chemokine Interleukin (IL)-8 in a time- and dose-dependent manner. IL-8 production was observed only in response to acapsular C. neoformans that was grown at 37°C. C. neoformans was also able to induce the expression of the chemokine CXCL1 and the transcription factor CAAT/enhancer-binding protein beta (CEBP/β) in BEAS-2B cells. NHBE was highly responsive to stimulation with C. neoformans; in addition to transcriptional up regulation of CXCL1, these primary cells exhibited the greatest IL-8 secretion and cell damage in response to stimulation with an acapsular strain of C. neoformans. Conclusion This study demonstrates that human bronchial epithelial cells mediate an acute inflammatory response to C. neoformans and are susceptible to damage by this fungal pathogen. The presence of capsular polysaccharide and in vitro fungal culture conditions modulate the host inflammatory response to C. neoformans. Human bronchial epithelial cells are likely to contribute to the initial stages of pulmonary host defense in vivo.
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Affiliation(s)
- Loïc Guillot
- McGill Centre for the Study of Host Resistance, Room L11-403, 1650 Cedar Avenue, Montreal, QC, H3G 1A4, Canada.
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Zaragoza O, Alvarez M, Telzak A, Rivera J, Casadevall A. The relative susceptibility of mouse strains to pulmonary Cryptococcus neoformans infection is associated with pleiotropic differences in the immune response. Infect Immun 2007; 75:2729-39. [PMID: 17371865 PMCID: PMC1932903 DOI: 10.1128/iai.00094-07] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
CBA/J mice were highly susceptible to intratracheal (i.t.) Cryptococcus neoformans infection relative to BALB/c mice, while both strains were equally susceptible to intravenous (i.v.) infection. Increased susceptibility in i.t. infection was associated with higher brain CFU, lower serum immunoglobulin M (IgM) and IgG responses to glucuronoxylomannan (GXM), lack of IgE regulation during infection, and alveolar macrophage permissiveness to intracellular replication in vitro. In contrast, for BALB/c mice, relative resistance was associated with increased interleukin-12 (IL-12) and decreased IL-10 pulmonary levels. In CBA/J mice, relative susceptibility was associated with a decreased proportion of CD4+ and CD8+ T cells and an increase in macrophage percentage in pulmonary infiltrates. In contrast, no significant differences in these cytokines or cell recruitment were observed in the i.v. model, consistent with no differences in the survival rate. Passive antibody (Ab) protection experiments revealed a prozone effect in the BALB/c mice with i.v. infection, such that Ab efficacy decreased at higher doses. In the i.t. model using CBA/J mice, low Ab doses were disease enhancing and protection was observed only at high doses. Our results show (i) that differences in mouse strain susceptibility are a function of the infection model, (ii) that susceptibility to pulmonary infection was associated with macrophage permissiveness for intracellular replication, and (iii) that the efficacy of passive Ab in pulmonary infection is a function of dose and mouse strain. The results highlight significant differences in the pathogenesis of cryptococcal infection among inbred mice and associate their relative susceptibility with differences in numerous components of the innate and adaptive immune responses.
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Affiliation(s)
- Oscar Zaragoza
- Departments of Microbiology and Immunology and Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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Eigenheer RA, Jin Lee Y, Blumwald E, Phinney BS, Gelli A. Extracellular glycosylphosphatidylinositol-anchored mannoproteins and proteases of Cryptococcus neoformans. FEMS Yeast Res 2007; 7:499-510. [PMID: 17233760 DOI: 10.1111/j.1567-1364.2006.00198.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Extracellular proteins of Cryptococcus neoformans are involved in the pathogenesis of cryptococcosis, and some are immunoreactive antigens that may potentially serve as candidates for vaccine development. To further study the extracellular proteome of the human fungal pathogen Cry. neoformans, we conducted a proteomic analysis of secreted and cell wall-bound proteins with an acapsular strain of Cry. neoformans. Proteins were identified from both intact cells and cell walls. In both cases, extracellular proteins were removed with trypsin or beta-glucanase, and then all proteins/peptides were purified by solid-phase extraction, spin dialysis, and HPLC, and identified by liquid chromatography-mass spectrometry. This study identified 29 extracellular proteins with a predicted N-terminal signal sequence and also a predicted glycosylphosphatidylinositol anchor motif in more than half. Among the novel proteins identified were five glycosylphosphatidylinositol-anchored proteins with extensive Ser/Thr-rich regions but no apparent functional domains, a glycosylphosphatidylinositol-anchored aspartic protease, and a metalloprotease with structural similarity to an elastinolytic metalloprotease of Aspergillus fumigatus. This study suggests that Cry. neoformans has the machinery required to target glycosylphosphatidylinositol-anchored proteins to the cell wall, and it confirms the extracellular proteolytic ability of Cry. neoformans.
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Affiliation(s)
- Richard A Eigenheer
- Department of Medical Pharmacology and Toxicology Genome and Biomedical Sciences Facility, University of California, California 95616, USA
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Current awareness on yeast. Yeast 2007. [DOI: 10.1002/yea.1322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Sitkiewicz I, Stockbauer KE, Musser JM. Secreted bacterial phospholipase A2 enzymes: better living through phospholipolysis. Trends Microbiol 2006; 15:63-9. [PMID: 17194592 DOI: 10.1016/j.tim.2006.12.003] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2006] [Revised: 11/23/2006] [Accepted: 12/13/2006] [Indexed: 11/23/2022]
Abstract
Phospholipases are ubiquitous and diverse enzymes that induce changes in membrane composition, activate the inflammatory cascade and alter cell signaling pathways. Recent evidence suggests that certain bacterial pathogens have acquired genes encoding secreted phospholipase A2 enzymes through lateral gene transfer events. The two best-studied members of this class of enzyme are ExoU and SlaA, which are produced by Pseudomonas aeruginosa and group A Streptococcus, respectively. These enzymes modulate the host inflammatory response, increase the severity of disease and otherwise alter host-pathogen interactions. We propose that a key function of ExoU and SlaA is to increase the fitness of the subclones expressing these enzymes, thereby increasing the population size of the PLA2-positive strains and enhancing the likelihood of encountering an at-risk host.
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Affiliation(s)
- Izabela Sitkiewicz
- Center for Molecular and Translational Human Infectious Diseases Research, The Methodist Hospital Research Institute, Houston, TX 77030, USA
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Erb-Downward JR, Huffnagle GB. Cryptococcus neoformans produces authentic prostaglandin E2 without a cyclooxygenase. EUKARYOTIC CELL 2006; 6:346-50. [PMID: 17158733 PMCID: PMC1797952 DOI: 10.1128/ec.00336-06] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Many single-celled eukaryotes produce prostaglandin-like molecules, but these have not been absolutely verified by mass spectrometry. We have isolated, and identified by liquid chromatography-tandem mass spectrometry, authentic prostaglandin E(2) from Cryptococcus neoformans. Cyclooxygenase inhibitors did not inhibit prostaglandin synthesis, and the cryptococcal genome lacks a cyclooxygenase homolog. Thus, novel enzymes must exist.
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Affiliation(s)
- John R Erb-Downward
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109-0642, USA
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Wright LC, Santangelo RM, Ganendren R, Payne J, Djordjevic JT, Sorrell TC. Cryptococcal lipid metabolism: phospholipase B1 is implicated in transcellular metabolism of macrophage-derived lipids. EUKARYOTIC CELL 2006; 6:37-47. [PMID: 17099081 PMCID: PMC1800365 DOI: 10.1128/ec.00262-06] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cryptococci survive and replicate within macrophages and can use exogenous arachidonic acid for the production of eicosanoids. Phospholipase B1 (PLB1) has a putative, but uninvestigated, role in these processes. We have shown that uptake and esterification of radiolabeled arachidonic, palmitic, and oleic acids by the Cryptococcus neoformans var. grubii H99 wild-type strain and its PLB1 deletion mutant strain (the Deltaplb1 strain) are independent of PLB1, except under hyperosmolar stress. Similarly, PLB1 was required for metabolism of 1-palmitoyl lysophosphatidylcholine (LysoPC), which is toxic to eukaryotic cell membranes, under hyperosmolar conditions. During both logarithmic and stationary phases of growth, the physiologically relevant phospholipids, dipalmitoyl phosphatidylcholine (DPPC) and dioleoyl phosphatidylcholine, were taken up and metabolized via PLB1. Exogenous DPPC did not enhance growth in the presence of glucose as a carbon source but could support it for at least 24 h in glucose-free medium. Detoxification of LysoPC by reacylation occurred in both the H99 wild-type and the Deltaplb1 strains in the presence of glucose, but PLB1 was required when LysoPC was the sole carbon source. This indicates that both energy-independent (via PLB1) and energy-dependent transacylation pathways are active in cryptococci. Phospholipase A(1) activity was identified by PLB1-independent degradation of 1-palmitoyl-2-arachidonoyl phosphatidylcholine, but the arachidonoyl LysoPC formed was not detoxified by reacylation. Using the human macrophage-like cell line THP-1, we demonstrated the PLB1-dependent incorporation of macrophage-derived arachidonic acid into cryptococcal lipids during cryptococcus-phagocyte interaction. This pool of arachidonate can be sequestered for eicosanoid production by the fungus and/or suppression of host phagocytic activity, thus diminishing the immune response.
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Affiliation(s)
- Lesley C Wright
- Centre for Infectious Diseases and Microbiology, Level 3, ICPMR Building, Westmead Hospital, Westmead NSW 2145, Australia.
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Barbosa FM, Fonseca FL, Figueiredo RT, Bozza MT, Casadevall A, Nimrichter L, Rodrigues ML. Binding of glucuronoxylomannan to the CD14 receptor in human A549 alveolar cells induces interleukin-8 production. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2006; 14:94-8. [PMID: 17093102 PMCID: PMC1797707 DOI: 10.1128/cvi.00296-06] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Glucuronoxylomannan (GXM) is the major capsular polysaccharide of Cryptococcus neoformans. GXM receptors have been characterized in phagocytes and endothelial cells, but epithelial molecules recognizing the polysaccharide remain unknown. In the current study, we demonstrate that GXM binds to the CD14 receptor in human type II alveolar epithelial cells, resulting in the production of the proinflammatory chemokine interleukin-8.
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Affiliation(s)
- Fabiane M Barbosa
- Laboratório de Estudos Integrados em Bioquímica Microbiana, Departamento de Microbiologia Geral, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude (CCS), Rio de Janeiro, Brazil
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Lipski SL, Akimana C, Timpe JM, Wooten RM, Lafontaine ER. The Moraxella catarrhalis autotransporter McaP is a conserved surface protein that mediates adherence to human epithelial cells through its N-terminal passenger domain. Infect Immun 2006; 75:314-24. [PMID: 17088358 PMCID: PMC1828417 DOI: 10.1128/iai.01330-06] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The protein McaP was previously shown to be an adhesin expressed by the Moraxella catarrhalis strain O35E, which also displays esterase and phospholipase B activities (J. M. Timpe et al., Infect. Immun. 71:4341-4350, 2003). In the present study, sequence analysis suggests that McaP is a conventional autotransporter protein that contains a 12-stranded beta-barrel transporter module (amino acids [aa] 383 to 650) linked to a surface-exposed passenger domain exhibiting lipolytic activity (aa 62 to 330). An in-frame deletion removing most of this predicted N-terminal passenger domain was engineered, and Escherichia coli expressing the truncated McaP protein exhibited greatly reduced adherence to A549 human lung epithelial cells compared to E. coli expressing wild-type McaP. Site-directed mutagenesis of a serine residue at position 62 of McaP, predicted to be important for the lipolytic activity of the protein, resulted in loss of hydrolysis of p-nitrophenyl ester of caproate. E. coli expressing this mutated McaP, however, adhered to A549 monolayers at levels greater than recombinant bacteria expressing the wild-type adhesin. These results indicate that the predicted passenger domain of McaP is involved in both the binding and the lipolytic activity of the molecule and demonstrate that the adhesive properties of McaP do not require its lipolytic activity. Sequence analysis of mcaP from eight Moraxella catarrhalis strains revealed that the gene product is highly conserved at the amino acid level (98 to 100% identity), and Western blot analysis demonstrated that a panel of 16 isolates all express McaP. Flow cytometry experiments using antibodies raised against various portions of McaP indicated that its predicted passenger domain as well as transporter module contain surface-exposed epitopes. In addition to binding to the surface of intact bacteria, these antibodies were found to decrease adherence of M. catarrhalis to A549 human lung cells by up to 47% and to reduce binding of recombinant E. coli expressing McaP by 98%. These results suggest that McaP should be considered as a potential vaccine antigen.
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Affiliation(s)
- Serena L Lipski
- Department of Medical Microbiology and Immunology, University of Toledo Health Sciences Campus, 3055 Arlington Avenue, Toledo, Ohio 43614, USA
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50
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Köhler GA, Brenot A, Haas-Stapleton E, Agabian N, Deva R, Nigam S. Phospholipase A2 and phospholipase B activities in fungi. BIOCHIMICA ET BIOPHYSICA ACTA 2006; 1761:1391-9. [PMID: 17081801 PMCID: PMC2077850 DOI: 10.1016/j.bbalip.2006.09.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Revised: 09/20/2006] [Accepted: 09/25/2006] [Indexed: 10/24/2022]
Abstract
As saprophytes or disease causing microorganisms, fungi acquire nutrients from dead organic material or living host organisms. Lipids as structural components of cell membranes and storage compartments play an important role as energy-rich food source. In recent years, it also has become clear that lipids have a wide range of bioactive properties including signal transduction and cell to cell communication. Thus, it is not surprising that fungi possess a broad range of hydrolytic enzymes that attack neutral lipids and phospholipids. Especially during infection of a mammalian host, phospholipase A(2) (PLA(2)) enzymes released by fungi could play important roles not only for nutrient acquisition and tissue invasion, but for intricate modulation of the host's immune response. Sequencing of fungal genomes has revealed a wide range of genes encoding PLA(2) activities in fungi. We are just beginning to become aware of the significance these enzymes could have for the fungal cells and their interaction with the host.
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Affiliation(s)
- Gerwald A. Köhler
- Department of Cell and Tissue Biology, University of California, San Francisco, U.S.A
| | - Audrey Brenot
- Department of Cell and Tissue Biology, University of California, San Francisco, U.S.A
| | - Eric Haas-Stapleton
- Department of Cell and Tissue Biology, University of California, San Francisco, U.S.A
| | - Nina Agabian
- Department of Cell and Tissue Biology, University of California, San Francisco, U.S.A
| | - Rupal Deva
- Eicosanoid Research Division and Center for Experimental Gynecology & Breast Research, Charité - Univ.-Klinikum Benjamin Franklin, D-12200 Berlin, Germany
| | - Santosh Nigam
- Eicosanoid Research Division and Center for Experimental Gynecology & Breast Research, Charité - Univ.-Klinikum Benjamin Franklin, D-12200 Berlin, Germany
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