1
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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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2
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Cheng X, Zhu H, Bai S, Zou Y, Xia Z, Yang R. Pathogenicity of phospholipase B1 of Trichosporon asahii in immunosuppressed mice. Mycoses 2023; 66:467-476. [PMID: 36680377 DOI: 10.1111/myc.13568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 12/28/2022] [Accepted: 01/16/2023] [Indexed: 01/22/2023]
Abstract
BACKGROUND Trichosporon asahii is an opportunistic pathogenic yeast-like fungus. Phospholipase B1 (PLB1) is an important virulence factor of pathogenic fungi such as Candida albicans and Cryptococcus neoformans, and there are few studies on the role of PLB1 in the pathogenicity of T. asahii. OBJECTIVES To investigate the role of PLB1 in the pathogenicity of T. asahii. METHODS A strain with low secretion of PLB1 (4848) was screened, a PLB1 overexpression strain (PLB1OX ) was constructed, and the differences in histopathology, fungal load of organ, survival time of mice, the levels of IL-6, IL-10, TNF-α, and GM-GSF in the serum and organs caused by the two strains were compared. RESULTS Histopathology showed that spores and hyphae were observed in both groups, and PLB1OX led to more fungal invasion. The fungal loads in the kidney, lung, spleen and liver in the PLB1OX group were significantly higher than those in the 4848 group, and the survival time of mice was significantly lower than that in the 4848 group. The levels of TNF-α in the serum, liver, spleen, lung and kidney of the PLB1OX group were lower than those of the 4848 group, while the level of IL-10 in the serum was higher than that of the 4848 group. CONCLUSIONS These results suggest that PLB1 can enhance the invasive function of T. asahii and affect the secretion of TNF-α and IL-10 which may affect the host antifungal immune response, providing evidence that PLB1 plays a role in the pathogenic infection of T. asahii.
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Affiliation(s)
- Xiaoxian Cheng
- Chinese PLA Medical School, Peking, China.,Department of Dermatology, The Seventh Medical Center of PLA General Hospital, Peking, China
| | - He Zhu
- Chinese PLA Medical School, Peking, China.,Department of Dermatology, The Seventh Medical Center of PLA General Hospital, Peking, China
| | - Shuang Bai
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China.,Department of Dermatology, Affiliated Hospital of Inner Mongolia Medical University, Inner Mongolia, China
| | - Yuekun Zou
- Chinese PLA Medical School, Peking, China.,Department of Geriatrics, The Sixth Medical Center of PLA General Hospital, Peking, China
| | - Zhikuan Xia
- Department of Dermatology, The Seventh Medical Center of PLA General Hospital, Peking, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Rongya Yang
- Chinese PLA Medical School, Peking, China.,Department of Dermatology, The Seventh Medical Center of PLA General Hospital, Peking, China
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3
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Hamed MF, Enriquez V, Munzen ME, Charles-Niño CL, Mihu MR, Khoshbouei H, Alviña K, Martinez LR. Clinical and pathological characterization of Central Nervous System cryptococcosis in an experimental mouse model of stereotaxic intracerebral infection. PLoS Negl Trop Dis 2023; 17:e0011068. [PMID: 36656900 PMCID: PMC9888703 DOI: 10.1371/journal.pntd.0011068] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/31/2023] [Accepted: 01/02/2023] [Indexed: 01/20/2023] Open
Abstract
Infection of the Central Nervous System (CNS) by the encapsulated fungus Cryptococcus neoformans can lead to high mortality meningitis, most commonly in immunocompromised patients. While the mechanisms by which the fungus crosses the blood-brain barrier to initiate infection in the CNS are well recognized, there are still substantial unanswered questions about the disease progression once the fungus is established in the brain. C. neoformans is characterized by a glucuronoxylomannan (GXM)-rich polysaccharide capsule which has been implicated in immune evasion, but its role during the host CNS infection needs further elucidation. Therefore, the present study aims to examine these key questions about the mechanisms underlying cryptococcal meningitis progression and the impact of fungal GXM release by using an intracerebral rodent infection model via stereotaxic surgery. After developing brain infection, we analyzed distinct brain regions and found that while fungal load and brain weight were comparable one-week post-infection, there were region-specific histopathological (with and without brain parenchyma involvement) and disease manifestations. Moreover, we also observed a region-specific correlation between GXM accumulation and glial cell recruitment. Furthermore, mortality was associated with the presence of subarachnoid hemorrhaging and GXM deposition in the meningeal blood vessels and meninges in all regions infected. Our results show that using the present infection model can facilitate clinical and neuropathological observations during the progression of neurocryptococcosis. Importantly, this mouse model can be used to further investigate disease progression as it develops in humans.
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Affiliation(s)
- 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
| | - Vanessa Enriquez
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, 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
- Department of Microbiology and Pathology, University Health Sciences Center, University of Guadalajara, Guadalajara, Mexico
| | - Mircea Radu Mihu
- Advanced Critical Care, Nazih Zuhdi Transplant Institute, Advanced Cardiac Care and 24/7 Shock Service, Integris Baptist Medical Center, Oklahoma City, Oklahoma, United States of America
- Department of Medicine/Cardiology, Oklahoma State University Health Science Center, Tulsa, Oklahoma, United States of America
| | - Habibeh Khoshbouei
- Department of Neuroscience, University of Florida, Gainesville, Florida, United States of America
- Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, United States of America
| | - Karina Alviña
- Department of Neuroscience, University of Florida, Gainesville, Florida, United States of America
- Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, United States of America
| | - Luis R. Martinez
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, United States of America
- Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, United States of America
- Center for Immunology and Transplantation, University of Florida, Gainesville, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
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4
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Pereira ABM, Oliveira JR, Souza ALJ, Andrade-Silva L, Silva MV, Silva PR, Silva-Vergara ML, Rogerio AP. Effects of cigarette smoke extract on bronchial epithelial cells stimulated with Cryptococcus neoformans. Med Microbiol Immunol 2021; 210:221-233. [PMID: 34228244 DOI: 10.1007/s00430-021-00715-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 06/14/2021] [Indexed: 10/20/2022]
Abstract
In the airways, the adhesion of Cryptococcus neoformans with airway epithelial cells is crucial for the establishment of cryptococcosis. Tobacco smoke is considered a risk factor for cryptococcosis. Here, we evaluated the effects of cigarette smoke extract (CSE) on human bronchial epithelial cells (BEAS-2B) stimulated with C. neoformans. Multiplicities of infection (MOIs) of 1-100 of C. neoformans per cell led to increased IL-8 production and no cytotoxic effects when compared to those of controls. C. neoformans (MOI 100) also significantly increased the concentration of IL-6. In cells stimulated with CSE doses (1.0, 2.5 and 5.0%) from one or five cigarettes, increased IL-1β production was observed only in doses from one (1.0%) and five (2.5%) cigarettes when compared to that of controls. However, only 1.0% CSE failed to show cytotoxic effects. In addition, CSE significantly increased the concentration of IL-8. Cells stimulated with both CSE and C. neoformans demonstrated a reduction in IL-6/STAT3 signalling compared to that in cells stimulated by C. neoformans. In addition, a significant increase in IL-10 production was also observed. No alterations in NF-kB or ICAM-1 expression were observed among the groups. The combination of CSE and C. neoformans favoured the increase of fungal numbers and extracellular adhering of C. neoformans on BEAS-2B cells. In addition, the internalization of C. neoformans on BEAS-2B cells was reduced after CSE stimulation. In conclusion, the association of CSE and C. neoformans induced an anti-inflammatory effect in bronchial epithelial cells, which might favour the development of C. neoformans infection in the airways.
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Affiliation(s)
- Aline Beatriz Mahler Pereira
- Laboratory of Experimental Immunopharmacology, Department of Clinical Medicine, Institute of Health Sciences, Federal University of Triangulo Mineiro, Street Vigário Carlos 162, Uberaba, MG, 38025-380, Brazil
| | - Jhony Robison Oliveira
- Laboratory of Experimental Immunopharmacology, Department of Clinical Medicine, Institute of Health Sciences, Federal University of Triangulo Mineiro, Street Vigário Carlos 162, Uberaba, MG, 38025-380, Brazil
| | - Ana Leticia Julio Souza
- Laboratory of Experimental Immunopharmacology, Department of Clinical Medicine, Institute of Health Sciences, Federal University of Triangulo Mineiro, Street Vigário Carlos 162, Uberaba, MG, 38025-380, Brazil
| | - Leonardo Andrade-Silva
- Laboratory of Mycology, Department of Clinical Medicine, Institute of Health Sciences, Federal University of Triangulo Mineiro, Uberaba, MG, Brazil
| | - Marcos Vinicius Silva
- Laboratory of Immunology, Institute Department of Clinical Medicine, of Health Sciences, Federal University of Triangulo Mineiro, Uberaba, MG, Brazil
| | - Paulo Roberto Silva
- Laboratory of Experimental Immunopharmacology, Department of Clinical Medicine, Institute of Health Sciences, Federal University of Triangulo Mineiro, Street Vigário Carlos 162, Uberaba, MG, 38025-380, Brazil
| | - Mario Leon Silva-Vergara
- Laboratory of Mycology, Department of Clinical Medicine, Institute of Health Sciences, Federal University of Triangulo Mineiro, Uberaba, MG, Brazil
| | - Alexandre Paula Rogerio
- Laboratory of Experimental Immunopharmacology, Department of Clinical Medicine, Institute of Health Sciences, Federal University of Triangulo Mineiro, Street Vigário Carlos 162, Uberaba, MG, 38025-380, Brazil.
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5
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Thanh LT, Toffaletti DL, Tenor JL, Giamberardino C, Sempowski GD, Asfaw Y, Phan HT, Van Duong A, Trinh NM, Thwaites GE, Ashton PM, Chau NVV, Baker SG, Perfect JR, Day JN. Assessing the virulence of Cryptococcus neoformans causing meningitis in HIV infected and uninfected patients in Vietnam. Med Mycol 2020; 58:1149-1161. [PMID: 32196550 PMCID: PMC7657091 DOI: 10.1093/mmy/myaa013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/14/2020] [Accepted: 02/25/2020] [Indexed: 12/17/2022] Open
Abstract
We previously observed a substantial burden of cryptococcal meningitis in Vietnam atypically arising in individuals who are uninfected with human immunodeficiency virus (HIV). This disease was associated with a single genotype of Cryptococcus neoformans (sequence type [ST]5), which was significantly less common in HIV-infected individuals. Aiming to compare the phenotypic characteristics of ST5 and non-ST5 C. neoformans, we selected 30 representative Vietnamese isolates and compared their in vitro pathogenic potential and in vivo virulence. ST5 and non-ST5 organisms exhibited comparable characteristics with respect to in vitro virulence markers including melanin production, replication at 37°C, and growth in cerebrospinal fluid. However, the ST5 isolates had significantly increased variability in cellular and capsular sizing compared with non-ST5 organisms (P < .001). Counterintuitively, mice infected with ST5 isolates had significantly longer survival with lower fungal burdens at day 7 than non-ST5 isolates. Notably, ST5 isolates induced significantly greater initial inflammatory responses than non-ST5 strains, measured by TNF-α concentrations (P < .001). Despite being generally less virulent in the mouse model, we hypothesize that the significant within strain variation seen in ST5 isolates in the tested phenotypes may represent an evolutionary advantage enabling adaptation to novel niches including apparently immunocompetent human hosts.
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Affiliation(s)
- Lam Tuan Thanh
- Oxford University Clinical Research Unit, Wellcome Trust Asia Africa Programme, Ho Chi Minh City, Vietnam
| | - Dena L Toffaletti
- Division of Infectious Diseases, Department of Medicine and Department of Molecular Genetics and Microbiology, Duke University, North Carolina, USA
| | - Jennifer L Tenor
- Division of Infectious Diseases, Department of Medicine and Department of Molecular Genetics and Microbiology, Duke University, North Carolina, USA
| | - Charles Giamberardino
- Division of Infectious Diseases, Department of Medicine and Department of Molecular Genetics and Microbiology, Duke University, North Carolina, USA
| | - Gregory D Sempowski
- Duke Human Vaccine Institute and Regional Biocontainment Laboratory, Duke University, North Carolina, USA
| | - Yohannes Asfaw
- Division of Laboratory Animal Resources, Duke University, North Carolina, USA
| | - Hai Trieu Phan
- Oxford University Clinical Research Unit, Wellcome Trust Asia Africa Programme, Ho Chi Minh City, Vietnam
| | - Anh Van Duong
- Oxford University Clinical Research Unit, Wellcome Trust Asia Africa Programme, Ho Chi Minh City, Vietnam
| | - Nguyen Mai Trinh
- Oxford University Clinical Research Unit, Wellcome Trust Asia Africa Programme, Ho Chi Minh City, Vietnam
| | - Guy E Thwaites
- Oxford University Clinical Research Unit, Wellcome Trust Asia Africa Programme, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Philip M Ashton
- Oxford University Clinical Research Unit, Wellcome Trust Asia Africa Programme, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | - Stephen G Baker
- Cambridge Institute of Therapeutic immunology and Infectious Disease, Department of Medicine, University of Cambridge, Cambridge, UK
| | - John R Perfect
- Division of Infectious Diseases, Department of Medicine and Department of Molecular Genetics and Microbiology, Duke University, North Carolina, USA
| | - Jeremy N Day
- Oxford University Clinical Research Unit, Wellcome Trust Asia Africa Programme, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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6
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Coelho C, Farrer RA. Pathogen and host genetics underpinning cryptococcal disease. ADVANCES IN GENETICS 2020; 105:1-66. [PMID: 32560785 DOI: 10.1016/bs.adgen.2020.02.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cryptococcosis is a severe fungal disease causing 220,000 cases of cryptococcal meningitis yearly. The etiological agents of cryptococcosis are taxonomically grouped into at least two species complexes belonging to the genus Cryptococcus. All of these yeasts are environmentally ubiquitous fungi (often found in soil, leaves and decaying wood, tree hollows, and associated with bird feces especially pigeon guano). Infection in a range of animals including humans begins following inhalation of spores or aerosolized yeasts. Recent advances provide fundamental insights into the factors from both the pathogen and its hosts which influence pathogenesis and disease. The complex interactions leading to disease in mammalian hosts have also updated from the availability of better genomic tools and datasets. In this review, we discuss recent genetic research on Cryptococcus, covering the epidemiology, ecology, and evolution of Cryptococcus pathogenic species. We also discuss the insights into the host immune response obtained from the latest genetic modified host models as well as insights from monogenic disorders in humans. Finally we highlight outstanding questions that can be answered in the near future using bioinformatics and genomic tools.
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Affiliation(s)
- Carolina Coelho
- Medical Research Council Centre for Medical Mycology at the University of Exeter, Exeter, United Kingdom
| | - Rhys A Farrer
- Medical Research Council Centre for Medical Mycology at the University of Exeter, Exeter, United Kingdom.
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7
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Shourian M, Qureshi ST. Resistance and Tolerance to Cryptococcal Infection: An Intricate Balance That Controls the Development of Disease. Front Immunol 2019; 10:66. [PMID: 30761136 PMCID: PMC6361814 DOI: 10.3389/fimmu.2019.00066] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 01/11/2019] [Indexed: 12/25/2022] Open
Abstract
Cryptococcus neoformans is a ubiquitous environmental yeast and a leading cause of invasive fungal infection in humans. The most recent estimate of global disease burden includes over 200,000 cases of cryptococcal meningitis each year. Cryptococcus neoformans expresses several virulence factors that may have originally evolved to protect against environmental threats, and human infection may be an unintended consequence of these acquired defenses. Traditionally, C. neoformans has been viewed as a purely opportunistic pathogen that targets severely immune compromised hosts; however, during the past decade the spectrum of susceptible individuals has grown considerably. In addition, the closely related strain Cryptococcus gattii has recently emerged in North America and preferentially targets individuals with intact immunity. In parallel to the changing epidemiology of cryptococcosis, an increasing role for host immunity in the pathogenesis of severe disease has been elucidated. Initially, the HIV/AIDS epidemic revealed the capacity of C. neoformans to cause host damage in the absence of adaptive immunity. Subsequently, the development and clinical implementation of highly active antiretroviral treatment (HAART) led to recognition of an immune reconstitution inflammatory syndrome (IRIS) in a subset of HIV+ individuals, demonstrating the pathological role of host immunity in disease. A post-infectious inflammatory syndrome (PIIRS) characterized by abnormal T cell-macrophage activation has also been documented in HIV-negative individuals following antifungal therapy. These novel clinical conditions illustrate the highly complex host-pathogen relationship that underlies severe cryptococcal disease and the intricate balance between tolerance and resistance that is necessary for effective resolution. In this article, we will review current knowledge of the interactions between cryptococci and mammalian hosts that result in a tolerant phenotype. Future investigations in this area have potential for translation into improved therapies for affected individuals.
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Affiliation(s)
- Mitra Shourian
- Translational Research in Respiratory Diseases Program, Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada
| | - Salman T Qureshi
- Translational Research in Respiratory Diseases Program, Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada
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8
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Teitz-Tennenbaum S, Viglianti SP, Roussey JA, Levitz SM, Olszewski MA, Osterholzer JJ. Autocrine IL-10 Signaling Promotes Dendritic Cell Type-2 Activation and Persistence of Murine Cryptococcal Lung Infection. THE JOURNAL OF IMMUNOLOGY 2018; 201:2004-2015. [PMID: 30097531 DOI: 10.4049/jimmunol.1800070] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 07/21/2018] [Indexed: 12/14/2022]
Abstract
The substantial morbidity and mortality caused by invasive fungal pathogens, including Cryptococcus neoformans, necessitates increased understanding of protective immune responses against these infections. Our previous work using murine models of cryptococcal lung infection demonstrated that dendritic cells (DCs) orchestrate critical transitions from innate to adaptive immunity and that IL-10 signaling blockade improves fungal clearance. To further understand interrelationships among IL-10 production, fungal clearance, and the effect of IL-10 on lung DCs, we performed a comparative temporal analysis of cryptococcal lung infection in wild type C57BL/6J mice (designated IL-10+/+) and IL-10-/- mice inoculated intratracheally with C. neoformans (strain 52D). Early and sustained IL-10 production by lung leukocytes was associated with persistent infection in IL-10+/+ mice, whereas fungal clearance was improved in IL-10-/- mice during the late adaptive phase of infection. Numbers of monocyte-derived DCs, T cells, and alveolar and exudate macrophages were increased in lungs of IL-10-/- versus IL-10+/+ mice concurrent with evidence of enhanced DC type-1, Th1/Th17 CD4 cell, and classical macrophage activation. Bone marrow-derived DCs stimulated with cryptococcal mannoproteins, a component of the fungal capsule, upregulated expression of IL-10 and IL-10R, which promoted DC type-2 activation in an autocrine manner. Thus, our findings implicate fungus-triggered autocrine IL-10 signaling and DC type-2 activation as important contributors to the development of nonprotective immune effector responses, which characterize persistent cryptococcal lung infection. Collectively, this study informs and strengthens the rationale for IL-10 signaling blockade as a novel treatment for fungal infections.
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Affiliation(s)
- Seagal Teitz-Tennenbaum
- Research Service, Ann Arbor Veterans Affairs Health System, Department of Veterans Affairs Health System, Ann Arbor, MI 48105.,Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109
| | - Steven P Viglianti
- Research Service, Ann Arbor Veterans Affairs Health System, Department of Veterans Affairs Health System, Ann Arbor, MI 48105
| | - Jonathan A Roussey
- Research Service, Ann Arbor Veterans Affairs Health System, Department of Veterans Affairs Health System, Ann Arbor, MI 48105.,Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109
| | - Stuart M Levitz
- Department of Medicine, University of Massachusetts Medical Center, Worcester, MA 01605
| | - Michal A Olszewski
- Research Service, Ann Arbor Veterans Affairs Health System, Department of Veterans Affairs Health System, Ann Arbor, MI 48105.,Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109.,Graduate Program in Immunology, University of Michigan Health System, Ann Arbor, MI 48109; and
| | - John J Osterholzer
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109; .,Graduate Program in Immunology, University of Michigan Health System, Ann Arbor, MI 48109; and.,Pulmonary Section Medical Service, Ann Arbor Veterans Affairs Health System, Department of Veterans Affairs Health System, Ann Arbor, MI 48105
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9
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Roussey JA, Olszewski MA, Osterholzer JJ. Immunoregulation in Fungal Diseases. Microorganisms 2016; 4:microorganisms4040047. [PMID: 27973396 PMCID: PMC5192530 DOI: 10.3390/microorganisms4040047] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 12/02/2016] [Accepted: 12/06/2016] [Indexed: 02/07/2023] Open
Abstract
This review addresses specific regulatory mechanisms involved in the host immune response to fungal organisms. We focus on key cells and regulatory pathways involved in these responses, including a brief overview of their broader function preceding a discussion of their specific relevance to fungal disease. Important cell types discussed include dendritic cells and regulatory T cells, with a focus on specific studies relating to their effects on immune responses to fungi. We highlight the interleukin-10, programmed cell death 1, and cytotoxic T lymphocyte-associated protein 4 signaling pathways and emphasize interrelationships between these pathways and the regulatory functions of dendritic cells and regulatory T cells. Throughout our discussion, we identify selected studies best illustrating the role of these cells and pathways in response to specific fungal pathogens to provide a contextual understanding of the tightly-controlled network of regulatory mechanisms critical to determining the outcome of exposure to fungal pathogens. Lastly, we discuss two unique phenomena relating to immunoregulation, protective tolerance and immune reactivation inflammatory syndrome. These two clinically-relevant conditions provide perspective as to the range of immunoregulatory mechanisms active in response to fungi.
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Affiliation(s)
- Jonathan A Roussey
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109, USA.
- Pulmonary Section, Medical Service, VA Ann Arbor Health System, Ann Arbor, MI 48105, USA.
| | - Michal A Olszewski
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109, USA.
- Pulmonary Section, Medical Service, VA Ann Arbor Health System, Ann Arbor, MI 48105, USA.
- Graduate Program in Immunology, University of Michigan Health System, Ann Arbor, MI 48109, USA.
| | - John J Osterholzer
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109, USA.
- Pulmonary Section, Medical Service, VA Ann Arbor Health System, Ann Arbor, MI 48105, USA.
- Graduate Program in Immunology, University of Michigan Health System, Ann Arbor, MI 48109, USA.
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10
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Coelho C, Casadevall A. Cryptococcal therapies and drug targets: the old, the new and the promising. Cell Microbiol 2016; 18:792-9. [PMID: 26990050 DOI: 10.1111/cmi.12590] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 02/28/2016] [Accepted: 03/08/2016] [Indexed: 01/09/2023]
Abstract
Half a century after the introduction of Amphotericin B the management of cryptococcosis remains unsatisfactory. The disease, caused primarily by the two fungal species Cryptococcus neoformans and Cryptococcus gattii, remains responsible for considerable morbidity and mortality despite standard medical care. Current therapeutic options are limited to Amphotericin B, azoles and 5-flucytosine. However, this organism has numerous well-characterized virulence mechanisms that are amenable to pharmacological interference and are thus potential therapeutic targets. Here, we discuss existing approved antifungal drugs, resistance mechanisms to these drugs and non-standard antifungal drugs that have potential in treatment of cryptococcosis, including immunomodulatory strategies that synergize with antifungal drugs, such as cytokine administration or monoclonal antibodies. Finally, we summarize attempts to target well-described virulence factors of Cryptococcus, the capsule or fungal melanin. This review emphasizes the pressing need for new therapeutic alternatives for cryptococcosis.
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Affiliation(s)
- Carolina Coelho
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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Day J, Imran D, Ganiem AR, Tjahjani N, Wahyuningsih R, Adawiyah R, Dance D, Mayxay M, Newton P, Phetsouvanh R, Rattanavong S, Chan AK, Heyderman R, van Oosterhout JJ, Chierakul W, Day N, Kamali A, Kibengo F, Ruzagira E, Gray A, Lalloo DG, Beardsley J, Binh TQ, Chau TTH, Chau NVV, Cuc NTK, Farrar J, Hien TT, Van Kinh N, Merson L, Phuong L, Tho LT, Thuy PT, Thwaites G, Wertheim H, Wolbers M. CryptoDex: a randomised, double-blind, placebo-controlled phase III trial of adjunctive dexamethasone in HIV-infected adults with cryptococcal meningitis: study protocol for a randomised control trial. Trials 2014; 15:441. [PMID: 25391338 PMCID: PMC4289250 DOI: 10.1186/1745-6215-15-441] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 09/16/2014] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Cryptococcal meningitis (CM) is a severe AIDS-defining illness with 90-day case mortality as high as 70% in sub-Saharan Africa, despite treatment. It is the leading cause of death in HIV patients in Asia and Africa.No major advance has been made in the treatment of CM since the 1970s. The mainstays of induction therapy are amphotericin B and flucytosine, but these are often poorly available where the disease burden is highest. Adjunctive treatments, such as dexamethasone, have had dramatic effects on mortality in other neurologic infections, but are untested in CM. Given the high death rates in patients receiving current optimal treatment, and the lack of new agents on the horizon, adjuvant treatments, which offer the potential to reduce mortality in CM, should be tested.The principal research question posed by this study is as follows: does adding dexamethasone to standard antifungal therapy for CM reduce mortality? Dexamethasone is a cheap, readily available, and practicable intervention. METHOD A double-blind placebo-controlled trial with parallel arms in which patients are randomised to receive either dexamethasone or placebo, in addition to local standard of care. The study recruits patients in both Asia and Africa to ensure the relevance of its results to the populations in which the disease burden is highest. The 10-week mortality risk in the control group is expected to be between 30% and 50%, depending on location, and the target hazard ratio of 0.7 corresponds to absolute risk reductions in mortality from 30% to 22%, or from 50% to 38%. Assuming an overall 10-week mortality of at least 30% in our study population, recruitment of 824 patients will be sufficient to observe the expected number of deaths. Allowing for some loss to follow-up, the total sample size for this study is 880 patients. To generate robust evidence across both continents, we aim to recruit roughly similar numbers of patients from each continent. The primary end point is 10-week mortality. Ethical approval has been obtained from Oxford University's Tropical Research Ethics Committee (OxTREC), and as locally mandated at each site. TRIAL REGISTRATION International Standard Randomised Controlled Trial Number: ISRCTN59144167 26-July-2012.
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Affiliation(s)
- Jeremy Day
- />Wellcome Trust Major Overseas Programme Vietnam, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Darma Imran
- />Cipto Mangunkusum Hospital, Jakarta, Indonesia
| | | | | | - Retno Wahyuningsih
- />Cipto Mangunkusum Hospital, Jakarta, Indonesia
- />Department of Parasitology, Indonesia Christian University, School of Medicine, Jakarta, Indonesia
| | - Robiatul Adawiyah
- />Department of Parasitology, Faculty of Medicine, University of Indonesia, Jakarta, Indonesia
| | - David Dance
- />Laos Oxford Mahosot Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Laos
| | - Mayfong Mayxay
- />Laos Oxford Mahosot Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Laos
| | - Paul Newton
- />Laos Oxford Mahosot Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Laos
| | | | - Sayaphet Rattanavong
- />Laos Oxford Mahosot Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Laos
| | | | - Robert Heyderman
- />Malawi-Liverpool-Wellcome Trust, Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi
| | | | - Wirongrong Chierakul
- />Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Nick Day
- />Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Anatoli Kamali
- />MRC/UVRI Uganda Research Unit on AIDS, Entebbe/Masaka, Uganda
| | - Freddie Kibengo
- />MRC/UVRI Uganda Research Unit on AIDS, Entebbe/Masaka, Uganda
| | - Eugene Ruzagira
- />MRC/UVRI Uganda Research Unit on AIDS, Entebbe/Masaka, Uganda
| | - Alastair Gray
- />Nuffield Department of Population Health, University of Oxford Health Economics Research Centre, Oxford, UK
| | - David G Lalloo
- />Wellcome Trust Tropical Centre Liverpool, Liverpool, UK
| | - Justin Beardsley
- />Wellcome Trust Major Overseas Programme Vietnam, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | | | - Tran Thi Hong Chau
- />Wellcome Trust Major Overseas Programme Vietnam, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | | | | | - Jeremy Farrar
- />Wellcome Trust Major Overseas Programme Vietnam, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Tran Tinh Hien
- />Wellcome Trust Major Overseas Programme Vietnam, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | | | - Laura Merson
- />Wellcome Trust Major Overseas Programme Vietnam, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Lan Phuong
- />Cho Ray Hospital, Ho Chi Minh City, Vietnam
| | - Loc Truong Tho
- />Wellcome Trust Major Overseas Programme Vietnam, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | | | - Guy Thwaites
- />Wellcome Trust Major Overseas Programme Vietnam, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Heiman Wertheim
- />National Hospital for Tropical Diseases Oxford University Clinical Research Unit, Hanoi, Vietnam
| | - Marcel Wolbers
- />Wellcome Trust Major Overseas Programme Vietnam, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
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12
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Murdock BJ, Teitz-Tennenbaum S, Chen GH, Dils AJ, Malachowski AN, Curtis JL, Olszewski MA, Osterholzer JJ. Early or late IL-10 blockade enhances Th1 and Th17 effector responses and promotes fungal clearance in mice with cryptococcal lung infection. THE JOURNAL OF IMMUNOLOGY 2014; 193:4107-16. [PMID: 25225664 DOI: 10.4049/jimmunol.1400650] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The potent immunoregulatory properties of IL-10 can counteract protective immune responses and, thereby, promote persistent infections, as evidenced by studies of cryptococcal lung infection in IL-10-deficient mice. To further investigate how IL-10 impairs fungal clearance, the current study used an established murine model of C57BL/6J mice infected with Cryptococcus neoformans strain 52D. Our results demonstrate that fungal persistence is associated with an early and sustained expression of IL-10 by lung leukocytes. To examine whether IL-10-mediated immune modulation occurs during the early or late phase of infection, assessments of fungal burden and immunophenotyping were performed on mice treated with anti-IL-10R-blocking Ab at 3, 6, and 9 d postinfection (dpi) (early phase) or at 15, 18, and 21 dpi (late phase). We found that both early and late IL-10 blockade significantly improved fungal clearance within the lung compared with isotype control treatment when assessed 35 dpi. Immunophenotyping identified that IL-10 blockade enhanced several critical effector mechanisms, including increased accumulation of CD4(+) T cells and B cells, but not CD8(+) T cells; specific increases in the total numbers of Th1 and Th17 cells; and increased accumulation and activation of CD11b(+) dendritic cells and exudate macrophages. Importantly, IL-10 blockade effectively abrogated dissemination of C. neoformans to the brain. Collectively, this study identifies early and late cellular and molecular mechanisms through which IL-10 impairs fungal clearance and highlights the therapeutic potential of IL-10 blockade in the treatment of fungal lung infections.
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Affiliation(s)
- Benjamin J Murdock
- Research Service, Veterans Affairs Ann Arbor Healthcare System, Department of Veterans Affairs Health System, Ann Arbor, MI 48105; Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109
| | - Seagal Teitz-Tennenbaum
- Research Service, Veterans Affairs Ann Arbor Healthcare System, Department of Veterans Affairs Health System, Ann Arbor, MI 48105; Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109
| | - Gwo-Hsiao Chen
- Research Service, Veterans Affairs Ann Arbor Healthcare System, Department of Veterans Affairs Health System, Ann Arbor, MI 48105; Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109
| | - Anthony J Dils
- Research Service, Veterans Affairs Ann Arbor Healthcare System, Department of Veterans Affairs Health System, Ann Arbor, MI 48105; Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109
| | - Antoni N Malachowski
- Research Service, Veterans Affairs Ann Arbor Healthcare System, Department of Veterans Affairs Health System, Ann Arbor, MI 48105; Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109
| | - Jeffrey L Curtis
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109; Pulmonary Section, Medical Service, Veterans Affairs Ann Arbor Healthcare System, Department of Veterans Affairs Health System, Ann Arbor, MI 48105; and Graduate Program in Immunology, University of Michigan Health System, Ann Arbor, MI 48109
| | - Michal A Olszewski
- Research Service, Veterans Affairs Ann Arbor Healthcare System, Department of Veterans Affairs Health System, Ann Arbor, MI 48105; Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109; Graduate Program in Immunology, University of Michigan Health System, Ann Arbor, MI 48109
| | - John J Osterholzer
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109; Pulmonary Section, Medical Service, Veterans Affairs Ann Arbor Healthcare System, Department of Veterans Affairs Health System, Ann Arbor, MI 48105; and Graduate Program in Immunology, University of Michigan Health System, Ann Arbor, MI 48109
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13
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Invasion of the central nervous system by Cryptococcus neoformans requires a secreted fungal metalloprotease. mBio 2014; 5:e01101-14. [PMID: 24895304 PMCID: PMC4049100 DOI: 10.1128/mbio.01101-14] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
UNLABELLED Cryptococcus spp. cause life-threatening fungal infection of the central nervous system (CNS), predominantly in patients with a compromised immune system. Why Cryptococcus neoformans has this remarkable tropism for the CNS is not clear. Recent research on cerebral pathogenesis of C. neoformans revealed a predominantly transcellular migration of cryptococci across the brain endothelium; however, the identities of key fungal virulence factors that function specifically to invade the CNS remain unresolved. Here we found that a novel, secreted metalloprotease (Mpr1) that we identified in the extracellular proteome of C. neoformans (CnMpr1) is required for establishing fungal disease in the CNS. Mpr1 belongs to a poorly characterized M36 class of fungalysins that are expressed in only some fungal species. A strain of C. neoformans lacking the gene encoding Mpr1 (mpr1Δ) failed to breach the endothelium in an in vitro model of the human blood-brain barrier (BBB). A mammalian host infected with the mpr1Δ null strain demonstrated significant improvement in survival due to a reduced brain fungal burden and lacked the brain pathology commonly associated with cryptococcal disease. The in vivo studies further indicate that Mpr1 is not required for fungal dissemination and Mpr1 likely targets the brain endothelium specifically. Remarkably, the sole expression of CnMPR1 in Saccharomyces cerevisiae resulted in a robust migration of yeast cells across the brain endothelium, demonstrating Mpr1's specific activity in breaching the BBB and suggesting that Mpr1 may function independently of the hyaluronic acid-CD44 pathway. This distinct role for Mpr1 may develop into innovative treatment options and facilitate a brain-specific drug delivery platform. IMPORTANCE Cryptococcus neoformans is a medically relevant fungal pathogen causing significant morbidity and mortality, particularly in immunocompromised individuals. An intriguing feature is its strong neurotropism, and consequently the hallmark of cryptococcal disease is a brain infection, cryptococcal meningoencephalitis. For C. neoformans to penetrate the central nervous system (CNS), it first breaches the blood-brain barrier via a transcellular pathway; however, the identities of fungal factors required for this transmigration remain largely unknown. In an effort to identify extracellular fungal proteins that could mediate interactions with the brain endothelium, we undertook a proteomic analysis of the extracellular proteome and identified a secreted metalloprotease (Mpr1) belonging to the M36 class of fungalysins. Here we found that Mpr1 promotes migration of C. neoformans across the brain endothelium and into the CNS by facilitating attachment of cryptococci to the endothelium surface, thus underscoring the critical role of M36 proteases in fungal pathogenesis.
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14
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Chang CC, Omarjee S, Lim A, Spelman T, Gosnell BI, Carr WH, Elliott JH, Moosa MYS, Ndung'u T, French MA, Lewin SR. Chemokine levels and chemokine receptor expression in the blood and the cerebrospinal fluid of HIV-infected patients with cryptococcal meningitis and cryptococcosis-associated immune reconstitution inflammatory syndrome. J Infect Dis 2013; 208:1604-12. [PMID: 23908492 DOI: 10.1093/infdis/jit388] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Human immunodeficiency virus-infected patients with treated cryptococcal meningitis who start combination antiretroviral therapy (cART) are at risk of further neurological deterioration, in part caused by paradoxical cryptococcosis-associated immune reconstitution inflammatory syndrome (C-IRIS). We hypothesized that C-IRIS is associated with alterations of chemokine receptor expression on T cells and chemokine concentrations in cerebrospinal fluid (CSF) that enhance recruitment of T-helper 1 cells and/or myeloid cells to the central nervous system. METHODS In a prospective study of 128 human immunodeficiency virus-infected patients with cryptococcal meningitis who received antifungal therapy followed by cART, we examined the proportions of CD4(+) and CD8(+) T cells expressing CCR5 and/or CXCR3, in CSF and whole blood and the concentrations of CXCL10, CCL2, and CCL3 in stored CSF and plasma. RESULTS The proportion of CD4(+) and CD8(+) T cells expressing CXCR3(+)CCR5(+) and the concentrations of CXCL10, CCL2 and CCL3 were increased in CSF compared with blood at cART initiation (P < .0001). Patients with C-IRIS (n = 26), compared with those with no neurological deterioration (n = 63), had higher CSF ratios of CCL2/CXCL10 and CCL3/CXCL10 and higher proportions of CXCR3(+)CCR5(+)CD8(+)T cells in CSF compared with blood at cART initiation (P = .03, .0053, and .02, respectively). CONCLUSION CD8(+) T-cell and myeloid cell trafficking to the central nervous system may predispose patients to C-IRIS.
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15
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Methamphetamine enhances Cryptococcus neoformans pulmonary infection and dissemination to the brain. mBio 2013; 4:mBio.00400-13. [PMID: 23900172 PMCID: PMC3735193 DOI: 10.1128/mbio.00400-13] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Methamphetamine (METH) is a major addictive drug of abuse in the United States and worldwide, and its use is linked to HIV acquisition. The encapsulated fungus Cryptococcus neoformans is the most common cause of fungal meningitis in patients with AIDS. In addition to functioning as a central nervous system stimulant, METH has diverse effects on host immunity. Using a systemic mouse model of infection and in vitro assays in order to critically assess the impact of METH on C. neoformans pathogenesis, we demonstrate that METH stimulates fungal adhesion, glucuronoxylomannan (GXM) release, and biofilm formation in the lungs. Interestingly, structural analysis of the capsular polysaccharide of METH-exposed cryptococci revealed that METH alters the carbohydrate composition of this virulence factor, an event of adaptation to external stimuli that can be advantageous to the fungus during pathogenesis. Additionally, we show that METH promotes C. neoformans dissemination from the respiratory tract into the brain parenchyma. Our findings provide novel evidence of the impact of METH abuse on host homeostasis and increased permissiveness to opportunistic microorganisms. Methamphetamine (METH) is a major health threat to our society, as it adversely changes people’s behavior, as well as increases the risk for the acquisition of diverse infectious diseases, particularly those that enter through the respiratory tract or skin. This report investigates the effects of METH use on pulmonary infection by the AIDS-related fungus Cryptococcus neoformans. This drug of abuse stimulates colonization and biofilm formation in the lungs, followed by dissemination of the fungus to the central nervous system. Notably, C. neoformans modifies its capsular polysaccharide after METH exposure, highlighting the fungus’s ability to adapt to environmental stimuli, a possible explanation for its pathogenesis. The findings may translate into new knowledge and development of therapeutic and public health strategies to deal with the devastating complications of METH abuse.
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16
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Chang CC, Crane M, Zhou J, Mina M, Post JJ, Cameron BA, Lloyd AR, Jaworowski A, French MA, Lewin SR. HIV and co-infections. Immunol Rev 2013; 254:114-42. [PMID: 23772618 PMCID: PMC3697435 DOI: 10.1111/imr.12063] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Despite significant reductions in morbidity and mortality secondary to availability of effective combination anti-retroviral therapy (cART), human immunodeficiency virus (HIV) infection still accounts for 1.5 million deaths annually. The majority of deaths occur in sub-Saharan Africa where rates of opportunistic co-infections are disproportionately high. In this review, we discuss the immunopathogenesis of five common infections that cause significant morbidity in HIV-infected patients globally. These include co-infection with Mycobacterium tuberculosis, Cryptococcus neoformans, hepatitis B virus, hepatitis C virus, and Plasmodium falciparum. Specifically, we review the natural history of each co-infection in the setting of HIV, the specific immune defects induced by HIV, the effects of cART on the immune response to the co-infection, the pathogenesis of immune restoration disease (IRD) associated with each infection, and advances in the areas of prevention of each co-infection via vaccination. Finally, we discuss the opportunities and gaps in knowledge for future research.
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Affiliation(s)
- Christina C Chang
- Department of Infectious Diseases, Alfred Hospital and Monash University, Melbourne, Australia
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17
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Animal Models In Mycology: What Have We Learned Over The Past 30 Years. CURRENT FUNGAL INFECTION REPORTS 2012. [DOI: 10.1007/s12281-012-0126-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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18
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Abstract
Fungal meningitis is a serious disease caused by a fungal infection of the central nervous system (CNS) mostly in individuals with immune system deficiencies. Fungal meningitis is often fatal without proper treatment, and the mortality rate remains unacceptably high even with antifungal drug interventions. Currently, cryptococcal meningitis is the most common fungal meningitis in HIV-1/AIDS, and its disease mechanism has been extensively studied. The key steps for fungi to infect brain and cause meningitis after establishment of local infection are the dissemination of fungal cells to the bloodstream and invasion through the blood brain barrier to reach the CNS. In this review, we use cryptococcal CNS infection as an example to describe the current molecular understanding of fungal meningitis, including the establishment of the infection, dissemination, and brain invasion. Host and microbial factors that contribute to these infection steps are also discussed.
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Affiliation(s)
- Tong-Bao Liu
- The Public Health Research Institute, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark, NJ, USA
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19
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Eisenman HC, Casadevall A, McClelland EE. New insights on the pathogenesis of invasive Cryptococcus neoformans infection. Curr Infect Dis Rep 2010; 9:457-64. [PMID: 17999881 DOI: 10.1007/s11908-007-0070-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Disseminated cryptococcosis begins with infection of the lungs via inhalation. This is followed by escape from the lungs and entry into the bloodstream allowing dissemination to the brain and central nervous system. We discuss the steps involved in dissemination and the host and microbial factors that influence each step. For the host, containment in the lung is accomplished with a combination of cell-mediated and antibody responses. Dissemination occurs when these systems fail and/or when phagocytic cells that fail to kill the yeast instead act as a niche for replication. One of the main microbial factors affecting dissemination is the polysaccharide capsule, a major virulence factor that promotes dissemination at every step. Secreted enzymes are important, including laccase and phospholipase B, which promote escape from the lungs, and urease, which contributes to crossing the blood-brain barrier. Lastly, a number of regulatory factors contribute, especially to growth of Cryptococcus neoformans in the brain.
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Affiliation(s)
- Helene C Eisenman
- Albert Einstein College of Medicine, 411 Forchheimer, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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20
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Therapeutic efficacy of a conjugate vaccine containing a peptide mimotope of cryptococcal capsular polysaccharide glucuronoxylomannan. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2008; 15:1176-87. [PMID: 18524882 DOI: 10.1128/cvi.00130-08] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Vaccination with P13, a peptide mimotope of the cryptococcal capsular polysaccharide glucuronoxylomannan (GXM), has been shown to confer protection against a subsequent lethal Cryptococcus neoformans challenge. In this study, we sought to investigate whether P13-based vaccines could be effective in an already-established infection. To address this question, we developed a systemic chronic cryptococcal infection model. We vaccinated chronically infected mice with P13-protein conjugates and monitored their survival. Compared to the controls, the conjugates prolonged the survival of chronically infected mice. The degree of protection was a function of the mouse strain (BALB/c or C57BL/6), the carrier protein (tetanus toxoid or diphtheria toxoid), and the route of infection (intraperitoneal or intravenous). Serum GXM levels were correlated with the day of death, but the correlation was driven by the carrier protein and mouse strain. The passive transfer of heat-treated sera from P13 conjugate-vaccinated mice conferred protection to naïve BALB/c mice, indicating that antibody immunity could contribute to protection. The measurement of peripheral blood cytokine (gamma interferon [IFN-gamma], interleukin-10 [IL-10], and IL-6) gene expression showed that P13 conjugate-vaccinated BALB/c and C57BL/6 mice mounted a strong Th2 (IL-10)-like response relative to the Th1 (IFN-gamma)-like response, with the degree depending on the mouse strain and carrier protein. Taken together, our data suggest that a vaccine could hold promise in the setting of chronic cryptococcosis, and that vaccine efficacy could depend on immunomodulation and augmentation of the natural immune response of the host.
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Hu G, Hacham M, Waterman SR, Panepinto J, Shin S, Liu X, Gibbons J, Valyi-Nagy T, Obara K, Jaffe HA, Ohsumi Y, Williamson PR. PI3K signaling of autophagy is required for starvation tolerance and virulenceof Cryptococcus neoformans. J Clin Invest 2008; 118:1186-97. [PMID: 18259613 DOI: 10.1172/jci32053] [Citation(s) in RCA: 150] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Accepted: 12/05/2007] [Indexed: 12/17/2022] Open
Abstract
Autophagy is a process by which cells recycle cytoplasm and defective organelles during stress situations such as nutrient starvation. It can also be used by host cells as an immune defense mechanism to eliminate infectious pathogens. Here we describe the use of autophagy as a survival mechanism and virulence-associated trait by the human fungal pathogen Cryptococcus neoformans. We report that a mutant form of C. neoformans lacking the Vps34 PI3K (vps34Delta), which is known to be involved in autophagy in ascomycete yeast, was defective in the formation of autophagy-related 8-labeled (Atg8-labeled) vesicles and showed a dramatic attenuation in virulence in mouse models of infection. In addition, autophagic vesicles were observed in WT but not vps34Delta cells after phagocytosis by a murine macrophage cell line, and Atg8 expression was exhibited in WT C. neoformans during human infection of brain. To dissect the contribution of defective autophagy in vps34Delta C. neoformans during pathogenesis, a strain of C. neoformans in which Atg8 expression was knocked down by RNA interference was constructed and these fungi also demonstrated markedly attenuated virulence in a mouse model of infection. These results demonstrated PI3K signaling and autophagy as a virulence-associated trait and survival mechanism during infection with a fungal pathogen. Moreover, the data show that molecular dissection of such pathogen stress-response pathways may identify new approaches for chemotherapeutic interventions.
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Affiliation(s)
- Guowu Hu
- Section of Infectious Diseases, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612, USA
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Charlier C, Dromer F, Lévêque C, Chartier L, Cordoliani YS, Fontanet A, Launay O, Lortholary O. Cryptococcal neuroradiological lesions correlate with severity during cryptococcal meningoencephalitis in HIV-positive patients in the HAART era. PLoS One 2008; 3:e1950. [PMID: 18414656 PMCID: PMC2293413 DOI: 10.1371/journal.pone.0001950] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Accepted: 02/13/2008] [Indexed: 11/18/2022] Open
Abstract
Cryptococcal meningoencephalitis has an overall global mortality rate of 20% in AIDS patients despite antifungals. There is a need for additional means of precise assessment of disease severity. We thus studied the radiological brain images available from 62 HIV-positive patients with cryptococcocal meningoencephalitis to analyse the brain lesions associated with cryptococcosis in relationship with disease severity, and the respective diagnostic contribution of magnetic resonance (MR) versus computed tomography (CT). In this retrospective multicenter analysis, two neuroradiologists blindly reviewed the brain imaging. Prospectively acquired clinical and mycological data were available at baseline and during follow-up. Baseline images were abnormal on 92% of the MR scans contrasting with 53% of the CT scans. MR/CT cryptococcosis-related lesions included mass(es) (21%/9%), dilated perivascular spaces (46%/5%) and pseudocysts (8%/4%). The presence compared to absence of cryptococcosis-related lesions was significantly associated with high serum (78% vs. 42%, p = 0.008) and CSF (81% vs. 50%, p = 0.024) antigen titers, independently of neurological abnormalities. MR detected significantly more cryptococcosis-related lesions than CT for 17 patients who had had both investigations (76% vs. 24%, p = 0.005). In conclusion, MR appears more effective than CT for the evaluation of AIDS-associated cerebral cryptococcosis. Furthermore, brain imaging is an effective tool to assess the initial disease severity in this setting. Given this, we suggest that investigation for cryptococcosis-related lesions is merited, even in the absence of neurological abnormality, if a high fungal burden is suspected on the basis of high serum and/or CSF antigen titers.
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Affiliation(s)
- Caroline Charlier
- Centre National de Référence Mycologie et Antifongiques, Unité de Mycologie Moléculaire, CNRS URA 3012, Institut Pasteur, Paris, France
- Faculté de Médecine Paris V René Descartes, Hôpital Necker-Enfants Malades, Service des Maladies Infectieuses et Tropicales, Centre d'Infectiologie Necker-Pasteur, Paris, France
| | - Françoise Dromer
- Centre National de Référence Mycologie et Antifongiques, Unité de Mycologie Moléculaire, CNRS URA 3012, Institut Pasteur, Paris, France
| | | | - Loïc Chartier
- Unité de Recherche et d'Expertise en Epidémiologie des Maladies Emergentes, Institut Pasteur, Paris, France
| | | | - Arnaud Fontanet
- Unité de Recherche et d'Expertise en Epidémiologie des Maladies Emergentes, Institut Pasteur, Paris, France
| | - Odile Launay
- Université Paris-Descartes, Faculté de Médecine, Hôpital Cochin, Pôle de Médecine Interne, CIC de Vaccinologie Cochin-Pasteur, Paris, France
| | - Olivier Lortholary
- Centre National de Référence Mycologie et Antifongiques, Unité de Mycologie Moléculaire, CNRS URA 3012, Institut Pasteur, Paris, France
- Faculté de Médecine Paris V René Descartes, Hôpital Necker-Enfants Malades, Service des Maladies Infectieuses et Tropicales, Centre d'Infectiologie Necker-Pasteur, Paris, France
- * E-mail:
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23
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Singh N, Husain S, Limaye AP, Pursell K, Klintmalm GB, Pruett TL, Somani J, Stosor V, del Busto R, Wagener MM, Steele C. Systemic and cerebrospinal fluid T-helper cytokine responses in organ transplant recipients with Cryptococcus neoformans infection. Transpl Immunol 2006; 16:69-72. [PMID: 16860707 DOI: 10.1016/j.trim.2006.03.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Accepted: 03/09/2006] [Indexed: 11/19/2022]
Abstract
BACKGROUND The role of Th1 and Th2 mediated cytokine responses in the pathogenesis of Cryptococcus neoformans infection in organ transplant recipients has not been defined. METHODS We assessed cytokine levels in the sera and CSF collected prospectively at the time of diagnosis of infection in 25 transplant recipients with cryptococcosis. Serum levels were compared with those in healthy individuals and transplant recipients without cryptococcosis. IFN-gamma or IL-12 (Th1)/IL-10 (Th2) ratio < 1.0 was considered a dominant Th2 response. RESULTS Cases had lower ratios of IFN-gamma/IL-10 (p = 0.03) and IL-12/IL-10 (p = 0.03) compared to healthy individuals. Cytokine responses, however, did not differ significantly for cases vs. transplant controls. Cases with fungemia compared to those without fungemia tended to have higher serum IL-10 levels (p = 0.07) and lower IL-12/IL-10 ratios (p = 0.06). CSF ratios of IFN-gamma/IL-10 (p = 0.04) and IL-12/IL-10 (p = 0.04) were lower in cases with cryptococcal meningitis compared to those without meningitis; 80% (8/10) of the cases with cryptococcal meningitis vs. 0% (4/4) of those without meningitis had CSF IFN-gamma/IL-10 ratio of < 1.0 (p = 0.015). The levels of IL-10 (p = 0.04) and IFN-gamma (p = 0.04) in the CSF in cases with cryptococcal meningitis were significantly higher than those in their serum, respectively. CONCLUSIONS High expression of Th2 phenotype in cryptococcal meningitis and in fungemia suggests that Th dysregulation may contribute to the pathogenesis of cryptococcosis in organ transplant recipients.
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Affiliation(s)
- Nina Singh
- University of Pittsburgh, Pittsburgh, PA, USA.
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24
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Charlier C, Chrétien F, Lortholary O, Dromer F. [Early capsule structure changes associated with Cryptococcus neoformans crossing of the blood-brain barrier]. Med Sci (Paris) 2005; 21:685-7. [PMID: 16115446 DOI: 10.1051/medsci/2005218-9685] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Caroline Charlier
- Unité de Mycologie moléculaire, CNRS FRE 2849, Institut Pasteur, 28 rue du Docteur Roux, 75015 Paris, France
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25
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Lortholary O, Sitbon K, Dromer F. Evidence for human immunodeficiency virus and Cryptococcus neoformans interactions in the pro-inflammatory and anti-inflammatory responses in blood during AIDS-associated cryptococcosis. Clin Microbiol Infect 2005; 11:296-300. [PMID: 15760426 DOI: 10.1111/j.1469-0691.2005.01074.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, -8 and-10 and soluble TNF receptor II (sTNFR II) levels were measured at baseline, and after antifungal therapy for 2 weeks and 3 months, in plasma from 75 human immunodeficiency virus (HIV)-positive and 14 HIV-negative patients with cryptococcosis, and in plasma from 14 HIV-positive controls. At baseline, TNF-alpha, IL-6 and sTNFR II levels, and cryptococcal antigen titres, were increased in patients with fungaemia compared to controls (p < 0.02). The mediator levels were not influenced by the severity of the disease or subsequent death, but sTNFR II and IL-10 levels were reduced, together with virus load, in patients receiving anti-retroviral agents (p < 0.01). During antifungal therapy, sTNFR II levels decreased (p 0.003) in parallel with the virus load and with an increase in CD4 T-cell numbers.
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Affiliation(s)
- O Lortholary
- Unité de Mycologie Moléculaire, Centre National de Référence Mycologie et Antifongiques, Institut Pasteur, Paris, France.
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26
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Charlier C, Chrétien F, Baudrimont M, Mordelet E, Lortholary O, Dromer F. Capsule structure changes associated with Cryptococcus neoformans crossing of the blood-brain barrier. THE AMERICAN JOURNAL OF PATHOLOGY 2005; 166:421-32. [PMID: 15681826 PMCID: PMC1602336 DOI: 10.1016/s0002-9440(10)62265-1] [Citation(s) in RCA: 153] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Cryptococcus neoformans is a yeast responsible for disseminated meningoencephalitis in patients with cellular immune defects. The major virulence factor is the polysaccharide capsule. We took advantage of a relevant murine model of disseminated meningoencephalitis to study the early events associated with blood-brain barrier (BBB) crossing. Mice were sacrificed at 1, 6, 24, and 48 hours post-intravenous inoculation, and classical histology, electron microscopy, and double immunofluorescence were used to study tissues and yeasts. Crossing of the BBB occurred early after inoculation, did not involve the choroid plexus but instead occurred at the level of the cortical capillaries, and caused early and severe damage to the structure of the microvessels. Seeding of the leptomeninges was not the primary event but occurred secondary to leakage of cortical pseudocysts. Organ invasion was associated with changes in cryptococcal capsule structure and cell size, which differed in terms of magnitude and kinetics, depending on both the organs involved, and potentially, on the bed structure of the local capillary. The rapid changes in capsule structure could contribute to inability of the host immune response to control cryptococcal infection in extrapulmonary spaces.
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Affiliation(s)
- Caroline Charlier
- Unité de Mycologie Moléculaire, CNRS FRE2948, Institut Pasteur, 25 rue du Dr. Roux, 75724 Paris cedex 15, France
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27
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Garcia-Hermoso D, Dromer F, Janbon G. Cryptococcus neoformans capsule structure evolution in vitro and during murine infection. Infect Immun 2004; 72:3359-65. [PMID: 15155641 PMCID: PMC415706 DOI: 10.1128/iai.72.6.3359-3365.2004] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cryptococcus neoformans capsule structure modifications after prolonged in vitro growth or in vivo passaging have been reported previously. However, nothing is known about the dynamics of these modifications or about their environmental specificities. In this study, capsule structure modifications after mouse passaging and prolonged in vitro culturing were analyzed by flow cytometry using the glucuronoxylomannan-specific monoclonal antibody E1. The capsule structures of strains recovered after 0, 1, 8, and 35 days were compared by using the level of E1-specific epitope expression and its cell-to-cell heterogeneity within a given cell population. In vitro, according to these parameters, the diversity of the strains was higher on day 35 than it was initially, suggesting the absence of selection during in vitro culturing. In contrast, the diversity of the strains recovered from the brain tended to decrease over time, suggesting that selection of more adapted strains had occurred. The strains recovered on day 35 from the spleen and the lungs had different phenotypes than the strains isolated from the brain of the same mouse on the same day, thus strongly suggesting that there is organ specificity for C. neoformans strain selection. Fingerprinting of the strains recovered in vitro and in vivo over time confirmed that genotypes evolved very differently in vitro and in vivo, depending on the environment. Overall, our results suggest that organ-specific selection can occur during cryptococcosis.
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28
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Maffei CML, Mirels LF, Sobel RA, Clemons KV, Stevens DA. Cytokine and inducible nitric oxide synthase mRNA expression during experimental murine cryptococcal meningoencephalitis. Infect Immun 2004; 72:2338-49. [PMID: 15039359 PMCID: PMC375146 DOI: 10.1128/iai.72.4.2338-2349.2004] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The immune events that take place in the central nervous system (CNS) during cryptococcal infection are incompletely understood. We used competitive reverse transcription-PCR to delineate the time course of the local expression of mRNAs encoding a variety of cytokines and inducible nitric oxide synthase (iNOS) during progressive murine cryptococcal meningoencephalitis and assessed the CNS inflammatory response using immunohistochemistry. Interleukin 18 (IL-18), transforming growth factor beta1, and IL-12p(40) mRNAs were constitutively expressed in the brains of infected and uninfected mice; IL-2 mRNA was not detected at any time. Increased levels of transcripts corresponding to IL-1 alpha, tumor necrosis factor alpha (TNF-alpha), and iNOS were detected as early as day 1 postinfection, with TNF-alpha rising by approximately 30-fold and iNOS increasing by approximately 5-fold by day 7. Each remained at these levels thereafter. IL-4, IL-6, and gamma interferon transcripts were detected on day 5, and IL-1 beta and IL-10 transcripts were detected beginning on day 7. Once detected, each remained at a relatively constant level through 28 days of infection. This cytokine profile does not suggest a polarized Th1 or Th2 response. Immunohistochemistry did not reveal inflammatory infiltrates before day 7, despite the presence of cryptococci. Intraparenchymal abscesses with inflammatory cells in their peripheries were found beginning on day 10. The infiltrates were comprised primarily of cells expressing CD4, CD8, or CD11b; low numbers of cells expressing CD45R/B220 were also present. The persistence of Cryptococcus observed in the CNS may result from an ineffective immune response, perhaps owing to an insufficient anticryptococcal effector function of endogenous glial cells resulting from competing pro- and anti-inflammatory cytokines. These data detail the immune response in the brain and could be important for the future design of specific immunomodulatory therapies for this important opportunistic infection.
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Affiliation(s)
- Claudia M L Maffei
- Department of Cellular and Molecular Biology, School of Medicine of Ribeirão Preto of the University of São Paulo, Ribeirão Preto, São Paulo 14049-900 Brazil
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29
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Neuville S, Dromer F, Morin O, Dupont B, Ronin O, Lortholary O. Primary cutaneous cryptococcosis: a distinct clinical entity. Clin Infect Dis 2003; 36:337-47. [PMID: 12539076 DOI: 10.1086/345956] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2002] [Accepted: 10/22/2002] [Indexed: 11/03/2022] Open
Abstract
Cryptococcus neoformans is an encapsulated yeast responsible for disseminated meningitis in immunocompromised hosts. Controversies persist on the existence of primary cutaneous cryptococcosis (PCC) versus cutaneous cryptococcosis being only secondary to hematogenous dissemination. Thus, we reviewed cryptococcosis cases associated with skin lesions reported in the French National Registry. Patients with PCC (n=28) differed significantly from those with secondary cutaneous cryptococcosis (n=80) or other forms of the disease (n=1866) by living area (mostly rural), age (older), ratio of men to women (approximately 1:1), and the lack of underlying disease. Evidence of PCC included the absence of dissemination and, predominantly, a solitary skin lesion on unclothed areas presenting as a whitlow or phlegmon, a history of skin injury, participation in outdoor activities, or exposure to bird droppings, and isolation of C. neoformans serotype D. Therefore, PCC is a distinct epidemiological and clinical entity with a favorable prognosis even for immunocompromised hosts.
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Affiliation(s)
- Ségolène Neuville
- Centre National de Référence des Mycoses et des Antifongiques, Unité de Mycologie Moléculaire, Institut Pasteur, 75724 Paris cedex 15, France
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30
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Hayley S, Merali Z, Anisman H. The acute and sensitization effects of tumor necrosis factor-α: implications for immunotherapy as well as psychiatric and neurological conditions. Acta Neuropsychiatr 2002; 14:322-35. [PMID: 26984578 DOI: 10.1034/j.1601-5215.2002.140606.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In addition to their role as signaling molecules of the immune system, cytokines may participate in central neurotransmission. Variations of the central and/or peripheral levels of the proinflammatory cytokines, tumor necrosis factor-α (TNF-α) and interleukin-β (IL-1β), impact on neuroendocrine processes as well as central neurotransmitter activity. To a considerable extent, these effects are reminiscent of those elicited by psychogenic stressors. The current review describes recent findings consistent with a role for these cytokines in the neurochemical and behavioral manifestations of clinical depression, as well as the cellular death associated with cerebral ischemia. Moreover, the increasing use of cytokines in the immunotherapeutic treatment of various autoimmune diseases (e.g. rheumatoid arthritis) and cancers prompted us to consider the potential role of central processes in subserving the mood-related side-effects elicited by these treatments. Finally, a single administration of TNF-α has been shown to elicit a time-dependent sensitization effect, wherein the behavioral and neurochemical responses elicited by later cytokine treatment are greatly enhanced. Thus, particular attention was devoted to the possibility that elevated levels of TNF-α, through either exogenous (e.g. immunotherapy) or endogenous (e.g. brain damage or stressors) means may sensitize neurotransmitter or second messenger pathways important for the pathology. Given the time-dependent nature of cytokine sensitization effects, the schedule of cytokine administration during immunotherapy, or the timing of cytokine up-regulation in response to traumatic or stressful events may favor the development of sensitized central processes, which may influence clinical outcome.
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Affiliation(s)
- Shawn Hayley
- 1Institute of Neuroscience, Carleton University, Ottawa
| | - Zul Merali
- 2Institute of Mental Health Research, Royal Ottawa Hospital, Ottawa, Ontario, Canada
| | - Hymie Anisman
- 1Institute of Neuroscience, Carleton University, Ottawa
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31
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Lortholary O, Improvisi L, Fitting C, Cavaillon JM, Dromer F. Influence of gender and age on course of infection and cytokine responses in mice with disseminated Cryptococcus neoformans infection. Clin Microbiol Infect 2002; 8:31-7. [PMID: 11906498 DOI: 10.1046/j.1469-0691.2002.00375.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To study the influence of gender and age on the course of infection and the cytokine response in a murine model of disseminated cryptococcosis. METHODS The course of the infection (survival and fungal load in blood and tissues) as well as pro-inflammatory and anti-inflammatory cytokine responses in plasma and organs were compared according to gender and age in outbred mice previously infected with Cryptococcus neoformans NIH52D. RESULTS Although survival and fungal load were similar in male and female mice, the expression of all cytokines in plasma and of tumour necrosis factor-alpha and interferon-gamma in spleen was significantly increased in female mice compared to male mice in two independent experiments. Young male mice had a significantly shortened survival, were significantly more infected and had predominant tumour necrosis factor-alpha and interferon-gamma responses in comparison with older male mice. CONCLUSION Host factors should be taken into account when studying the immune response to experimental C. neoformans infection. Our data support epidemiological and clinical data showing differences in susceptibility to cryptococcosis according to gender and age.
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Affiliation(s)
- O Lortholary
- Unité de Mycologie Moléculaire, Institut Pasteur, Paris, France
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32
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Janbon G, Himmelreich U, Moyrand F, Improvisi L, Dromer F. Cas1p is a membrane protein necessary for the O-acetylation of the Cryptococcus neoformans capsular polysaccharide. Mol Microbiol 2001; 42:453-67. [PMID: 11703667 DOI: 10.1046/j.1365-2958.2001.02651.x] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The capsule is certainly the most obvious virulence factor for Cryptococcus neoformans. The main capsule constituents are glucuronoxylomannans (GXM). Several studies have focused on the structure and chemistry of the GXM component of the capsule, yet little is known about the genetic basis of the capsule construction. Using a monoclonal antibody specific to a sugar epitope, we isolated a capsule-structure mutant strain and cloned by complementation a gene named CAS1 that codes for a putative membrane protein. Although no sequence homology was found with any known protein in the different databases, protein analysis using the PROPSEARCH software classified Cas1p as a putative glycosyltransferase. Cas1p is a well-conserved evolutionary protein, as we identified one orthologue in the human genome, one in the drosophila genome and four in the plant Arabidopsis thaliana genome. Analysis of the capsule structure after CAS1 deletion showed that it is required for GXM O-acetylation.
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Affiliation(s)
- G Janbon
- Unité de Mycologie Moléculaire, Institut Pasteur, 25 rue du Dr Roux, 75724 Paris Cedex, France.
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33
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Beenhouwer DO, Shapiro S, Feldmesser M, Casadevall A, Scharff MD. Both Th1 and Th2 cytokines affect the ability of monoclonal antibodies to protect mice against Cryptococcus neoformans. Infect Immun 2001; 69:6445-55. [PMID: 11553589 PMCID: PMC98780 DOI: 10.1128/iai.69.10.6445-6455.2001] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Variable-region-identical mouse immunoglobulin G1 (IgG1), IgG2b, and IgG2a monoclonal antibodies to the capsular polysaccharide of Cryptococcus neoformans prolong the lives of mice infected with this fungus, while IgG3 is either not protective or enhances infection. CD4+ T cells are required for IgG1-mediated protection, and CD8+ T cells are required for IgG3-mediated enhancement. Gamma interferon is required for both effects. These findings revealed that T cells and cytokines play a role in the modulation of cryptococcal infection by antibodies and suggested that it was important to more fully define the cytokine requirements of each of the antibody isotypes. We therefore investigated the efficacy of passively administered variable-region-identical IgG1, IgG2a, IgG2b, and IgG3 monoclonal antibodies against intravenous infection with C. neoformans in mice genetically deficient in interleukin-12 (IL-12), IL-6, IL-4, or IL-10, as well as in the parental C57BL/6J strain. The relative inherent susceptibilities of these mouse strains to C. neoformans were as follows: IL-12(-/-) > IL-6(-/-) > C57BL/6J approximately IL-4(-/-) >> IL-10(-/-). This is consistent with the notion that a Th1 response is necessary for natural immunity against cryptococcal infection. However, none of the IgG isotypes prolonged survival in IL-12(-/-), IL-6(-/-), or IL-4(-/-) mice, and all isotypes significantly enhanced infection in IL-10(-/-) mice. These results indicate that passive antibody-mediated protection against C. neoformans requires both Th1- and Th2-associated cytokines and reveal the complexity of the mechanisms through which antibodies modulate infection with this organism.
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MESH Headings
- Animals
- Antibodies, Fungal/administration & dosage
- Antibodies, Fungal/immunology
- Antibodies, Monoclonal/administration & dosage
- Antibodies, Monoclonal/immunology
- Antigens, Fungal/immunology
- Cells, Cultured
- Cryptococcosis/immunology
- Cryptococcosis/mortality
- Cryptococcosis/pathology
- Cryptococcosis/prevention & control
- Cryptococcus neoformans/growth & development
- Cryptococcus neoformans/immunology
- Disease Models, Animal
- Disease Susceptibility/immunology
- Female
- Immunization, Passive/methods
- Immunoglobulin G/immunology
- Immunoglobulin Isotypes/immunology
- Interleukin-10/genetics
- Interleukin-10/immunology
- Interleukin-12/genetics
- Interleukin-12/immunology
- Interleukin-4/genetics
- Interleukin-4/immunology
- Interleukin-6/genetics
- Interleukin-6/immunology
- Macrophages, Peritoneal/cytology
- Macrophages, Peritoneal/immunology
- Macrophages, Peritoneal/microbiology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Phagocytosis/immunology
- Polysaccharides/immunology
- Th1 Cells/immunology
- Th2 Cells/immunology
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Affiliation(s)
- D O Beenhouwer
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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34
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Chiapello L, Iribarren P, Cervi L, Rubinstein H, Masih DT. Mechanisms for induction of immunosuppression during experimental cryptococcosis: role of glucuronoxylomannan. Clin Immunol 2001; 100:96-106. [PMID: 11414750 DOI: 10.1006/clim.2001.5046] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In previous work we have demonstrated that spleen mononuclear (Spm) cells from rats obtained 14 days after infection with Cryptococcus neoformans showed a diminution in proliferative response to Concanavalin A (Con A). In this study we further investigate some characteristics of the Spm cell population involved in the immunosuppressor phenomenon induced by C. neoformans. We observed that unstimulated Spm cells expressing T-cell receptor (TCR+) from infected rats were reduced in number after 96 h of culture. When the Spm cells from infected rats were stimulated with Con A, increased production of IL-10, reduced levels of IL-2, and decreased CD11a surface expression were shown. These immunosuppressor phenomena were also observed when the capsular polysaccharide, glucuronoxylomannan (GXM), was added to cultures of Spm cells from normal rats. However, GXM had a more pronounced effect in reducing the number of cells surviving in culture than that observed during infection and produced an increase in IL-4 production by Con-A-stimulated Spm cells. Addition of anti-IL-10 monoclonal antibody to cultures restored the lymphoproliferation of Spm cells from infected animals, indicating that IL-10 production is a suppressor mechanism of cell-mediated immunity during experimental infection. The results presented here indicate that at least two mechanisms mediate the nonspecific suppression in this model of cryptococcosis: IL-10 production and diminution of the number of T cells. GXM could be involved, since it has a pronounced effect in the reduction of Spm cells in vitro.
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Affiliation(s)
- L Chiapello
- Micología, Universidad Nacional de Córdoba, Córdoba, 5000, Argentina
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35
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Abstract
Cryptococcosis is a fungal infection that is potentially deadly for and common among AIDS patients, in the United States and worldwide. Subacute meningitis and meningoencephalitis are typical, clinically. This article will review relevant aspects of cryptococcal meningitis in AIDS, focusing on the most recent information pertaining to pathogenesis, epidemiology, clinical syndromes, and treatment of this devastating disease.
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Affiliation(s)
- WG Powderly
- Division of Infectious Diseases, Washington University School of Medicine, 660 S. Euclid, St. Louis, MO 63110, USA.
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36
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Rayhane N, Fitting C, Lortholary O, Dromer F, Cavaillon JM. Administration of endotoxin associated with lipopolysaccharide tolerance protects mice against fungal infection. Infect Immun 2000; 68:3748-53. [PMID: 10816541 PMCID: PMC97672 DOI: 10.1128/iai.68.6.3748-3753.2000] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Lipopolysaccharide (LPS) pretreatment of mice resulted in a significantly enhanced survival after disseminated Cryptococcus neoformans infection. The survival was associated with reduced fungal burden in tissues. LPS-pretreated mice had lower levels of cytokines in blood, spleen, and lungs and higher levels in brain. Pentoxifylline abolished the beneficial effect of LPS pretreatment.
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Affiliation(s)
- N Rayhane
- Unité d'Immuno-Allergie, Institut Pasteur, 75015 Paris, France
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37
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Neuville S, Lortholary O, Dromer F. Do kinetics of the humoral response to Cryptococcus neoformans proteins during murine cryptococcosis reflect outcome? Infect Immun 2000; 68:3724-6. [PMID: 10816535 PMCID: PMC97666 DOI: 10.1128/iai.68.6.3724-3726.2000] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The kinetics of the humoral response to Cryptococcus neoformans proteins were studied in outbred mice infected with isolate NIH52D. Future nonsurvivors had earlier and stronger (i.e., more bands recognized) humoral responses than survivors. In addition, antibodies to a 56- to 60-kDa membrane antigen and to a 39- to 40-kDa cytosolic antigen were detected more frequently in samples from future nonsurvivors and from survivors, respectively (P < 0.05).
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Affiliation(s)
- S Neuville
- Unité de Mycologie, Institut Pasteur, Paris Cedex 15, France
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