101
|
Abstract
Cryptococcus species are encapsulated fungi found in the environment that predominantly cause disease in immunocompromised hosts after inhalation into the lungs. Even with contemporary antifungal regimens, patients with cryptococcosis continue to have high morbidity and mortality rates. The development of more effective therapies may depend on our understanding of the cellular and molecular mechanisms by which the host promotes sterilizing immunity against the fungus. This review will highlight our current knowledge of how Cryptococcus, primarily the species C. neoformans, is sensed by the mammalian host and how subsequent signaling pathways direct the anti-cryptococcal response by effector cells of the innate immune system.
Collapse
Affiliation(s)
- Lena J Heung
- Infectious Diseases Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| |
Collapse
|
102
|
Panackal AA, Rosen LB, Uzel G, Davis MJ, Hu G, Adeyemo A, Tekola-Ayele F, Lisco A, Diachok C, Kim JD, Shaw D, Sereti I, Stoddard J, Niemela J, Rosenzweig SD, Bennett JE, Williamson PR. Susceptibility to Cryptococcal Meningoencephalitis Associated With Idiopathic CD4 + Lymphopenia and Secondary Germline or Acquired Defects. Open Forum Infect Dis 2017. [PMID: 28638843 DOI: 10.1093/ofid/ofx082] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Idiopathic CD4+ lymphopenia (ICL) predisposes to opportunistic infections (OIs) but can often remain asymptomatic and does not have a strong association with monogenic mutations. Likewise, cryptococcal meningoencephalitis, the most common OI in ICL, is not strongly associated with monogenic mutations. In this study, we describe 2 patients with ICL plus an additional immune defect: one from an E57K genetic mutation in the nuclear factor-κβ essential modulator, and the other with acquired autoantibodies to granulocyte-macrophage colony-stimulating factor. Thus, these cases may exemplify a "multi-hit model" in patients with ICL who acquire OIs.
Collapse
Affiliation(s)
- Anil A Panackal
- Laboratory of Clinical Infectious Diseases, Division of Intramural Research (DIR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH).,Division of Infectious Diseases, Department of Medicine, F. Hebert School of Medicine, Uniformed Services University of the Health Sciences
| | - Lindsey B Rosen
- Laboratory of Clinical Infectious Diseases, Division of Intramural Research (DIR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH)
| | - Gulbu Uzel
- Laboratory of Clinical Infectious Diseases, Division of Intramural Research (DIR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH)
| | - Michael J Davis
- Laboratory of Clinical Infectious Diseases, Division of Intramural Research (DIR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH)
| | - Guowu Hu
- Laboratory of Clinical Infectious Diseases, Division of Intramural Research (DIR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH)
| | - Adebowale Adeyemo
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, NIH
| | - Fasil Tekola-Ayele
- Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland
| | | | - Christopher Diachok
- Laboratory of Clinical Infectious Diseases, Division of Intramural Research (DIR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH)
| | - Jonathan D Kim
- Laboratory of Clinical Infectious Diseases, Division of Intramural Research (DIR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH)
| | - Dawn Shaw
- Leidos Biomedical Research, Inc., Frederick, Maryland
| | | | - Jennifer Stoddard
- Immunology Service, Department of Laboratory Medicine, Clinical Center, NIH, Bethesda, Maryland
| | - Julie Niemela
- Immunology Service, Department of Laboratory Medicine, Clinical Center, NIH, Bethesda, Maryland
| | - Sergio D Rosenzweig
- Immunology Service, Department of Laboratory Medicine, Clinical Center, NIH, Bethesda, Maryland
| | - John E Bennett
- Laboratory of Clinical Infectious Diseases, Division of Intramural Research (DIR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH).,Division of Infectious Diseases, Department of Medicine, F. Hebert School of Medicine, Uniformed Services University of the Health Sciences
| | - Peter R Williamson
- Laboratory of Clinical Infectious Diseases, Division of Intramural Research (DIR), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH)
| |
Collapse
|
103
|
Scott FJ, Nichol RJO, Khalaf AI, Giordani F, Gillingwater K, Ramu S, Elliott A, Zuegg J, Duffy P, Rosslee MJ, Hlaka L, Kumar S, Ozturk M, Brombacher F, Barrett M, Guler R, Suckling CJ. An evaluation of Minor Groove Binders as anti-fungal and anti-mycobacterial therapeutics. Eur J Med Chem 2017; 136:561-572. [PMID: 28544982 DOI: 10.1016/j.ejmech.2017.05.039] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 05/07/2017] [Accepted: 05/16/2017] [Indexed: 02/01/2023]
Abstract
This study details the synthesis and biological evaluation of a collection of 19 structurally related Minor Groove Binders (MGBs), derived from the natural product distamycin, which were designed to probe antifungal and antimycobacterial activity. From this initial set, we report several MGBs that are worth more detailed investigation and optimisation. MGB-4, MGB-317 and MGB-325 have promising MIC80s of 2, 4 and 0.25 μg/mL, respectively, against the fungus C. neoformans.MGB-353 and MGB-354 have MIC99s of 3.1 μM against the mycobacterium M. tuberculosis. The selectivity and activity of these compounds is related to their physicochemical properties and the cell wall/membrane characteristics of the infective agents.
Collapse
Affiliation(s)
- Fraser J Scott
- School of Chemistry, University of Lincoln, Brayford Pool, Lincoln, Lincolnshire, LN6 7TS, United Kingdom.
| | - Ryan J O Nichol
- WestCHEM Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, United Kingdom
| | - Abedawn I Khalaf
- WestCHEM Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, United Kingdom
| | - Federica Giordani
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation and Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, United Kingdom
| | - Kirsten Gillingwater
- Parasite Chemotherapy Unit, Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland; University of Basel, Petersplatz 1, 4003 Basel, Switzerland
| | - Soumya Ramu
- Community for Open Antimicrobial Drug Discovery (CO-ADD), Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Alysha Elliott
- Community for Open Antimicrobial Drug Discovery (CO-ADD), Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Johannes Zuegg
- Community for Open Antimicrobial Drug Discovery (CO-ADD), Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Paula Duffy
- WestCHEM Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, United Kingdom
| | - Michael-Jon Rosslee
- University of Cape Town, Institute of Infectious Diseases and Molecular Medicine (IDM), Division of Immunology and South African Medical Research Council (SAMRC) Immunology of Infectious Diseases, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; International Centre for Genetic Engineering and Biotechnology, Cape Town Component, Cape Town 7925, South Africa
| | - Lerato Hlaka
- University of Cape Town, Institute of Infectious Diseases and Molecular Medicine (IDM), Division of Immunology and South African Medical Research Council (SAMRC) Immunology of Infectious Diseases, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; International Centre for Genetic Engineering and Biotechnology, Cape Town Component, Cape Town 7925, South Africa
| | - Santosh Kumar
- University of Cape Town, Institute of Infectious Diseases and Molecular Medicine (IDM), Division of Immunology and South African Medical Research Council (SAMRC) Immunology of Infectious Diseases, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; International Centre for Genetic Engineering and Biotechnology, Cape Town Component, Cape Town 7925, South Africa
| | - Mumin Ozturk
- University of Cape Town, Institute of Infectious Diseases and Molecular Medicine (IDM), Division of Immunology and South African Medical Research Council (SAMRC) Immunology of Infectious Diseases, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; International Centre for Genetic Engineering and Biotechnology, Cape Town Component, Cape Town 7925, South Africa
| | - Frank Brombacher
- University of Cape Town, Institute of Infectious Diseases and Molecular Medicine (IDM), Division of Immunology and South African Medical Research Council (SAMRC) Immunology of Infectious Diseases, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; International Centre for Genetic Engineering and Biotechnology, Cape Town Component, Cape Town 7925, South Africa
| | - Michael Barrett
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation and Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, United Kingdom
| | - Reto Guler
- University of Cape Town, Institute of Infectious Diseases and Molecular Medicine (IDM), Division of Immunology and South African Medical Research Council (SAMRC) Immunology of Infectious Diseases, Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; International Centre for Genetic Engineering and Biotechnology, Cape Town Component, Cape Town 7925, South Africa
| | - Colin J Suckling
- WestCHEM Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, United Kingdom
| |
Collapse
|
104
|
Abstract
Purpose of the review Cryptococcal disease is most often thought of in the context of HIV infection. Much of our knowledge of the disease originates from its management in the HIV-positive population over the last 30 years. While the majority of cases globally continue to occur in the setting of advanced HIV, Cryptococcus species is increasingly responsible for disease in HIV-negative populations including those considered normal hosts and these HIV-negative populations will be the focus of this review. Recent findings Currently available data indicated that significant differences exist in epidemiology, clinical presentation, management and outcomes of cryptococcal disease in HIV-negative populations when compared to those living with HIV. Summary Further research is required to improve our knowledge of cryptococcal disease in particular in HIV-negative cohorts so as to optimise management of the disease in the future.
Collapse
|
105
|
Fishman JA. Infection in Organ Transplantation. Am J Transplant 2017; 17:856-879. [PMID: 28117944 DOI: 10.1111/ajt.14208] [Citation(s) in RCA: 454] [Impact Index Per Article: 64.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 01/09/2017] [Indexed: 01/25/2023]
Abstract
The prevention, diagnosis, and management of infectious disease in transplantation are major contributors to improved outcomes in organ transplantation. The risk of serious infections in organ recipients is determined by interactions between the patient's epidemiological exposures and net state of immune suppression. In organ recipients, there is a significant incidence of drug toxicity and a propensity for drug interactions with immunosuppressive agents used to maintain graft function. Thus, every effort must be made to establish specific microbiologic diagnoses to optimize therapy. A timeline can be created to develop a differential diagnosis of infection in transplantation based on common patterns of infectious exposures, immunosuppressive management, and antimicrobial prophylaxis. Application of quantitative molecular microbial assays and advanced antimicrobial therapies have advanced care. Pathogen-specific immunity, genetic polymorphisms in immune responses, and dynamic interactions between the microbiome and the risk of infection are beginning to be explored. The role of infection in the stimulation of alloimmune responses awaits further definition. Major hurdles include the shifting worldwide epidemiology of infections, increasing antimicrobial resistance, suboptimal assays for the microbiologic screening of organ donors, and virus-associated malignancies. Transplant infectious disease remains a key to the clinical and scientific investigation of organ transplantation.
Collapse
Affiliation(s)
- J A Fishman
- Transplant Infectious Disease and Immunocompromised Host Program and MGH Transplant Center, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| |
Collapse
|
106
|
Trojan Horse Transit Contributes to Blood-Brain Barrier Crossing of a Eukaryotic Pathogen. mBio 2017; 8:mBio.02183-16. [PMID: 28143979 PMCID: PMC5285505 DOI: 10.1128/mbio.02183-16] [Citation(s) in RCA: 154] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The blood-brain barrier (BBB) protects the central nervous system (CNS) by restricting the passage of molecules and microorganisms. Despite this barrier, however, the fungal pathogen Cryptococcus neoformans invades the brain, causing a meningoencephalitis that is estimated to kill over 600,000 people annually. Cryptococcal infection begins in the lung, and experimental evidence suggests that host phagocytes play a role in subsequent dissemination, although this role remains ill defined. Additionally, the disparate experimental approaches that have been used to probe various potential routes of BBB transit make it impossible to assess their relative contributions, confounding any integrated understanding of cryptococcal brain entry. Here we used an in vitro model BBB to show that a “Trojan horse” mechanism contributes significantly to fungal barrier crossing and that host factors regulate this process independently of free fungal transit. We also, for the first time, directly imaged C. neoformans-containing phagocytes crossing the BBB, showing that they do so via transendothelial pores. Finally, we found that Trojan horse crossing enables CNS entry of fungal mutants that cannot otherwise traverse the BBB, and we demonstrate additional intercellular interactions that may contribute to brain entry. Our work elucidates the mechanism of cryptococcal brain invasion and offers approaches to study other neuropathogens. The fungal pathogen Cryptococcus neoformans invades the brain, causing a meningoencephalitis that kills hundreds of thousands of people each year. One route that has been proposed for this brain entry is a Trojan horse mechanism, whereby the fungus crosses the blood-brain barrier (BBB) as a passenger inside host phagocytes. Although indirect experimental evidence supports this intriguing mechanism, it has never been directly visualized. Here we directly image Trojan horse transit and show that it is regulated independently of free fungal entry, contributes to cryptococcal BBB crossing, and allows mutant fungi that cannot enter alone to invade the brain.
Collapse
|
107
|
Klein RS, Garber C, Howard N. Infectious immunity in the central nervous system and brain function. Nat Immunol 2017; 18:132-141. [PMID: 28092376 DOI: 10.1038/ni.3656] [Citation(s) in RCA: 141] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 12/02/2016] [Indexed: 11/09/2022]
Abstract
Inflammation is emerging as a critical mechanism underlying neurological disorders of various etiologies, yet its role in altering brain function as a consequence of neuroinfectious disease remains unclear. Although acute alterations in mental status due to inflammation are a hallmark of central nervous system (CNS) infections with neurotropic pathogens, post-infectious neurologic dysfunction has traditionally been attributed to irreversible damage caused by the pathogens themselves. More recently, studies indicate that pathogen eradication within the CNS may require immune responses that interfere with neural cell function and communication without affecting their survival. In this Review we explore inflammatory processes underlying neurological impairments caused by CNS infection and discuss their potential links to established mechanisms of psychiatric and neurodegenerative diseases.
Collapse
Affiliation(s)
- Robyn S Klein
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Neuroscience, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Charise Garber
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Nicole Howard
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| |
Collapse
|
108
|
|
109
|
Panackal AA, Komori M, Kosa P, Khan O, Hammoud DA, Rosen LB, Browne SK, Lin YC, Romm E, Ramaprasad C, Fries BC, Bennett JE, Bielekova B, Williamson PR. Spinal Arachnoiditis as a Complication of Cryptococcal Meningoencephalitis in Non-HIV Previously Healthy Adults. Clin Infect Dis 2016; 64:275-283. [PMID: 28011613 DOI: 10.1093/cid/ciw739] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 11/07/2016] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Cryptococcus can cause meningoencephalitis (CM) among previously healthy non-HIV adults. Spinal arachnoiditis is under-recognized, since diagnosis is difficult with concomitant central nervous system (CNS) pathology. METHODS We describe 6 cases of spinal arachnoiditis among 26 consecutively recruited CM patients with normal CD4 counts who achieved microbiologic control. We performed detailed neurological exams, cerebrospinal fluid (CSF) immunophenotyping and biomarker analysis before and after adjunctive immunomodulatory intervention with high dose pulse corticosteroids, affording causal inference into pathophysiology. RESULTS All 6 exhibited severe lower motor neuron involvement in addition to cognitive changes and gait disturbances from meningoencephalitis. Spinal involvement was associated with asymmetric weakness and urinary retention. Diagnostic specificity was improved by MRI imaging which demonstrated lumbar spinal nerve root enhancement and clumping or lesions. Despite negative fungal cultures, CSF inflammatory biomarkers, sCD27 and sCD21, as well as the neuronal damage biomarker, neurofilament light chain (NFL), were elevated compared to healthy donor (HD) controls. Elevations in these biomarkers were associated with clinical symptoms and showed improvement with adjunctive high dose pulse corticosteroids. CONCLUSIONS These data suggest that a post-infectious spinal arachnoiditis is an important complication of CM in previously healthy individuals, requiring heightened clinician awareness. Despite microbiological control, this syndrome causes significant pathology likely due to increased inflammation and may be amenable to suppressive therapeutics.
Collapse
Affiliation(s)
- Anil A Panackal
- Laboratory of Clinical Infectious Diseases (LCID), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda,Maryland; .,Division of Infectious Diseases, Department of Medicine, F. Hebert School of Medicine, Uniformed Services University of the Health Sciences (USUHS), Bethesda, Maryland
| | - Mika Komori
- Neuroimmunological Diseases Unit, Neuroimmunology Branch, National Institute of Neurological Diseases and Stroke (NINDS), NIH, Bethesda, Maryland
| | - Peter Kosa
- Neuroimmunological Diseases Unit, Neuroimmunology Branch, National Institute of Neurological Diseases and Stroke (NINDS), NIH, Bethesda, Maryland
| | - Omar Khan
- Neurology Consult Service, NINDS, NIH, Bethesda, Maryland
| | - Dima A Hammoud
- Center for Infectious Disease Imaging, Radiology and Imaging Sciences, NIH Clinical Center, Bethesda, Maryland
| | - Lindsey B Rosen
- Laboratory of Clinical Infectious Diseases (LCID), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda,Maryland
| | - Sarah K Browne
- Laboratory of Clinical Infectious Diseases (LCID), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda,Maryland
| | - Yen-Chih Lin
- Neuroimmunological Diseases Unit, Neuroimmunology Branch, National Institute of Neurological Diseases and Stroke (NINDS), NIH, Bethesda, Maryland
| | - Elena Romm
- Neuroimmunological Diseases Unit, Neuroimmunology Branch, National Institute of Neurological Diseases and Stroke (NINDS), NIH, Bethesda, Maryland
| | - Charu Ramaprasad
- Infectious Diseases, Kaiser San Jose Medical Center, San Jose, California
| | - Bettina C Fries
- Division of Infectious Diseases, Stony Brook University, Stony Brook, New York
| | - John E Bennett
- Laboratory of Clinical Infectious Diseases (LCID), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda,Maryland.,Division of Infectious Diseases, Department of Medicine, F. Hebert School of Medicine, Uniformed Services University of the Health Sciences (USUHS), Bethesda, Maryland
| | - Bibiana Bielekova
- Neuroimmunological Diseases Unit, Neuroimmunology Branch, National Institute of Neurological Diseases and Stroke (NINDS), NIH, Bethesda, Maryland
| | - Peter R Williamson
- Laboratory of Clinical Infectious Diseases (LCID), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda,Maryland
| |
Collapse
|
110
|
|
111
|
Aye C, Henderson A, Yu H, Norton R. Cryptococcosis-the impact of delay to diagnosis. Clin Microbiol Infect 2016; 22:632-5. [PMID: 27172806 DOI: 10.1016/j.cmi.2016.04.022] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 04/18/2016] [Accepted: 04/30/2016] [Indexed: 12/11/2022]
Abstract
Cryptococcosis is a mycotic disease caused by the yeast Cryptococcus sp. It is associated with significant mortality and morbidity, including long-term neurological sequelae. It is not known whether the high morbidity observed is related to a delay in diagnosis. A retrospective chart review of all cryptococcal infections that had been diagnosed in the region between 1997 and 2015 was performed. Twenty-nine cases were identified. Overall mortality rate was 10.3%, with an attributable mortality rate of 6.9%. Forty-five per cent of patients with central nervous system involvement developed long-term neurological deficits. Significant associations were noted between those with and without long-term neurological deficits and in both time from onset of symptoms to diagnosis (median of 45.5 days versus 18.5 days, respectively) and time from presentation to diagnosis (median 14.5 days versus 7 days, respectively). In addition, raised intracranial pressure (p 0.03) and female gender (p 0.02) were significantly associated with poor neurological outcomes. This highlights the importance of early diagnosis and the need to limit raised intracranial pressure to minimize long-term neurological deficits.
Collapse
Affiliation(s)
- C Aye
- Department of Infectious Diseases, Townsville Hospital, Douglas, Queensland, Australia.
| | - A Henderson
- Department of Infectious Diseases, Townsville Hospital, Douglas, Queensland, Australia; Department of Microbiology, Pathology Queensland, Townsville Hospital, Douglas, Queensland, Australia
| | - H Yu
- Department of Infectious Diseases, Townsville Hospital, Douglas, Queensland, Australia
| | - R Norton
- Department of Infectious Diseases, Townsville Hospital, Douglas, Queensland, Australia; Department of Microbiology, Pathology Queensland, Townsville Hospital, Douglas, Queensland, Australia
| |
Collapse
|
112
|
All about that fat: Lipid modification of proteins in Cryptococcus neoformans. J Microbiol 2016; 54:212-22. [PMID: 26920881 DOI: 10.1007/s12275-016-5626-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 02/01/2016] [Accepted: 02/01/2016] [Indexed: 12/17/2022]
Abstract
Lipid modification of proteins is a widespread, essential process whereby fatty acids, cholesterol, isoprenoids, phospholipids, or glycosylphospholipids are attached to polypeptides. These hydrophobic groups may affect protein structure, function, localization, and/or stability; as a consequence such modifications play critical regulatory roles in cellular systems. Recent advances in chemical biology and proteomics have allowed the profiling of modified proteins, enabling dissection of the functional consequences of lipid addition. The enzymes that mediate lipid modification are specific for both the lipid and protein substrates, and are conserved from fungi to humans. In this article we review these enzymes, their substrates, and the processes involved in eukaryotic lipid modification of proteins. We further focus on its occurrence in the fungal pathogen Cryptococcus neoformans, highlighting unique features that are both relevant for the biology of the organism and potentially important in the search for new therapies.
Collapse
|
113
|
Innate host defenses against Cryptococcus neoformans. J Microbiol 2016; 54:202-11. [PMID: 26920880 DOI: 10.1007/s12275-016-5625-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 01/11/2016] [Accepted: 01/11/2016] [Indexed: 12/21/2022]
Abstract
Cryptococcus neoformans, the predominant etiological agent of cryptococcosis, can cause life-threatening infections of the central nervous system in immunocompromised and immunocompetent individuals. Cryptococcal meningoencephalitis is the most common disseminated fungal infection in AIDS patients, and remains the third most common invasive fungal infection among organ transplant recipients. The administration of highly active antiretroviral therapy (HAART) has resulted in a decrease in the number of cases of AIDS-related cryptococcosis in developed countries, but in developing countries where HAART is not readily available, Cryptococcus is still a major concern. Therefore, there is an urgent need for the development of novel therapies and/or vaccines to combat cryptococcosis. Understanding the protective immune responses against Cryptococcus is critical for development of vaccines and immunotherapies to combat cryptococcosis. Consequently, this review focuses on our current knowledge of protective immune responses to C. neoformans, with an emphasis on innate immune responses.
Collapse
|
114
|
|
115
|
Bojarczuk A, Miller KA, Hotham R, Lewis A, Ogryzko NV, Kamuyango AA, Frost H, Gibson RH, Stillman E, May RC, Renshaw SA, Johnston SA. Cryptococcus neoformans Intracellular Proliferation and Capsule Size Determines Early Macrophage Control of Infection. Sci Rep 2016; 6:21489. [PMID: 26887656 PMCID: PMC4757829 DOI: 10.1038/srep21489] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 01/26/2016] [Indexed: 01/02/2023] Open
Abstract
Cryptococcus neoformans is a significant fungal pathogen of immunocompromised patients. Many questions remain regarding the function of macrophages in normal clearance of cryptococcal infection and the defects present in uncontrolled cryptococcosis. Two current limitations are: 1) The difficulties in interpreting studies using isolated macrophages in the context of the progression of infection, and 2) The use of high resolution imaging in understanding immune cell behavior during animal infection. Here we describe a high-content imaging method in a zebrafish model of cryptococcosis that permits the detailed analysis of macrophage interactions with C. neoformans during infection. Using this approach we demonstrate that, while macrophages are critical for control of C. neoformans, a failure of macrophage response is not the limiting defect in fatal infections. We find phagocytosis is restrained very early in infection and that increases in cryptococcal number are driven by intracellular proliferation. We show that macrophages preferentially phagocytose cryptococci with smaller polysaccharide capsules and that capsule size is greatly increased over twenty-four hours of infection, a change that is sufficient to severely limit further phagocytosis. Thus, high-content imaging of cryptococcal infection in vivo demonstrates how very early interactions between macrophages and cryptococci are critical in the outcome of cryptococcosis.
Collapse
Affiliation(s)
- Aleksandra Bojarczuk
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, UK.,Bateson Centre, University of Sheffield, Sheffield, UK
| | - Katie A Miller
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, UK.,Bateson Centre, University of Sheffield, Sheffield, UK
| | - Richard Hotham
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, UK.,Bateson Centre, University of Sheffield, Sheffield, UK
| | - Amy Lewis
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, UK.,Bateson Centre, University of Sheffield, Sheffield, UK
| | - Nikolay V Ogryzko
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, UK.,Bateson Centre, University of Sheffield, Sheffield, UK
| | - Alfred A Kamuyango
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, UK.,Bateson Centre, University of Sheffield, Sheffield, UK
| | - Helen Frost
- Institute of Microbiology and Infection and School of Biosciences, University of Birmingham, Birmingham, UK
| | - Rory H Gibson
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, UK.,Bateson Centre, University of Sheffield, Sheffield, UK
| | - Eleanor Stillman
- School of Mathematics and Statistics, University of Sheffield, Sheffield, UK
| | - Robin C May
- Institute of Microbiology and Infection and School of Biosciences, University of Birmingham, Birmingham, UK.,NIHR Surgical Reconstruction and Microbiology Research Centre, University Hospitals of Birmingham NHS Foundation Trust, Queen Elizabeth Hospital, Birmingham, UK
| | - Stephen A Renshaw
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, UK.,Bateson Centre, University of Sheffield, Sheffield, UK
| | - Simon A Johnston
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, UK.,Bateson Centre, University of Sheffield, Sheffield, UK
| |
Collapse
|
116
|
Leopold Wager CM, Hole CR, Wozniak KL, Wormley FL. Cryptococcus and Phagocytes: Complex Interactions that Influence Disease Outcome. Front Microbiol 2016; 7:105. [PMID: 26903984 PMCID: PMC4746234 DOI: 10.3389/fmicb.2016.00105] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 01/19/2016] [Indexed: 12/18/2022] Open
Abstract
Cryptococcus neoformans and C. gattii are fungal pathogens that cause life-threatening disease. These fungi commonly enter their host via inhalation into the lungs where they encounter resident phagocytes, including macrophages and dendritic cells, whose response has a pronounced impact on the outcome of disease. Cryptococcus has complex interactions with the resident and infiltrating innate immune cells that, ideally, result in destruction of the yeast. These phagocytic cells have pattern recognition receptors that allow recognition of specific cryptococcal cell wall and capsule components. However, Cryptococcus possesses several virulence factors including a polysaccharide capsule, melanin production and secretion of various enzymes that aid in evasion of the immune system or enhance its ability to thrive within the phagocyte. This review focuses on the intricate interactions between the cryptococci and innate phagocytic cells including discussion of manipulation and evasion strategies used by Cryptococcus, anti-cryptococcal responses by the phagocytes and approaches for targeting phagocytes for the development of novel immunotherapeutics.
Collapse
Affiliation(s)
- Chrissy M Leopold Wager
- Department of Biology, The University of Texas at San AntonioSan Antonio, TX, USA; The South Texas Center for Emerging Infectious Diseases, The University of Texas at San AntonioSan Antonio, TX, USA
| | - Camaron R Hole
- Department of Biology, The University of Texas at San AntonioSan Antonio, TX, USA; The South Texas Center for Emerging Infectious Diseases, The University of Texas at San AntonioSan Antonio, TX, USA
| | - Karen L Wozniak
- Department of Biology, The University of Texas at San AntonioSan Antonio, TX, USA; The South Texas Center for Emerging Infectious Diseases, The University of Texas at San AntonioSan Antonio, TX, USA
| | - Floyd L Wormley
- Department of Biology, The University of Texas at San AntonioSan Antonio, TX, USA; The South Texas Center for Emerging Infectious Diseases, The University of Texas at San AntonioSan Antonio, TX, USA
| |
Collapse
|
117
|
Xu L, Huang Q, Lin JR, Zhu CY, Li XH, Ye SK, Zhu AH, Chen DH, Zhang CF, Chen L, Ling Y. Clinical Immunophenotype at Disease Onset in Previously Healthy Patients With Cryptococcal Meningitis. Medicine (Baltimore) 2016; 95:e2744. [PMID: 26871820 PMCID: PMC4753916 DOI: 10.1097/md.0000000000002744] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Cryptococcal meningitis (CM) is a global disease with significant morbidity and mortality. Although low peripheral blood cluster of differentiation 4 (CD4) cell counts are found to be related to a high burden of cryptococcus in HIV-infected patients, little is known about possible immune defects in previously healthy patients (PHPs). We performed a retrospective study of 41 CM patients treated from January 2005 to December 2014 who did not have HIV-infection. There were 33 PHPs and 8 not previously healthy patients (non-PHPs). We analyzed clinical test data pertaining to peripheral blood T cells, antibodies, inflammation markers, and cerebral spinal fluid (CSF) completed during the disease onset phase and 5 years following diagnosis. PHPs had significantly higher counts of cluster of differentiation 3 (CD3), cluster of differentiation 4 (CD4), and cluster of differentiation 45 (CD45) cells, and lower percentages of CD8 cells than non-PHPs (P < 0.05). Measurements of inflammatory markers and immunoglobulin in blood were comparable except for lower immunoglobulin A (IgA) levels in non-PHPs (P = 0.0410). Examination of CSF revealed lower white blood cell (WBC) counts in non-PHPs. Five-year mortality in PHPs was higher than in non-PHPs (22.0% vs 12.5%) but this was not statistically significant (P > 0.05). Multivariate analysis revealed that higher immunoglobulin G (IgG) levels in serum during disease onset may be an independent predictor of mortality (P = 0.015). In conclusion, PHPs demonstrate an immunophenotype that is distinct from that of non-PHPs, leading to an improved understanding of the immunology of cryptococcal meningitis.
Collapse
Affiliation(s)
- Lie Xu
- From the Department of Infectious Disease (LX, QH, C-YZ, S-KY, A-HZ, YL), Medical Inspection Department (D-HC), Department of Hepatology, Shanghai Public Health Clinical Center (LC); Dermatological Department, Huashan Hospital, Fudan University, Shanghai (J-RL, C-FZ); and Department of Infectious Diseases (X-HL), The Third Affiliated Hospital of Sun-Yat-Sen University, Guangzhou, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
118
|
Panackal AA, Williamson KC, van de Beek D, Boulware DR, Williamson PR. Fighting the Monster: Applying the Host Damage Framework to Human Central Nervous System Infections. mBio 2016; 7:e01906-15. [PMID: 26814182 PMCID: PMC4742705 DOI: 10.1128/mbio.01906-15] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The host damage-response framework states that microbial pathogenesis is a product of microbial virulence factors and collateral damage from host immune responses. Immune-mediated host damage is particularly important within the size-restricted central nervous system (CNS), where immune responses may exacerbate cerebral edema and neurological damage, leading to coma and death. In this review, we compare human host and therapeutic responses in representative nonviral generalized CNS infections that induce archetypal host damage responses: cryptococcal menigoencephalitis and tuberculous meningitis in HIV-infected and non-HIV-infected patients, pneumococcal meningitis, and cerebral malaria. Consideration of the underlying patterns of host responses provides critical insights into host damage and may suggest tailored adjunctive therapeutics to improve disease outcome.
Collapse
Affiliation(s)
- Anil A Panackal
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Kim C Williamson
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Diederik van de Beek
- Department of Neurology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - David R Boulware
- Division of Infectious Diseases and International Medicine, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | - Peter R Williamson
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| |
Collapse
|
119
|
CNS infections in 2015: emerging catastrophic infections and new insights into neuroimmunological host damage. Lancet Neurol 2015; 15:17-9. [PMID: 26700901 DOI: 10.1016/s1474-4422(15)00359-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 11/16/2015] [Accepted: 11/23/2015] [Indexed: 02/07/2023]
|