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Key Players and Biomarkers of the Adaptive Immune System in the Pathogenesis of Sarcoidosis. Int J Mol Sci 2020; 21:ijms21197398. [PMID: 33036432 PMCID: PMC7582702 DOI: 10.3390/ijms21197398] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 10/03/2020] [Accepted: 10/05/2020] [Indexed: 12/16/2022] Open
Abstract
Sarcoidosis is a systemic inflammatory disease characterized by development of granulomas in the affected organs. Sarcoidosis is often a diagnosis of exclusion, and traditionally used tests for sarcoidosis demonstrate low sensitivity and specificity. We propose that accuracy of diagnosis can be improved if biomarkers of altered lymphocyte populations and levels of signaling molecules involved in disease pathogenesis are measured for patterns suggestive of sarcoidosis. These distinctive biomarkers can also be used to determine disease progression, predict prognosis, and make treatment decisions. Many subsets of T lymphocytes, including CD8+ T-cells and regulatory T-cells, have been shown to be dysfunctional in sarcoidosis, and the predominant CD4+ T helper cell subset in granulomas appears to be a strong indicator of disease phenotype and outcome. Studies of altered B cell populations, B cell signaling molecules, and immune complexes in sarcoidosis patients reveal promising biomarkers as well as possible explanations of disease etiology. Furthermore, examined biomarkers raise questions about new treatment methods and sarcoidosis antigens.
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Skipper C, Schleiss MR, Bangdiwala AS, Hernandez-Alvarado N, Taseera K, Nabeta HW, Musubire AK, Lofgren SM, Wiesner DL, Rhein J, Rajasingham R, Schutz C, Meintjes G, Muzoora C, Meya DB, Boulware DR. Cytomegalovirus Viremia Associated With Increased Mortality in Cryptococcal Meningitis in Sub-Saharan Africa. Clin Infect Dis 2020; 71:525-531. [PMID: 31504335 PMCID: PMC7384323 DOI: 10.1093/cid/ciz864] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 08/30/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Cryptococcal meningitis and tuberculosis are both important causes of death in persons with advanced human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). Cytomegalovirus (CMV) viremia may be associated with increased mortality in persons living with HIV who have tuberculosis. It is unknown whether concurrent CMV viremia is associated with mortality in other AIDS-related opportunistic infections. METHODS We prospectively enrolled Ugandans living with HIV who had cryptococcal meningitis from 2010-2012. Subsequently, we analyzed stored baseline plasma samples from 111 subjects for CMV DNA. We compared 10-week survival rates among those with and without CMV viremia. RESULTS Of 111 participants, 52% (58/111) had detectable CMV DNA (median plasma viral load 498 IU/mL, interquartile range [IQR] 259-2390). All samples tested were positive on immunoglobin G serology. The median CD4+ T cell count was 19 cells/µL (IQR 9-70) and did not differ by the presence of CMV viremia (P = .47). The 10-week mortality rates were 40% (23/58) in those with CMV viremia and 21% (11/53) in those without CMV viremia (hazard ratio 2.19, 95% confidence interval [CI] 1.07-4.49; P = .03), which remained significant after a multivariate adjustment for known risk factors of mortality (adjusted hazard ratio 3.25, 95% CI 1.49-7.10; P = .003). Serum and cerebrospinal fluid cytokine levels were generally similar and cryptococcal antigen-specific immune stimulation responses did not differ between groups. CONCLUSIONS Half of persons with advanced AIDS and cryptococcal meningitis had detectable CMV viremia. CMV viremia was associated with an over 2-fold higher mortality rate. It remains unclear whether CMV viremia in severely immunocompromised persons with cryptococcal meningitis contributes directly to this mortality or may reflect an underlying immune dysfunction (ie, cause vs effect). CLINICAL TRIALS REGISTRATION NCT01075152.
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Affiliation(s)
- Caleb Skipper
- University of Minnesota Medical School, Minneapolis, Minnesota, USA
- Infectious Disease Institute, Makerere University, Kampala, Uganda
| | - Mark R Schleiss
- University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | | | | | - Kabanda Taseera
- Department of Medicine, Mbarara University of Science and Technology, Uganda
| | - Henry W Nabeta
- Infectious Disease Institute, Makerere University, Kampala, Uganda
| | - Abdu K Musubire
- Infectious Disease Institute, Makerere University, Kampala, Uganda
| | - Sarah M Lofgren
- University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Darin L Wiesner
- University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Joshua Rhein
- University of Minnesota Medical School, Minneapolis, Minnesota, USA
- Infectious Disease Institute, Makerere University, Kampala, Uganda
| | | | - Charlotte Schutz
- Wellcome Centre for Infectious Diseases Research in Africa, Institute of Infectious Disease and Molecular Medicine, and Department of Medicine, University of Cape Town, South Africa
| | - Graeme Meintjes
- Wellcome Centre for Infectious Diseases Research in Africa, Institute of Infectious Disease and Molecular Medicine, and Department of Medicine, University of Cape Town, South Africa
| | - Conrad Muzoora
- Department of Medicine, Mbarara University of Science and Technology, Uganda
| | - David B Meya
- Infectious Disease Institute, Makerere University, Kampala, Uganda
| | - David R Boulware
- University of Minnesota Medical School, Minneapolis, Minnesota, USA
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53
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Cryptococcus neoformans Evades Pulmonary Immunity by Modulating Xylose Precursor Transport. Infect Immun 2020; 88:IAI.00288-20. [PMID: 32423915 DOI: 10.1128/iai.00288-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 05/15/2020] [Indexed: 11/20/2022] Open
Abstract
Cryptococcus neoformans is a fungal pathogen that kills almost 200,000 people each year and is distinguished by abundant and unique surface glycan structures that are rich in xylose. A mutant strain of C. neoformans that cannot transport xylose precursors into the secretory compartment is severely attenuated in virulence in mice yet surprisingly is not cleared. We found that this strain failed to induce the nonprotective T helper cell type 2 (Th2) responses characteristic of wild-type infection, instead promoting sustained interleukin 12p40 (IL-12p40) induction and increased IL-17A (IL-17) production. It also stimulated dendritic cells to release high levels of proinflammatory cytokines, a behavior we linked to xylose expression. We further discovered that inducible bronchus-associated lymphoid tissue (iBALT) forms in response to infection with either wild-type cryptococci or the mutant strain with reduced surface xylose; although iBALT formation is slowed in the latter case, the tissue is better organized. Finally, our temporal studies suggest that lymphoid structures in the lung restrict the spread of mutant fungi for at least 18 weeks after infection, which is in contrast to ineffective control of the pathogen after infection with wild-type cells. These studies demonstrate the role of xylose in modulation of host response to a fungal pathogen and show that cryptococcal infection triggers iBALT formation.
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Chang D, Sharma L, Dela Cruz CS. Chitotriosidase: a marker and modulator of lung disease. Eur Respir Rev 2020; 29:29/156/190143. [PMID: 32350087 PMCID: PMC9488994 DOI: 10.1183/16000617.0143-2019] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 12/02/2019] [Indexed: 12/18/2022] Open
Abstract
Chitotriosidase (CHIT1) is a highly conserved and regulated chitinase secreted by activated macrophages; it is a member of the 18-glycosylase family (GH18). CHIT1 is the most prominent chitinase in humans, can cleave chitin and participates in the body's immune response and is associated with inflammation, infection, tissue damage and remodelling processes. Recently, CHIT1 has been reported to be involved in the molecular pathogenesis of pulmonary fibrosis, bronchial asthma, COPD and pulmonary infections, shedding new light on the role of these proteins in lung pathophysiology. The potential roles of CHIT1 in lung diseases are reviewed in this article. This is the first review of chitotriosidase in lung diseasehttp://bit.ly/2LpZUQI
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Affiliation(s)
- De Chang
- The 3rd Medical Center of Chinese PLA General Hospital, Beijing, China.,Section of Pulmonary and Critical Care and Sleep Medicine, Dept of Medicine, Yale University School of Medicine, New Haven, CT, USA.,Both authors contributed equally
| | - Lokesh Sharma
- Section of Pulmonary and Critical Care and Sleep Medicine, Dept of Medicine, Yale University School of Medicine, New Haven, CT, USA.,Both authors contributed equally
| | - Charles S Dela Cruz
- Section of Pulmonary and Critical Care and Sleep Medicine, Dept of Medicine, Yale University School of Medicine, New Haven, CT, USA
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55
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Przysucha N, Górska K, Krenke R. Chitinases and Chitinase-Like Proteins in Obstructive Lung Diseases - Current Concepts and Potential Applications. Int J Chron Obstruct Pulmon Dis 2020; 15:885-899. [PMID: 32368034 PMCID: PMC7185641 DOI: 10.2147/copd.s236640] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 03/10/2020] [Indexed: 01/14/2023] Open
Abstract
Chitinases, enzymes that cleave chitin’s chain to low molecular weight chitooligomers, are widely distributed in nature. Mammalian chitinases belong to the 18-glycosyl-hydrolase family and can be divided into two groups: true chitinases with enzymatic activity (AMCase and chitotriosidase) and chitinase-like proteins (CLPs) molecules which can bind to chitin or chitooligosaccharides but lack enzymatic activity (eg, YKL-40). Chitinases are thought to be part of an innate immunity against chitin-containing parasites and fungal infections. Both groups of these hydrolases are lately evaluated also as chemical mediators or biomarkers involved in airway inflammation and fibrosis. The aim of this article is to present the current knowledge on the potential role of human chitinases and CLPs in the pathogenesis, diagnosis, and course of obstructive lung diseases. We also assessed the potential role of chitinase and CLPs inhibitors as therapeutic targets in chronic obstructive pulmonary disease and asthma.
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Affiliation(s)
- Natalia Przysucha
- Department of Internal Medicine, Pulmonary Diseases and Allergy, Medical University of Warsaw, Warsaw, Poland
| | - Katarzyna Górska
- Department of Internal Medicine, Pulmonary Diseases and Allergy, Medical University of Warsaw, Warsaw, Poland
| | - Rafal Krenke
- Department of Internal Medicine, Pulmonary Diseases and Allergy, Medical University of Warsaw, Warsaw, Poland
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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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Poh TY, Tiew PY, Lim AYH, Thng KX, Binte Mohamed Ali NA, Narayana JK, Mac Aogáin M, Tien Z, Chew WM, Wai Chan AK, Keir HR, Dicker AJ, Hassan TM, Xu H, Tee AKH, Ong TH, Koh MS, Abisheganaden JA, Chalmers JD, Chotirmall SH. Increased Chitotriosidase Is Associated With Aspergillus and Frequent Exacerbations in South-East Asian Patients With Bronchiectasis. Chest 2020; 158:512-522. [PMID: 32184111 DOI: 10.1016/j.chest.2020.02.048] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 02/17/2020] [Accepted: 02/19/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Chitinase activity is an important innate immune defence mechanism against infection that includes fungi. The 2 human chitinases: chitotriosidase (CHIT1) and acidic mammalian chitinase are associated to allergy, asthma, and COPD; however, their role in bronchiectasis and bronchiectasis-COPD overlap (BCO) is unknown. RESEARCH QUESTION What is the association between chitinase activity, airway fungi and clinical outcomes in bronchiectasis and bronchiectasis-COPD overlap? STUDY DESIGN AND METHODS A prospective cohort of 463 individuals were recruited across five hospital sites in three countries (Singapore, Malaysia, and Scotland) including individuals who were not diseased (n = 35) and who had severe asthma (n = 54), COPD (n = 90), bronchiectasis (n = 241) and BCO (n = 43). Systemic chitinase levels were assessed for bronchiectasis and BCO and related to clinical outcomes, airway Aspergillus status, and underlying pulmonary mycobiome profiles. RESULTS Systemic chitinase activity is elevated significantly in bronchiectasis and BCO and exceed the activity in other airway diseases. CHIT1 activity strongly predicts bronchiectasis exacerbations and is associated with the presence of at least one Aspergillus species in the airway and frequent exacerbations (≥3 exacerbations/y). Subgroup analysis reveals an association between CHIT1 activity and the "frequent exacerbator" phenotype in South-East Asian patients whose airway mycobiome profiles indicate the presence of novel fungal taxa that include Macroventuria, Curvularia and Sarocladium. These taxa, enriched in frequently exacerbating South-East Asian patients with high CHIT1 may have potential roles in bronchiectasis exacerbations. INTERPRETATION Systemic CHIT1 activity may represent a useful clinical tool for the identification of fungal-driven "frequent exacerbators" with bronchiectasis in South-East Asian populations.
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Affiliation(s)
- Tuang Yeow Poh
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Pei Yee Tiew
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore; Department of Respiratory and Critical Care Medicine, Singapore General Hospital, Singapore
| | - Albert Yick Hou Lim
- Department of Respiratory and Critical Care Medicine, Tan Tock Seng Hospital, Singapore
| | - Kai Xian Thng
- School of Biological Sciences, Nanyang Technological University, Singapore
| | | | | | - Micheál Mac Aogáin
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Zhijun Tien
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Wui Mei Chew
- Department of Respiratory and Critical Care Medicine, Singapore General Hospital, Singapore
| | - Adrian Kwok Wai Chan
- Department of Respiratory and Critical Care Medicine, Singapore General Hospital, Singapore
| | - Holly R Keir
- Ninewells Hospital and Medical School, University of Dundee, Scotland
| | - Alison J Dicker
- Ninewells Hospital and Medical School, University of Dundee, Scotland
| | | | - Huiying Xu
- Department of Respiratory and Critical Care Medicine, Tan Tock Seng Hospital, Singapore
| | - Augustine K H Tee
- Department of Respiratory and Critical Care Medicine, Changi General Hospital, Singapore
| | - Thun How Ong
- Department of Respiratory and Critical Care Medicine, Singapore General Hospital, Singapore
| | - Mariko Siyue Koh
- Duke-NUS Medical School, Singapore; Department of Respiratory and Critical Care Medicine, Singapore General Hospital, Singapore
| | | | - James D Chalmers
- Ninewells Hospital and Medical School, University of Dundee, Scotland
| | - Sanjay H Chotirmall
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.
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58
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Evans RJ, Johnston SA. PPAR-gamma Fun(gi) With Prostaglandin. NUCLEAR RECEPTOR SIGNALING 2020; 17:1550762919899641. [PMID: 35582457 PMCID: PMC9109145 DOI: 10.1177/1550762919899641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 12/11/2019] [Indexed: 11/16/2022]
Abstract
In our recent publication, we show for the first time that the fungal pathogen Cryptococcus neoformans is able to manipulate host cells by producing eicosanoids that mimic those found in the host. Using complementary in vivo zebrafish and in vitro macrophage cell culture models of Cryptococcus infection, we found that these eicosanoids manipulate host innate immune cells by activating the host receptor PPAR-gamma which is an important regulator of macrophage inflammatory phenotypes. We initially identified PGE2 as the eicosanoid species responsible for this effect; however, we later found that a derivative of PGE2—15-keto-PGE2—was ultimately responsible and that this eicosanoid acted as a partial agonist to PPAR-gamma. In this commentary, we will discuss some of the concepts and conclusions in our original publication and expand on their implications and future directions.
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59
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Garcia-Rubio R, de Oliveira HC, Rivera J, Trevijano-Contador N. The Fungal Cell Wall: Candida, Cryptococcus, and Aspergillus Species. Front Microbiol 2020; 10:2993. [PMID: 31993032 PMCID: PMC6962315 DOI: 10.3389/fmicb.2019.02993] [Citation(s) in RCA: 368] [Impact Index Per Article: 92.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 12/10/2019] [Indexed: 01/23/2023] Open
Abstract
The fungal cell wall is located outside the plasma membrane and is the cell compartment that mediates all the relationships of the cell with the environment. It protects the contents of the cell, gives rigidity and defines the cellular structure. The cell wall is a skeleton with high plasticity that protects the cell from different stresses, among which osmotic changes stand out. The cell wall allows interaction with the external environment since some of its proteins are adhesins and receptors. Since, some components have a high immunogenic capacity, certain wall components can drive the host's immune response to promote fungus growth and dissemination. The cell wall is a characteristic structure of fungi and is composed mainly of glucans, chitin and glycoproteins. As the components of the fungal cell wall are not present in humans, this structure is an excellent target for antifungal therapy. In this article, we review recent data on the composition and synthesis, influence of the components of the cell wall in fungi-host interaction and the role as a target for the next generation of antifungal drugs in yeasts (Candida and Cryptococcus) and filamentous fungi (Aspergillus).
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Affiliation(s)
- Rocio Garcia-Rubio
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, United States
| | | | - Johanna Rivera
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, New York, NY, United States
| | - Nuria Trevijano-Contador
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, New York, NY, United States
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60
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Hatinguais R, Willment JA, Brown GD. PAMPs of the Fungal Cell Wall and Mammalian PRRs. Curr Top Microbiol Immunol 2020; 425:187-223. [PMID: 32180018 DOI: 10.1007/82_2020_201] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Fungi are opportunistic pathogens that infect immunocompromised patients and are responsible for an estimated 1.5 million deaths every year. The antifungal innate immune response is mediated through the recognition of pathogen-associated molecular patterns (PAMPs) by the host's pattern recognition receptors (PRRs). PRRs are immune receptors that ensure the internalisation and the killing of fungal pathogens. They also mount the inflammatory response, which contributes to initiate and polarise the adaptive response, controlled by lymphocytes. Both the innate and adaptive immune responses are required to control fungal infections. The immune recognition of fungal pathogen primarily occurs at the interface between the membrane of innate immune cells and the fungal cell wall, which contains a number of PAMPs. This chapter will focus on describing the main mammalian PRRs that have been shown to bind to PAMPs from the fungal cell wall of the four main fungal pathogens: Candida albicans, Aspergillus fumigatus, Cryptococcus neoformans and Pneumocystis jirovecii. We will describe these receptors, their functions and ligands to provide the reader with an overview of how the immune system recognises fungal pathogens and responds to them.
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Affiliation(s)
- Remi Hatinguais
- MRC Centre for Medical Mycology at University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, UK
| | - Janet A Willment
- MRC Centre for Medical Mycology at University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, UK
| | - Gordon D Brown
- MRC Centre for Medical Mycology at University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, UK.
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61
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Zafar H, Altamirano S, Ballou ER, Nielsen K. A titanic drug resistance threat in Cryptococcus neoformans. Curr Opin Microbiol 2019; 52:158-164. [PMID: 31765991 DOI: 10.1016/j.mib.2019.11.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 10/01/2019] [Accepted: 11/01/2019] [Indexed: 10/25/2022]
Abstract
Increasing resistance to frontline antifungals is a growing threat to global health. In the face of high rates of relapse for patients with cryptococcal meningitis and frequent drug resistance in clinical isolates, recent insights into Cryptococcus neoformans morphogenesis and genome plasticity take on new and urgent meaning. Here we review the state of the understanding of mechanisms of drug resistance in the context of host-relevant changes in Cryptococcus morphology and cell ploidy.
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Affiliation(s)
- Hanna Zafar
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Sophie Altamirano
- Department of Microbiology and Immunology, University of Minnesota, Minneapolis, MN, 55455 USA
| | - Elizabeth R Ballou
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
| | - Kirsten Nielsen
- Department of Microbiology and Immunology, University of Minnesota, Minneapolis, MN, 55455 USA.
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Hadebe S, Brombacher F. Environment and Host-Genetic Determinants in Early Development of Allergic Asthma: Contribution of Fungi. Front Immunol 2019; 10:2696. [PMID: 31824491 PMCID: PMC6879655 DOI: 10.3389/fimmu.2019.02696] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 11/01/2019] [Indexed: 12/16/2022] Open
Abstract
Asthma is a chronic debilitating airway disease affecting millions of people worldwide. Although largely thought to be a disease of the first world, it is now clear that it is on the rise in many middle- and lower-income countries. The disease is complex, and its etiology is poorly understood, which explains failure of most treatment strategies. We know that in children, asthma is closely linked to poor lung function in the first 3-years of life, when the lung is still undergoing post-natal alveolarization phase. Epidemiological studies also suggest that environmental factors around that age do play a critical part in the establishment of early wheezing which persists until adulthood. Some of the factors that contribute to early development of asthma in children in Western world are clear, however, in low- to middle-income countries this is likely to differ significantly. The contribution of fungal species in the development of allergic diseases is known in adults and in experimental models. However, it is unclear whether early exposure during perinatal or post-natal lung development influences a protective or promotes allergic asthma. Host immune cells and responses will play a crucial part in early development of allergic asthma. How immune cells and their receptors may recognize fungi and promote allergic asthma or protect by tolerance among other immune mechanisms is not fully understood in this early lung development stage. The aim of this review is to discuss what fungal species are present during early exposure as well as their contribution to the development of allergic responses. We also discuss how the host has evolved to promote tolerance to limit hyper-responsiveness to innocuous fungi, and how host evasion by fungi during early development consequentially results in allergic diseases.
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Affiliation(s)
- Sabelo Hadebe
- Division of Immunology and South African Medical Research Council (SAMRC) Immunology of Infectious Diseases, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Frank Brombacher
- Division of Immunology and South African Medical Research Council (SAMRC) Immunology of Infectious Diseases, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Cape Town, South Africa
- Division of Immunology, Faculty of Health Sciences, Institute of Infectious Diseases and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
- Faculty of Health Sciences, Wellcome Centre for Infectious Diseases Research in Africa (CIDRI-Africa), Institute of Infectious Diseases and Molecular Medicine (IDM), University of Cape Town, Cape Town, South Africa
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Fa Z, Xu J, Yi J, Sang J, Pan W, Xie Q, Yang R, Fang W, Liao W, Olszewski MA. TNF-α-Producing Cryptococcus neoformans Exerts Protective Effects on Host Defenses in Murine Pulmonary Cryptococcosis. Front Immunol 2019; 10:1725. [PMID: 31404168 PMCID: PMC6677034 DOI: 10.3389/fimmu.2019.01725] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 07/09/2019] [Indexed: 12/13/2022] Open
Abstract
Tumor necrosis factor alpha (TNF-α) plays a critical role in the control of cryptococcal infection, and its insufficiency promotes cryptococcal persistence. To explore the therapeutic potential of TNF-α supplementation as a booster of host anti-cryptococcal responses, we engineered a C. neoformans strain expressing murine TNF-α. Using a murine model of pulmonary cryptococcosis, we demonstrated that TNF-α-producing C. neoformans strain enhances protective elements of host response including preferential T-cell accumulation and improved Th1/Th2 cytokine balance, diminished pulmonary eosinophilia and alternative activation of lung macrophages at the adaptive phase of infection compared to wild type strain-infected mice. Furthermore, TNF-α expression by C. neoformans enhanced the fungicidal activity of macrophages in vitro. Finally, mice infected with the TNF-α-producing C. neoformans strain showed improved fungal control and considerably prolonged survival compared to wild type strain-infected mice, but could not induce sterilizing immunity. Taken together, our results support that TNF-α expression by an engineered C. neoformans strain while insufficient to drive complete immune protection, strongly enhanced protective responses during primary cryptococcal infection.
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Affiliation(s)
- Zhenzong Fa
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI, United States.,Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Naval Medical University, Shanghai, China.,Department of Dermatology, The Sixth Medical Center of PLA General Hospital, Beijing, China
| | - Jintao Xu
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI, United States.,Ann Arbor VA Health System, Department of Veterans Affairs Health System, Ann Arbor, MI, United States
| | - Jiu Yi
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Junjun Sang
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Weihua Pan
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Qun Xie
- Department of Anesthesiology, The Fourth Medical Center of PLA General Hospital, Beijing, China
| | - Runping Yang
- Department of Dermatology, The Sixth Medical Center of PLA General Hospital, Beijing, China
| | - Wei Fang
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Wanqing Liao
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Michal A Olszewski
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI, United States.,Ann Arbor VA Health System, Department of Veterans Affairs Health System, Ann Arbor, MI, United States
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Skipper C, Abassi M, Boulware DR. Diagnosis and Management of Central Nervous System Cryptococcal Infections in HIV-Infected Adults. J Fungi (Basel) 2019; 5:jof5030065. [PMID: 31330959 PMCID: PMC6787675 DOI: 10.3390/jof5030065] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 07/15/2019] [Accepted: 07/17/2019] [Indexed: 11/24/2022] Open
Abstract
Cryptococcal meningitis persists as a significant source of morbidity and mortality in persons with HIV/AIDS, particularly in sub-Saharan Africa. Despite increasing access to antiretrovirals, persons presenting with advanced HIV disease remains common, and Cryptococcus remains the most frequent etiology of adult meningitis. We performed a literature review and herein present the most up-to-date information on the diagnosis and management of cryptococcosis. Recent advances have dramatically improved the accessibility of timely and affordable diagnostics. The optimal initial antifungal management has been newly updated after the completion of a landmark clinical trial. Beyond antifungals, the control of intracranial pressure and mitigation of toxicities remain hallmarks of effective treatment. Cryptococcal meningitis continues to present challenging complications and continued research is needed.
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Affiliation(s)
- Caleb Skipper
- Department of Medicine, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Mahsa Abassi
- Department of Medicine, University of Minnesota, Minneapolis, MN 55455, USA
| | - David R Boulware
- Department of Medicine, University of Minnesota, Minneapolis, MN 55455, USA
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Hernández-Castellano LE, Moreno-Indias I, Sánchez-Macías D, Morales-delaNuez A, Torres A, Argüello A, Castro N. Sheep and goats raised in mixed flocks have diverse immune status around parturition. J Dairy Sci 2019; 102:8478-8485. [PMID: 31255264 DOI: 10.3168/jds.2019-16731] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 05/06/2019] [Indexed: 01/07/2023]
Abstract
Several physiological and metabolic changes take place in dairy ruminants around parturition (late pregnancy, parturition, and early lactation). Dairy species are genetically selected for their higher milk production compared with non-dairy species. This fact causes a constant stress that impairs the immune status of the animal, with consequences for its welfare and performance. In the present study, we assessed the immune status of high-yield dairy sheep and goats by quantifying IgG and IgM concentrations, as well as chitotriosidase (ChT) and complement system [total complement system (TC) and alternative complement pathway (AC)] activity in blood plasma around parturition. We also measured IgG and IgM concentrations and ChT activity in colostrum and milk during the first 40 d postpartum. The lowest blood IgG concentration was at parturition in both species. We detected no differences in blood IgG concentrations between species. Blood IgM concentrations were constant in both species throughout the study period. However, blood IgM concentrations were greater in sheep than in goats. Blood ChT activity was greater in goats than in sheep, and both species showed constant activity of this enzyme throughout the study period. We observed no differences in complement system (TC and AC) activity between sheep and goats. In addition, both TC and AC activity were constant in both species throughout the experiment. In general, IgG and IgM concentrations were greater in sheep colostrum than in goat colostrum, but these differences disappeared after d 4 (IgG) and d 3 (IgM) postpartum. In both species, the highest IgG and IgM concentrations were measured in colostrum, gradually decreasing during the first days postpartum. Chitotriosidase activity decreased in both species from colostrum to milk, although goats always showed greater ChT activity than sheep. Both sheep and goats seemed to be more susceptible to infectious diseases around parturition. As well, goats showed greater ChT activity in blood, colostrum, and milk than sheep. This fact may give these animals additional protection against parasite and fungal infections.
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Affiliation(s)
| | - Isabel Moreno-Indias
- Unidad de Gestión Clínica de Endocrinología y Nutrición, Laboratorio del Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Universitario de Málaga (Virgen de la Victoria), Universidad de Málaga, 29010 Málaga, Spain; Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBERObn), 28029 Madrid, Spain
| | - Davinia Sánchez-Macías
- Animal Production and Industrialization Unit, Department of Agroindustrial Engineering, Universidad Nacional de Chimborazo, 060150 Riobamba, Ecuador
| | - Antonio Morales-delaNuez
- Agrobiotechnology Group, Instituto de Productos Naturales y Agrobiología, IPNA, CSIC Spanish Research Council, 38206 La Laguna, Tenerife, Spain
| | - Alexandr Torres
- Instituto Canario de Investigaciones Agrarias, 38200 La Laguna, Tenerife, Spain
| | - Anastasio Argüello
- Animal Production and Biotechnology Group, Institute of Animal Health and Food Safety, Universidad de Las Palmas de Gran Canaria, 35413 Arucas, Gran Canaria, Spain
| | - Noemí Castro
- Animal Production and Biotechnology Group, Institute of Animal Health and Food Safety, Universidad de Las Palmas de Gran Canaria, 35413 Arucas, Gran Canaria, Spain
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Pulmonary Iron Limitation Induced by Exogenous Type I IFN Protects Mice from Cryptococcus gattii Independently of T Cells. mBio 2019; 10:mBio.00799-19. [PMID: 31213551 PMCID: PMC6581853 DOI: 10.1128/mbio.00799-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cryptococcus neoformans and Cryptococcus gattii cause fatal infection in immunodeficient and immunocompetent individuals. While these fungi are sibling species, C. gattii infects very few AIDS patients, while C. neoformans infection is an AIDS-defining illness, suggesting that the host response to HIV selects C. neoformans over C. gattii. We used a viral mimic molecule (pICLC) to stimulate the immune response, and pICLC treatment improved mouse outcomes from both species. pICLC-induced action against C. neoformans was due to activation of well-defined immune pathways known to deter C. neoformans, whereas these immune pathways were dispensable for pICLC treatment of C. gattii. Since these immune pathways are eventually destroyed by HIV/AIDS, our data help explain why the antiviral immune response in AIDS patients is unable to control C. neoformans infection but is protective against C. gattii. Furthermore, pICLC induced tighter control of iron in the lungs of mice, which inhibited C. gattii, thus suggesting an entirely new mode of nutritional immunity activated by viral signals. Cryptococcus neoformans causes deadly mycosis primarily in AIDS patients, whereas Cryptococcus gattii infects mostly non-HIV patients, even in regions with high burdens of HIV/AIDS and an established environmental presence of C. gattii. As HIV induces type I IFN (t1IFN), we hypothesized that t1IFN would differentially affect the outcome of C. neoformans and C. gattii infections. Exogenous t1IFN induction using stabilized poly(I·C) (pICLC) improved murine outcomes in either cryptococcal infection. In C. neoformans-infected mice, pICLC activity was associated with C. neoformans containment and classical Th1 immunity. In contrast, pICLC activity against C. gattii did not require any immune factors previously associated with C. neoformans immunity: T, B, and NK cells, IFN-γ, and macrophages were all dispensable. Interestingly, C. gattii pICLC activity depended on β-2-microglobulin, which impacts iron levels among other functions. Iron supplementation reversed pICLC activity, suggesting C. gattii pICLC activity requires iron limitation. Also, pICLC induced a set of iron control proteins, some of which were directly inhibitory to cryptococcus in vitro, suggesting t1IFN regulates iron availability in the pulmonary air space fluids. Thus, exogenous induction of t1IFN significantly improves the outcome of murine infection by C. gattii and C. neoformans but by distinct mechanisms; the C. gattii effect was mediated by iron limitation, while the effect on C. neoformans infection was through induction of classical T-cell-dependent immunity. Together this difference in types of T-cell-dependent t1IFN immunity for different Cryptococcus species suggests a possible mechanism by which HIV infection may select against C. gattii but not C. neoformans.
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Kang SA, Park MK, Park SK, Choi JH, Lee DI, Song SM, Yu HS. Adoptive transfer of Trichinella spiralis-activated macrophages can ameliorate both Th1- and Th2-activated inflammation in murine models. Sci Rep 2019; 9:6547. [PMID: 31024043 PMCID: PMC6484028 DOI: 10.1038/s41598-019-43057-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 04/15/2019] [Indexed: 02/06/2023] Open
Abstract
Trichinella spiralis is a zoonotic nematode and food borne parasite and infection with T. spiralis leads to suppression of the host immune response and other immunopathologies. Alternative activated macrophages (M2) as well as Treg cells, a target for immunomodulation by the helminth parasite, play a critical role in initiating and modulating the host immune response to parasite. The precise mechanism by which helminths modulate host immune response is not fully understood. To determine the functions of parasite-induced M2 macrophages, we compared the effects of M1 and M2 macrophages obtained from Trichinella spiralis-infected mice with those of T. spiralis excretory/secretory (ES) protein-treated macrophages on experimental intestinal inflammation and allergic airway inflammation. T. spiralis infection induced M2 macrophage polarization by increasing the expression of CD206, ARG1, and Fizz2. In a single application, we introduced macrophages obtained from T. spiralis-infected mice and T. spiralis ES protein-treated macrophages into mice tail veins before the induction of dextran sulfate sodium (DSS)-induced colitis, ovalbumin (OVA)-alum sensitization, and OVA challenge. Colitis severity was assessed by determining the severity of colitis symptoms, colon length, histopathologic parameters, and Th1-related inflammatory cytokine levels. Compared with the DSS-colitis group, T. spiralis-infected mice and T. spiralis ES protein-treated macrophages showed significantly lower disease activity index (DAI) at sacrifice and smaller reductions of body weight and proinflammatory cytokine level. The severity of allergic airway inflammation was assessed by determining the severity of symptoms of inflammation, airway hyperresponsiveness (AHR), differential cell counts, histopathologic parameters, and levels of Th2-related inflammatory cytokines. Severe allergic airway inflammation was induced after OVA-alum sensitization and OVA challenge, which significantly increased Th2-related cytokine levels, eosinophil infiltration, and goblet cell hyperplasia in the lung. However, these severe allergic symptoms were significantly decreased in T. spiralis-infected mice and T. spiralis ES protein-treated macrophages. Helminth infection and helminth ES proteins induce M2 macrophages. Adoptive transfer of macrophages obtained from helminth-infected mice and helminth ES protein-activated macrophages is an effective treatment for preventing and treating airway allergy in mice and is promising as a therapeutic for treating inflammatory diseases.
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Affiliation(s)
- Shin Ae Kang
- Department of Parasitology and Tropical Medicine, School of Medicine, Pusan National University, Yangsan, Gyeongsangnam-do, Republic of Korea
| | - Mi-Kyung Park
- Department of Parasitology and Tropical Medicine, School of Medicine, Pusan National University, Yangsan, Gyeongsangnam-do, Republic of Korea
| | - Sang Kyun Park
- Department of Parasitology and Tropical Medicine, School of Medicine, Pusan National University, Yangsan, Gyeongsangnam-do, Republic of Korea
| | - Jun Ho Choi
- Department of Parasitology and Tropical Medicine, School of Medicine, Pusan National University, Yangsan, Gyeongsangnam-do, Republic of Korea
| | - Da In Lee
- Department of Parasitology and Tropical Medicine, School of Medicine, Pusan National University, Yangsan, Gyeongsangnam-do, Republic of Korea
| | - So Myong Song
- Department of Parasitology and Tropical Medicine, School of Medicine, Pusan National University, Yangsan, Gyeongsangnam-do, Republic of Korea
| | - Hak Sun Yu
- Department of Parasitology and Tropical Medicine, School of Medicine, Pusan National University, Yangsan, Gyeongsangnam-do, Republic of Korea.
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68
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Probert M, Zhou X, Goodall M, Johnston SA, Bielska E, Ballou ER, May RC. A Glucuronoxylomannan Epitope Exhibits Serotype-Specific Accessibility and Redistributes towards the Capsule Surface during Titanization of the Fungal Pathogen Cryptococcus neoformans. Infect Immun 2019; 87:IAI.00731-18. [PMID: 30670549 PMCID: PMC6434129 DOI: 10.1128/iai.00731-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 12/23/2018] [Indexed: 11/20/2022] Open
Abstract
Disseminated infections with the fungal species Cryptococcus neoformans or, less frequently, Cryptococcus gattii are an important cause of mortality in immunocompromised individuals. Central to the virulence of both species is an elaborate polysaccharide capsule that consists predominantly of glucuronoxylomannan (GXM). Due to its abundance, GXM is an ideal target for host antibodies, and several monoclonal antibodies (mAbs) have previously been derived using purified GXM or whole capsular preparations as antigens. In addition to their application in the diagnosis of cryptococcosis, anti-GXM mAbs are invaluable tools for studying capsule structure. In this study, we report the production and characterization of a novel anti-GXM mAb, Crp127, that unexpectedly reveals a role for GXM remodeling during the process of fungal titanization. We show that Crp127 recognizes a GXM epitope in an O-acetylation-dependent, but xylosylation-independent, manner. The epitope is differentially expressed by the four main serotypes of Cryptococcus neoformans and C. gattii, is heterogeneously expressed within clonal populations of C. gattii serotype B strains, and is typically confined to the central region of the enlarged capsule. Uniquely, however, this epitope redistributes to the capsular surface in titan cells, a recently characterized morphotype where haploid 5-μm cells convert to highly polyploid cells of >10 μm with distinct but poorly understood capsular characteristics. Titan cells are produced in the host lung and critical for successful infection. Crp127 therefore advances our understanding of cryptococcal morphological change and may hold significant potential as a tool to differentially identify cryptococcal strains and subtypes.
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Affiliation(s)
- Mark Probert
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Xin Zhou
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Margaret Goodall
- Institute of Immunology and Immunotherapy, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Simon A Johnston
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
- Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Ewa Bielska
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Elizabeth R Ballou
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Robin C May
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
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69
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Heung LJ, Hohl TM. Inflammatory monocytes are detrimental to the host immune response during acute infection with Cryptococcus neoformans. PLoS Pathog 2019; 15:e1007627. [PMID: 30897162 PMCID: PMC6428256 DOI: 10.1371/journal.ppat.1007627] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 02/07/2019] [Indexed: 12/30/2022] Open
Abstract
Cryptococcus neoformans is a leading cause of invasive fungal infections among immunocompromised patients. However, the cellular constituents of the innate immune response that promote clearance versus progression of infection upon respiratory acquisition of C. neoformans remain poorly defined. In this study, we found that during acute C. neoformans infection, CCR2+ Ly6Chi inflammatory monocytes (IM) rapidly infiltrate the lungs and mediate fungal trafficking to lung-draining lymph nodes. Interestingly, this influx of IM is detrimental to the host, since ablating IM or impairing their recruitment to the lungs improves murine survival and reduces fungal proliferation and dissemination. Using a novel conditional gene deletion strategy, we determined that MHC class II expression by IM did not mediate their deleterious impact on the host. Furthermore, although ablation of IM reduced the number of lymphocytes, innate lymphoid cells, and eosinophils in the lungs, the effects of IM were not dependent on these cells. We ascertained that IM in the lungs upregulated transcripts associated with alternatively activated (M2) macrophages in response to C. neoformans, consistent with the model that IM assume a cellular phenotype that is permissive for fungal growth. We also determined that conditional knockout of the prototypical M2 marker arginase 1 in IM and deletion of the M2-associated transcription factor STAT6 were not sufficient to reverse the harmful effects of IM. Overall, our findings indicate that C. neoformans can subvert the fungicidal potential of IM to enable the progression of infection through a mechanism that is not dependent on lymphocyte priming, eosinophil recruitment, or downstream M2 macrophage polarization pathways. These results give us new insight into the plasticity of IM function during fungal infections and the level of control that C. neoformans can exert on host immune responses. Cryptococcus neoformans is a fungus that is prevalent throughout the environment and can cause a fatal infection of the central nervous system when inhaled into the lungs by patients with impaired immune systems. Our understanding of the immune responses that either help clear C. neoformans from the lungs or permit development of disease remains limited. In this study, we used a mouse model of lethal C. neoformans infection to determine that inflammatory monocytes, immune cells that are often among the first responders to infections, actually facilitate the progression of infection rather than clearance. These findings establish a foundation for future work to target the immune response of inflammatory monocytes as a strategy to improve the outcomes of patients that develop C. neoformans infections.
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Affiliation(s)
- Lena J. Heung
- Infectious Diseases Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
- * E-mail: (LJH); (TMH)
| | - Tobias M. Hohl
- Infectious Diseases Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
- * E-mail: (LJH); (TMH)
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70
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Synthesis, homology modeling, molecular docking, dynamics, and antifungal screening of new 4-hydroxycoumarin derivatives as potential chitinase inhibitors. J Mol Struct 2019. [DOI: 10.1016/j.molstruc.2018.11.099] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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71
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Characterization of the 6-O-acetylated lipoglucuronomannogalactan a novel Cryptococcus neoformans cell wall polysaccharide. Carbohydr Res 2019; 475:1-10. [PMID: 30742969 DOI: 10.1016/j.carres.2019.01.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 01/25/2019] [Accepted: 01/28/2019] [Indexed: 12/15/2022]
Abstract
Glucuronoxylomannogalactans (GXMGals) are characteristic capsular polysaccharides produced by the opportunistic fungus C. neoformans, which are implicated in cryptococcal virulence, via impairment of the host immune response. We determined for the first time the structure of a lipoglucuronomannogalactan (LGMGal), isolated from the surface of a mutant C. neoformans carrying a deletion in the UDP-GlcA decarboxylase gene. Monosaccharide composition and methylation analyses, as well as nuclear magnetic resonance spectroscopy were employed in discerning the structure. Our results show that the polysaccharide structure of the LGMGal differs from GXMGal by the absence of xylose and 2-O-acetylated mannose residues. LGMGal consists of a galactan main chain -[-6-α-Gal-]-, where every second Gal residue is substituted at O-3 with an oligosaccharide α-Man6OAc-3-α-Man-4-(β-GlcA-3)-β-Gal-; components in italic being non-stoichiometric. The substitution rate of β-Galp units by GlcpA is 35%. Additionally, we determined that the glycolipid anchor of the LGMGal is based on an myo-inositol phosphoceramide composed of C18-phytosphingosine and monohydroxylated lignoceric acid (2OHC24:0 fatty acid).
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72
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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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73
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Jiang X, Bao H, Merzendorfer H, Yang Q. Immune Responses of Mammals and Plants to Chitin-Containing Pathogens. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1142:61-81. [PMID: 31102242 DOI: 10.1007/978-981-13-7318-3_4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Chitin-containing organisms, such as fungi and arthropods, use chitin as a structural component to protect themselves from harsh environmental conditions. Hosts such as mammals and plants, however, sense chitin to initiate innate and adaptive immunity and exclude chitin-containing organisms. A number of protein factors are then expressed, and several signaling pathways are triggered. In this chapter, we focus on the responses and signal transduction pathways that are activated in mammals and plants upon invasion by chitin-containing organisms. As host chitinases play important roles in the glycolytic processing of chitin, which is then recognized by pattern-recognition receptors, we also pay special attention to the chitinases that are involved in immune recognition.
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Affiliation(s)
- Xi Jiang
- School of Bioengineering, Dalian University of Technology, No. 2 Linggong Road, Dalian, 116023, China
| | - Han Bao
- School of Bioengineering, Dalian University of Technology, No. 2 Linggong Road, Dalian, 116023, China
| | - Hans Merzendorfer
- Department of Chemistry and Biology - Molecular Biology, University of Siegen, 57076, Siegen, Germany
| | - Qing Yang
- School of Bioengineering, Dalian University of Technology, No. 2 Linggong Road, Dalian, 116023, China. .,State Laboratory of Biology for Plant Diseases and Insect Pests, Institute of Plant Protection at Chinese Academy of Agricultural Sciences, No. 2 Yuanmingyuan West Road, Beijing, 100193, China.
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74
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Balasko A, Keynan Y. Shedding light on IRIS: from Pathophysiology to Treatment of Cryptococcal Meningitis and Immune Reconstitution Inflammatory Syndrome in HIV-Infected Individuals. HIV Med 2018; 20:1-10. [PMID: 30362282 DOI: 10.1111/hiv.12676] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2018] [Indexed: 12/31/2022]
Abstract
OBJECTIVES The aim of this work was to review current treatment options and propose alternatives for immune reconstitution inflammatory syndrome (IRIS) in HIV-infected individuals with cryptococcal meningitis (CM) (termed 'HIV-CM IRIS'). As a consequence of the immunocompromised state of these individuals, the initial immune response to CM is predominantly type 2 T helper (Th2) /Th17 rather than Th1, leading to inefficient fungal clearance at the time of antiretroviral initiation, and a subsequent overexaggeration of the Th1 response and life-threatening IRIS development. METHODS An article-based and clinical trial-based search was conducted to investigate HIV-CM IRIS pathophysiology and current treatment practices. RESULTS Guidelines for CM treatment, based on the Cryptococcal Optimal Antiretroviral Timing (COAT) trial, recommend delayed antiretroviral therapy (ART) following antifungal treatment. The approach aims to decrease fungal burden and allow immune balance restoration prior to ART initiation. If the initial immune balance is not restored, the fungal burden is not sufficiently reduced and there is a risk of developing IRIS post-ART, highlighted by a Th1 immune overcompensation, leading to increased mortality. The mainstay treatment for Th1-biased IRIS is corticosteroids; however, this treatment has been shown to correlate with increased mortality and significant associated adverse events. We emphasize targeting a more specific Th1 mechanism via the tumour necrosis factor (TNF)-α cytokine antagonist thalidomide, as it is the only TNF-α antagonist currently approved for use in infectious disease settings and has been shown to decrease Th1 overreaction, restoring immune balance in HIV-CM IRIS. CONCLUSIONS Although the side effects and limitations of thalidomide must be considered, it is currently being successfully used in infectious disease settings and warrants mainstream application as a therapeutic option for treatment of IRIS in HIV-infected patients with CM.
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Affiliation(s)
- A Balasko
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
| | - Y Keynan
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada.,Department of Internal Medicine, University of Manitoba, Winnipeg, MB, Canada.,Department of Community Health Sciences, University of Manitoba, Winnipeg, MB, Canada
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75
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Zhou X, Ballou ER. The Cryptococcus neoformans Titan Cell: From In Vivo Phenomenon to In Vitro Model. CURRENT CLINICAL MICROBIOLOGY REPORTS 2018. [DOI: 10.1007/s40588-018-0107-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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76
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Elieh Ali Komi D, Sharma L, Dela Cruz CS. Chitin and Its Effects on Inflammatory and Immune Responses. Clin Rev Allergy Immunol 2018; 54:213-223. [PMID: 28251581 DOI: 10.1007/s12016-017-8600-0] [Citation(s) in RCA: 149] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Chitin, a potential allergy-promoting pathogen-associated molecular pattern (PAMP), is a linear polymer composed of N-acetylglucosamine residues which are linked by β-(1,4)-glycosidic bonds. Mammalians are potential hosts for chitin-containing protozoa, fungi, arthropods, and nematodes; however, mammalians themselves do not synthetize chitin and thus it is considered as a potential target for recognition by mammalian immune system. Chitin is sensed primarily in the lungs or gut where it activates a variety of innate (eosinophils, macrophages) and adaptive immune cells (IL-4/IL-13 expressing T helper type-2 lymphocytes). Chitin induces cytokine production, leukocyte recruitment, and alternative macrophage activation. Intranasal or intraperitoneal administration of chitin (varying in size, degree of acetylation and purity) to mice has been applied as a routine approach to investigate chitin's priming effects on innate and adaptive immunity. Structural chitin present in microorganisms is actively degraded by host true chitinases, including acidic mammalian chitinases and chitotriosidase into smaller fragments that can be sensed by mammalian receptors such as FIBCD1, NKR-P1, and RegIIIc. Immune recognition of chitin also involves pattern recognition receptors, mainly via TLR-2 and Dectin-1, to activate immune cells to induce cytokine production and creation of an immune network that results in inflammatory and allergic responses. In this review, we will focus on various immunological aspects of the interaction between chitin and host immune system such as sensing, interactions with immune cells, chitinases as chitin degrading enzymes, and immunologic applications of chitin.
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Affiliation(s)
- Daniel Elieh Ali Komi
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, East Azerbayjan, Iran.,Department of Immunology, Tabriz University of Medical Sciences, Tabriz, East Azerbayjan, Iran
| | - Lokesh Sharma
- Section of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | - Charles S Dela Cruz
- Section of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA. .,Department of Microbial Pathogenesis, Yale School of Medicine, Cedar Street, New Haven, CT, TACS441D, USA.
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77
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Duan Y, Liu T, Zhou Y, Dou T, Yang Q. Glycoside hydrolase family 18 and 20 enzymes are novel targets of the traditional medicine berberine. J Biol Chem 2018; 293:15429-15438. [PMID: 30135205 DOI: 10.1074/jbc.ra118.004351] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 08/03/2018] [Indexed: 02/01/2023] Open
Abstract
Berberine is a traditional medicine that has multiple medicinal and agricultural applications. However, little is known about whether berberine can be a bioactive molecule toward carbohydrate-active enzymes, which play numerous vital roles in the life process. In this study, berberine and its analogs were discovered to be competitive inhibitors of glycoside hydrolase family 20 β-N-acetyl-d-hexosaminidase (GH20 Hex) and GH18 chitinase from both humans and the insect pest Ostrinia furnacalis Berberine and its analog SYSU-1 inhibit insect GH20 Hex from O. furnacalis (OfHex1), with Ki values of 12 and 8.5 μm, respectively. Co-crystallization of berberine and its analog SYSU-1 in complex with OfHex1 revealed that the positively charged conjugate plane of berberine forms π-π stacking interactions with Trp490, which are vital to its inhibitory activity. Moreover, the 1,3-dioxole group of berberine binds an unexplored pocket formed by Trp322, Trp483, and Val484, which also contributes to its inhibitory activity. Berberine was also found to be an inhibitor of human GH20 Hex (HsHexB), human GH18 chitinase (HsCht and acidic mammalian chitinase), and insect GH18 chitinase (OfChtI). Besides GH18 and GH20 enzymes, berberine was shown to weakly inhibit human GH84 O-GlcNAcase (HsOGA) and Saccharomyces cerevisiae GH63 α-glucosidase I (ScGluI). By analyzing the published crystal structures, berberine was revealed to bind with its targets in an identical mechanism, namely via π-π stacking and electrostatic interactions with the aromatic and acidic residues in the binding pockets. This paper reports new molecular targets of berberine and may provide a berberine-based scaffold for developing multitarget drugs.
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Affiliation(s)
- Yanwei Duan
- From the State Key Laboratory of Fine Chemical Engineering, School of Life Science and Biotechnology and School of Software, Dalian University of Technology, Dalian 116024
| | - Tian Liu
- From the State Key Laboratory of Fine Chemical Engineering, School of Life Science and Biotechnology and School of Software, Dalian University of Technology, Dalian 116024,
| | - Yong Zhou
- From the State Key Laboratory of Fine Chemical Engineering, School of Life Science and Biotechnology and School of Software, Dalian University of Technology, Dalian 116024
| | - Tongyi Dou
- the School of Life Science and Medicine, Dalian University of Technology, Panjin 124221, and
| | - Qing Yang
- From the State Key Laboratory of Fine Chemical Engineering, School of Life Science and Biotechnology and School of Software, Dalian University of Technology, Dalian 116024, .,the Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
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78
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Hong JY, Kim M, Sol IS, Kim KW, Lee CM, Elias JA, Sohn MH, Lee CG. Chitotriosidase inhibits allergic asthmatic airways via regulation of TGF-β expression and Foxp3 + Treg cells. Allergy 2018; 73:1686-1699. [PMID: 29420850 PMCID: PMC6047905 DOI: 10.1111/all.13426] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2018] [Indexed: 01/28/2023]
Abstract
BACKGROUND Chitotriosidase (chitinase 1, Chit1), a major true chitinase in humans, is induced in childhood asthma and has been implicated in the pathogenesis of a variety of inflammatory and tissue remodeling responses. However, the role and the mechanisms that underlie these contributions to the diseases have not been defined. We hypothesized that Chit1 plays a significant role in the pathogenesis of allergic asthma. METHODS Wild-type and Chit1-deficient mice and cells in culture were used to define the roles of Chit1 in models of allergic adaptive Th2 inflammation. In addition, the levels of sputum Chit1 were evaluated in pediatric asthma patients and compared to control. RESULTS The levels of sputum Chit1 were significantly increased in the patients with childhood asthma. Mice with Chit1 null mutation demonstrated enhanced allergic Th2 inflammatory and cytokine and IgE responses to OVA or house dust mite allergen sensitization and challenge. However, the expression levels of TGF-β1 were significantly decreased with a diminished number of Foxp3+ regulatory T cells (Treg) in the lungs of Chit1-/- mice compared to WT controls. In vitro, the absence of Chit1 significantly reduced TGF-β-stimulated conversion of CD4+ CD25- naïve T cells to CD4+ Foxp3+ Treg cells, suggesting Chit1 is required for optimal effect of TGF-β1 in Treg cell differentiation. CONCLUSION Chit1 plays a protective role in the pathogenesis of allergic inflammation and asthmatic airway responses via regulation of TGF-β expression and Foxp3+ Treg cells.
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Affiliation(s)
- Jung Yeon Hong
- Department of Pediatrics and Institute of Allergy, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - Mina Kim
- Department of Pediatrics and Institute of Allergy, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - In Suk Sol
- Department of Pediatrics and Institute of Allergy, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - Kyung Won Kim
- Department of Pediatrics and Institute of Allergy, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - Chang-Min Lee
- Molecular Microbiology and Immunology, Brown University, RI., USA
| | - Jack A. Elias
- Molecular Microbiology and Immunology, Brown University, RI., USA
| | - Myung Hyun Sohn
- Department of Pediatrics and Institute of Allergy, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - Chun Geun Lee
- Molecular Microbiology and Immunology, Brown University, RI., USA
- Department of Internal Medicine, Hanyang University, Seoul, Korea
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79
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Niu S, Yang L, Zuo H, Zheng J, Weng S, He J, Xu X. A chitinase from pacific white shrimp Litopenaeus vannamei involved in immune regulation. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 85:161-169. [PMID: 29678533 DOI: 10.1016/j.dci.2018.04.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 04/15/2018] [Accepted: 04/15/2018] [Indexed: 06/08/2023]
Abstract
Chitinases are a group of hydrolytic enzymes that hydrolyze chitin and widely exist in organisms. Studies in mammals have demonstrated that chitinases play important roles in regulation of humoral and cellular immune responses. In arthropods, although it is well known that chitinases are involved in growth, molting and development, the current knowledge on the role of chitinases in immunity, especially in immune regulation, remains largely unknown. In this study, a chitinase (LvChi5) from Litopenaeus vannamei was representatively selected for studying its immune function. The start codon of LvChi5 was corrected by 5'RACE analysis and its protein sequence was reanalyzed. LvChi5 contains a catalytic domain and a chitin binding domain and shows no inhibitory effect on growth of bacteria in vitro. However, in vivo experiments demonstrated that silencing of LvChi5 increased the mortality of shrimp infected with white spot syndrome virus (WSSV) and Vibro parahaemolyticus and significantly upregulated the load of pathogens in tissues. The expression of various immune related genes, including transcription factors, antimicrobial peptides and other functional proteins with antibacterial and antiviral activities, was widely changed in LvChi5 silencing shrimp. Moreover, the recombinant LvChi5 protein could enhance the phagocytic activity of hemocytes against bacteria. These suggested that shrimp chitinase could play a role in regulation of both humoral and cellular immune responses in shrimp.
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Affiliation(s)
- Shengwen Niu
- MOE Key Laboratory of Aquatic Product Safety / State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Linwei Yang
- MOE Key Laboratory of Aquatic Product Safety / State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Hongliang Zuo
- MOE Key Laboratory of Aquatic Product Safety / State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Jiefu Zheng
- MOE Key Laboratory of Aquatic Product Safety / State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Shaoping Weng
- MOE Key Laboratory of Aquatic Product Safety / State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Jianguo He
- MOE Key Laboratory of Aquatic Product Safety / State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China; South China Sea Resource Exploitation and Protection Collaborative Innovation Center (SCS-REPIC), Guangzhou, PR China.
| | - Xiaopeng Xu
- MOE Key Laboratory of Aquatic Product Safety / State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China; South China Sea Resource Exploitation and Protection Collaborative Innovation Center (SCS-REPIC), Guangzhou, PR China.
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80
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Sharma L, Amick AK, Vasudevan S, Lee SW, Marion CR, Liu W, Brady V, Losier A, Bermejo SD, Britto CJ, Lee CG, Elias JA, Dela Cruz CS. Regulation and Role of Chitotriosidase during Lung Infection with Klebsiella pneumoniae. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2018; 201:615-626. [PMID: 29891554 PMCID: PMC6291403 DOI: 10.4049/jimmunol.1701782] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 05/15/2018] [Indexed: 12/20/2022]
Abstract
Chitinases and chitinase-like proteins are an evolutionary conserved group of proteins. In the absence of chitin synthesis in mammals, the conserved presence of chitinases suggests their roles in physiology and immunity, but experimental evidence to prove these roles is scarce. Chitotriosidase (chit1) is one of the two true chitinases present in mammals and the most prevalent chitinase in humans. In this study, we investigated the regulation and the role of chit1 in a mouse model of Klebsiella pneumoniae lung infection. We show that chitinase activity in bronchoalveolar lavage fluid is significantly reduced during K. pneumoniae lung infection. This reduced activity is inversely correlated with the number of neutrophils. Further, instilling neutrophil lysates in lungs decreased chitinase activity. We observed degradation of chit1 by neutrophil proteases. In a mouse model, chit1 deficiency provided a significant advantage to the host during K. pneumoniae lung infection by limiting bacterial dissemination. This phenotype was independent of inflammatory changes in chit1-/- mice as they exerted a similar inflammatory response. The decreased dissemination resulted in improved survival in chit1-/- mice infected with K. pneumoniae in the presence or absence of antibiotic therapy. The beneficial effects of chit1 deficiency were associated with altered Akt activation in the lungs. Chit1-/- mice induced a more robust Akt activation postinfection. The role of the Akt pathway in K. pneumoniae lung infection was confirmed by using an Akt inhibitor, which impaired health and survival. These data suggest a detrimental role of chit1 in K. pneumoniae lung infections.
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Affiliation(s)
- Lokesh Sharma
- Section of Pulmonary and Critical Care and Sleep Medicine, Department of Medicine, Yale University School of Medicine, New Haven, CT 06520
| | - Alyssa K Amick
- Section of Pulmonary and Critical Care and Sleep Medicine, Department of Medicine, Yale University School of Medicine, New Haven, CT 06520
| | - Swathy Vasudevan
- Section of Pulmonary and Critical Care and Sleep Medicine, Department of Medicine, Yale University School of Medicine, New Haven, CT 06520
| | - Sei Won Lee
- Section of Pulmonary and Critical Care and Sleep Medicine, Department of Medicine, Yale University School of Medicine, New Haven, CT 06520
| | - Chad R Marion
- Section of Pulmonary and Critical Care and Sleep Medicine, Department of Medicine, Yale University School of Medicine, New Haven, CT 06520
| | - Wei Liu
- Section of Pulmonary and Critical Care and Sleep Medicine, Department of Medicine, Yale University School of Medicine, New Haven, CT 06520
| | - Virginia Brady
- Section of Pulmonary and Critical Care and Sleep Medicine, Department of Medicine, Yale University School of Medicine, New Haven, CT 06520
| | - Ashley Losier
- Section of Pulmonary and Critical Care and Sleep Medicine, Department of Medicine, Yale University School of Medicine, New Haven, CT 06520
| | - Santos D Bermejo
- Section of Pulmonary and Critical Care and Sleep Medicine, Department of Medicine, Yale University School of Medicine, New Haven, CT 06520
| | - Clemente J Britto
- Section of Pulmonary and Critical Care and Sleep Medicine, Department of Medicine, Yale University School of Medicine, New Haven, CT 06520
| | - Chun Geun Lee
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912; and
| | - Jack A Elias
- Department of Molecular Microbiology and Immunology, Brown University, Providence, RI 02912; and
| | - Charles S Dela Cruz
- Section of Pulmonary and Critical Care and Sleep Medicine, Department of Medicine, Yale University School of Medicine, New Haven, CT 06520;
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06520
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81
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McDermott AJ, Klein BS. Helper T-cell responses and pulmonary fungal infections. Immunology 2018; 155:155-163. [PMID: 29781185 DOI: 10.1111/imm.12953] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 05/02/2018] [Accepted: 05/11/2018] [Indexed: 12/14/2022] Open
Abstract
The mucosal surface of the respiratory tract encounters microbes, such as fungal particles, with every inhaled breath. When pathogenic fungi breach the physical barrier and innate immune system within the lung to establish an infection, adaptive immunity is engaged, often in the form of helper CD4 T-cell responses. Type 1 responses, characterized by interferon-γ production from CD4 cells, promote clearance of Histoplasma capsulatum and Cryptococcus neoformans infection. Likewise, interleukin-17A (IL-17A) production from Th17 cells promotes immunity to Blastomyces dermatitidis and Coccidioides species infection by recruiting neutrophils. In contrast the development of T helper type 2 responses, characterized by IL-5 production from T cells and eosinophil influx into the lungs, drives allergic bronchopulmonary aspergillosis and poor outcomes during C. neoformans infection. Experimental vaccines against several endemic mycoses, including Histoplasma capsulatum, Coccidioides, Cryptococcus and Blastomyces dermatitidis, induce protective T-cell responses and foreshadow the development of vaccines against pulmonary fungal infections for use in humans. Additionally, recent work using antifungal T cells as immunotherapy to protect immune-compromised patients from opportunist fungal infections also shows great promise. This review covers the role of T-cell responses in driving protection and pathology in response to pulmonary fungal infections, and highlights promising therapeutic applications of antifungal T cells.
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Affiliation(s)
- Andrew J McDermott
- Departments of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Bruce S Klein
- Departments of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.,Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.,Internal Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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82
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Rodrigues J, Ramos CL, Frases S, Godinho RMDC, Fonseca FL, Rodrigues ML. Lack of chitin synthase genes impacts capsular architecture and cellular physiology in Cryptococcus neoformans. Cell Surf 2018; 2:14-23. [PMID: 32743128 PMCID: PMC7389344 DOI: 10.1016/j.tcsw.2018.05.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/21/2018] [Accepted: 05/25/2018] [Indexed: 02/06/2023] Open
Abstract
Cryptococcus neoformans mutants lacking each of the eight putative chitin synthase genes (CHS) have been previously generated. However, it is still unclear how deletion of chitin synthase genes affects the cryptococcal capsule. Since the connections between chitin metabolism and capsular polysaccharides in C. neoformans are numerous, we analyzed the effects of deletion of CHS genes on capsular and capsule-related structures of C. neoformans. CHS deletion affected capsular morphology in multiple ways, as determined by scanning electron microscopy and immunofluorescence analysis. Molecular diameter, serological reactivity and export of capsular polysaccharide were also affected in most of the chsΔ mutants, but the most prominent alterations were observed in the chs3Δ strain. C. neoformans cells lacking CHS genes also had altered formation of extracellular vesicles and variable chitinase activity under stress conditions. These results reveal previously unknown functions of CHS genes that greatly impact the physiology of C. neoformans.
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Affiliation(s)
- Jessica Rodrigues
- Instituto de Microbiologia Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Caroline L Ramos
- Instituto de Microbiologia Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Susana Frases
- Instituto de Biofísica Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rodrigo M da C Godinho
- Instituto de Microbiologia Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fernanda L Fonseca
- Centro de Desenvolvimento Tecnológico em Saúde (CDTS) da Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro, Brazil
| | - Marcio L Rodrigues
- Instituto de Microbiologia Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto Carlos Chagas (ICC), Fundação Oswaldo Cruz (Fiocruz), Curitiba, PR, Brazil
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83
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Esher SK, Ost KS, Kohlbrenner MA, Pianalto KM, Telzrow CL, Campuzano A, Nichols CB, Munro C, Wormley FL, Alspaugh JA. Defects in intracellular trafficking of fungal cell wall synthases lead to aberrant host immune recognition. PLoS Pathog 2018; 14:e1007126. [PMID: 29864141 PMCID: PMC6002136 DOI: 10.1371/journal.ppat.1007126] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 06/14/2018] [Accepted: 05/29/2018] [Indexed: 11/19/2022] Open
Abstract
The human fungal pathogen, Cryptococcus neoformans, dramatically alters its cell wall, both in size and composition, upon entering the host. This cell wall remodeling is essential for host immune avoidance by this pathogen. In a genetic screen for mutants with changes in their cell wall, we identified a novel protein, Mar1, that controls cell wall organization and immune evasion. Through phenotypic studies of a loss-of-function strain, we have demonstrated that the mar1Δ mutant has an aberrant cell surface and a defect in polysaccharide capsule attachment, resulting in attenuated virulence. Furthermore, the mar1Δ mutant displays increased staining for exposed cell wall chitin and chitosan when the cells are grown in host-like tissue culture conditions. However, HPLC analysis of whole cell walls and RT-PCR analysis of cell wall synthase genes demonstrated that this increased chitin exposure is likely due to decreased levels of glucans and mannans in the outer cell wall layers. We observed that the Mar1 protein differentially localizes to cellular membranes in a condition dependent manner, and we have further shown that the mar1Δ mutant displays defects in intracellular trafficking, resulting in a mislocalization of the β-glucan synthase catalytic subunit, Fks1. These cell surface changes influence the host-pathogen interaction, resulting in increased macrophage activation to microbial challenge in vitro. We established that several host innate immune signaling proteins are required for the observed macrophage activation, including the Card9 and MyD88 adaptor proteins, as well as the Dectin-1 and TLR2 pattern recognition receptors. These studies explore novel mechanisms by which a microbial pathogen regulates its cell surface in response to the host, as well as how dysregulation of this adaptive response leads to defective immune avoidance.
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Affiliation(s)
- Shannon K. Esher
- Departments of Molecular Genetics and Microbiology/Medicine, Duke University School of Medicine, Durham, NC, United States of America
| | - Kyla S. Ost
- Departments of Molecular Genetics and Microbiology/Medicine, Duke University School of Medicine, Durham, NC, United States of America
| | - Maria A. Kohlbrenner
- Departments of Molecular Genetics and Microbiology/Medicine, Duke University School of Medicine, Durham, NC, United States of America
| | - Kaila M. Pianalto
- Departments of Molecular Genetics and Microbiology/Medicine, Duke University School of Medicine, Durham, NC, United States of America
| | - Calla L. Telzrow
- Departments of Molecular Genetics and Microbiology/Medicine, Duke University School of Medicine, Durham, NC, United States of America
| | - Althea Campuzano
- Department of Biology, University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - Connie B. Nichols
- Departments of Molecular Genetics and Microbiology/Medicine, Duke University School of Medicine, Durham, NC, United States of America
| | - Carol Munro
- MRC Centre for Medical Mycology, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
| | - Floyd L. Wormley
- Department of Biology, University of Texas at San Antonio, San Antonio, Texas, United States of America
| | - J. Andrew Alspaugh
- Departments of Molecular Genetics and Microbiology/Medicine, Duke University School of Medicine, Durham, NC, United States of America
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84
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Breyne K, Steenbrugge J, Demeyere K, Lee CG, Elias JA, Petzl W, Smith DGE, Germon P, Meyer E. Immunomodulation of Host Chitinase 3-Like 1 During a Mammary Pathogenic Escherichia coli Infection. Front Immunol 2018; 9:1143. [PMID: 29892291 PMCID: PMC5985307 DOI: 10.3389/fimmu.2018.01143] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 05/07/2018] [Indexed: 12/05/2022] Open
Abstract
Chitin is a N-acetyl-d-glucosamine biopolymer that can be recognized by chitin-binding proteins. Although mammals lack chitin synthase, they induce proteins responsible for detecting chitin in response to bacterial infections. Our aim was to investigate whether chitinase 3-like 1 (CHI3L1) has a potential role in the innate immunity of the Escherichia coli (E. coli) infected mammary gland. CHI3L1 protein was found to be secreted in whey of naturally coliform-affected quarters compared to whey samples isolated from healthy udders. In addition, gene expression of CHI3L1 was confirmed in udder tissue of cows experimentally infected with a mammary pathogenic E. coli (MPEC) strain. Despite the known anatomical differences, the bovine udders’ innate immune response was mimicked by applying an experimental mouse model using MPEC or non-MPEC isolates. The effect of CHI3L1 expression in the murine mammary gland in response to coliform bacteria was investigated through the use of CHI3L1−/− mice as well as through treatment with either a pan-caspase inhibitor or chitin particles in wild-type mice. The local induction of CHI3L1 postinfection with different E. coli strains was demonstrated to be independent of both bacterial growth and mammary interleukin (IL)-8 levels. Indeed, CHI3L1 emerged as a regulator impacting on the transcytosis of Ly6G-positive cells from the interstitial space into the alveolar lumen of the mammary tissue. Furthermore, CHI3L1 was found to be upstream regulated by caspase activity and had a major downstream effect on the local pro-inflammatory cytokine profile, including IL-1beta, IL-6, and RANTES/CCL5. In conclusion, CHI3L1 was demonstrated to play a key role in the cytokine and caspase signaling during E. coli triggered inflammation of the mammary gland.
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Affiliation(s)
- Koen Breyne
- Laboratory of Biochemistry, Department of Pharmacology, Toxicology and Biochemistry, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Jonas Steenbrugge
- Laboratory of Biochemistry, Department of Pharmacology, Toxicology and Biochemistry, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Kristel Demeyere
- Laboratory of Biochemistry, Department of Pharmacology, Toxicology and Biochemistry, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Chun Geun Lee
- Division of Biology and Medicine, Warren Alpert School of Medicine at Brown University, Providence, RI, United States
| | - Jack A Elias
- Division of Biology and Medicine, Warren Alpert School of Medicine at Brown University, Providence, RI, United States
| | - Wolfram Petzl
- Clinic for Ruminants with Ambulance and Herd Health Services, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - David G E Smith
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University, Edinburgh, United Kingdom
| | - Pierre Germon
- INRA UMR 1282 Infectiologie et Santé Publique (ISP), Université François Rabelais de Tours, Nouzilly, France
| | - Evelyne Meyer
- Laboratory of Biochemistry, Department of Pharmacology, Toxicology and Biochemistry, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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85
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Hommel B, Mukaremera L, Cordero RJB, Coelho C, Desjardins CA, Sturny-Leclère A, Janbon G, Perfect JR, Fraser JA, Casadevall A, Cuomo CA, Dromer F, Nielsen K, Alanio A. Titan cells formation in Cryptococcus neoformans is finely tuned by environmental conditions and modulated by positive and negative genetic regulators. PLoS Pathog 2018; 14:e1006982. [PMID: 29775480 PMCID: PMC5959062 DOI: 10.1371/journal.ppat.1006982] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 03/19/2018] [Indexed: 01/06/2023] Open
Abstract
The pathogenic fungus Cryptococcus neoformans exhibits morphological changes in cell size during lung infection, producing both typical size 5 to 7 μm cells and large titan cells (> 10 μm and up to 100 μm). We found and optimized in vitro conditions that produce titan cells in order to identify the ancestry of titan cells, the environmental determinants, and the key gene regulators of titan cell formation. Titan cells generated in vitro harbor the main characteristics of titan cells produced in vivo including their large cell size (>10 μm), polyploidy with a single nucleus, large vacuole, dense capsule, and thick cell wall. Here we show titan cells derived from the enlargement of progenitor cells in the population independent of yeast growth rate. Change in the incubation medium, hypoxia, nutrient starvation and low pH were the main factors that trigger titan cell formation, while quorum sensing factors like the initial inoculum concentration, pantothenic acid, and the quorum sensing peptide Qsp1p also impacted titan cell formation. Inhibition of ergosterol, protein and nucleic acid biosynthesis altered titan cell formation, as did serum, phospholipids and anti-capsular antibodies in our settings. We explored genetic factors important for titan cell formation using three approaches. Using H99-derivative strains with natural genetic differences, we showed that titan cell formation was dependent on LMP1 and SGF29 genes. By screening a gene deletion collection, we also confirmed that GPR4/5-RIM101, and CAC1 genes were required to generate titan cells and that the PKR1, TSP2, USV101 genes negatively regulated titan cell formation. Furthermore, analysis of spontaneous Pkr1 loss-of-function clinical isolates confirmed the important role of the Pkr1 protein as a negative regulator of titan cell formation. Through development of a standardized and robust in vitro assay, our results provide new insights into titan cell biogenesis with the identification of multiple important factors/pathways.
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Affiliation(s)
- Benjamin Hommel
- Institut Pasteur, Molecular Mycology Unit, Département de Mycologie, Paris, France
- CNRS UMR2000, Paris, France
- Laboratoire de Parasitologie-Mycologie, Hôpital Saint-Louis, Groupe Hospitalier Lariboisière, Saint-Louis, Fernand Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Liliane Mukaremera
- Department of Microbiology and Immunology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Radames J. B. Cordero
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD., United States of America
| | - Carolina Coelho
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD., United States of America
| | | | - Aude Sturny-Leclère
- Institut Pasteur, Molecular Mycology Unit, Département de Mycologie, Paris, France
- CNRS UMR2000, Paris, France
| | - Guilhem Janbon
- Institut Pasteur, Unité Biologie des ARN des Pathogènes Fongiques, Département de Mycologie, Paris, France
| | - John R. Perfect
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - James A. Fraser
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD., United States of America
| | - Christina A. Cuomo
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Françoise Dromer
- Institut Pasteur, Molecular Mycology Unit, Département de Mycologie, Paris, France
- CNRS UMR2000, Paris, France
| | - Kirsten Nielsen
- Department of Microbiology and Immunology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Alexandre Alanio
- Institut Pasteur, Molecular Mycology Unit, Département de Mycologie, Paris, France
- CNRS UMR2000, Paris, France
- Laboratoire de Parasitologie-Mycologie, Hôpital Saint-Louis, Groupe Hospitalier Lariboisière, Saint-Louis, Fernand Widal, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD., United States of America
- * E-mail:
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86
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Dambuza IM, Drake T, Chapuis A, Zhou X, Correia J, Taylor-Smith L, LeGrave N, Rasmussen T, Fisher MC, Bicanic T, Harrison TS, Jaspars M, May RC, Brown GD, Yuecel R, MacCallum DM, Ballou ER. The Cryptococcus neoformans Titan cell is an inducible and regulated morphotype underlying pathogenesis. PLoS Pathog 2018; 14:e1006978. [PMID: 29775474 PMCID: PMC5959070 DOI: 10.1371/journal.ppat.1006978] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 03/16/2018] [Indexed: 02/06/2023] Open
Abstract
Fungal cells change shape in response to environmental stimuli, and these morphogenic transitions drive pathogenesis and niche adaptation. For example, dimorphic fungi switch between yeast and hyphae in response to changing temperature. The basidiomycete Cryptococcus neoformans undergoes an unusual morphogenetic transition in the host lung from haploid yeast to large, highly polyploid cells termed Titan cells. Titan cells influence fungal interaction with host cells, including through increased drug resistance, altered cell size, and altered Pathogen Associated Molecular Pattern exposure. Despite the important role these cells play in pathogenesis, understanding the environmental stimuli that drive the morphological transition, and the molecular mechanisms underlying their unique biology, has been hampered by the lack of a reproducible in vitro induction system. Here we demonstrate reproducible in vitro Titan cell induction in response to environmental stimuli consistent with the host lung. In vitro Titan cells exhibit all the properties of in vivo generated Titan cells, the current gold standard, including altered capsule, cell wall, size, high mother cell ploidy, and aneuploid progeny. We identify the bacterial peptidoglycan subunit Muramyl Dipeptide as a serum compound associated with shift in cell size and ploidy, and demonstrate the capacity of bronchial lavage fluid and bacterial co-culture to induce Titanisation. Additionally, we demonstrate the capacity of our assay to identify established (cAMP/PKA) and previously undescribed (USV101) regulators of Titanisation in vitro. Finally, we investigate the Titanisation capacity of clinical isolates and their impact on disease outcome. Together, these findings provide new insight into the environmental stimuli and molecular mechanisms underlying the yeast-to-Titan transition and establish an essential in vitro model for the future characterization of this important morphotype.
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Affiliation(s)
- Ivy M. Dambuza
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
| | - Thomas Drake
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
| | - Ambre Chapuis
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
| | - Xin Zhou
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
| | - Joao Correia
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
| | - Leanne Taylor-Smith
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
| | - Nathalie LeGrave
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Aberdeen, United Kingdom
- Francis Crick Institute, London, United Kingdom
| | - Tim Rasmussen
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Aberdeen, United Kingdom
- Institut für Biochemie, Universität Würzburg, Wurzburg, Germany
| | - Matthew C. Fisher
- Dpt. Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Tihana Bicanic
- Institute of Infection and Immunity, St George’s University of London, London, United Kingdom
| | - Thomas S. Harrison
- Institute of Infection and Immunity, St George’s University of London, London, United Kingdom
| | - Marcel Jaspars
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Aberdeen, United Kingdom
| | - Robin C. May
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
| | - Gordon D. Brown
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
| | - Raif Yuecel
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
| | - Donna M. MacCallum
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
| | - Elizabeth R. Ballou
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
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87
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Esher SK, Zaragoza O, Alspaugh JA. Cryptococcal pathogenic mechanisms: a dangerous trip from the environment to the brain. Mem Inst Oswaldo Cruz 2018; 113:e180057. [PMID: 29668825 PMCID: PMC5909089 DOI: 10.1590/0074-02760180057] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 03/08/2018] [Indexed: 12/16/2022] Open
Abstract
Cryptococcus neoformans is an opportunistic pathogenic yeast that causes serious infections, most commonly of the central nervous system (CNS). C. neoformans is mainly found in the environment and acquired by inhalation. It could be metaphorically imagined that cryptococcal disease is a "journey" for the microorganism that starts in the environment, where this yeast loads its suitcase with virulence traits. C. neoformans first encounters the infected mammalian host in the lungs, a site in which it must choose the right elements from its "virulence suitcase" to survive the pulmonary immune response. However, the lung is often only the first stop in this journey, and in some individuals the fungal trip continues to the brain. To enter the brain, C. neoformans must "open" the main barrier that protects this organ, the blood brain barrier (BBB). Once in the brain, C. neoformans expresses a distinct set of protective attributes that confers a strong neurotropism and the ability to cause brain colonisation. In summary, C. neoformans is a unique fungal pathogen as shown in its ability to survive in the face of multiple stress factors and to express virulence factors that contribute to the development of disease.
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Affiliation(s)
- Shannon K Esher
- Duke University School of Medicine, Department of Molecular Genetics and Microbiology, Department of Medicine, Durham, USA
| | - Oscar Zaragoza
- Instituto de Salud Carlos III, National Centre for Microbiology, Mycology Reference Laboratory, Madrid, Spain
| | - James Andrew Alspaugh
- Duke University School of Medicine, Department of Molecular Genetics and Microbiology, Department of Medicine, Durham, USA
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88
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Watkins RA, Andrews A, Wynn C, Barisch C, King JS, Johnston SA. Cryptococcus neoformans Escape From Dictyostelium Amoeba by Both WASH-Mediated Constitutive Exocytosis and Vomocytosis. Front Cell Infect Microbiol 2018; 8:108. [PMID: 29686972 PMCID: PMC5900056 DOI: 10.3389/fcimb.2018.00108] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 03/19/2018] [Indexed: 01/01/2023] Open
Abstract
Cryptococcus neoformans is an environmental yeast that can cause opportunistic infections in humans. As infecting animals does not form part of its normal life-cycle, it has been proposed that the virulence traits that allow cryptococci to resist immune cells were selected through interactions with environmental phagocytes such as amoebae. Here, we investigate the interactions between C. neoformans and the social amoeba Dictyostelium discoideum. We show that like macrophages, D. discoideum is unable to kill C. neoformans upon phagocytosis. Despite this, we find that the yeast pass through the amoebae with an apparently normal phagocytic transit and are released alive by constitutive exocytosis after ~80 min. This is the canonical pathway in amoebae, used to dispose of indigestible material after nutrient extraction. Surprisingly however, we show that upon either genetic or pharmacological blockage of constitutive exocytosis, C. neoformans still escape from D. discoideum by a secondary mechanism. We demonstrate that constitutive exocytosis-independent egress is stochastic and actin-independent. This strongly resembles the non-lytic release of cryptococci by vomocytosis from macrophages, which do not perform constitutive exocytosis and normally retain phagocytosed material. Our data indicate that vomocytosis is functionally redundant for escape from amoebae, which thus may not be the primary driver for its evolutionary selection. Nonetheless, we show that vomocytosis of C. neoformans is mechanistically conserved in hosts ranging from amoebae to man, providing new avenues to understand this poorly-understood but important virulence mechanism.
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Affiliation(s)
- Rhys A. Watkins
- Bateson Centre, University of Sheffield, Sheffield, United Kingdom
- Department of Infection Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Alexandre Andrews
- Bateson Centre, University of Sheffield, Sheffield, United Kingdom
- Department of Infection Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Charlotte Wynn
- Bateson Centre, University of Sheffield, Sheffield, United Kingdom
- Department of Infection Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Caroline Barisch
- Department of Biochemistry, Faculty of Science, University of Geneva, Geneva, Switzerland
| | - Jason S. King
- Bateson Centre, University of Sheffield, Sheffield, United Kingdom
- Department of Biomedical Sciences, University of Sheffield, Sheffield, United Kingdom
| | - Simon A. Johnston
- Bateson Centre, University of Sheffield, Sheffield, United Kingdom
- Department of Infection Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
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89
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Elsegeiny W, Marr KA, Williamson PR. Immunology of Cryptococcal Infections: Developing a Rational Approach to Patient Therapy. Front Immunol 2018; 9:651. [PMID: 29670625 PMCID: PMC5893745 DOI: 10.3389/fimmu.2018.00651] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 03/16/2018] [Indexed: 12/13/2022] Open
Abstract
Cryptococcal meningoencephalitis is responsible for upwards of 15% of HIV-related deaths worldwide and is currently the most common cause of non-viral meningitis in the US, affecting both previously healthy and people with immune suppression caused by cancer chemotherapy, transplantation, and biologic therapies. Despite a continued 30-50% attributable mortality, recommended therapeutic strategies have remained largely unchanged since the 1950s. Recent murine models and human studies examining the role of the immune system in both susceptibility to the infection as well as host damage have begun to influence patient care decisions. The Damage Framework Response, originally proposed in 1999, was recently used to discuss dichotomous etiologies of host damage in cryptococcal disease. These include patients suffering microbiological damage with low host immunity (especially those immunosuppressed with HIV) and those having low (live) microbiological burden but high immune-mediated damage (HIV-related immune reconstitution syndrome and non-HIV-related postinfectious inflammatory response syndrome). Cryptococcal disease in previously healthy hosts, albeit rare, has been known for a long time. Immunophenotyping and dendritic cell-T cell signaling studies on cerebral spinal fluid of these rare patients reveal immune capacity for recognition and T-cell activation pathways including increased levels of HLA-DR and CD56. However, despite effective T-cell signals, brain biopsy and autopsy specimens demonstrated an M2 alternative macrophage polarization and poor phagocytosis of fungal cells. These studies expand the paradigm for cryptococcal disease susceptibility to include a prominent role for immune-mediated damage and suggest a need for careful individual consideration of immune activation during therapy of cryptococcal disease in diverse hosts.
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Affiliation(s)
- Waleed Elsegeiny
- Laboratory of Clinical Immunology and Microbiology (LCIM), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD, United States
| | | | - Peter R. Williamson
- Laboratory of Clinical Immunology and Microbiology (LCIM), National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD, United States
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90
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Wozniak KL. Interactions of Cryptococcus with Dendritic Cells. J Fungi (Basel) 2018; 4:jof4010036. [PMID: 29543719 PMCID: PMC5872339 DOI: 10.3390/jof4010036] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 03/12/2018] [Accepted: 03/14/2018] [Indexed: 12/15/2022] Open
Abstract
The fungal pathogens Cryptococcus neoformans and Cryptococcus gattii can cause life-threatening infections in immune compromised and immune competent hosts. These pathogens enter the host via inhalation, and respiratory tract innate immune cells such as dendritic cells (DCs) are one of the first host cells they encounter. The interactions between Cryptococcus and innate immune cells play a critical role in the progression of disease in the host. This review will focus specifically on the interactions between Cryptococcus and dendritic cells (DCs), including recognition/processing by DCs, effects of immune mediators on DC recruitment and activity, and the potential for DC vaccination against cryptococcosis.
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Affiliation(s)
- Karen L Wozniak
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74078, USA.
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91
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Mukaremera L, Lee KK, Wagener J, Wiesner DL, Gow NA, Nielsen K. Titan cell production in Cryptococcus neoformans reshapes the cell wall and capsule composition during infection. Cell Surf 2018; 1:15-24. [PMID: 30123851 PMCID: PMC6095662 DOI: 10.1016/j.tcsw.2017.12.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Revised: 12/05/2017] [Accepted: 12/31/2017] [Indexed: 12/21/2022] Open
Abstract
Cryptococcus neoformans is a human fungal pathogen that often causes infections in immunocompromised individuals. Upon inhalation into the lungs C. neoformans differentiates into cells with altered size and morphology, including production of large titan cells. Titan cells possess thickened cell wall and dense, cross-linked capsule when compared to in vitro grown cells. In addition, titan cells have increased cell wall chitin that is associated with a detrimental anti-inflammatory immune response. Here we examined the cell wall and capsule composition of in vitro, in vivo typical-sized and in vivo titan cells using High Performance Liquid Chromatography (HPLC). The monomer composition of cell wall polysaccharides showed that in vivo C. neoformans cells contained more glucosamine and less glucose than in vitro cells, suggesting alteration in abundance of both chitin and glucans, respectively. Low levels of galactosamine were also detected in carbohydrates from both in vivo and vitro cells. Within the in vivo cell population, differences in the proportions of cell wall and capsule monomers between typical and titan cells were also observed. Taken together, these results demonstrate that C. neoformans reshapes its cell wall and capsule composition during infection. These cell wall and capsule alterations likely help C. neoformans escape recognition by, and allow modulation of, the host immune system.
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Affiliation(s)
- Liliane Mukaremera
- Department of Microbiology and Immunology, Medical School, University of Minnesota, Minneapolis, USA
| | - Keunsook K. Lee
- MRC Centre for Medical Mycology, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | - Jeanette Wagener
- MRC Centre for Medical Mycology, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | - Darin L. Wiesner
- Department of Microbiology and Immunology, Medical School, University of Minnesota, Minneapolis, USA
| | - Neil A.R. Gow
- MRC Centre for Medical Mycology, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | - Kirsten Nielsen
- Department of Microbiology and Immunology, Medical School, University of Minnesota, Minneapolis, USA
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92
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Dutra FF, Albuquerque PC, Rodrigues ML, Fonseca FL. Warfare and defense: The host response to Cryptococcus infection. FUNGAL BIOL REV 2018. [DOI: 10.1016/j.fbr.2017.09.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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93
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Mechanisms of Pulmonary Escape and Dissemination by Cryptococcus neoformans. J Fungi (Basel) 2018; 4:jof4010025. [PMID: 29463005 PMCID: PMC5872328 DOI: 10.3390/jof4010025] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 02/09/2018] [Accepted: 02/16/2018] [Indexed: 12/15/2022] Open
Abstract
Cryptococcus neoformans is a common environmental saprophyte and human fungal pathogen that primarily causes disease in immunocompromised individuals. Similar to many environmentally acquired human fungal pathogens, C. neoformans initiates infection in the lungs. However, the main driver of mortality is invasive cryptococcosis leading to fungal meningitis. After C. neoformans gains a foothold in the lungs, a critical early step in invasion is transversal of the respiratory epithelium. In this review, we summarize current knowledge relating to pulmonary escape. We focus on fungal factors that allow C. neoformans to disseminate from the lungs via intracellular and extracellular routes.
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94
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Hartl D, Tirouvanziam R, Laval J, Greene CM, Habiel D, Sharma L, Yildirim AÖ, Dela Cruz CS, Hogaboam CM. Innate Immunity of the Lung: From Basic Mechanisms to Translational Medicine. J Innate Immun 2018; 10:487-501. [PMID: 29439264 DOI: 10.1159/000487057] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 01/18/2018] [Indexed: 12/16/2022] Open
Abstract
The respiratory tract is faced daily with 10,000 L of inhaled air. While the majority of air contains harmless environmental components, the pulmonary immune system also has to cope with harmful microbial or sterile threats and react rapidly to protect the host at this intimate barrier zone. The airways are endowed with a broad armamentarium of cellular and humoral host defense mechanisms, most of which belong to the innate arm of the immune system. The complex interplay between resident and infiltrating immune cells and secreted innate immune proteins shapes the outcome of host-pathogen, host-allergen, and host-particle interactions within the mucosal airway compartment. Here, we summarize and discuss recent findings on pulmonary innate immunity and highlight key pathways relevant for biomarker and therapeutic targeting strategies for acute and chronic diseases of the respiratory tract.
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Affiliation(s)
- Dominik Hartl
- Department of Pediatrics I, Children's Hospital, University of Tübingen, Tübingen, .,Roche Pharma Research and Early Development (pRED), Immunology, Inflammation and Infectious Diseases (I3) Discovery and Translational Area, Roche Innovation Center Basel, Basel,
| | - Rabindra Tirouvanziam
- Department of Pediatrics, Emory University School of Medicine, Center for Cystic Fibrosis and Airways Disease Research, Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Julie Laval
- Department of Pediatrics I, Children's Hospital, University of Tübingen, Tübingen, Germany
| | - Catherine M Greene
- Department of Clinical Microbiology, Royal College of Surgeons in Ireland Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - David Habiel
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Lokesh Sharma
- Section of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Ali Önder Yildirim
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease, Helmholtz Zentrum München, Neuherberg, Germany
| | - Charles S Dela Cruz
- Section of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine and Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Cory M Hogaboam
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA
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95
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Identification of T helper (Th)1- and Th2-associated antigens of Cryptococcus neoformans in a murine model of pulmonary infection. Sci Rep 2018; 8:2681. [PMID: 29422616 PMCID: PMC5805727 DOI: 10.1038/s41598-018-21039-z] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 01/29/2018] [Indexed: 12/24/2022] Open
Abstract
Cryptococcosis, caused by Cryptococcus neoformans, has been demonstrated to be controlled by T helper (Th)1 cells while Th2 cells are associated with fungal growth and dissemination. Although cryptococcal immunoreactive protein antigens were previously identified, their association with Th1 or Th2 immune responses was not provided. In mice, Th1-dependent IFN-γ induces the production of IgG2a, whereas the Th2 cytokine IL-4 stimulates the expression of IgG1 rendering each isotype an indicator of the underlying Th cell response. Therefore, we performed an immunoproteomic study that distinguishes Th1- and Th2-associated antigens by their reactivity with Th1-dependent IgG2a or Th2-dependent IgG1 antibodies in sera from C. neoformans-infected wild-type mice. We additionally analysed sera from Th2-prone IL-12-deficient and Th1-prone IL-4Rα-deficient mice extending the results found in wild-type mice. In total, ten, four, and three protein antigens associated with IgG1, IgG2a, or both isotypes, respectively, were identified. Th2-associated antigens represent promising candidates for development of immunotherapy regimens, whereas Th1-associated antigens may serve as candidates for vaccine development. In conclusion, this study points to intrinsic immunomodulatory effects of fungal antigens on the process of Th cell differentiation based on the identification of cryptococcal protein antigens specifically associated with Th1 or Th2 responses throughout mice of different genotypes.
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96
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Abstract
Cryptococcus neoformans is the main etiologic agent of cryptococcal meningitis and causes a significant number of deadly infections per year. Although it is well appreciated that host immune responses are crucial for defense against cryptococcosis, our understanding of factors that control the development of effective immunity to this fungus remains incomplete. In previous studies, we identified the F-box protein Fbp1 as a novel determinant of C. neoformans virulence. In this study, we found that the hypovirulence of the fbp1Δ mutant is linked to the development of a robust host immune response. Infection with the fbp1Δ mutant induces a rapid influx of CCR2+ monocytes and their differentiation into monocyte-derived dendritic cells (mo-DCs). Depletion of CCR2+ monocytes and their derivative mo-DCs resulted in impaired activation of a protective inflammatory response and the rapid death of mice infected with the fbp1Δ mutant. Mice lacking B and T cells also developed fungal meningitis and succumbed to infection with the fbp1Δ mutant, demonstrating that adaptive immune responses to the fbp1Δ mutant help to maintain the long-term survival of the host. Adaptive immune responses to the fbp1Δ mutant were characterized by enhanced differentiation of Th1 and Th17 CD4+ T cells together with diminished Th2 responses compared to the H99 parental strain. Importantly, we found that the enhanced immunogenicity of fbp1Δ mutant yeast cells can be harnessed to confer protection against a subsequent infection with the virulent H99 parental strain. Altogether, our findings suggest that Fbp1 functions as a novel virulence factor that shapes the immunogenicity of C. neoformansIMPORTANCECryptococcus neoformans is the most common cause of deadly fungal meningitis, with over 270,000 infections per year. Immune responses are critically required for the prevention of cryptococcosis, and patients with impaired immunity and low CD4+ T cell numbers are at high risk of developing these deadly infections. Although it is well appreciated that the development of protective immunity is shaped by the interactions of the host immune system with fungal cells, our understanding of fungal products that influence this process remains poor. In this study, we found that the activity of F-box protein 1 (Fbp1) in highly virulent C. neoformans clinical strain H99 shapes its immunogenicity and thus affects the development of protective immune responses in the host. The identification of this new mechanism of virulence may facilitate the future development of therapeutic interventions aimed at boosting antifungal host immunity.
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97
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Fonseca FL, Reis FCG, Sena BAG, Jozefowicz LJ, Kmetzsch L, Rodrigues ML. The Overlooked Glycan Components of the Cryptococcus Capsule. Curr Top Microbiol Immunol 2018; 422:31-43. [PMID: 30203395 DOI: 10.1007/82_2018_140] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Pathogenic species of Cryptococcus kill approximately 200,000 people each year. The most important virulence mechanism of C. neoformans and C. gattii, the causative agents of human and animal cryptococcosis, is the ability to form a polysaccharide capsule. Acapsular mutants of C. neoformans are avirulent in mice models of infection, and extracellularly released capsular polysaccharides are deleterious to the immune system. The principal capsular component in the Cryptococcus genus is a complex mannan substituted with xylosyl and glucuronyl units, namely glucuronoxylomannan (GXM). The second most abundant component of the cryptococcal capsule is a galactan with multiple glucuronyl, xylosyl, and mannosyl substitutions, namely glucuronoxylomannogalactan (GXMGal). The literature about the structure and functions of these two polysaccharides is rich, and a number of comprehensive reviews on this topic are available. Here, we focus our discussion on the less explored glycan components associated with the cryptococcal capsule, including mannoproteins and chitin-derived molecules. These glycans were selected for discussion on the basis that i) they have been consistently detected not only in the cell wall but also within the cryptococcal capsular network and ii) they have functions that impact immunological and/or pathogenic mechanisms in the Cryptococcus genus. The reported functions of these molecules strongly indicate that the biological roles of the cryptococcal capsule go far beyond the well-known properties of GXM and GXMGal.
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Affiliation(s)
- Fernanda L Fonseca
- Centro de Desenvolvimento Tecnológico Em Saúde (CDTS), Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Flavia C G Reis
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (Fiocruz), Curitiba, Brazil
| | - Bianca A G Sena
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (Fiocruz), Curitiba, Brazil
| | - Luísa J Jozefowicz
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (Fiocruz), Curitiba, Brazil
| | - Livia Kmetzsch
- Centro de Biotecnologia, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Brazil.,Departamento de Biologia Molecular E Biotecnologia, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Brazil
| | - Marcio L Rodrigues
- Instituto Carlos Chagas, Fundação Oswaldo Cruz (Fiocruz), Curitiba, Brazil. .,Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal Do Rio de Janeiro, Rio de Janeiro, Brazil. .,Cidade Industrial de Curitiba, Rua Professor Algacyr Munhoz Mader, 2135-2261, Curitiba, PR, 81310-020, Brazil.
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98
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Abstract
Cryptococcus neoformans is a human pathogenic yeast that causes hundreds of thousands of deaths worldwide among susceptible individuals, in particular, HIV+ patients. This yeast has developed several adaptation mechanisms that allow replication within the host. During decades, this yeast has been well known for a very peculiar and unique structure that contributes to virulence, a complex polysaccharide capsule that surrounds the cell wall. In contrast to other fungal pathogens, such as Candida albicans or Aspergillus fumigatus, the role of morphological transitions has not been studied in the virulence of Cryptococcus neoformans since this yeast does not form hyphae during infection. However, in the last years, different groups have described the ability of this fungus to change its size during infection. In particular, Cryptococcus can form "titan cells," which are blastoconidia of an abnormal large size. Since their discovery, there is increasing evidence that these cells contribute, not only to long-term persistence in the host, but they can also actively participate in the development of the disease. Recently, several groups have simultaneously described different media that induce the appearance of titan cells in laboratory conditions. Using these conditions, new inducing factors and signaling pathways involved in this transition have been described. In this article, we will review the main phenotypic features of these cells, factors, and transduction pathways that induce cell growth, and how titan cells contribute to the disease caused by this pathogen.
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99
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Mazur M, Bartoszewicz A, Dymek B, Salamon M, Andryianau G, Kowalski M, Olejniczak S, Matyszewski K, Pluta E, Borek B, Stefaniak F, Zagozdzon A, Mazurkiewicz M, Koralewski R, Czestkowski W, Piotrowicz M, Niedziejko P, Gruza MM, Dzwonek K, Golebiowski A, Golab J, Olczak J. Discovery of selective, orally bioavailable inhibitor of mouse chitotriosidase. Bioorg Med Chem Lett 2017; 28:310-314. [PMID: 29292229 DOI: 10.1016/j.bmcl.2017.12.047] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 12/08/2017] [Accepted: 12/21/2017] [Indexed: 12/17/2022]
Abstract
This article describes our work towards the identification of a potent and selective inhibitor of mouse chitotriosidase (mCHIT1). A series of small molecule inhibitors of mCHIT1 and mAMCase have been developed from early lead compound 1. Examination of synthetized analogues led to discovery of several novel highly potent compounds. Among them compound 9 (OAT-2068) displays a remarkable 143-fold mCHIT1 vs. mAMCase selectivity. To explain the observed SAR molecular docking experiments were performed, which were in line with the experimental data from the enzymatic assays. Inhibitor 9 (OAT-2068) was found to have an excellent pharmacokinetic profile. This, together with high activity and selectivity, makes the compound an ideal and unique tool for studying the role of CHIT1 in biological models.
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Affiliation(s)
- Marzena Mazur
- OncoArendi Therapeutics SA, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | | | - Barbara Dymek
- OncoArendi Therapeutics SA, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Magdalena Salamon
- OncoArendi Therapeutics SA, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Gleb Andryianau
- OncoArendi Therapeutics SA, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Michał Kowalski
- OncoArendi Therapeutics SA, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Sylwia Olejniczak
- OncoArendi Therapeutics SA, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | | | - Elżbieta Pluta
- OncoArendi Therapeutics SA, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Bartłomiej Borek
- OncoArendi Therapeutics SA, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Filip Stefaniak
- OncoArendi Therapeutics SA, Żwirki i Wigury 101, 02-089 Warsaw, Poland; Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Ks. Trojdena 4, 02-109 Warsaw, Poland
| | | | | | - Robert Koralewski
- OncoArendi Therapeutics SA, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | | | - Michał Piotrowicz
- OncoArendi Therapeutics SA, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Piotr Niedziejko
- OncoArendi Therapeutics SA, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Mariusz M Gruza
- OncoArendi Therapeutics SA, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Karolina Dzwonek
- OncoArendi Therapeutics SA, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Adam Golebiowski
- OncoArendi Therapeutics SA, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Jakub Golab
- OncoArendi Therapeutics SA, Żwirki i Wigury 101, 02-089 Warsaw, Poland; Department of Immunology, Medical University of Warsaw, Banacha 1a, 02-097 Warsaw, Poland
| | - Jacek Olczak
- OncoArendi Therapeutics SA, Żwirki i Wigury 101, 02-089 Warsaw, Poland
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100
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Abstract
Morphological changes are a very common and effective strategy for pathogens to survive in the mammalian host. During interactions with their host, human pathogenic fungi undergo an array of morphological changes that are tightly associated with virulence. Candida albicans switches between yeast cells and hyphae during infection. Thermally dimorphic pathogens, such as Histoplasma capsulatum and Blastomyces species transform from hyphal growth to yeast cells in response to host stimuli. Coccidioides and Pneumocystis species produce spherules and cysts, respectively, which allow for the production of offspring in a protected environment. Finally, Cryptococcus species suppress hyphal growth and instead produce an array of yeast cells—from large polyploid titan cells to micro cells. While the morphology changes produced by human fungal pathogens are diverse, they all allow for the pathogens to evade, manipulate, and overcome host immune defenses to cause disease. In this review, we summarize the morphology changes in human fungal pathogens—focusing on morphological features, stimuli, and mechanisms of formation in the host.
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Affiliation(s)
| | - Kirsten Nielsen
- Correspondence: ; Tel.: +1-612-625-4979; Fax: +1-612-626-0623
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