157 results on '"Hube, B"'
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2. Charakterisierung der Interaktion zwischen Candida albicans und Wirtszellen
- Author
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Schaller, M., Zakikhany, K., Weindl, G., Borelli, C., Korting, H.C., and Hube, B.
- Abstract
Zusammenfassung: Die mikrobiologische Grundlagenforschung benötigt geeignete Modellsysteme, um infektionsbiologische Fragestellungen in sinnvoller Weise bearbeiten zu können. Zum gegenwärtigen Zeitpunkt erfolgen solche Infektionsstudien meist im Rahmen von Tierversuchen, was aus ethischen Gründen aber umstritten ist. Eine mögliche Alternative, gerade für lokalisierte Infektionen, bieten Modelle auf der Basis von in vitro rekonstituiertem humanem Epithel oder rekonstituierter humaner Epidermis (RHE). In den letzten Jahren wurden diese Modellsysteme erfolgreich zur Evaluierung der Wirksamkeit topischer Antiinfektiva, zur Charakterisierung von fungalen Virulenzfaktoren und zur Beschreibung der Immunantwort bei lokalisierten Candida-albicans-Infektionen eingesetzt. Erst kürzlich wurden diese Modelle um weitere infektionsrelevante Immunzellen wie Lymphozyten, polymorphkernige Leukozyten, Mastzellen oder dendritische Zellen erweitert um deren Einfluss auf den Infektionslauf und die Interaktion zwischen Hautbarrieren und akzessorischen Immunzellen zu charakterisieren. Obgleich für RHE-Modelle die größte Erfahrung bei Candida-albicans-Infektionen besteht, können solche Modellsysteme auch für Infektionen mit anderen Pilzen oder auch Bakterien eingesetzt werden. more...
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- 2024
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Catalog
3. The impact of the Fungus-Host-Microbiota interplay upon Candida albicans infections: current knowledge and new perspectives
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D'Enfert, C., Kaune, A.K., Alaban, L.R., Chakraborty, S., Cole, N., Delavy, M., Kosmala, D., Marsaux, B., Fróis-Martins, R., Morelli, M., Rosati, D., Valentine, M., Xie, Z., Emritloll, Y., Warn, P.A., Bequet, F., Bougnoux, M.E., Bornes, S., Gresnigt, M.S., Hube, B., Jacobsen, I.D., Legrand, M., Leibundgut-Landmann, S., Manichanh, C., Munro, C.A., Netea, M.G., Queiroz, K., Roget, K., Thomas, V., Thoral, C., Abbeele, P. Van den, Walker, A.W., Brown, A.J., D'Enfert, C., Kaune, A.K., Alaban, L.R., Chakraborty, S., Cole, N., Delavy, M., Kosmala, D., Marsaux, B., Fróis-Martins, R., Morelli, M., Rosati, D., Valentine, M., Xie, Z., Emritloll, Y., Warn, P.A., Bequet, F., Bougnoux, M.E., Bornes, S., Gresnigt, M.S., Hube, B., Jacobsen, I.D., Legrand, M., Leibundgut-Landmann, S., Manichanh, C., Munro, C.A., Netea, M.G., Queiroz, K., Roget, K., Thomas, V., Thoral, C., Abbeele, P. Van den, Walker, A.W., and Brown, A.J. more...
- Abstract
Contains fulltext : 235356.pdf (Publisher’s version ) (Open Access), Candida albicans is a major fungal pathogen of humans. It exists as a commensal in the oral cavity, gut or genital tract of most individuals, constrained by the local microbiota, epithelial barriers and immune defences. Their perturbation can lead to fungal outgrowth and the development of mucosal infections such as oropharyngeal or vulvovaginal candidiasis, and patients with compromised immunity are susceptible to life-threatening systemic infections. The importance of the interplay between fungus, host and microbiota in driving the transition from C. albicans commensalism to pathogenicity is widely appreciated. However, the complexity of these interactions, and the significant impact of fungal, host and microbiota variability upon disease severity and outcome, are less well understood. Therefore, we summarise the features of the fungus that promote infection, and how genetic variation between clinical isolates influences pathogenicity. We discuss antifungal immunity, how this differs between mucosae, and how individual variation influences a person's susceptibility to infection. Also, we describe factors that influence the composition of gut, oral and vaginal microbiotas, and how these affect fungal colonisation and antifungal immunity. We argue that a detailed understanding of these variables, which underlie fungal-host-microbiota interactions, will present opportunities for directed antifungal therapies that benefit vulnerable patients. more...
- Published
- 2021
4. Candidalysin is required for neutrophil recruitment and virulence during systemic Candida albicans infection
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Swidergall, M., Khalaji, M., Solis, N.V., Moyes, D.L., Drummond, R.A., Hube, B., Lionakis, M.S., Murdoch, C., Filler, S.G., and Naglik, J.R.
- Abstract
Background\ud \ud Candidalysin is a cytolytic peptide toxin secreted by Candida albicans hyphae and has significantly advanced our understanding of fungal pathogenesis. Candidalysin is critical for mucosal C albicans infections and is known to activate epithelial cells to induce downstream innate immune responses that are associated with protection or immunopathology during oral or vaginal infections. Furthermore, candidalysin activates the NLRP3 inflammasome and causes cytolysis in mononuclear phagocytes. However, the role of candidalysin in driving systemic infections is unknown.\ud \ud Methods\ud \ud In this study, using candidalysin-producing and candidalysin-deficient C albicans strains, we show that candidalysin activates mitogen-activated protein kinase (MAPK) signaling and chemokine secretion in endothelial cells in vitro.\ud \ud Results\ud \ud Candidalysin induces immune activation and neutrophil recruitment in vivo, and it promotes mortality in zebrafish and murine models of systemic fungal infection.\ud \ud Conclusions\ud \ud The data demonstrate a key role for candidalysin in neutrophil recruitment and fungal virulence during disseminated systemic C albicans infections. more...
- Published
- 2019
5. Recent trends in molecular diagnostics of yeast infections: from PCR to NGS
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Arastehfar, A, Boekhout, T, Butler, G, De Cesare, G Buda, Dolk, E, Gabaldón, T, Hafez, A, Hube, B, Hagen, F, Hovhannisyan, H, Iracane, E, Kostrzewa, M, Lackner, M, Lass-Flörl, C, Llorens, C, Mixão, V, Munro, C, Oliveira-Pacheco, J, Pekmezovic, M, Pérez-Hansen, A, Sanchez, A Rodriguez, Sauer, F M, Sparbier, K, Stavrou, A A, Vaneechoutte, M, Vatanshenassan, M, and Gabaldón, Toni more...
- Subjects
Proteomics ,Antifungal Agents ,diagnosis ,Antifungal drugs ,Review Article ,Drug resistance ,Polymerase Chain Reaction ,DESORPTION IONIZATION-TIME ,Yeast pathogens ,CULTURE IDENTIFICATION PANEL ,Yeasts ,Diagnosis ,Medicine and Health Sciences ,Sequencing ,Pathology, Molecular ,Candida ,AcademicSubjects/SCI01150 ,0303 health sciences ,CLINICAL-PRACTICE GUIDELINE ,High-Throughput Nucleotide Sequencing ,Drug susceptibility ,sequencing ,3. Good health ,INTERNAL TRANSCRIBED SPACER ,Infectious Diseases ,Identification (biology) ,BLOOD-STREAM INFECTIONS ,Point-of-Care Systems ,Computational biology ,Biology ,Microbiology ,Rapid detection ,LASER-DESORPTION/IONIZATION-TIME ,03 medical and health sciences ,proteomics ,Drug Resistance, Multiple, Fungal ,Humans ,MALDI-TOF MS ,030304 developmental biology ,Whole Genome Sequencing ,030306 microbiology ,ESCMID-ASTERISK GUIDELINE ,candidemia ,Candidemia ,Biology and Life Sciences ,IN-SITU HYBRIDIZATION ,Molecular diagnostics ,Yeast ,Bench to bedside ,Editor's Choice ,Mycoses ,FLIGHT MASS-SPECTROMETRY ,yeast pathogens - Abstract
The incidence of opportunistic yeast infections in humans has been increasing over recent years. These infections are difficult to treat and diagnose, in part due to the large number and broad diversity of species that can underlie the infection. In addition, resistance to one or several antifungal drugs in infecting strains is increasingly being reported, severely limiting therapeutic options and showcasing the need for rapid detection of the infecting agent and its drug susceptibility profile. Current methods for species and resistance identification lack satisfactory sensitivity and specificity, and often require prior culturing of the infecting agent, which delays diagnosis. Recently developed high-throughput technologies such as next generation sequencing or proteomics are opening completely new avenues for more sensitive, accurate and fast diagnosis of yeast pathogens. These approaches are the focus of intensive research, but translation into the clinics requires overcoming important challenges. In this review, we provide an overview of existing and recently emerged approaches that can be used in the identification of yeast pathogens and their drug resistance profiles. Throughout the text we highlight the advantages and disadvantages of each methodology and discuss the most promising developments in their path from bench to bedside., The authors discuss the current status of the use of high-throughput (-omics) technologies on the diagnostics of yeast infections. more...
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- 2019
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6. 662 Extracellular ATP released from Candida albicans activates non-peptidergic nerves to augment skin immunity
- Author
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Edwards, T.N., primary, Zhang, S., additional, Mogavero, S., additional, Bougnoux, M., additional, Berman, J., additional, Hube, B., additional, d'Enfert, C., additional, and Kaplan, D.H., additional
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- 2019
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7. The fungal peptide toxin Candidalysin activates the NLRP3 inflammasome and causes cytolysis in mononuclear phagocytes
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Kasper, L., Konig, A., Koenig, P.A., Gresnigt, M.S., Westman, J., Drummond, R.A., Lionakis, M.S., Gross, O., Ruland, J., Naglik, J.R., Hube, B., Kasper, L., Konig, A., Koenig, P.A., Gresnigt, M.S., Westman, J., Drummond, R.A., Lionakis, M.S., Gross, O., Ruland, J., Naglik, J.R., and Hube, B. more...
- Abstract
Contains fulltext : 200455.pdf (publisher's version ) (Open Access), Clearance of invading microbes requires phagocytes of the innate immune system. However, successful pathogens have evolved sophisticated strategies to evade immune killing. The opportunistic human fungal pathogen Candida albicans is efficiently phagocytosed by macrophages, but causes inflammasome activation, host cytolysis, and escapes after hypha formation. Previous studies suggest that macrophage lysis by C. albicans results from early inflammasome-dependent cell death (pyroptosis), late damage due to glucose depletion and membrane piercing by growing hyphae. Here we show that Candidalysin, a cytolytic peptide toxin encoded by the hypha-associated gene ECE1, is both a central trigger for NLRP3 inflammasome-dependent caspase-1 activation via potassium efflux and a key driver of inflammasome-independent cytolysis of macrophages and dendritic cells upon infection with C. albicans. This suggests that Candidalysin-induced cell damage is a third mechanism of C. albicans-mediated mononuclear phagocyte cell death in addition to damage caused by pyroptosis and the growth of glucose-consuming hyphae. more...
- Published
- 2018
8. Gene Function Analysis in the Ubiquitous Human Commensal and Pathogen Malassezia Genus
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Hube, B, Ianiri, G, Averette, AF, Kingsbury, JM, Heitman, J, Idnurm, A, Hube, B, Ianiri, G, Averette, AF, Kingsbury, JM, Heitman, J, and Idnurm, A
- Abstract
UNLABELLED: The genus Malassezia includes 14 species that are found on the skin of humans and animals and are associated with a number of diseases. Recent genome sequencing projects have defined the gene content of all 14 species; however, to date, genetic manipulation has not been possible for any species within this genus. Here, we develop and then optimize molecular tools for the transformation of Malassezia furfur and Malassezia sympodialis using Agrobacterium tumefaciens delivery of transfer DNA (T-DNA) molecules. These T-DNAs can insert randomly into the genome. In the case of M. furfur, targeted gene replacements were also achieved via homologous recombination, enabling deletion of the ADE2 gene for purine biosynthesis and of the LAC2 gene predicted to be involved in melanin biosynthesis. Hence, the introduction of exogenous DNA and direct gene manipulation are feasible in Malassezia species. IMPORTANCE: Species in the genus Malassezia are a defining component of the microbiome of the surface of mammals. They are also associated with a wide range of skin disease symptoms. Many species are difficult to culture in vitro, and although genome sequences are available for the species in this genus, it has not been possible to assess gene function to date. In this study, we pursued a series of possible transformation methods and identified one that allows the introduction of DNA into two species of Malassezia, including the ability to make targeted integrations into the genome such that genes can be deleted. This research opens a new direction in terms of now being able to analyze gene functions in this little understood genus. These tools will contribute to define the mechanisms that lead to the commensalism and pathogenicity in this group of obligate fungi that are predominant on the skin of mammals. more...
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- 2016
9. Essential Gene Discovery in the Basidiomycete Cryptococcus neoformans for Antifungal Drug Target Prioritization
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Kronstad, J, Hube, B, Ianiri, G, Idnurm, A, Kronstad, J, Hube, B, Ianiri, G, and Idnurm, A
- Abstract
UNLABELLED: Fungal diseases represent a major burden to health care globally. As with other pathogenic microbes, there is a limited number of agents suitable for use in treating fungal diseases, and resistance to these agents can develop rapidly. Cryptococcus neoformans is a basidiomycete fungus that causes cryptococcosis worldwide in both immunocompromised and healthy individuals. As a basidiomycete, it diverged from other common pathogenic or model ascomycete fungi more than 500 million years ago. Here, we report C. neoformans genes that are essential for viability as identified through forward and reverse genetic approaches, using an engineered diploid strain and genetic segregation after meiosis. The forward genetic approach generated random insertional mutants in the diploid strain, the induction of meiosis and sporulation, and selection for haploid cells with counterselection of the insertion event. More than 2,500 mutants were analyzed, and transfer DNA (T-DNA) insertions in several genes required for viability were identified. The genes include those encoding the thioredoxin reductase (Trr1), a ribosome assembly factor (Rsa4), an mRNA-capping component (Cet1), and others. For targeted gene replacement, the C. neoformans homologs of 35 genes required for viability in ascomycete fungi were disrupted, meiosis and sporulation were induced, and haploid progeny were evaluated for their ability to grow on selective media. Twenty-one (60%) were found to be required for viability in C. neoformans. These genes are involved in mitochondrial translation, ergosterol biosynthesis, and RNA-related functions. The heterozygous diploid mutants were evaluated for haploinsufficiency on a number of perturbing agents and drugs, revealing phenotypes due to the loss of one copy of an essential gene in C. neoformans. This study expands the knowledge of the essential genes in fungi using a basidiomycete as a model organism. Genes that have no mammalian homologs and are essential in b more...
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- 2015
10. Genome analysis of the humanpathogenic fungus Conidiobolus coronatus Entomophthoromycota, Zygomycota)
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Möckel, Lars, Vogel, Heiko, Felder, M, Groth, M, Grützmann, K, Kaltenpoth, Martin, Mogavero, S, Müller, S., Scherlach, K, Shelest, Ekaterina, Schwartze, Volker, Winter, S, Böcker, S, Hammel, J, Hube, B, Platzer, M, Schuster, S, de Fine Licht, Henrik Hjarvard, Beutel, Rolf, Voigt, Kerstin, Möckel, Lars, Vogel, Heiko, Felder, M, Groth, M, Grützmann, K, Kaltenpoth, Martin, Mogavero, S, Müller, S., Scherlach, K, Shelest, Ekaterina, Schwartze, Volker, Winter, S, Böcker, S, Hammel, J, Hube, B, Platzer, M, Schuster, S, de Fine Licht, Henrik Hjarvard, Beutel, Rolf, and Voigt, Kerstin more...
- Published
- 2015
11. 662 Extracellular ATP released from Candida albicansactivates non-peptidergic nerves to augment skin immunity
- Author
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Edwards, T.N., Zhang, S., Mogavero, S., Bougnoux, M., Berman, J., Hube, B., d'Enfert, C., and Kaplan, D.H.
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- 2019
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12. Role of amino acid substitutions on proteolytic stability of histatin 5 in the presence of secreted aspartyl proteases and salivary proteases.
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Makambi WK, Chiu VL, Kasper L, Hube B, and Karlsson AJ
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- Humans, Aspartic Acid Proteases metabolism, Aspartic Acid Proteases chemistry, Aspartic Acid Proteases genetics, Fungal Proteins chemistry, Fungal Proteins metabolism, Fungal Proteins genetics, Saliva enzymology, Protein Stability, Aspartic Acid Endopeptidases metabolism, Aspartic Acid Endopeptidases chemistry, Aspartic Acid Endopeptidases genetics, Secreted Aspartic Proteases, Histatins chemistry, Histatins metabolism, Histatins genetics, Proteolysis, Candida albicans enzymology, Candida albicans genetics, Amino Acid Substitution
- Abstract
Histatin 5 (Hst5) is a 24-amino-acid peptide naturally present in human saliva that has been proposed as a potential antifungal therapeutic. However, Hst5 is susceptible to degradation by secreted aspartyl proteases (Saps) produced by Candida albicans, which could limit its efficacy as a therapeutic. To better understand the role of the lysine residues of Hst5 in proteolysis by C. albicans Saps (Sap1, Sap2, Sap3, Sap5, Sap6, Sap9, and Sap10), we studied variants of Hst5 with substitutions to leucine or arginine at the lysine residues (K5, K11, K13, and K17). Sap5, Sap6, and Sap10 did not degrade Hst5 or the variants. However, we observed degradation of the peptides by Sap1, Sap2, Sap3, and Sap9, and the degradation depended on the site of substitution and the substituent residue. Some modifications, such as K11L and K13L, were particularly susceptible to proteolysis by Sap1, Sap2, Sap3, and Sap9. In contrast, the K17L modification substantially increased the stability and antifungal activity of Hst5 in the presence of Saps. We used mass spectrometry to characterize the proteolysis products, which allowed us to identify fragments likely to have maintained or lost antifungal activity. We also evaluated the proteolytic stability of the Hst5 variants in saliva. Both K17L and K5R showed improved stability; however, the enhancements were modest, suggesting that further engineering is required to achieve significant improvements. Our approach demonstrates the potential of simple, rational substitutions to enhance peptide efficacy and proteolytic stability, providing a promising strategy for improving the properties of antifungal peptides., (© 2024 The Author(s). Protein Science published by Wiley Periodicals LLC on behalf of The Protein Society.) more...
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- 2025
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13. Alpha1-antitrypsin impacts innate host-pathogen interactions with Candida albicans by stimulating fungal filamentation.
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Jaeger M, Dietschmann A, Austermeier S, Dinçer S, Porschitz P, Vornholz L, Maas RJA, Sprenkeler EGG, Ruland J, Wirtz S, Azam T, Joosten LAB, Hube B, Netea MG, Dinarello CA, and Gresnigt MS
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- Humans, Host-Pathogen Interactions, Macrophages microbiology, Monocytes microbiology, Candida albicans metabolism, beta-Glucans metabolism
- Abstract
Our immune system possesses sophisticated mechanisms to cope with invading microorganisms, while pathogens evolve strategies to deal with threats imposed by host immunity. Human plasma protein α1-antitrypsin (AAT) exhibits pleiotropic immune-modulating properties by both preventing immunopathology and improving antimicrobial host defence. Genetic associations suggested a role for AAT in candidemia, the most frequent fungal blood stream infection in intensive care units, yet little is known about how AAT influences interactions between Candida albicans and the immune system. Here, we show that AAT differentially impacts fungal killing by innate phagocytes. We observed that AAT induces fungal transcriptional reprogramming, associated with cell wall remodelling and downregulation of filamentation repressors. At low concentrations, the cell-wall remodelling induced by AAT increased immunogenic β-glucan exposure and consequently improved fungal clearance by monocytes. Contrastingly, higher AAT concentrations led to excessive C. albicans filamentation and thus promoted fungal immune escape from monocytes and macrophages. This underscores that fungal adaptations to the host protein AAT can differentially define the outcome of encounters with innate immune cells, either contributing to improved immune recognition or fungal immune escape. more...
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- 2024
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14. Shining a light on Candida -induced epithelial damage with a luciferase reporter.
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Tesfamariam M, Vij R, Trümper V, Hube B, and Brunke S
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- Humans, Cell Line, Luminescent Measurements methods, Luciferases genetics, Luciferases metabolism, Candida albicans genetics, Candida albicans pathogenicity, Genes, Reporter, Epithelial Cells microbiology
- Abstract
Host cell damage is a key parameter for research in infection biology, drug testing, and substance safety screening. In this study, we introduce a luciferase reporter system as a new and reliable assay to measure cell damage and validate it with the pathogenic yeast, Candida albicans , as a test case. We transduced human epithelial cell lines with a lentiviral vector to stably express an optimized luciferase enzyme, Nanoluc. Upon cell damage, the release of cytoplasmic luciferase into the extracellular space can be easily detected by a luminometer. We used the luciferase reporter system to investigate the damage caused by C. albicans to different newly generated epithelial reporter cell lines. We found that fungus-induced cell damage, as determined by established methods, correlated tightly with the release of the luciferase. The new luciferase reporter system is a simple, sensitive, robust, and inexpensive method for measuring host cell damage and has a sensitivity comparable to the standard assay, release of lactate dehydrogenase. It is suitable for high-throughput studies of pathogenesis mechanisms of any microbe, for antimicrobial drug screening, and many other applications.IMPORTANCEWe present a quick, easy, inexpensive, and reliable assay to measure damage to mammalian cells. To this end, we created reporter cell lines which artificially express luciferase, an enzyme that can be easily detected in the supernatant when these cells are damaged. We used infections with the well-investigated fungal pathogen of humans, Candida albicans , as a test case of our system. Using our reporter, we were able to recapitulate the known effects of strain variability, gene deletions, and antifungal treatments on host cell damage. This easily adaptable reporter system can be used to screen for damage in infection models with different microbial species, assay cell-damaging potential of substances, discover new non-toxic antibiotics, and many other damage-based applications., Competing Interests: Work from this paper has been used to register the patent "Cytotoxicity assay for detecting cellular damage" (L31002DE) with the Deutsches Patent-und Markenamt authors R.V., M.T., V.T., S.B., and B.H. and Leibniz-HKI as beneficiaries. more...
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- 2024
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15. Leveraging Organ-on-Chip Models to Investigate Host-Microbiota Dynamics and Targeted Therapies for Inflammatory Bowel Disease.
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Kaden T, Alonso-Román R, Stallhofer J, Gresnigt MS, Hube B, and Mosig AS
- Abstract
Inflammatory bowel disease (IBD) is an idiopathic gastrointestinal disease with drastically increasing incidence rates. Due to its multifactorial etiology, a precise investigation of the pathogenesis is extremely difficult. Although reductionist cell culture models and more complex disease models in animals have clarified the understanding of individual disease mechanisms and contributing factors of IBD in the past, it remains challenging to bridge research and clinical practice. Conventional 2D cell culture models cannot replicate complex host-microbiota interactions and stable long-term microbial culture. Further, extrapolating data from animal models to patients remains challenging due to genetic and environmental diversity leading to differences in immune responses. Human intestine organ-on-chip (OoC) models have emerged as an alternative in vitro model approach to investigate IBD. OoC models not only recapitulate the human intestinal microenvironment more accurately than 2D cultures yet may also be advantageous for the identification of important disease-driving factors and pharmacological interventions targets due to the possibility of emulating different complexities. The predispositions and biological hallmarks of IBD focusing on host-microbiota interactions at the intestinal mucosal barrier are elucidated here. Additionally, the potential of OoCs to explore microbiota-related therapies and personalized medicine for IBD treatment is discussed., (© 2024 The Author(s). Advanced Healthcare Materials published by Wiley‐VCH GmbH.) more...
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- 2024
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16. Essential role of Hepcidin in host resistance to disseminated candidiasis.
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Arekar T, Katikaneni D, Kasem S, Desai D, Acharya T, Cole A, Khodayari N, Vaulont S, Hube B, Nemeth E, Drakesmith A, Lionakis MS, Mehrad B, and Scindia Y
- Abstract
Candida albicans is a leading cause of life-threatening invasive infections with up to 40% mortality rates in hospitalized individuals despite antifungal therapy. Patients with chronic liver disease are at an increased risk of candidemia, but the mechanisms underlying this susceptibility are incompletely defined. One consequence of chronic liver disease is attenuated ability to produce hepcidin and maintain organismal control of iron homeostasis. To address the biology underlying this critical clinical problem, we demonstrate the mechanistic link between hepcidin insufficiency and candida infection using genetic and inducible hepcidin knockout mice. Hepcidin deficiency led to unrestrained fungal growth and increased transition to the invasive hypha morphology with exposed 1,3, β-glucan that exacerbated kidney injury, independent of the fungal pore-forming toxin candidalysin in immunocompetent mice. Of translational relevance, the therapeutic administration of PR-73, a hepcidin mimetic, improved the outcomes of infection. Thus, we identify hepcidin deficiency as a novel host susceptibility factor against C. albicans and hepcidin mimetics as a potential intervention. more...
- Published
- 2024
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17. Variations in candidalysin amino acid sequence influence toxicity and host responses.
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Wickramasinghe DN, Lyon CM, Lee S, Hepworth OW, Priest EL, Maufrais C, Ryan AP, Permal E, Sullivan D, McManus BA, Hube B, Butler G, d'Enfert C, Naglik JR, and Richardson JP
- Subjects
- Humans, Candidiasis microbiology, Candidiasis immunology, Amino Acid Sequence, Genetic Variation, Candida genetics, Candida pathogenicity, Candida tropicalis genetics, Candida tropicalis metabolism, Fungal Proteins genetics, Fungal Proteins metabolism, Fungal Proteins chemistry, Candida albicans genetics, Candida albicans drug effects, Epithelial Cells microbiology
- Abstract
Candida albicans causes millions of mucosal infections in humans annually. Hyphal overgrowth on mucosal surfaces is frequently associated with tissue damage caused by candidalysin, a secreted peptide toxin that destabilizes the plasma membrane of host cells thereby promoting disease and immunopathology. Candidalysin was first identified in C. albicans strain SC5314, but recent investigations have revealed candidalysin "variants" of differing amino acid sequence in isolates of C. albicans , and the related species C. dubliniensis , and C tropicalis , suggesting that sequence variation among candidalysins may be widespread in natural populations of these Candida species. Here, we analyzed ECE1 gene sequences from 182 C . albicans isolates, 10 C . dubliniensis isolates, and 78 C . tropicalis isolates and identified 10, 3, and 2 candidalysin variants in these species, respectively. Application of candidalysin variants to epithelial cells revealed differences in the ability to cause cellular damage, changes in metabolic activity, calcium influx, MAPK signalling, and cytokine secretion, while biophysical analyses indicated that variants exhibited differences in their ability to interact with and permeabilize a membrane. This study identifies candidalysin variants with differences in biological activity that are present in medically relevant Candida species., Importance: Fungal infections are a significant burden to health. Candidalysin is a toxin produced by Candida albicans that damages host tissues, facilitating infection. Previously, we demonstrated that candidalysins exist in the related species C. dubliniensis and C. tropicalis , thereby identifying these molecules as a toxin family. Recent genomic analyses have highlighted the presence of a small number of candidalysin "variant" toxins, which have different amino acid sequences to those originally identified. Here, we screened genome sequences of isolates of C. albicans , C. dubliniensis , and C. tropicalis and identified candidalysin variants in all three species. When applied to epithelial cells, candidalysin variants differed in their ability to cause damage, activate intracellular signaling pathways, and induce innate immune responses, while biophysical analysis revealed differences in the ability of candidalysin variants to interact with lipid bilayers. These findings suggest that intraspecies variation in candidalysin amino acid sequence may influence fungal pathogenicity., Competing Interests: The authors declare no conflict of interest. more...
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- 2024
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18. Isotope labeled 3D-Raman confocal imaging and atomic force microscopy study on epithelial cells interacting with the fungus Candida albicans.
- Author
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Stanca SE, Mogavero S, Fritzsche W, Krafft C, Hube B, and Popp J
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- Humans, Candidiasis microbiology, Microscopy, Confocal methods, Isotope Labeling, Imaging, Three-Dimensional, Deuterium chemistry, Candida albicans metabolism, Epithelial Cells microbiology, Epithelial Cells metabolism, Microscopy, Atomic Force methods, Spectrum Analysis, Raman methods
- Abstract
The human pathogenic fungus Candida albicans damages epithelial cells during superficial infections. Here we use three-dimensional-sequential-confocal Raman spectroscopic imaging and atomic force microscopy to investigate the interaction of C. albicans wild type cells, the secreted C. albicans peptide toxin candidalysin and mutant cells lacking candidalysin with epithelial cells. The candidalysin is responsible for epithelial cell damage and exhibits in its deuterated form an identifiable Raman signal in a frequency region distinct from the cellular frequency region. Vibration modes at 2100-2200 cm
-1 attributed to carbon‑deuterium bending and at 477 cm-1 , attributed to the nitrogen‑deuterium out-of-plane bending, found around the nucleus, can be assigned to deuterated candidalysin. Atomic force microscopy visualized 100 nm deep lesions on the cell and force-distance curves indicate the higher adhesion on pore surrounding after incubation with candidalysin. Candidalysin targets the plasma membrane, but is also found inside of the cytosol of epithelial cells during C. albicans infection., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024. Published by Elsevier Inc.) more...- Published
- 2024
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19. Candida albicans and Candida glabrata : global priority pathogens.
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Katsipoulaki M, Stappers MHT, Malavia-Jones D, Brunke S, Hube B, and Gow NAR
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- Humans, Animals, Candidemia microbiology, Candidemia epidemiology, Phylogeny, Host-Pathogen Interactions, Candida glabrata pathogenicity, Candida albicans pathogenicity, Drug Resistance, Fungal, Candidiasis microbiology, Antifungal Agents pharmacology, Antifungal Agents therapeutic use
- Abstract
SUMMARYA significant increase in the incidence of Candida -mediated infections has been observed in the last decade, mainly due to rising numbers of susceptible individuals. Recently, the World Health Organization published its first fungal pathogen priority list, with Candida species listed in medium, high, and critical priority categories. This review is a synthesis of information and recent advances in our understanding of two of these species -Candida albicans and Candida glabrata . Of these, C. albicans is the most common cause of candidemia around the world and is categorized as a critical priority pathogen. C. glabrata is considered a high-priority pathogen and has become an increasingly important cause of candidemia in recent years. It is now the second most common causative agent of candidemia in many geographical regions. Despite their differences and phylogenetic divergence, they are successful as pathogens and commensals of humans. Both species can cause a broad variety of infections, ranging from superficial to potentially lethal systemic infections. While they share similarities in certain infection strategies, including tissue adhesion and invasion, they differ significantly in key aspects of their biology, interaction with immune cells, host damage strategies, and metabolic adaptations. Here we provide insights on key aspects of their biology, epidemiology, commensal and pathogenic lifestyles, interactions with the immune system, and antifungal resistance., Competing Interests: The authors declare no conflict of interest. more...
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- 2024
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20. Modeling of intravenous caspofungin administration using an intestine-on-chip reveals altered Candida albicans microcolonies and pathogenicity.
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Kaden T, Alonso-Roman R, Akbarimoghaddam P, Mosig AS, Graf K, Raasch M, Hoffmann B, Figge MT, Hube B, and Gresnigt MS
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- Humans, Caspofungin pharmacology, Caspofungin therapeutic use, Antifungal Agents pharmacology, Virulence, Intestines, Candida albicans, Candidiasis drug therapy, Candidiasis microbiology
- Abstract
Candida albicans is a commensal yeast of the human intestinal microbiota that, under predisposing conditions, can become pathogenic and cause life-threatening systemic infections (candidiasis). Fungal-host interactions during candidiasis are commonly studied using conventional 2D in vitro models, which have provided critical insights into the pathogenicity. However, microphysiological models with a higher biological complexity may be more suitable to mimic in vivo-like infection processes and antifungal drug efficacy. Therefore, a 3D intestine-on-chip model was used to investigate fungal-host interactions during the onset of invasive candidiasis and evaluate antifungal treatment under clinically relevant conditions. By combining microbiological and image-based analyses we quantified infection processes such as invasiveness and fungal translocation across the epithelial barrier. Additionally, we obtained novel insights into fungal microcolony morphology and association with the tissue. Our results demonstrate that C. albicans microcolonies induce injury to the epithelial tissue by disrupting apical cell-cell contacts and causing inflammation. Caspofungin treatment effectively reduced the fungal biomass and induced substantial alterations in microcolony morphology during infection with a wild-type strain. However, caspofungin showed limited effects after infection with an echinocandin-resistant clinical isolate. Collectively, this organ-on-chip model can be leveraged for in-depth characterization of pathogen-host interactions and alterations due to antimicrobial treatment., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Alexander S. Mosig and Martin Raasch hold equity in Dynamic42 GmbH. The other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.) more...
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- 2024
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21. Competitive fungal commensalism mitigates candidiasis pathology.
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Sekeresova Kralova J, Donic C, Dassa B, Livyatan I, Jansen PM, Ben-Dor S, Fidel L, Trzebanski S, Narunsky-Haziza L, Asraf O, Brenner O, Dafni H, Jona G, Boura-Halfon S, Stettner N, Segal E, Brunke S, Pilpel Y, Straussman R, Zeevi D, Bacher P, Hube B, Shlezinger N, and Jung S more...
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- Humans, Animals, Mice, Symbiosis, Immunosuppression Therapy, Candidiasis, Gastrointestinal Microbiome
- Abstract
The mycobiota are a critical part of the gut microbiome, but host-fungal interactions and specific functional contributions of commensal fungi to host fitness remain incompletely understood. Here, we report the identification of a new fungal commensal, Kazachstania heterogenica var. weizmannii, isolated from murine intestines. K. weizmannii exposure prevented Candida albicans colonization and significantly reduced the commensal C. albicans burden in colonized animals. Following immunosuppression of C. albicans colonized mice, competitive fungal commensalism thereby mitigated fatal candidiasis. Metagenome analysis revealed K. heterogenica or K. weizmannii presence among human commensals. Our results reveal competitive fungal commensalism within the intestinal microbiota, independent of bacteria and immune responses, that could bear potential therapeutic value for the management of C. albicans-mediated diseases., (© 2024 Sekeresova Kralova et al.) more...
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- 2024
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22. Organ-on-chip models for infectious disease research.
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Alonso-Roman R, Mosig AS, Figge MT, Papenfort K, Eggeling C, Schacher FH, Hube B, and Gresnigt MS
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- Animals, Microfluidics, Communicable Diseases
- Abstract
Research on microbial pathogens has traditionally relied on animal and cell culture models to mimic infection processes in the host. Over recent years, developments in microfluidics and bioengineering have led to organ-on-chip (OoC) technologies. These microfluidic systems create conditions that are more physiologically relevant and can be considered humanized in vitro models. Here we review various OoC models and how they have been applied for infectious disease research. We outline the properties that make them valuable tools in microbiology, such as dynamic microenvironments, vascularization, near-physiological tissue constitutions and partial integration of functional immune cells, as well as their limitations. Finally, we discuss the prospects for OoCs and their potential role in future infectious disease research., (© 2024. Springer Nature Limited.) more...
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- 2024
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23. Nanobody-mediated neutralization of candidalysin prevents epithelial damage and inflammatory responses that drive vulvovaginal candidiasis pathogenesis.
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Valentine M, Rudolph P, Dietschmann A, Tsavou A, Mogavero S, Lee S, Priest EL, Zhurgenbayeva G, Jablonowski N, Timme S, Eggeling C, Allert S, Dolk E, Naglik JR, Figge MT, Gresnigt MS, and Hube B
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- Humans, Female, Quality of Life, Candida albicans metabolism, Inflammation, Candidiasis, Vulvovaginal microbiology, Single-Domain Antibodies metabolism, Candidiasis microbiology, Fungal Proteins
- Abstract
Candida albicans can cause mucosal infections in humans. This includes oropharyngeal candidiasis, which is commonly observed in human immunodeficiency virus infected patients, and vulvovaginal candidiasis (VVC), which is the most frequent manifestation of candidiasis. Epithelial cell invasion by C. albicans hyphae is accompanied by the secretion of candidalysin, a peptide toxin that causes epithelial cell cytotoxicity. During vaginal infections, candidalysin-driven tissue damage triggers epithelial signaling pathways, leading to hyperinflammatory responses and immunopathology, a hallmark of VVC. Therefore, we proposed blocking candidalysin activity using nanobodies to reduce epithelial damage and inflammation as a therapeutic strategy for VVC. Anti-candidalysin nanobodies were confirmed to localize around epithelial-invading C. albicans hyphae, even within the invasion pocket where candidalysin is secreted. The nanobodies reduced candidalysin-induced damage to epithelial cells and downstream proinflammatory responses. Accordingly, the nanobodies also decreased neutrophil activation and recruitment. In silico mathematical modeling enabled the quantification of epithelial damage caused by candidalysin under various nanobody dosing strategies. Thus, nanobody-mediated neutralization of candidalysin offers a novel therapeutic approach to block immunopathogenic events during VVC and alleviate symptoms.IMPORTANCEWorldwide, vaginal infections caused by Candida albicans (VVC) annually affect millions of women, with symptoms significantly impacting quality of life. Current treatments are based on anti-fungals and probiotics that target the fungus. However, in some cases, infections are recurrent, called recurrent VVC, which often fails to respond to treatment. Vaginal mucosal tissue damage caused by the C. albicans peptide toxin candidalysin is a key driver in the induction of hyperinflammatory responses that fail to clear the infection and contribute to immunopathology and disease severity. In this pre-clinical evaluation, we show that nanobody-mediated candidalysin neutralization reduces tissue damage and thereby limits inflammation. Implementation of candidalysin-neutralizing nanobodies may prove an attractive strategy to alleviate symptoms in complicated VVC cases., Competing Interests: E.D. is the CEO of Q.V.Q who produced the anti-candidalysin nanobodies. more...
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- 2024
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24. Candida albicans translocation through the intestinal epithelial barrier is promoted by fungal zinc acquisition and limited by NFκB-mediated barrier protection.
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Sprague JL, Schille TB, Allert S, Trümper V, Lier A, Großmann P, Priest EL, Tsavou A, Panagiotou G, Naglik JR, Wilson D, Schäuble S, Kasper L, and Hube B
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- Humans, Zinc, Epithelial Cells, Intestines, Candida albicans, Candidiasis
- Abstract
The opportunistic fungal pathogen Candida albicans thrives on human mucosal surfaces as a harmless commensal, but frequently causes infections under certain predisposing conditions. Translocation across the intestinal barrier into the bloodstream by intestine-colonizing C. albicans cells serves as the main source of disseminated candidiasis. However, the host and microbial mechanisms behind this process remain unclear. In this study we identified fungal and host factors specifically involved in infection of intestinal epithelial cells (IECs) using dual-RNA sequencing. Our data suggest that host-cell damage mediated by the peptide toxin candidalysin-encoding gene ECE1 facilitates fungal zinc acquisition. This in turn is crucial for the full virulence potential of C. albicans during infection. IECs in turn exhibit a filamentation- and damage-specific response to C. albicans infection, including NFκB, MAPK, and TNF signaling. NFκB activation by IECs limits candidalysin-mediated host-cell damage and mediates maintenance of the intestinal barrier and cell-cell junctions to further restrict fungal translocation. This is the first study to show that candidalysin-mediated damage is necessary for C. albicans nutrient acquisition during infection and to explain how IECs counteract damage and limit fungal translocation via NFκB-mediated maintenance of the intestinal barrier., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Sprague et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.) more...
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- 2024
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25. "We've got to get out"-Strategies of human pathogenic fungi to escape from phagocytes.
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Sonnberger J, Kasper L, Lange T, Brunke S, and Hube B
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- Humans, Phagocytes microbiology, Fungi genetics, Macrophages microbiology, Host-Pathogen Interactions, Immune Evasion
- Abstract
Human fungal pathogens are a deadly and underappreciated risk to global health that most severely affect immunocompromised individuals. A virulence attribute shared by some of the most clinically relevant fungal species is their ability to survive inside macrophages and escape from these immune cells. In this review, we discuss the mechanisms behind intracellular survival and elaborate how escape is mediated by lytic and non-lytic pathways as well as strategies to induce programmed host cell death. We also discuss persistence as an alternative to rapid host cell exit. In the end, we address the consequences of fungal escape for the host immune response and provide future perspectives for research and development of targeted therapies., (© 2023 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.) more...
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- 2024
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26. Secretion of the fungal toxin candidalysin is dependent on conserved precursor peptide sequences.
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Müller R, König A, Groth S, Zarnowski R, Visser C, Handrianz T, Maufrais C, Krüger T, Himmel M, Lee S, Priest EL, Yildirim D, Richardson JP, Blango MG, Bougnoux ME, Kniemeyer O, d'Enfert C, Brakhage AA, Andes DR, Trümper V, Nehls C, Kasper L, Mogavero S, Gutsmann T, Naglik JR, Allert S, and Hube B more...
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- Candida albicans metabolism, Peptides pharmacology, Peptides metabolism, Fungal Proteins genetics, Fungal Proteins metabolism, Mycotoxins metabolism
- Abstract
The opportunistic fungal pathogen Candida albicans damages host cells via its peptide toxin, candidalysin. Before secretion, candidalysin is embedded in a precursor protein, Ece1, which consists of a signal peptide, the precursor of candidalysin and seven non-candidalysin Ece1 peptides (NCEPs), and is found to be conserved in clinical isolates. Here we show that the Ece1 polyprotein does not resemble the usual precursor structure of peptide toxins. C. albicans cells are not susceptible to their own toxin, and single NCEPs adjacent to candidalysin are sufficient to prevent host cell toxicity. Using a series of Ece1 mutants, mass spectrometry and anti-candidalysin nanobodies, we show that NCEPs play a role in intracellular Ece1 folding and candidalysin secretion. Removal of single NCEPs or modifications of peptide sequences cause an unfolded protein response (UPR), which in turn inhibits hypha formation and pathogenicity in vitro. Our data indicate that the Ece1 precursor is not required to block premature pore-forming toxicity, but rather to prevent intracellular auto-aggregation of candidalysin sequences., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.) more...
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- 2024
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27. Hyphal-associated protein expression is crucial for Candida albicans-induced eicosanoid biosynthesis in immune cells.
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Schimanski J, Gresnigt MS, Brunner E, Werz O, Hube B, and Garscha U
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- Humans, HEK293 Cells, Eicosanoids metabolism, Leukotrienes metabolism, Candida albicans, Hyphae
- Abstract
Candida albicans causes opportunistic infections ranging from mucosal mycoses to life-threatening systemic infections in immunocompromised patients. During C. albicans infection, leukotrienes and prostaglandins are formed from arachidonic acid by 5-lipoxygenase (5-LOX) and cyclooxygenases, respectively to amplify inflammatory conditions, but also to initiate macrophage infiltration to achieve tissue homeostasis. Since less is known about the cellular mechanisms triggering such lipid mediator biosynthesis, we investigated the eicosanoid formation in monocyte-derived M1 and M2 macrophages, neutrophils and HEK293 cells transfected with 5-LOX and 5-LOX-activating protein (FLAP) in response to C. albicans yeast or hyphae. Leukotriene biosynthesis was exclusively induced by hyphae in neutrophils and macrophages, whereas prostaglandin E
2 was also formed in response to yeast cells by M1 macrophages. Eicosanoid biosynthesis was significantly higher in M1 compared to M2 macrophages. In HEK_5-LOX/FLAP cells only hyphae activated the essential 5-LOX translocation to the nuclear membrane. Using yeast-locked C. albicans mutants, we demonstrated that hyphal-associated protein expression is critical in eicosanoid formation. For neutrophils and HEK_5-LOX/FLAP cells, hyphal wall protein 1 was identified as the essential surface protein that stimulates leukotriene biosynthesis. In summary, our data suggest that hyphal-associated proteins of C. albicans are central triggers of eicosanoid biosynthesis in human phagocytes., (© 2024 The Authors. European Journal of Immunology published by Wiley-VCH GmbH.) more...- Published
- 2024
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28. The hyphal-specific toxin candidalysin promotes fungal gut commensalism.
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Liang SH, Sircaik S, Dainis J, Kakade P, Penumutchu S, McDonough LD, Chen YH, Frazer C, Schille TB, Allert S, Elshafee O, Hänel M, Mogavero S, Vaishnava S, Cadwell K, Belenky P, Perez JC, Hube B, Ene IV, and Bennett RJ more...
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- Animals, Female, Humans, Male, Mice, Bacteria growth & development, Bacteria immunology, Immunoglobulin A immunology, Virulence, Candida albicans growth & development, Candida albicans immunology, Candida albicans metabolism, Candida albicans pathogenicity, Fungal Proteins metabolism, Gastrointestinal Microbiome immunology, Hyphae growth & development, Hyphae immunology, Hyphae metabolism, Intestines immunology, Intestines microbiology, Mycotoxins metabolism, Symbiosis
- Abstract
The fungus Candida albicans frequently colonizes the human gastrointestinal tract, from which it can disseminate to cause systemic disease. This polymorphic species can transition between growing as single-celled yeast and as multicellular hyphae to adapt to its environment. The current dogma of C. albicans commensalism is that the yeast form is optimal for gut colonization, whereas hyphal cells are detrimental to colonization but critical for virulence
1-3 . Here, we reveal that this paradigm does not apply to multi-kingdom communities in which a complex interplay between fungal morphology and bacteria dictates C. albicans fitness. Thus, whereas yeast-locked cells outcompete wild-type cells when gut bacteria are absent or depleted by antibiotics, hyphae-competent wild-type cells outcompete yeast-locked cells in hosts with replete bacterial populations. This increased fitness of wild-type cells involves the production of hyphal-specific factors including the toxin candidalysin4,5 , which promotes the establishment of colonization. At later time points, adaptive immunity is engaged, and intestinal immunoglobulin A preferentially selects against hyphal cells1,6 . Hyphal morphotypes are thus under both positive and negative selective pressures in the gut. Our study further shows that candidalysin has a direct inhibitory effect on bacterial species, including limiting their metabolic output. We therefore propose that C. albicans has evolved hyphal-specific factors, including candidalysin, to better compete with bacterial species in the intestinal niche., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.) more...- Published
- 2024
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29. The glycerophosphocholine acyltransferase Gpc1 contributes to phosphatidylcholine biosynthesis, long-term viability, and embedded hyphal growth in Candida albicans.
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King WR, Singer J, Warman M, Wilson D, Hube B, Lager I, and Patton-Vogt J
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- Animals, Humans, Mice, Glycerylphosphorylcholine metabolism, Phosphatidylcholines metabolism, Acyltransferases genetics, Acyltransferases metabolism, Candida albicans genetics, Candida albicans growth & development, Candida albicans metabolism
- Abstract
Candida albicans is a commensal fungus, opportunistic pathogen, and the most common cause of fungal infection in humans. The biosynthesis of phosphatidylcholine (PC), a major eukaryotic glycerophospholipid, occurs through two primary pathways. In Saccharomyces cerevisiae and some plants, a third PC synthesis pathway, the PC deacylation/reacylation pathway (PC-DRP), has been characterized. PC-DRP begins with the acylation of the lipid turnover product, glycerophosphocholine (GPC), by the GPC acyltransferase, Gpc1, to form Lyso-PC. Lyso-PC is then acylated by lysolipid acyltransferase, Lpt1, to produce PC. Importantly, GPC, the substrate for Gpc1, is a ubiquitous metabolite available within the host. GPC is imported by C. albicans, and deletion of the major GPC transporter, Git3, leads to decreased virulence in a murine model. Here we report that GPC can be directly acylated in C. albicans by the protein product of orf19.988, a homolog of ScGpc1. Through lipidomic studies, we show loss of Gpc1 leads to a decrease in PC levels. This decrease occurs in the absence of exogenous GPC, indicating that the impact on PC levels may be greater in the human host where GPC is available. A gpc1Δ/Δ strain exhibits several sensitivities to antifungals that target lipid metabolism. Furthermore, loss of Gpc1 results in both a hyphal growth defect in embedded conditions and a decrease in long-term cell viability. These results demonstrate for the first time the importance of Gpc1 and this alternative PC biosynthesis route (PC-DRP) to the physiology of a pathogenic fungus., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.) more...
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- 2024
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30. Respiration supports intraphagosomal filamentation and escape of Candida albicans from macrophages.
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Case NT, Westman J, Hallett MT, Plumb J, Farheen A, Maxson ME, MacAlpine J, Liston SD, Hube B, Robbins N, Whitesell L, Grinstein S, and Cowen LE
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- Mice, Animals, Hyphae growth & development, Hyphae genetics, Hyphae metabolism, Glycolysis, Protein Serine-Threonine Kinases metabolism, Protein Serine-Threonine Kinases genetics, Fungal Proteins genetics, Fungal Proteins metabolism, Glucose metabolism, Candidiasis microbiology, Virulence, Humans, Ribosomes metabolism, Candida albicans genetics, Candida albicans metabolism, Candida albicans physiology, Candida albicans pathogenicity, Macrophages microbiology
- Abstract
Importance: Candida albicans is a leading human fungal pathogen that often causes life-threatening infections in immunocompromised individuals. The ability of C. albicans to transition between yeast and filamentous forms is key to its virulence, and this occurs in response to many host-relevant cues, including engulfment by host macrophages. While previous efforts identified C. albicans genes required for filamentation in other conditions, the genes important for this morphological transition upon internalization by macrophages remained largely enigmatic. Here, we employed a functional genomic approach to identify genes that enable C. albicans filamentation within macrophages and uncovered a role for the mitochondrial ribosome, respiration, and the SNF1 AMP-activated kinase complex. Additionally, we showed that glucose uptake and glycolysis by macrophages support C. albicans filamentation. This work provides insights into the metabolic dueling that occurs during the interaction of C. albicans with macrophages and identifies vulnerabilities in C. albicans that could serve as promising therapeutic targets., Competing Interests: L.E.C. and L.W. are co-founders and shareholders in Bright Angel Therapeutics, a platform company for the development of novel antifungal therapeutics. L.E.C. is a science advisor for Kapoose Creek, a company that harnesses the therapeutic potential of fungi. S.D.L. is currently employed by Bright Angel Therapeutics. All other authors have no competing interests to report. more...
- Published
- 2023
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31. Candida albicans induces neutrophil extracellular traps and leucotoxic hypercitrullination via candidalysin.
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Unger L, Skoluda S, Backman E, Amulic B, Ponce-Garcia FM, Etiaba CN, Yellagunda S, Krüger R, von Bernuth H, Bylund J, Hube B, Naglik JR, and Urban CF
- Subjects
- Calcium metabolism, Fungal Proteins metabolism, Candida albicans metabolism, Extracellular Traps metabolism
- Abstract
The peptide toxin candidalysin, secreted by Candida albicans hyphae, promotes stimulation of neutrophil extracellular traps (NETs). However, candidalysin alone triggers a distinct mechanism for NET-like structures (NLS), which are more compact and less fibrous than canonical NETs. Candidalysin activates NADPH oxidase and calcium influx, with both processes contributing to morphological changes in neutrophils resulting in NLS formation. NLS are induced by leucotoxic hypercitrullination, which is governed by calcium-induced protein arginine deaminase 4 activation and initiation of intracellular signalling events in a dose- and time-dependent manner. However, activation of signalling by candidalysin does not suffice to trigger downstream events essential for NET formation, as demonstrated by lack of lamin A/C phosphorylation, an event required for activation of cyclin-dependent kinases that are crucial for NET release. Candidalysin-triggered NLS demonstrate anti-Candida activity, which is resistant to nuclease treatment and dependent on the deprivation of Zn
2+ . This study reveals that C. albicans hyphae releasing candidalysin concurrently trigger canonical NETs and NLS, which together form a fibrous sticky network that entangles C. albicans hyphae and efficiently inhibits their growth., (© 2023 The Authors. Published under the terms of the CC BY 4.0 license.) more...- Published
- 2023
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32. Toll-like receptor 4 and CD11b expressed on microglia coordinate eradication of Candida albicans cerebral mycosis.
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Wu Y, Du S, Bimler LH, Mauk KE, Lortal L, Kichik N, Griffiths JS, Osicka R, Song L, Polsky K, Kasper L, Sebo P, Weatherhead J, Knight JM, Kheradmand F, Zheng H, Richardson JP, Hube B, Naglik JR, and Corry DB more...
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- Animals, Mice, Alzheimer Disease metabolism, Alzheimer Disease microbiology, Amyloid beta-Peptides metabolism, Candida albicans metabolism, Fungal Proteins metabolism, Microglia metabolism, Microglia microbiology, Mycoses genetics, Mycoses metabolism, Toll-Like Receptor 4 metabolism, CD11b Antigen metabolism
- Abstract
The fungal pathogen Candida albicans is linked to chronic brain diseases such as Alzheimer's disease (AD), but the molecular basis of brain anti-Candida immunity remains unknown. We show that C. albicans enters the mouse brain from the blood and induces two neuroimmune sensing mechanisms involving secreted aspartic proteinases (Saps) and candidalysin. Saps disrupt tight junction proteins of the blood-brain barrier (BBB) to permit fungal brain invasion. Saps also hydrolyze amyloid precursor protein (APP) into amyloid β (Aβ)-like peptides that bind to Toll-like receptor 4 (TLR4) and promote fungal killing in vitro while candidalysin engages the integrin CD11b (Mac-1) on microglia. Recognition of Aβ-like peptides and candidalysin promotes fungal clearance from the brain, and disruption of candidalysin recognition through CD11b markedly prolongs C. albicans cerebral mycosis. Thus, C. albicans is cleared from the brain through innate immune mechanisms involving Saps, Aβ, candidalysin, and CD11b., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.) more...
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- 2023
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33. Selection of cross-reactive T cells by commensal and food-derived yeasts drives cytotoxic T H 1 cell responses in Crohn's disease.
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Martini GR, Tikhonova E, Rosati E, DeCelie MB, Sievers LK, Tran F, Lessing M, Bergfeld A, Hinz S, Nikolaus S, Kümpers J, Matysiak A, Hofmann P, Saggau C, Schneiders S, Kamps AK, Jacobs G, Lieb W, Maul J, Siegmund B, Seegers B, Hinrichsen H, Oberg HH, Wesch D, Bereswill S, Heimesaat MM, Rupp J, Kniemeyer O, Brakhage AA, Brunke S, Hube B, Aden K, Franke A, Iliev ID, Scheffold A, Schreiber S, and Bacher P more...
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- Humans, CD4-Positive T-Lymphocytes, T-Lymphocytes, Helper-Inducer, Clone Cells pathology, Intestinal Mucosa pathology, Th17 Cells pathology, Th1 Cells pathology, Crohn Disease microbiology, Inflammatory Bowel Diseases pathology
- Abstract
Aberrant CD4
+ T cell reactivity against intestinal microorganisms is considered to drive mucosal inflammation in inflammatory bowel diseases. The disease-relevant microbial species and the corresponding microorganism-specific, pathogenic T cell phenotypes remain largely unknown. In the present study, we identified common gut commensal and food-derived yeasts, as direct activators of altered CD4+ T cell reactions in patients with Crohn's disease (CD). Yeast-responsive CD4+ T cells in CD display a cytotoxic T helper cell (TH 1 cell) phenotype and show selective expansion of T cell clones that are highly cross-reactive to several commensal, as well as food-derived, fungal species. This indicates cross-reactive T cell selection by repeated encounter with conserved fungal antigens in the context of chronic intestinal disease. Our results highlighted a role of yeasts as drivers of aberrant CD4+ T cell reactivity in patients with CD and suggest that both gut-resident fungal commensals and daily dietary intake of yeasts might contribute to chronic activation of inflammatory CD4+ T cell responses in patients with CD., (© 2023. The Author(s).) more...- Published
- 2023
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34. Candida expansion in the gut of lung cancer patients associates with an ecological signature that supports growth under dysbiotic conditions.
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Seelbinder B, Lohinai Z, Vazquez-Uribe R, Brunke S, Chen X, Mirhakkak M, Lopez-Escalera S, Dome B, Megyesfalvi Z, Berta J, Galffy G, Dulka E, Wellejus A, Weiss GJ, Bauer M, Hube B, Sommer MOA, and Panagiotou G more...
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- Male, Cross-Sectional Studies, Dysbiosis, Female, Humans, Lactic Acid, Candidiasis, Candida, Lung Neoplasms
- Abstract
Candida species overgrowth in the human gut is considered a prerequisite for invasive candidiasis, but our understanding of gut bacteria promoting or restricting this overgrowth is still limited. By integrating cross-sectional mycobiome and shotgun metagenomics data from the stool of 75 male and female cancer patients at risk but without systemic candidiasis, bacterial communities in high Candida samples display higher metabolic flexibility yet lower contributional diversity than those in low Candida samples. We develop machine learning models that use only bacterial taxa or functional relative abundances to predict the levels of Candida genus and species in an external validation cohort with an AUC of 78.6-81.1%. We propose a mechanism for intestinal Candida overgrowth based on an increase in lactate-producing bacteria, which coincides with a decrease in bacteria that regulate short chain fatty acid and oxygen levels. Under these conditions, the ability of Candida to harness lactate as a nutrient source may enable Candida to outcompete other fungi in the gut., (© 2023. The Author(s).) more...
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- 2023
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35. Antigen specificity and cross-reactivity drive functionally diverse anti-Aspergillus fumigatus T cell responses in cystic fibrosis.
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Schwarz C, Eschenhagen P, Schmidt H, Hohnstein T, Iwert C, Grehn C, Roehmel J, Steinke E, Stahl M, Lozza L, Tikhonova E, Rosati E, Stervbo U, Babel N, Mainz JG, Wisplinghoff H, Ebel F, Jia LJ, Blango MG, Hortschansky P, Brunke S, Hube B, Brakhage AA, Kniemeyer O, Scheffold A, and Bacher P more...
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- Aspergillus fumigatus, Immunity, Immunoglobulin E, Inflammation, Cystic Fibrosis, Aspergillosis, Allergic Bronchopulmonary
- Abstract
BACKGROUNDThe fungus Aspergillus fumigatus causes a variety of clinical phenotypes in patients with cystic fibrosis (pwCF). Th cells orchestrate immune responses against fungi, but the types of A. fumigatus-specific Th cells in pwCF and their contribution to protective immunity or inflammation remain poorly characterized.METHODSWe used antigen-reactive T cell enrichment (ARTE) to investigate fungus-reactive Th cells in peripheral blood of pwCF and healthy controls.RESULTSWe show that clonally expanded, high-avidity A. fumigatus-specific effector Th cells, which were absent in healthy donors, developed in pwCF. Individual patients were characterized by distinct Th1-, Th2-, or Th17-dominated responses that remained stable over several years. These different Th subsets target different A. fumigatus proteins, indicating that differential antigen uptake and presentation directs Th cell subset development. Patients with allergic bronchopulmonary aspergillosis (ABPA) are characterized by high frequencies of Th2 cells that cross-recognize various filamentous fungi.CONCLUSIONOur data highlight the development of heterogenous Th responses targeting different protein fractions of a single fungal pathogen and identify the development of multispecies cross-reactive Th2 cells as a potential risk factor for ABPA.FUNDINGGerman Research Foundation (DFG), under Germany's Excellence Strategy (EXC 2167-390884018 "Precision Medicine in Chronic Inflammation" and EXC 2051-390713860 "Balance of the Microverse"); Oskar Helene Heim Stiftung; Christiane Herzog Stiftung; Mukoviszidose Institut gGmb; German Cystic Fibrosis Association Mukoviszidose e.V; German Federal Ministry of Education and Science (BMBF) InfectControl 2020 Projects AnDiPath (BMBF 03ZZ0838A+B). more...
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- 2023
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36. "Under Pressure" - How fungi evade, exploit, and modulate cells of the innate immune system.
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Lange T, Kasper L, Gresnigt MS, Brunke S, and Hube B
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- Humans, Macrophages, Fungi, Host-Pathogen Interactions, Immune Evasion
- Abstract
The human immune system uses an arsenal of effector mechanisms to prevent and counteract infections. Yet, some fungal species are extremely successful as human pathogens, which can be attributed to a wide variety of strategies by which these fungi evade, exploit, and modulate the immune system. These fungal pathogens normally are either harmless commensals or environmental fungi. In this review we discuss how commensalism, but also life in an environmental niche without human contact, can drive the evolution of diverse and specialized immune evasion mechanisms. Correspondingly, we discuss the mechanisms contributing to the ability of these fungi to cause superficial to life-threatening infections., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.) more...
- Published
- 2023
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37. Ecological Niche-Inspired Genome Mining Leads to the Discovery of Crop-Protecting Nonribosomal Lipopeptides Featuring a Transient Amino Acid Building Block.
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Götze S, Vij R, Burow K, Thome N, Urbat L, Schlosser N, Pflanze S, Müller R, Hänsch VG, Schlabach K, Fazlikhani L, Walther G, Dahse HM, Regestein L, Brunke S, Hube B, Hertweck C, Franken P, and Stallforth P more...
- Subjects
- Amino Acids genetics, Antifungal Agents pharmacology, Antifungal Agents metabolism, Genomics, Multigene Family, Lipopeptides pharmacology, Lipopeptides chemistry, Anti-Infective Agents
- Abstract
Investigating the ecological context of microbial predator-prey interactions enables the identification of microorganisms, which produce multiple secondary metabolites to evade predation or to kill the predator. In addition, genome mining combined with molecular biology methods can be used to identify further biosynthetic gene clusters that yield new antimicrobials to fight the antimicrobial crisis. In contrast, classical screening-based approaches have limitations since they do not aim to unlock the entire biosynthetic potential of a given organism. Here, we describe the genomics-based identification of keanumycins A-C. These nonribosomal peptides enable bacteria of the genus Pseudomonas to evade amoebal predation. While being amoebicidal at a nanomolar level, these compounds also exhibit a strong antimycotic activity in particular against the devastating plant pathogen Botrytis cinerea and they drastically inhibit the infection of Hydrangea macrophylla leaves using only supernatants of Pseudomonas cultures. The structures of the keanumycins were fully elucidated through a combination of nuclear magnetic resonance, tandem mass spectrometry, and degradation experiments revealing an unprecedented terminal imine motif in keanumycin C extending the family of nonribosomal amino acids by a highly reactive building block. In addition, chemical synthesis unveiled the absolute configuration of the unusual dihydroxylated fatty acid of keanumycin A, which has not yet been reported for this lipodepsipeptide class. Finally, a detailed genome-wide microarray analysis of Candida albicans exposed to keanumycin A shed light on the mode-of-action of this potential natural product lead, which will aid the development of new pharmaceutical and agrochemical antifungals. more...
- Published
- 2023
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38. Candidalysin Is the Hemolytic Factor of Candida albicans .
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Mogavero S, Höfs S, Lauer AN, Müller R, Brunke S, Allert S, Gerwien F, Groth S, Dolk E, Wilson D, Gutsmann T, and Hube B
- Subjects
- Fungal Proteins, Candida, Mucous Membrane, Virulence Factors toxicity, Candida albicans, Hemolysis
- Abstract
Candida albicans produces an important virulence factor, the hypha-associated Ece1 -derived secreted peptide toxin candidalysin, which is crucial for the establishment of mucosal and systemic infections. C. albicans has also long been known to be hemolytic, yet the hemolytic factor has not been clearly identified. Here, we show that candidalysin is the hemolytic factor of C. albicans . Its hemolytic activity is modulated by fragments of another Ece1 peptide, P7. Hemolysis by candidalysin can be neutralized by the purinergic receptor antagonist pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid (PPADS). PPADS also affects candidalysin's ability to intercalate into synthetic membranes. We also describe the neutralization potential of two anti-candidalysin nanobodies, which are promising candidates for future anti- Candida therapy. This work provides evidence that the historically proposed hemolytic factor of C. albicans is in fact candidalysin and sheds more light on the complex roles of this toxin in C. albicans biology and pathogenicity. more...
- Published
- 2022
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39. From environmental adaptation to host survival: Attributes that mediate pathogenicity of Candida auris .
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Allert S, Schulz D, Kämmer P, Großmann P, Wolf T, Schäuble S, Panagiotou G, Brunke S, and Hube B
- Subjects
- Antifungal Agents pharmacology, Candida genetics, Candida albicans, Candida glabrata, Humans, Virulence, Candida auris, Candidiasis microbiology
- Abstract
Candida species are a major cause of invasive fungal infections. While Candida albicans, C. glabrata, C. parapsilosis , and C. tropicalis are the most dominant species causing life-threatening candidiasis, C. auris recently emerged as a new species causing invasive infections with high rates of clinical treatment failures. To mimic initial phases of systemic Candida infections with dissemination via the bloodstream and to elucidate the pathogenic potential of C. auris , we used an ex vivo whole blood infection model. Similar to other clinically relevant Candida spp., C. auris is efficiently killed in human blood, but showed characteristic patterns of immune cell association, survival rates, and cytokine induction. Dual-species transcriptional profiling of C. auris -infected blood revealed a unique C. auris gene expression program during infection, while the host response proofed similar and conserved compared to other Candida species. C. auris -specific responses included adaptation and survival strategies, such as counteracting oxidative burst of immune cells, but also expression of potential virulence factors, (drug) transporters, and cell surface-associated genes. Despite comparable pathogenicity to other Candida species in our model, C. auris -specific transcriptional adaptations as well as its increased stress resistance and long-term environmental survival, likely contribute to the high risk of contamination and distribution in a nosocomial setting. Moreover, infections of neutrophils with pre-starved C. auris cells suggest that environmental preconditioning can have modulatory effects on the early host interaction. In summary, we present novel insights into C. auris pathogenicity, revealing adaptations to human blood and environmental niches distinctive from other Candida species. more...
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- 2022
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40. Targeted Suppression of Peptide Degradation in Ag-Based Surface-Enhanced Raman Spectra by Depletion of Hot Carriers.
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Yao X, Höppener C, Schneidewind H, Hoeppener S, Tang Z, Buchholz A, König A, Mogavero S, Diegel M, Dellith J, Turchanin A, Plass W, Hube B, and Deckert V
- Subjects
- Microscopy, Atomic Force, Iodides, Spectrum Analysis, Raman methods
- Abstract
Sample degradation, in particular of biomolecules, frequently occurs in surface-enhanced Raman spectroscopy (SERS) utilizing supported silver SERS substrates. Currently, thermal and/or photocatalytic effects are considered to cause sample degradation. This paper establishes the efficient inhibition of sample degradation using iodide which is demonstrated by a systematic SERS study of a small peptide in aqueous solution. Remarkably, a distinct charge separation-induced surface potential difference is observed for SERS substrates under laser irradiation using Kelvin probe force microscopy. This directly unveils the photocatalytic effect of Ag-SERS substrates. Based on the presented results, it is proposed that plasmonic photocatalysis dominates sample degradation in SERS experiments and the suppression of typical SERS sample degradation by iodide is discussed by means of the energy levels of the substrate under mild irradiation conditions. This approach paves the way toward more reliable and reproducible SERS studies of biomolecules under physiological conditions., (© 2022 The Authors. Small published by Wiley-VCH GmbH.) more...
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- 2022
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41. Author Correction: Immune regulation by fungal strain diversity in inflammatory bowel disease.
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Li XV, Leonardi I, Putzel GG, Semon A, Fiers WD, Kusakabe T, Lin WY, Gao IH, Doron I, Gutierrez-Guerrero A, DeCelie MB, Carriche GM, Mesko M, Yang C, Naglik JR, Hube B, Scherl EJ, and Iliev ID
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- 2022
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42. Emergence and evolution of virulence in human pathogenic fungi.
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Siscar-Lewin S, Hube B, and Brunke S
- Subjects
- Humans, Virulence genetics, Virulence Factors genetics, Fungi genetics, Mycoses microbiology
- Abstract
One billion people worldwide are affected by fungal pathogens, of which 1.6 million succumb to fungal infections per year. This review discusses the emergence and evolution of fungal pathogenesis in humans in the form of opportunistic commensal and environmental fungi. We explore the attributes that contribute to their success as pathogens and the scenarios which may have caused the evolutionary selection of virulence factors. This includes antivirulence and avirulence genes, notions that are new for fungal pathogens of humans but which are based on well established concepts in bacterial pathogens and phytopathogenic fungi. These ideas will ultimately help us to better understand the pathogenicity of fungi that infect humans: from the emergence to the finer adjustment of virulence to promote pathogen persistence., Competing Interests: Declaration of interests No interests are declared., (Copyright © 2022 Elsevier Ltd. All rights reserved.) more...
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- 2022
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43. Lactobacillus rhamnosus colonisation antagonizes Candida albicans by forcing metabolic adaptations that compromise pathogenicity.
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Alonso-Roman R, Last A, Mirhakkak MH, Sprague JL, Möller L, Großmann P, Graf K, Gratz R, Mogavero S, Vylkova S, Panagiotou G, Schäuble S, Hube B, and Gresnigt MS
- Subjects
- Candida, Candida albicans, Virulence, Candidiasis microbiology, Lacticaseibacillus rhamnosus
- Abstract
Intestinal microbiota dysbiosis can initiate overgrowth of commensal Candida species - a major predisposing factor for disseminated candidiasis. Commensal bacteria such as Lactobacillus rhamnosus can antagonize Candida albicans pathogenicity. Here, we investigate the interplay between C. albicans, L. rhamnosus, and intestinal epithelial cells by integrating transcriptional and metabolic profiling, and reverse genetics. Untargeted metabolomics and in silico modelling indicate that intestinal epithelial cells foster bacterial growth metabolically, leading to bacterial production of antivirulence compounds. In addition, bacterial growth modifies the metabolic environment, including removal of C. albicans' favoured nutrient sources. This is accompanied by transcriptional and metabolic changes in C. albicans, including altered expression of virulence-related genes. Our results indicate that intestinal colonization with bacteria can antagonize C. albicans by reshaping the metabolic environment, forcing metabolic adaptations that reduce fungal pathogenicity., (© 2022. The Author(s).) more...
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- 2022
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44. Immune regulation by fungal strain diversity in inflammatory bowel disease.
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Li XV, Leonardi I, Putzel GG, Semon A, Fiers WD, Kusakabe T, Lin WY, Gao IH, Doron I, Gutierrez-Guerrero A, DeCelie MB, Carriche GM, Mesko M, Yang C, Naglik JR, Hube B, Scherl EJ, and Iliev ID
- Subjects
- Animals, CRISPR-Cas Systems, Candida albicans, Genetic Variation, Humans, Immunity, Inflammation, Mammals, Fungi genetics, Fungi pathogenicity, Gastrointestinal Microbiome, Inflammatory Bowel Diseases, Microbiota, Mycobiome
- Abstract
The fungal microbiota (mycobiota) is an integral part of the complex multikingdom microbial community colonizing the mammalian gastrointestinal tract and has an important role in immune regulation <superscript>1-6 . Although aberrant changes in the mycobiota have been linked to several diseases, including inflammatory bowel disease
3-9 , it is currently unknown whether fungal species captured by deep sequencing represent living organisms and whether specific fungi have functional consequences for disease development in affected individuals. Here we developed a translational platform for the functional analysis of the mycobiome at the fungal-strain- and patient-specific level. Combining high-resolution mycobiota sequencing, fungal culturomics and genomics, a CRISPR-Cas9-based fungal strain editing system, in vitro functional immunoreactivity assays and in vivo models, this platform enables the examination of host-fungal crosstalk in the human gut. We discovered a rich genetic diversity of opportunistic Candida albicans strains that dominate the colonic mucosa of patients with inflammatory bowel disease. Among these human-gut-derived isolates, strains with high immune-cell-damaging capacity (HD strains) reflect the disease features of individual patients with ulcerative colitis and aggravated intestinal inflammation in vivo through IL-1β-dependent mechanisms. Niche-specific inflammatory immunity and interleukin-17A-producing T helper cell (TH 17 cell) antifungal responses by HD strains in the gut were dependent on the C. albicans-secreted peptide toxin candidalysin during the transition from a benign commensal to a pathobiont state. These findings reveal the strain-specific nature of host-fungal interactions in the human gut and highlight new diagnostic and therapeutic targets for diseases of inflammatory origin., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.) more...- Published
- 2022
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45. Candidalysins Are a New Family of Cytolytic Fungal Peptide Toxins.
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Richardson JP, Brown R, Kichik N, Lee S, Priest E, Mogavero S, Maufrais C, Wickramasinghe DN, Tsavou A, Kotowicz NK, Hepworth OW, Gallego-Cortés A, Ponde NO, Ho J, Moyes DL, Wilson D, D'Enfert C, Hube B, and Naglik JR more...
- Subjects
- Humans, Calcium metabolism, Fungal Proteins metabolism, Candida albicans metabolism, Candida tropicalis, Peptides metabolism, Cytokines metabolism, Mycotoxins
- Abstract
Candidalysin is the first cytolytic peptide toxin identified in any human fungal pathogen. Candidalysin is secreted by Candida albicans and is critical for driving infection and host immune responses in several model systems. However, Candida infections are also caused by non-C. albicans species. Here, we identify and characterize orthologs of C. albicans candidalysin in C. dubliniensis and C. tropicalis. The candidalysins have different amino acid sequences, are amphipathic, and adopt a predominantly α-helical secondary structure in solution. Comparative functional analysis demonstrates that each candidalysin causes epithelial damage and calcium influx and activates intracellular signaling pathways and cytokine secretion. Importantly, C. dubliniensis and C. tropicalis candidalysins have higher damaging and activation potential than C. albicans candidalysin and exhibit more rapid membrane binding and disruption, although both fungal species cause less damage to epithelial cells than C. albicans. This study identifies the first family of peptide cytolysins in human-pathogenic fungi. IMPORTANCE Pathogenic fungi kill an estimated 1.5 million people every year. Recently, we discovered that the fungal pathogen Candida albicans secretes a peptide toxin called candidalysin during mucosal infection. Candidalysin causes damage to host cells, a process that supports disease progression. However, fungal infections are also caused by Candida species other than C. albicans. In this work, we identify and characterize two additional candidalysin toxins present in the related fungal pathogens C. dubliniensis and C. tropicalis. While the three candidalysins have different amino acid sequences, all three toxins are α-helical and amphipathic. Notably, the candidalysins from C. dubliniensis and C. tropicalis are more potent at inducing cell damage, calcium influx, mitogen-activated protein kinase signaling, and cytokine responses than C. albicans candidalysin, with the C. dubliniensis candidalysin having the most rapid membrane binding kinetics. These observations identify the candidalysins as the first family of peptide toxins in human-pathogenic fungi. more...
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- 2022
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46. Calcium-dependent ESCRT recruitment and lysosome exocytosis maintain epithelial integrity during Candida albicans invasion.
- Author
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Westman J, Plumb J, Licht A, Yang M, Allert S, Naglik JR, Hube B, Grinstein S, and Maxson ME
- Subjects
- Animals, Calcium metabolism, Cell Line, Cell Membrane physiology, Epithelial Cells metabolism, Exocytosis physiology, Fungal Proteins genetics, Host-Pathogen Interactions, Humans, Hyphae growth & development, Mice, Mucous Membrane cytology, Mucous Membrane microbiology, Phosphotransferases (Alcohol Group Acceptor) metabolism, RAW 264.7 Cells, Candida albicans metabolism, Candidiasis pathology, Endosomal Sorting Complexes Required for Transport metabolism, Fungal Proteins metabolism, Lysosomes metabolism, Mucous Membrane physiology
- Abstract
Candida albicans is both a commensal and an opportunistic fungal pathogen. Invading hyphae of C. albicans secrete candidalysin, a pore-forming peptide toxin. To prevent cell death, epithelial cells must protect themselves from direct damage induced by candidalysin and by the mechanical forces exerted by expanding hyphae. We identify two key Ca
2+ -dependent repair mechanisms employed by epithelial cells to withstand candidalysin-producing hyphae. Using camelid nanobodies, we demonstrate candidalysin secretion directly into the invasion pockets induced by elongating C. albicans hyphae. The toxin induces oscillatory increases in cytosolic [Ca2+ ], which cause hydrolysis of PtdIns(4,5)P2 and loss of cortical actin. Epithelial cells dispose of damaged membrane regions containing candidalysin by an Alg-2/Alix/ESCRT-III-dependent blebbing process. At later stages, plasmalemmal tears induced mechanically by invading hyphae are repaired by exocytic insertion of lysosomal membranes. These two repair mechanisms maintain epithelial integrity and prevent mucosal damage during both commensal growth and infection by C. albicans., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.) more...- Published
- 2022
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47. Membrane protective role of autophagic machinery during infection of epithelial cells by Candida albicans .
- Author
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Lapaquette P, Ducreux A, Basmaciyan L, Paradis T, Bon F, Bataille A, Winckler P, Hube B, d'Enfert C, Esclatine A, Dubus E, Bringer MA, Morel E, and Dalle F
- Subjects
- Autophagy-Related Protein 5 genetics, Autophagy-Related Protein 5 metabolism, Autophagy-Related Proteins genetics, Autophagy-Related Proteins metabolism, Candida albicans genetics, Candidiasis genetics, Candidiasis metabolism, Candidiasis physiopathology, Epithelial Cells cytology, Epithelial Cells metabolism, Gastrointestinal Microbiome, Host-Pathogen Interactions, Humans, Membrane Proteins genetics, Membrane Proteins metabolism, Phosphate-Binding Proteins genetics, Phosphate-Binding Proteins metabolism, Autophagy, Candida albicans physiology, Candidiasis microbiology, Cell Membrane microbiology, Epithelial Cells microbiology
- Abstract
Candida albicans ( C. albicans ) is an opportunistic pathogen causing infections ranging from superficial to life-threatening disseminated infections. In a susceptible host, C. albicans is able to translocate through the gut barrier, promoting its dissemination into deeper organs. C. albicans hyphae can invade human epithelial cells by two well-documented mechanisms: epithelial-driven endocytosis and C. albicans -driven active penetration. One mechanism by which host cells protect themselves against intracellular C. albicans is termed autophagy. The protective role of autophagy during C. albicans infection has been investigated in myeloid cells; however, far less is known regarding the role of this process during the infection of epithelial cells. In the present study, we investigated the role of autophagy-related proteins during the infection of epithelial cells, including intestinal epithelial cells and gut explants, by C. albicans . Using cell imaging, we show that key molecular players of the autophagy machinery (LC3-II, PI3P, ATG16L1, and WIPI2) were recruited at Candida invasion sites. We deepened these observations by electron microscopy analyses that reveal the presence of autophagosomes in the vicinity of invading hyphae. Importantly, these events occur during active penetration of C. albicans into host cells and are associated with plasma membrane damage. In this context, we show that the autophagy-related key proteins ATG5 and ATG16L1 contribute to plasma membrane repair mediated by lysosomal exocytosis and participate in protecting epithelial cells against C. albicans -induced cell death. Our findings provide a novel mechanism by which epithelial cells, forming the first line of defense against C. albicans in the gut, can react to limit C. albicans invasion. more...
- Published
- 2022
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48. From intestinal colonization to systemic infections: Candida albicans translocation and dissemination.
- Author
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Sprague JL, Kasper L, and Hube B
- Subjects
- Humans, Intestines, Candida albicans, Gastrointestinal Microbiome
- Abstract
Candida species are the most prevalent cause of invasive fungal infections, of which Candida albicans is the most common. Translocation across the epithelial barrier into the bloodstream by intestinal-colonizing C. albicans cells serves as the main source for systemic infections. Understanding the fungal mechanisms behind this process will give valuable insights on how to prevent such infections and keep C. albicans in the commensal state in patients with predisposing conditions. This review will focus on recent developments in characterizing fungal translocation mechanisms, compare what we know about enteric bacterial pathogens with C. albicans , and discuss the different proposed hypotheses for how C. albicans enters and disseminates through the bloodstream immediately following translocation. more...
- Published
- 2022
- Full Text
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49. Functionality of the human antibody response to Candida albicans .
- Author
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Wich M, Greim S, Ferreira-Gomes M, Krüger T, Kniemeyer O, Brakhage AA, Jacobsen ID, Hube B, and Jungnickel B
- Subjects
- Antibody Formation, Antifungal Agents pharmacology, Aspartic Acid Endopeptidases, Humans, Aspartic Acid Proteases, Candida albicans
- Abstract
Candida albicans is a common commensal on human mucosal surfaces, but can become pathogenic, e.g. if the host is immunocompromised. While neutrophils, macrophages and T cells are regarded as major players in the defense against pathogenic C. albicans , the role of B cells and the protective function of their antibodies are less well characterized. In this study, we show that human serum antibodies are able to enhance the association of human THP-1 monocyte-like cells with C. albicans cells. Human serum antibodies are also capable of inhibiting the adherence and damage dealt to epithelial cells. Furthermore, human serum antibodies impair C. albicans invasion of human oral epithelial cells by blocking induced endocytosis and consequently host cell damage. While aspartic proteases secreted by C. albicans are able to cleave human IgG, this process does not appear to affect the protective function of human antibodies. Thus, humans are equipped with a robust antibody response to C. albicans , which can enhance antifungal activities and prevent fungal-mediated epithelial damage. more...
- Published
- 2021
- Full Text
- View/download PDF
50. Candida albicans elicits protective allergic responses via platelet mediated T helper 2 and T helper 17 cell polarization.
- Author
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Wu Y, Zeng Z, Guo Y, Song L, Weatherhead JE, Huang X, Zeng Y, Bimler L, Chang CY, Knight JM, Valladolid C, Sun H, Cruz MA, Hube B, Naglik JR, Luong AU, Kheradmand F, and Corry DB
- Subjects
- Blood Platelets metabolism, Hypersensitivity metabolism, Lymphocyte Activation immunology, T-Lymphocyte Subsets metabolism, Th17 Cells immunology, Th17 Cells metabolism, Th2 Cells immunology, Th2 Cells metabolism, Blood Platelets immunology, Candida albicans physiology, Candidiasis complications, Candidiasis immunology, Disease Susceptibility, Host-Pathogen Interactions immunology, Hypersensitivity complications, Hypersensitivity immunology, T-Lymphocyte Subsets immunology
- Abstract
Fungal airway infection (airway mycosis) is an important cause of allergic airway diseases such as asthma, but the mechanisms by which fungi trigger asthmatic reactions are poorly understood. Here, we leverage wild-type and mutant Candida albicans to determine how this common fungus elicits characteristic Th2 and Th17 cell-dependent allergic airway disease in mice. We demonstrate that rather than proteinases that are essential virulence factors for molds, C. albicans instead promoted allergic airway disease through the peptide toxin candidalysin. Candidalysin activated platelets through the Von Willebrand factor (VWF) receptor GP1bα to release the Wnt antagonist Dickkopf-1 (Dkk-1) to drive Th2 and Th17 cell responses that correlated with reduced lung fungal burdens. Platelets simultaneously precluded lethal pulmonary hemorrhage resulting from fungal lung invasion. Thus, in addition to hemostasis, platelets promoted protection against C. albicans airway mycosis through an antifungal pathway involving candidalysin, GP1bα, and Dkk-1 that promotes Th2 and Th17 responses., Competing Interests: Declaration of interests D.B.C is a scientific consultant to Atrapos Therapeutics, LLC and Pulmocide, LLC., (Copyright © 2021 Elsevier Inc. All rights reserved.) more...
- Published
- 2021
- Full Text
- View/download PDF
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