Role of Soluble Innate Effector Molecules in Pulmonary Defense against Fungal Pathogens

Grapevine trunk diseases (GTDs) are considered a serious problem to viticulture worldwide. Several GTD fungal pathogens produce phytotoxic metabolites (PMs) that were hypothesized to migrate to the foliage where they cause distinct symptoms. The role of PMs in the expression of Botryosphaeria dieback (BD) symptoms in naturally infected and artificially inoculated wood using molecular and analytical chemistry techniques was investigated. Wood samples from field vines naturally infected with BD and one-year-old vines inoculated with Diplodia seriata, Spencermartinsia viticola and Dothiorella vidmadera were analysed by cultural isolations, quantitative PCR (qPCR) and targeted LC-MS/MS to detect three PMs: (R)-mellein, protocatechuic acid and spencertoxin. (R)-mellein was detected in symptomatic naturally infected wood and vines artificially inoculated with D. seriata but was absent in all non-symptomatic wood. The amount of (R)-mellein detected was correlated with the amount of pathogen DNA detected by qPCR. Protocatechuic acid and spencertoxin were absent in all inoculated wood samples. (R)-mellein may be produced by the pathogen during infection to break down the wood, however it was not translocated into other parts of the vine. The foliar symptoms previously reported in vineyards may be due to a combination of PMs produced and climatic and physiological factors that require further investigation.

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Telomeric and Sub-Telomeric Structure and Implications in Fungal Opportunistic Pathogens

Microorganisms ◽

10.3390/microorganisms9071405 ◽

2021 ◽

Vol 9 (7) ◽

pp. 1405

Author(s):

Raffaella Diotti ◽

Michelle Esposito ◽

Chang Hui Shen

Keyword(s):

Fungal Pathogens ◽

Functional Abilities ◽

Opportunistic Pathogens ◽

Telomeric Sequences ◽

Coding Regions ◽

Telomeric Structure ◽

Linear Chromosomes ◽

Dna Ends ◽

Telomere Structure

Telomeres are long non-coding regions found at the ends of eukaryotic linear chromosomes. Although they have traditionally been associated with the protection of linear DNA ends to avoid gene losses during each round of DNA replication, recent studies have demonstrated that the role of these sequences and their adjacent regions go beyond just protecting chromosomal ends. Regions nearby to telomeric sequences have now been identified as having increased variability in the form of duplications and rearrangements that result in new functional abilities and biodiversity. Furthermore, unique fungal telomeric and chromatin structures have now extended clinical capabilities and understanding of pathogenicity levels. In this review, telomere structure, as well as functional implications, will be examined in opportunistic fungal pathogens, including Aspergillus fumigatus, Candida albicans, Candida glabrata, and Pneumocystis jirovecii.

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Post-Translational Modifications Drive Success and Failure of Fungal–Host Interactions

Journal of Fungi ◽

10.3390/jof7020124 ◽

2021 ◽

Vol 7 (2) ◽

pp. 124

Author(s):

Charmaine Retanal ◽

Brianna Ball ◽

Jennifer Geddes-McAlister

Keyword(s):

Fungal Pathogens ◽

Fungal Infections ◽

Treatment Options ◽

Global Scale ◽

Host Cells ◽

Candida Spp ◽

Post Translational Modifications ◽

Fungal Host ◽

Resistant Species

Post-translational modifications (PTMs) change the structure and function of proteins and regulate a diverse array of biological processes. Fungal pathogens rely on PTMs to modulate protein production and activity during infection, manipulate the host response, and ultimately, promote fungal survival. Given the high mortality rates of fungal infections on a global scale, along with the emergence of antifungal-resistant species, identifying new treatment options is critical. In this review, we focus on the role of PTMs (e.g., phosphorylation, acetylation, ubiquitination, glycosylation, and methylation) among the highly prevalent and medically relevant fungal pathogens, Candida spp., Aspergillus spp., and Cryptococcus spp. We explore the role of PTMs in fungal stress response and host adaptation, the use of PTMs to manipulate host cells and the immune system upon fungal invasion, and the importance of PTMs in conferring antifungal resistance. We also provide a critical view on the current knowledgebase, pose questions key to our understanding of the intricate roles of PTMs within fungal pathogens, and provide research opportunities to uncover new therapeutic strategies.

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Comparison of different extraction kits to isolate microRNA fromGalleria mellonella(wax moth) larvae infected withMetarhizium brunneum(ARSEF4556)

10.1101/606004 ◽

2019 ◽

Author(s):

Muneefah A. Alenezi ◽

Tariq M. Butt ◽

Daniel C. Eastwood

Keyword(s):

Fungal Pathogens ◽

High Throughput Sequencing ◽

Galleria Mellonella ◽

Host Tissue ◽

Tissue Cultures ◽

Complex Environments ◽

Infected Insect ◽

Sequencing And Expression ◽

Wax Moth

ABSTRACTMicroRNAs (miRNAs) play an important role in regulating gene expression and are involved in developmental processes in animals, plants and fungi. To understand the role of miRNAs in a biological system, it is important to optimise the extraction procedures to obtain high quality and quantity nucleic acid that enable high throughput sequencing and expression analysis. Numerous kit-based miRNA extraction protocols have been optimised generally to single cell or tissue cultures. Fungi, however, often occupy physically and chemically complex environments which miRNA make extraction challenging, such as fungal pathogens interacting within plant or animal host tissue. We used aGalleria mellonella(wax moth) larvae and entomopathogenic fungusMetarhizium brunneum ARSEF 4556host/pathogen model to compare commercially available miRNA extraction kits (Invitrogen PureLink™ miRNA Isolation Kit, Ambion mirVana™miRNA Isolation Kit and Norgen microRNA purification Kit). Our results showed reproducible and significant differences in miRNAs extraction between the kits, with the Invitrogen PureLink™ miRNA Isolation protocol demonstrating the best performance in terms of miRNA quantity, quality and integrity isolated from fungus-infected insect tissue.

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Iron metabolismin conditions of infection. Review

Alexander Saltanov Intensive Care Herald ◽

10.21320/1818-474x-2020-1-90-99 ◽

2020 ◽

pp. 90-99

Author(s):

Yuriy P. Orlov ◽

N. V Govorova ◽

V. N Lukach ◽

G. A Baitugaeva ◽

A. V Klementyev ◽

...

Keyword(s):

Fungal Pathogens ◽

Medical Literature ◽

Bacterial Flora ◽

Medical Community ◽

Therapeutic Approaches ◽

Iron Supply ◽

Review Analysis ◽

The Relationship ◽

Iron Exchange

The purpose of writing the review. Analysis of publications on the role of iron metabolism in the manifestation of the septic process and the dependence of bacterial flora activity on the conditions of their access to iron. Methods. More than 200 publications in pubmed, Medline, EMBASE medical literature databases were analyzed between 2000 and 2018 using the search words: iron and infection, iron and sepsis, iron exchange, iron and bacteria - including and available works in domestic (e-library) literature. Results. The review uses materials from 61 publications that meet the challenges of the search and reflect both the relationship between iron exchange and the development of the septic process and the importance for the medical community of understanding the identified relationships in the search for future therapeutic approaches. Conclusion. The review provides evidence of direct iron involvement in the manifestation of the septic process caused by various bacterial (q/-) and fungal flora. Introduction of iron-hesing agents and ciderophon - conjugate drugs to infected patients today seems to be a biologically acceptable approach as an auxiliary therapy in the treatment of septic process caused by pathogens dependent on iron supply (many bacterial and fungal pathogens), but the problem that is being raised certainly requires further experimental and clinical research.

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Lipids Affect the Cryptococcus neoformans-Macrophage Interaction and Promote Nonlytic Exocytosis

Infection and Immunity ◽

10.1128/iai.00564-17 ◽

2017 ◽

Vol 85 (12) ◽

Cited By ~ 6

Author(s):

Sabrina J. Nolan ◽

Man Shun Fu ◽

Isabelle Coppens ◽

Arturo Casadevall

Keyword(s):

Oleic Acid ◽

Cryptococcus Neoformans ◽

Lipid Droplets ◽

Fungal Pathogens ◽

Cellular Lipid ◽

Content Type ◽

Acid Supplementation

ABSTRACT Many microbes exploit host cellular lipid droplets during the host-microbe interaction, but this phenomenon has not been extensively studied for fungal pathogens. In this study, we analyzed the role of lipid droplets during the interaction of Cryptococcus neoformans with macrophages in the presence and the absence of exogenous lipids, in particular, oleate. The addition of oleic acid increased the frequency of lipid droplets in both C. neoformans and macrophages. C. neoformans responded to oleic acid supplementation by faster growth inside and outside macrophages. Fungal cells were able to harvest lipids from macrophage lipid droplets. Supplementation of C. neoformans and macrophages with oleic acid significantly increased the rate of nonlytic exocytosis while having no effect on lytic exocytosis. The process for lipid modulation of nonlytic exocytosis was associated with actin changes in macrophages. In summary, C. neoformans harvests lipids from macrophages, and the C. neoformans-macrophage interaction is modulated by exogenous lipids, providing a new tool for studying nonlytic exocytosis.

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Disparate Role of LIGHT in Organ-specific Donor T Cells Activation and Effector Molecules in MHC Class II Disparate GVHD

Journal of Clinical Immunology ◽

10.1007/s10875-009-9337-1 ◽

2009 ◽

Vol 30 (1) ◽

pp. 178-184 ◽

Cited By ~ 4

Author(s):

Geri R. Brown ◽

George W. Lane ◽

Bonnie J. Whittington

Keyword(s):

T Cells ◽

Mhc Class Ii ◽

Class Ii ◽

Effector Molecules ◽

Donor T Cells ◽

Organ Specific ◽

Role Of Light

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Plant Resistance Genes for Fungal Pathogens - Physiological Models and Identification in Cereal Crops

Zeitschrift für Naturforschung C ◽

10.1515/znc-1991-11-1208 ◽

1991 ◽

Vol 46 (11-12) ◽

pp. 969-981 ◽

Cited By ~ 11

Author(s):

Wolfgang Knogge

Keyword(s):

Plant Defense ◽

Resistance Genes ◽

Fungal Pathogens ◽

Plant Protection ◽

Defense Responses ◽

Avirulence Gene ◽

Physiological Models ◽

Plant Genes ◽

Plant Pathogen Interaction

The complex biological phenomenon “resistance” can be reduced to single Mendelian traits acting on both the plant and the pathogen side in a number of pathosystems. According to the “gene-for-gene hypothesis”, the outcome of a plant/pathogen interaction in these cases is incompatibility if a plant carrying a particular resistance gene and a pathogen with the complementary avirulence gene meet. This suggests a causal role of resistance genes in a recognition process initiating active plant defense responses. Fundamentally different strategies are followed to identify these genes molecularly depending on the plant and pathogen species involved. Fungal diseases of crop plants, especially those of cereals, cause dramatic yield losses worldwide. It is assumed that a molecular characterization of plant genes conferring resistance to fungal pathogens will lead to a better understanding of the plant defense system in general permitting the development of new methods of crop plant protection.

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Genetic analysis of Hsp90 function in Cryptococcus neoformans highlights key roles in stress tolerance and virulence

Genetics ◽

10.1093/genetics/iyab164 ◽

2021 ◽

Author(s):

Ci Fu ◽

Sarah R Beattie ◽

Andrew J Jezewski ◽

Nicole Robbins ◽

Luke Whitesell ◽

...

Keyword(s):

Drug Resistance ◽

Cryptococcus Neoformans ◽

Molecular Chaperone ◽

Fungal Pathogens ◽

Genetic Characterization ◽

Great Promise ◽

Report Generation ◽

Conditional Expression ◽

Expression Strain

Abstract The opportunistic human fungal pathogen Cryptococcus neoformans has tremendous impact on global health, causing 181,000 deaths annually. Current treatment options are limited, and the frequent development of drug resistance exacerbates the challenge of managing invasive cryptococcal infections. In diverse fungal pathogens, the essential molecular chaperone Hsp90 governs fungal survival, drug resistance, and virulence. Therefore, targeting this chaperone has emerged as a promising approach to combat fungal infections. However, the role of Hsp90 in supporting C. neoformans pathogenesis remains largely elusive due to a lack of genetic characterization. To help dissect the functions of Hsp90 in C. neoformans, we generated a conditional expression strain in which HSP90 is under control of the copper-repressible promoter CTR4-2. Addition of copper to culture medium depleted Hsp90 transcript and protein levels in this strain, resulting in compromised fungal growth at host temperature; increased sensitivity to stressors, including the azole class of antifungals; altered C. neoformans morphology; and impaired melanin production. Finally, leveraging the fact that copper concentrations vary widely in different mouse tissues, we demonstrated attenuated virulence for the CTR4-2p-HSP90 mutant specifically in an inhalation model of Cryptococcus infection. During invasion and establishment of infection in this mouse model, the pathogen is exposed to the relatively high copper concentrations found in the lung as compared to blood. Overall, this work generates a tractable genetic system to study the role of Hsp90 in supporting the pathogenicity of C. neoformans and provides proof-of-principle that targeting Hsp90 holds great promise as a strategy to control cryptococcal infection. Article Summary Hsp90 is a conserved molecular chaperone that modulates virulence traits and drug resistance in fungal pathogens. Despite the potential of Hsp90 as a target for antifungal development, genetic characterization remains lacking in Cryptococcus neoformans. Here, we report generation of a C. neoformans HSP90 conditional expression strain. Utilizing this genetic tool, we found depletion of Hsp90 impacted tolerance to environmental stresses, growth at physiological temperature, and virulence in vivo. Thus, we suggest targeting Hsp90 is a viable strategy for treating cryptococcosis.

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Comparative Genomics and Functional Studies of Wheat BED-NLR Loci

Genes ◽

10.3390/genes11121406 ◽

2020 ◽

Vol 11 (12) ◽

pp. 1406

Author(s):

Clemence Marchal ◽

Georg Haberer ◽

Manuel Spannagl ◽

Cristobal Uauy ◽

Keyword(s):

Cell Death ◽

Fungal Pathogens ◽

Plant Pathogens ◽

Functional Studies ◽

Network Analyses ◽

Binding Factor ◽

Localization Signal ◽

Integrated Domains ◽

Genomic Regions

Nucleotide-binding leucine-rich-repeat (LRR) receptors (NLRs) with non-canonical integrated domains (NLR-IDs) are widespread in plant genomes. Zinc-finger BED (named after the Drosophila proteins Boundary Element-Associated Factor and DNA Replication-related Element binding Factor, named BED hereafter) are among the most frequently found IDs. Five BED-NLRs conferring resistance against bacterial and fungal pathogens have been characterized. However, it is unknown whether BED-NLRs function in a manner similar to other NLR-IDs. Here, we used chromosome-level assemblies of wheat to explore the Yr7 and Yr5a genomic regions and show that, unlike known NLR-ID loci, there is no evidence for a NLR-partner in their vicinity. Using neighbor-network analyses, we observed that BED domains from BED-NLRs share more similarities with BED domains from single-BED proteins and from BED-containing proteins harboring domains that are conserved in transposases. We identified a nuclear localization signal (NLS) in Yr7, Yr5, and the other characterized BED-NLRs. We thus propose that this is a feature of BED-NLRs that confer resistance to plant pathogens. We show that the NLS was functional in truncated versions of the Yr7 protein when expressed in N. benthamiana. We did not observe cell-death upon the overexpression of Yr7 full-length, truncated, and ‘MHD’ variants in N. benthamiana. This suggests that either this system is not suitable to study BED-NLR signaling or that BED-NLRs require additional components to trigger cell death. These results define novel future directions to further understand the role of BED domains in BED-NLR mediated resistance.

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