-
Immunity Apr 2020Innate lymphoid cells (ILCs) play an important role in the control and maintenance of barrier immunity. However, chronic activation of ILCs results in immune-mediated...
Innate lymphoid cells (ILCs) play an important role in the control and maintenance of barrier immunity. However, chronic activation of ILCs results in immune-mediated pathology. Here, we show that tissue-resident type 2 ILCs (ILC2s) display a distinct metabolic signature upon chronic activation. In the context of allergen-driven airway inflammation, ILC2s increase their uptake of both external lipids and glucose. Externally acquired fatty acids are transiently stored in lipid droplets and converted into phospholipids to promote the proliferation of ILC2s. This metabolic program is imprinted by interleukin-33 (IL-33) and regulated by the genes Pparg and Dgat1, which are both controlled by glucose availability and mTOR signaling. Restricting dietary glucose by feeding mice a ketogenic diet largely ablated ILC2-mediated airway inflammation by impairing fatty acid metabolism and the formation of lipid droplets. Together, these results reveal that pathogenic ILC2 responses require lipid metabolism and identify ketogenic diet as a potent intervention strategy to treat airway inflammation.
Topics: Allergens; Alternaria; Animals; Asthma; Cell Lineage; Cytokines; Diacylglycerol O-Acyltransferase; Diet, Ketogenic; Disease Models, Animal; Fatty Acids; Gene Expression Regulation; Glucose; Immunity, Innate; Interleukin-33; Interleukins; Lipid Droplets; Lung; Mice; Mice, Inbred C57BL; Mice, Knockout; PPAR gamma; Papain; Phospholipids; Primary Cell Culture; T-Lymphocyte Subsets; TOR Serine-Threonine Kinases; Thymic Stromal Lymphopoietin
PubMed: 32268121
DOI: 10.1016/j.immuni.2020.03.003 -
Microbiology (Reading, England) Mar 2022is a common species of fungus frequently isolated from plants as both an endophyte and a pathogen. Although the current definition of rests on a foundation of... (Review)
Review
is a common species of fungus frequently isolated from plants as both an endophyte and a pathogen. Although the current definition of rests on a foundation of morphological, genetic and genomic analyses, doubts persist regarding the scope of within the genus due to the varied symbiotic interactions and wide host range observed in these fungi. These doubts may be due in large part to the history of unstable taxonomy in , based on limited morphological characters for species delimitation and host specificity associated with toxins encoded by genes carried on conditionally dispensable chromosomes. This review explores the history of taxonomy, focusing in particular on the use of nutritional mode and host associations in species delimitation, with the goal of evaluating as it currently stands based on taxonomic best practice. Given the recombination detected among isolates of , different symbiotic associations in this species should not be considered phylogenetically informative.
Topics: Alternaria; Endophytes; Host Specificity; Plant Diseases
PubMed: 35348451
DOI: 10.1099/mic.0.001153 -
Journal of Fungi (Basel, Switzerland) Oct 2021is a saprophytic mold whose spores are disseminated in warm dry air, the typical weather of the Mediterranean climate region (from 30° to 45°), with a peak during the... (Review)
Review
is a saprophytic mold whose spores are disseminated in warm dry air, the typical weather of the Mediterranean climate region (from 30° to 45°), with a peak during the late summer and early autumn. spores are known to be biological contaminants and a potent source of aeroallergens. One consequence of human exposure to is an increased risk of developing asthma, with Alt a 1 as its main elicitor and a marker of primary sensitization. Although the action mechanism needs further investigation, a key role of the epithelium in cytokine production, TLR-activated alveolar macrophages and innate lymphoid cells in the adaptive response was demonstrated. Furthermore, sensitization to seems to be a trigger for the development of co-sensitization to other allergen sources and may act as an exacerbator of symptoms and an elicitor of food allergies. The prevalence of allergy is increasing and has led to expanding research on the role of this fungal species in the induction of IgE-mediated respiratory diseases. Indeed, recent research has allowed new perspectives to be considered in the assessment of exposure and diagnosis of fungi-induced allergies, although more studies are needed for the standardization of immunotherapy formulations.
PubMed: 34682259
DOI: 10.3390/jof7100838 -
International Journal of Molecular... Dec 2021Natural dibenzo-α-pyrones (DAPs) can be viewed from two opposite angles. From one angle, the gastrointestinal metabolites urolithins are regarded as beneficial, while... (Review)
Review
Natural dibenzo-α-pyrones (DAPs) can be viewed from two opposite angles. From one angle, the gastrointestinal metabolites urolithins are regarded as beneficial, while from the other, the emerging mycotoxin alternariol and related fungal metabolites are evaluated critically with regards to potential hazardous effects. Thus, the important question is: can the structural characteristics of DAP subgroups be held responsible for distinct bioactivity patterns? If not, certain toxicological and/or pharmacological aspects of natural DAPs might yet await elucidation. Thus, this review focuses on comparing published data on the two groups of natural DAPs regarding both adverse and beneficial effects on human health. Literature on genotoxic, estrogenic, endocrine-disruptive effects, as well as on the induction of the cellular anti-oxidative defense system, anti-inflammatory properties, the inhibition of kinases, the activation of mitophagy and the induction of autophagy, is gathered and critically reviewed. Indeed, comparing published data suggests similar bioactivity profiles of alternariol and urolithin A. Thus, the current stratification into hazardous toxins and healthy urolithins seems debatable. An extrapolation of bioactivities to the other DAP sub-class could serve as a promising base for further research. Conclusively, urolithins should be further evaluated toward high-dose toxicity, while alternariol derivatives could be promising chemicals for the development of therapeutics.
Topics: Alternaria; Animals; Anti-Inflammatory Agents, Non-Steroidal; Coumarins; Estrogens; Gastrointestinal Microbiome; Humans; Lactones; Mitophagy; Mutagenicity Tests; Mycotoxins
PubMed: 34884865
DOI: 10.3390/ijms222313063 -
Indian Journal of Microbiology Sep 2020species are mainly saprophytic fungi, but some pathotypes of infect economically important plants including cereal crops, vegetables and fruits. Specially, .... (Review)
Review
species are mainly saprophytic fungi, but some pathotypes of infect economically important plants including cereal crops, vegetables and fruits. Specially, . generates toxins which contaminate food and feed. To date, management of . relies primarily on fungicides. However, the control efficacy in most cases is below expectation due to ubiquity of . and resistance to fungicides. To mitigate resistance and develop long-lasting fungicides, uncovering multiple rather than single target is a prerequisite. Membrane proteins are potential targets of fungicides owing to wide participation in myriad biochemical events especially material transport, signal transduction and pathogenicity. However, so far, little is known about the distribution and molecular structure of membrane proteins (AAMPs). Herein we summarize AAMPs by data mining and subsequent structure prediction. We also outline the state-of-the-art research advances of AAMPs especially those closely related to pathogenicity. Overall, this review aims to portray a picture of AAMPs and provide valuable insights for future development of highly efficient fungicides towards . or beyond.
PubMed: 32647391
DOI: 10.1007/s12088-020-00873-8 -
Molecular Plant Pathology Mar 2024Alternaria spp. cause different diseases in potato and tomato crops. Early blight caused by Alternaria solani and brown spot caused by Alternaria alternata are most... (Review)
Review
UNLABELLED
Alternaria spp. cause different diseases in potato and tomato crops. Early blight caused by Alternaria solani and brown spot caused by Alternaria alternata are most common, but the disease complex is far more diverse. We first provide an overview of the Alternaria species infecting the two host plants to alleviate some of the confusion that arises from the taxonomic rearrangements in this fungal genus. Highlighting the diversity of Alternaria fungi on both solanaceous hosts, we review studies investigating the genetic diversity and genomes, before we present recent advances from studies elucidating host-pathogen interactions and fungicide resistances.
TAXONOMY
Kingdom Fungi, Phylum Ascomycota, Class Dothideomycetes, Order Pleosporales, Family Pleosporaceae, Genus Alternaria.
BIOLOGY AND HOST RANGE
Alternaria spp. adopt diverse lifestyles. We specifically review Alternaria spp. that cause disease in the two solanaceous crops potato (Solanum tuberosum) and tomato (Solanum lycopersicum). They are necrotrophic pathogens with no known sexual stage, despite some signatures of recombination.
DISEASE SYMPTOMS
Symptoms of the early blight/brown spot disease complex include foliar lesions that first present as brown spots, depending on the species with characteristic concentric rings, which eventually lead to severe defoliation and considerable yield loss.
CONTROL
Good field hygiene can keep the disease pressure low. Some potato and tomato cultivars show differences in susceptibility, but there are no fully resistant varieties known. Therefore, the main control mechanism is treatment with fungicides.
Topics: Alternaria; Solanum tuberosum; Solanum lycopersicum; Plant Diseases; Fungicides, Industrial
PubMed: 38476108
DOI: 10.1111/mpp.13435 -
Frontiers in Plant Science 2023Mycotoxins are toxic secondary metabolites produced by certain fungi, which can contaminate various food commodities, including fruits and their derived products.... (Review)
Review
Mycotoxins are toxic secondary metabolites produced by certain fungi, which can contaminate various food commodities, including fruits and their derived products. Patulin and toxins are among the most commonly encountered mycotoxins in fruit and their derived products. In this review, the sources, toxicity, and regulations related to these mycotoxins, as well as their detection and mitigation strategies are widely discussed. Patulin is a mycotoxin produced mainly by the fungal genera , , and . toxins, produced by fungi in the genus, are another common group of mycotoxins found in fruits and fruit products. The most prevalent toxins are alternariol (AOH) and alternariol monomethyl ether (AME). These mycotoxins are of concern due to their potential negative effects on human health. Ingesting fruits contaminated with these mycotoxins can cause acute and chronic health problems. Detection of patulin and toxins in fruit and their derived products can be challenging due to their low concentrations and the complexity of the food matrices. Common analytical methods, good agricultural practices, and contamination monitoring of these mycotoxins are important for safe consumption of fruits and derived products. And Future research will continue to explore new methods for detecting and managing these mycotoxins, with the ultimate goal of ensuring the safety and quality of fruits and derived product supply.
PubMed: 37077634
DOI: 10.3389/fpls.2023.1139757 -
Molecules (Basel, Switzerland) Apr 2022A series of 30 succinate dehydrogenase inhibitors (SDHIs) of 4-amino coumarin-based derivatives were designed and synthesized. According to the analysis of fungicidal...
A series of 30 succinate dehydrogenase inhibitors (SDHIs) of 4-amino coumarin-based derivatives were designed and synthesized. According to the analysis of fungicidal activity in vitro, most of the compounds expressed broad-spectrum antifungal activity against four plant pathogenic fungi ( and ) using the mycelium growth inhibition method. The results showed that compounds with the group of 2-ene-3-methyl-butyl and with the group of 2-bromo-1-oxo-hexyl displayed excellent activity against and , with EC values of 92~145 μg/mL. Molecular docking showed that the inhibitor was completely locked into the cavity of SDH, forming a conventional hydrogen bond interacting with the amino acid residue TYR58. The present work indicates that these derivatives would serve as novel potential fungicides targeting SDH.
Topics: Alternaria; Aminocoumarins; Antifungal Agents; Botrytis; Coumarins; Fungicides, Industrial; Molecular Docking Simulation; Structure-Activity Relationship
PubMed: 35566096
DOI: 10.3390/molecules27092738 -
Journal of Fungi (Basel, Switzerland) May 2023Fungal allergy is the third most frequent cause of respiratory pathologies and the most related to a poor prognosis of asthma. The genera and are the most frequently... (Review)
Review
Fungal allergy is the third most frequent cause of respiratory pathologies and the most related to a poor prognosis of asthma. The genera and are the most frequently associated with allergic respiratory diseases, with being the one with the highest prevalence of sensitization. is an outdoor fungus whose spores disseminate in warm and dry air, reaching peak levels in temperate summers. can also be found in damp and insufficiently ventilated houses, causing what is known as sick building syndrome. Thus, exposure to fungal allergens can occur outdoors and indoors. However, not only spores but also fungal fragments contain detectable amounts of allergens and may function as aeroallergenic sources. Allergenic extracts of hyphae and spores are still in use for the diagnosis and treatment of allergic diseases but are variable and insufficiently standardised, as they are often a random mixture of allergenic ingredients and casual impurities. Thus, diagnosis of fungal allergy has been difficult, and knowledge about new fungal allergens is stuck. The number of allergens described in Fungi remains almost constant while new allergens are being found in the Plantae and Animalia kingdoms. Given Alt a 1 is not the unique allergen eliciting allergy symptoms, component-resolved diagnosis strategies should be applied to diagnose fungal allergy. To date, twelve allergens are accepted in the WHO/IUIS Allergen Nomenclature Subcommittee, many of them are enzymes: Alt a 4 (disulfide isomerase), Alt a 6 (enolase), Alt a 8 (mannitol de-hydrogenase), Alt a 10 (aldehyde dehydrogenase), Alt a 13 (glutathione-S-transferase) and Alt a MnSOD (Mn superoxide dismutase), and others have structural and regulatory functions such as Alt a 5 and Alt a 12, Alt a 3, Alt a 7. The function of Alt a 1 and Alt a 9 remains unknown. Other four allergens are included in other medical databases (e.g., Allergome): Alt a NTF2, Alt a TCTP, and Alt a 70 kDa. Despite Alt a 1 being the major allergen, other allergens, such as enolase, Alt a 6 or MnSOD, Alt a 14 have been suggested to be included in the diagnosis panel of fungal allergy.
PubMed: 37233293
DOI: 10.3390/jof9050582 -
Scientific Reports May 2023The fungal genus Alternaria is a pan-global pathogen of > 100 crops, and is associated with the globally expanding Alternaria leaf blotch in apple (Malus x domestica...
The fungal genus Alternaria is a pan-global pathogen of > 100 crops, and is associated with the globally expanding Alternaria leaf blotch in apple (Malus x domestica Borkh.) which leads to severe leaf necrosis, premature defoliation, and large economic losses. Up to date, the epidemiology of many Alternaria species is still not resolved as they can be saprophytic, parasitic or shift between both lifestyles and are also classified as primary pathogen able to infect healthy tissue. We argue that Alternaria spp. does not act as primary pathogen, but only as a necrosis-dependent opportunist. We studied the infection biology of Alternaria spp. under controlled conditions and monitored disease prevalence in real orchards and validated our ideas by applying fungicide-free treatments in 3-years field experiments. Alternaria spp. isolates were not able to induce necroses in healthy tissue, but only when prior induced damages existed. Next, leaf-applied fertilizers, without fungicidal effect, reduced Alternaria-associated symptoms (- 72.7%, SE: ± 2.5%) with the same efficacy as fungicides. Finally, low leaf magnesium, sulphur, and manganese concentrations were consistently linked with Alternaria-associated leaf blotch. Fruit spot incidence correlated positively with leaf blotch, was also reduced by fertilizer treatments, and did not expand during storage unlike other fungus-mediated diseases. Our findings suggest that Alternaria spp. may be a consequence of leaf blotch rather than its primary cause, as it appears to colonize the physiologically induced leaf blotch. Taking into account existing observations that Alternaria infection is connected to weakened hosts, the distinction may appear slight, but is of great significance, as we can now (a) explain the mechanism of how different stresses result in colonization with Alternaria spp. and (b) substitute fungicides for a basic leaf fertilizer. Therefore, our findings can result in significant decreases in environmental costs due to reduced fungicide use, especially if the same mechanism applies to other crops.
Topics: Malus; Fruit; Alternaria; Fertilizers; Crops, Agricultural; Fungicides, Industrial; Necrosis; Plant Leaves
PubMed: 37225789
DOI: 10.1038/s41598-023-35448-2