Expression of immune response genes in human corneal epithelial cells interacting with Asperrgillus flavus conidia
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE175824 | GEO | 2021/06/01
REPOSITORIES: GEO
Similar Datasets
Project description:Mycotic leratitis is the corneal inflammation predominantly caused by Fusarium and Aspergillus species. Corneal epithelium is the earliest cell type encounter the invading pathogen. The innate immune responses of human corneal epithelial cells against Aspergillus flavus is not known. Here we studied the role of human corneal epithelial cells against Aspergillus flavus infection. The results showed that corneal epithelial cells internalized Aspergillus flavus conidia through actin mediated polymerization surrounding the conidia. Further the actin inhibitor cytochalasin D treatment reduced the formation actin ring around the conidia. The engulfed conidia acquired endosomal proteins as revealed by immunofluorescence analsyisis. Mass spectromtery of phagosomal proteins confirmed the recruitment of endosomal proteins and other proteins involved in phagocytosis. These results show the involvement of corneal epithelial cells in anti fungal defense.
2021-04-07 | PXD019512 | Pride
Project description:Expression of immune response genes in human corneal epithelial cells interacting with Asperrgillus flavus conidia
| PRJNA733997 | ENA
Project description:A. flavus exoproteome reference map as well as identification of the exoproteins from corneal isolates.
2015-01-07 | PXD001296 | Pride
Project description:Objective: Aspergillus flavus aflR, a gene encoding a Zn(II)2Cys6 DNA-binding domain, is an important transcriptional regulator of the aflatoxin biosynthesis gene cluster. Our previous results of GO analysis for the binding sites of AflR in A. flavus suggest that AflR may play an integrative regulatory role. This study aimed to investigate the integrative function of the aflR gene in A. flavus. Design: In this study, we used Aspergillus flavus NRRL3357 as a wild-type strain (WT) and constructed a knockout strain of A. flavus ΔaflR by homologous recombination. Based on the transcriptomics technology, we investigated the metabolic effects of aflR gene on growth, development and toxin synthesis of A. flavus, and discussed the overall regulation mechanism of aflR gene on A. flavus at the transcriptional level. Results: The disruption of aflR severely affected the aflatoxin biosynthetic pathway, resulting in a significant decrease in aflatoxin production. In addition, disrupted strains of the aflR gene produced relatively sparse conidia and a very small number of sclerotia. However, the biosynthesis of cyclopiazonic acid (CPA) was not affected by aflR gene disruption. Transcriptomic analysis of the ΔaflR strain grown on potato dextrose agar (PDA) plates at 0 h, 24 h, and 72 h showed that expression of clustering genes involved in the biosynthesis of aflatoxin was significantly down-regulated. Meanwhile, the ΔaflR strain showed significant expression differences in genes involved in spore germination, sclerotial development, and carbohydrate metabolism compared to the WT strain. Conclusions: The results showed that the A. flavus aflR gene also played a positive role in the growth and development of fungi.
2021-07-16 | GSE179978 | GEO
Project description:Linking cell reproduction and survival is a key task of all life forms. All fungi in the genus Aspergillus reproduce by forming asexual spores called conidia, of which formation is governed by the central regulatory circuit, BrlA->AbaA->WetA. Here, we report that WetA is a key multi-functional regulator that bridged spore differentiation, long-term survival, and chemical development in Aspergillus flavus.
2017-06-04 | GSE95711 | GEO
Project description:A. flavus keratitis is one of the predominant fungal infections affecting the tropical parts of the world. Melanin is a virulence factor in numerous pathogenic fungi and the melanin layer maintains the cell wall structure and provides chemical and physical protection to the organism. However, the molecular and biological mechanisms modulating melanin-mediated host-pathogen interaction in A. flavus keratitis are not well understood. This work aimed to compare the morphology, surface proteome profile and virulence of melanized and non-melanized conidia of A. flavus. An environmental isolate and two clinical isolates were included in this study. L-DOPA melanin pathway-specific inhibitor kojic acid (KA) as used to prepare non-melanized conidia. Conidial surface proteins were extracted using 100% formic acid at 0 ºC and the extracted proteins were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS PAGE). Formic acid extracts were analyzed in an Orbitrap Velos pro-mass spectrometer. Conidial surface morphology difference was examined using scanning electron microscopy (SEM). Furthermore, lactophenol and calcofluor staining were performed to check the morphology and staining efficiency of melanized conidia (MC) and non-melanized conidia (NMC). A Galleria mellonella insect model was used to examine the virulence efficiency of MC and NMC. Kojic acid treatment inhibited melanin synthesis in A. flavus and the conidial surface protein profile was significantly different in kojic acid-treated non-melanized conidia. Several cell wall-associated proteins and proteins responsible for oxidative stress, carbohydrate, and chitin metabolic pathway were found only in the formic acid extracts of NMC. SEM analysis showed the conidial surface morphology difference between the NMC and MC indicating the role of melanin in the structural integrity of the conidial cell wall. The levels of calcofluor staining efficiency were different, but there was no microscopic morphology difference in lactophenol cotton blue staining of MC and NMC. Evaluation of virulence of MC and NMC in G. mellonella model showed NMC was less virulent compared to MC . Our results showed that the integrity of the conidial surface is controlled by the melanin layer. The alteration in the surface protein profile indicated that many surface proteins are masked by the melanin layer and hence melanin can modulate the host response by preventing the exposure of fungal proteins to the host immune defense system. G. mellonella in vivo virulence assay also confirmed that the non-melanized conidia were susceptible to host defense as in other Aspergillus pathogens.
2024-05-23 | PXD037707 | Pride
Project description:Aflatoxin contamination caused by the opportunistic pathogen A. flavus is a major concern in maize production prior to harvest and during storage. Previous studies indicate that both constitutive and induced resistance are involved in maize kernel defense against A. flavus infection, little is known about molecular mechanisms of mature kernels in response to fungal infection. The purpose of this study is to determine gene expression differences in maize kernels between resistant and susceptible lines in response to A. flavus challenge. To avoid the environmental effects in the field inoculation, a laboratory based inoculation technique Kernel Screening Assay (KSA) was used to challenge kernels with A. flavus. After 72 hours incubation of inoculated and noninculated mature kernels, gene expression profiles of two Near Isogenic Lines (NIL) of Eyl25 (A. flavus resistant) and Eyl31 (A. flavus susceptible) were compared using oligonucleotide array.
2010-10-01 | GSE19883 | GEO
Project description:Aspergillus flavus and A. parasiticus are two of the most important aflatoxin-producing species that contaminate agricultural commodities worldwide. Both species are heterothallic and undergo sexual reproduction in laboratory crosses. Here, we examine the possibility of interspecific matings between A. flavus and A. parasiticus. These species can be distinguished morphologically and genetically, as well as by their mycotoxin profiles. Aspergillus flavus produces both B aflatoxins and cyclopiazonic acid (CPA), B aflatoxins or CPA alone, or neither mycotoxin; Aspergillus parasiticus produces B and G aflatoxins or the aflatoxin precursor O-methylsterigmatocystin, but not CPA. Only four out of forty-five attempted interspecific crosses between compatible mating types of A. flavus and A. parasiticus were fertile and produced viable ascospores. Single ascospore strains from each cross were isolated and were shown to be recombinant hybrids using multilocus genotyping and array comparative genome hybridization. Conidia of parents and their hybrid progeny were haploid and predominantly monokaryons and dikaryons based on flow cytometry. Multilocus phylogenetic inference showed that experimental hybrid progeny were grouped with naturally occurring A. flavus L strain and A. parasiticus. Higher total aflatoxin concentrations in some F1 progeny strains compared to midpoint parent aflatoxin levels indicate synergism in aflatoxin production; moreover, three progeny strains synthesized G aflatoxins that were not produced by the parents, and there was evidence of putative allopolyploidization in one strain. These results suggest that hybridization is an important diversifying force resulting in the genesis of novel toxin profiles in these agriculturally important species.
2015-10-01 | GSE61981 | GEO
Project description:Aflatoxin contamination caused by the opportunistic pathogen A. flavus is a major concern in maize production prior to harvest and during storage. Previous studies indicate that both constitutive and induced resistance are involved in maize kernel defense against A. flavus infection, little is known about molecular mechanisms of mature kernels in response to fungal infection. The purpose of this study is to determine gene expression differences in maize kernels between resistant and susceptible lines in response to A. flavus challenge. To avoid the environmental effects in the field inoculation, a laboratory based inoculation technique Kernel Screening Assay (KSA) was used to challenge kernels with A. flavus. After 72 hours incubation of inoculated and noninculated mature kernels, gene expression profiles of two Near Isogenic Lines (NIL) of Eyl25 (A. flavus resistant) and Eyl31 (A. flavus susceptible) were compared using oligonucleotide array. Direct comparisons were designed. The comparisons of NIL Eyl25 and Eyl31 include: Treated/Control, Control/Control and Treated/Treated. After 72 hours incubation under KSA conditions, forty seeds used in each A. flavus inoculated and noninculated group were bulked to extract total RNA. Four technical replications were performed in each comparison including two dye-swaps, total 16 hybridization reactions.
2010-10-01 | E-GEOD-19883 | biostudies-arrayexpress
Project description:Aspergillus fumigatus is an important human fungal pathogen and its conidia are constantly inhaled by humans. In immunocompromised individuals, conidia can grow out as hyphae that damage lung epithelium. The resulting invasive aspergillosis is associated with devastating mortality rates. Since infection is a race between the innate immune system and the outgrowth of A. fumigatus conidia, we use dynamic optimization to obtain insight into the recruitment and depletion of alveolar macrophages and neutrophils. We illustrate by modeling the active, but so far neglected, major role of alveolar epithelial cells in phagocytosis and cytokine release as well as the importance of fungal growth states for virulence.
Hence, we discovered that germination speed is a key virulence trait of fungal pathogens due to the vulnerability of conidia against host defense. We proved this by linking measured germination kinetics of four Aspergillus spp. with their cytotoxicity against epithelial cells in silico and in vitro.Furthermore, we could reveal by modeling and ex vivo measurements, that epithelial cells are not only important phagocytes to clear conidia, but also potent mediators of cytokine release.
In conclusion, our findings illustrate an underestimated role of epithelial cells in invasive aspergillosis. Further, our model affirms the importance of neutrophils and underlines that the role of macrophages in invasive aspergillosis remains elusive.
We expect that our model will contribute to improvement of treatment protocols by focusing on
the critical components of immune response to fungi but also fungal virulence.
2021-11-24 | MODEL2105110001 | BioModels