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1.
bioRxiv ; 2024 May 23.
Article in English | MEDLINE | ID: mdl-38826446

ABSTRACT

Candidalysin is a cytolytic peptide produced by the opportunistic fungal pathogen Candida albicans. This peptide is a key virulence factor in mouse models of mucosal and hematogenously disseminated candidiasis. Despite intense interest in the role of candidalysin in C. albicans pathogenicity, its host cell targets have remained elusive. To fill this knowledge gap, we performed a genome-wide loss-of-function CRISPR screen in a human oral epithelial cell line to identify specific host factors required for susceptibility to candidalysin-induced cellular damage. Among the top hits were XYLT2, B3GALT6 and B3GAT3, genes that function in glycosaminoglycan (GAG) biosynthesis. Deletion of these genes led to the absence of GAGs such as heparan sulfate on the epithelial cell surface and increased resistance to damage induced by both candidalysin and live C. albicans. Biophysical analyses including surface plasmon resonance and atomic force and electron microscopy indicated that candidalysin physically binds to sulfated GAGs, facilitating its oligomerization or enrichment on the host cell surface. The addition of exogenous sulfated GAGs or the GAG analogue dextran sulfate protected cells against candidalysin-induced damage. Dextran sulfate, but not non-sulfated dextran, also inhibited epithelial cell endocytosis of C. albicans and fungal-induced epithelial cell cytokine and chemokine production. In a murine model of vulvovaginal candidiasis, topical dextran sulfate administration reduced host tissue damage and decreased intravaginal IL-1ß and neutrophil levels. Collectively, these data indicate that GAGs are epithelial cell targets of candidalysin and can be used therapeutically to protect cells from candidalysin-induced damage.

2.
Immunity ; 57(5): 1141-1159.e11, 2024 May 14.
Article in English | MEDLINE | ID: mdl-38670113

ABSTRACT

Broadly neutralizing antibodies (bnAbs) targeting the hemagglutinin (HA) stem of influenza A viruses (IAVs) tend to be effective against either group 1 or group 2 viral diversity. In rarer cases, intergroup protective bnAbs can be generated by human antibody paratopes that accommodate the conserved glycan differences between the group 1 and group 2 stems. We applied germline-engaging nanoparticle immunogens to elicit a class of cross-group bnAbs from physiological precursor frequency within a humanized mouse model. Cross-group protection depended on the presence of the human bnAb precursors within the B cell repertoire, and the vaccine-expanded antibodies enriched for an N55T substitution in the CDRH2 loop, a hallmark of the bnAb class. Structurally, this single mutation introduced a flexible fulcrum to accommodate glycosylation differences and could alone enable cross-group protection. Thus, broad IAV immunity can be expanded from the germline repertoire via minimal antigenic input and an exceptionally simple antibody development pathway.


Subject(s)
Antibodies, Neutralizing , Antibodies, Viral , Influenza A virus , Influenza Vaccines , Orthomyxoviridae Infections , Vaccination , Animals , Mice , Humans , Antibodies, Viral/immunology , Influenza Vaccines/immunology , Influenza A virus/immunology , Antibodies, Neutralizing/immunology , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/prevention & control , Hemagglutinin Glycoproteins, Influenza Virus/immunology , Amino Acid Substitution , B-Lymphocytes/immunology , Influenza, Human/immunology , Influenza, Human/prevention & control , Broadly Neutralizing Antibodies/immunology
3.
Science ; 383(6679): 205-211, 2024 01 12.
Article in English | MEDLINE | ID: mdl-38207021

ABSTRACT

Antibodies are produced at high rates to provide immunoprotection, which puts pressure on the B cell translational machinery. Here, we identified a pattern of codon usage conserved across antibody genes. One feature thereof is the hyperutilization of codons that lack genome-encoded Watson-Crick transfer RNAs (tRNAs), instead relying on the posttranscriptional tRNA modification inosine (I34), which expands the decoding capacity of specific tRNAs through wobbling. Antibody-secreting cells had increased I34 levels and were more reliant on I34 for protein production than naïve B cells. Furthermore, antibody I34-dependent codon usage may influence B cell passage through regulatory checkpoints. Our work elucidates the interface between the tRNA pool and protein production in the immune system and has implications for the design and selection of antibodies for vaccines and therapeutics.


Subject(s)
Antibodies , Antibody Formation , B-Lymphocytes , Codon Usage , Immunoglobulin Heavy Chains , Inosine , RNA, Transfer , Antibody Formation/genetics , Codon/genetics , Inosine/genetics , Inosine/metabolism , RNA, Transfer/genetics , Antibodies/genetics , Humans , B-Lymphocytes/immunology , Immunoglobulin Heavy Chains/genetics
4.
PLoS Pathog ; 19(8): e1011579, 2023 08.
Article in English | MEDLINE | ID: mdl-37611070

ABSTRACT

Fungal invasion of the oral epithelium is central to the pathogenesis of oropharyngeal candidiasis (OPC). Candida albicans invades the oral epithelium by receptor-induced endocytosis but this process is incompletely understood. We found that C. albicans infection of oral epithelial cells induces c-Met to form a multi-protein complex with E-cadherin and the epidermal growth factor receptor (EGFR). E-cadherin is necessary for C. albicans to activate both c-Met and EGFR and to induce the endocytosis of C. albicans. Proteomics analysis revealed that c-Met interacts with C. albicans Hyr1, Als3 and Ssa1. Both Hyr1 and Als3 are required for C. albicans to stimulate c-Met and EGFR in oral epithelial cells in vitro and for full virulence during OPC in mice. Treating mice with small molecule inhibitors of c-Met and EGFR ameliorates OPC, demonstrating the potential therapeutic efficacy of blocking these host receptors for C. albicans.


Subject(s)
Candida albicans , Candidiasis, Oral , Animals , Mice , Cell Membrane , ErbB Receptors , Cadherins , Epithelial Cells
5.
mSphere ; 8(5): e0031423, 2023 10 24.
Article in English | MEDLINE | ID: mdl-37578262

ABSTRACT

During the initiation of invasive aspergillosis, inhaled Aspergillus fumigatus conidia are deposited on the epithelial cells lining the bronchi, terminal bronchioles, and alveoli. While the interactions of A. fumigatus with bronchial and type II alveolar cell lines have been investigated in vitro, little is known about the interactions of this fungus with terminal bronchiolar epithelial cells. Using the HSAEC1-KT human small airway epithelial (HSAE) cell line, we developed an in vitro model to study the interaction of two strains of A. fumigatus with these cells. We then compared the interactions of A. fumigatus with the A549 type II alveolar epithelial cell line and the HSAE cell line. We found that A. fumigatus conidia were poorly endocytosed by A549 cells, but avidly endocytosed by HSAE cells. A. fumigatus germlings invaded both cell types by induced endocytosis, but not by active penetration. A549 cell endocytosis of A. fumigatus was independent of fungal viability, more dependent on host microfilaments than microtubules, and induced by A. fumigatus CalA interacting with host cell integrin α5ß1. By contrast, HSAE cell endocytosis required fungal viability, was more dependent on microtubules than microfilaments, and did not require CalA or integrin α5ß1. HSAE cells were more susceptible than A549 cells to damage caused by direct contact with killed A. fumigatus germlings and by secreted fungal products. In response to A. fumigatus infection, A549 cells secreted a broader profile of cytokines and chemokines than HSAE cells. Taken together, these results demonstrate that studies of HSAE cells provide complementary data to A549 cells and thus represent a useful model for probing the interactions of A. fumigatus with bronchiolar epithelial cells in vitro. Importance During the initiation of invasive aspergillosis, Aspergillus fumigatus interacts with the epithelial cells that line the airways and alveoli. Previous studies of A. fumigatus-epithelial cell interactions in vitro used either large airway epithelial cell lines or the A549 type II alveolar epithelial cell line; the interactions of fungi with terminal bronchiolar epithelial cells were not investigated. Using the TERT-immortalized human small airway epithelial HSAEC1-KT (HSAE) cell line, we developed an in vitro model of the interactions of A. fumigatus with bronchiolar epithelial cells. We discovered that A. fumigatus invades and damages A549 and HSAE cell lines by distinct mechanisms. Also, the proinflammatory responses of the cell lines to A. fumigatus are different. These results provide insight into how A. fumigatus interacts with different types of epithelial cells during invasive aspergillosis and demonstrate that HSAE cells are useful in vitro model for investigating the interactions of this fungus with bronchiolar epithelial cells.


Subject(s)
Aspergillosis , Aspergillus fumigatus , Humans , Aspergillus fumigatus/metabolism , Integrin alpha5beta1/metabolism , Epithelial Cells/microbiology , Lung/microbiology , Cell Line
6.
bioRxiv ; 2023 Apr 18.
Article in English | MEDLINE | ID: mdl-37131584

ABSTRACT

During the initiation of invasive aspergillosis, inhaled Aspergillus fumigatus conidia are deposited on the epithelial cells lining the bronchi, terminal bronchioles, and alveoli. While the interactions of A. fumigatus with bronchial and type II alveolar cell lines have been investigated in vitro , little is known about the interactions of this fungus with terminal bronchiolar epithelial cells. We compared the interactions of A. fumigatus with the A549 type II alveolar epithelial cell line and the HSAEC1-KT human small airway epithelial (HSAE) cell line. We found that A. fumigatus conidia were poorly endocytosed by A549 cells, but avidly endocytosed by HSAE cells. A. fumigatus germlings invaded both cell types by induced endocytosis, but not by active penetration. A549 cell endocytosis of A. fumigatus was independent of fungal viability, more dependent on host microfilaments than microtubules, and induced by A. fumigatus CalA interacting with host cell integrin α5ß1. By contrast, HSAE cell endocytosis required fungal viability, was more dependent on microtubules than microfilaments, and did not require CalA or integrin α5ß1. HSAE cells were more susceptible than A549 cells to damage caused by direct contact with killed A. fumigatus germlings and by secreted fungal products. In response to A. fumigatus infection, A549 cells secreted a broader profile of cytokines and chemokines than HSAE cells. Taken together, these results demonstrate that studies of HSAE cells provide complementary data to A549 cells and thus represent a useful model for probing the interactions of A. fumigatus with bronchiolar epithelial cells in vitro . Importance: During the initiation of invasive aspergillosis, Aspergillus fumigatus invades, damages, and stimulates the epithelial cells that line the airways and alveoli. Previous studies of A. fumigatus - epithelial cell interactions in vitro have used either large airway epithelial cell lines or the A549 type II alveolar epithelial cell line. The interactions of fungi with terminal bronchiolar epithelial cells have not been investigated. Here, we compared the interactions of A. fumigatus with A549 cells and the Tert-immortalized human small airway epithelial HSAEC1-KT (HSAE) cell line. We discovered that A. fumigatus invades and damages these two cell lines by distinct mechanisms. Also, the proinflammatory responses of the cell lines to A. fumigatus are different. These results provide insight into how A. fumigatus interacts with different types of epithelial cells during invasive aspergillosis and demonstrate that HSAE cells are useful in vitro model for investigating the interactions of this fungus with bronchiolar epithelial cells.

7.
bioRxiv ; 2023 Feb 23.
Article in English | MEDLINE | ID: mdl-36865306

ABSTRACT

Fungal invasion of the oral epithelium is central to the pathogenesis of oropharyngeal candidiasis (OPC). Candida albicans invades the oral epithelium by receptor-induced endocytosis but this process is incompletely understood. We found that C. albicans infection of oral epithelial cells induces c-Met to form a multi-protein complex with E-cadherin and the epidermal growth factor receptor (EGFR). E-cadherin is necessary for C. albicans to activate both c-Met and EGFR and to induce the endocytosis of C. albicans . Proteomics analysis revealed that c-Met interacts with C. albicans Hyr1, Als3 and Ssa1. Both Hyr1 and Als3 were required for C. albicans stimulation of c-Met and EGFR in oral epithelial cells in vitro and for full virulence during OPC in mice. Treating mice with small molecule inhibitors of c-Met and EGFR ameliorated OPC, demonstrating the potential therapeutic efficacy of blocking these host receptors for C. albicans . Highlights: c-Met is an oral epithelial cell receptor for Candida albicans C. albicans infection causes c-Met and the epidermal growth factor receptor (EGFR) to form a complex with E-cadherin, which is required for c-Met and EGFR function C. albicans Hyr1 and Als3 interact with c-Met and EGFR, inducing oral epithelial cell endocytosis and virulence during oropharyngeal candidiasis Dual blockade of c-Met and EGFR ameliorates oropharyngeal candidiasis.

8.
Mitochondrial DNA B Resour ; 8(11): 1174-1178, 2023.
Article in English | MEDLINE | ID: mdl-38188443

ABSTRACT

Callicarpa dichotoma (Lour.) K.Koch is a shrub species with distribution from East Asia to Southeast Asia. We assembled and annotated for the first time the complete chloroplast (cp) genome of C. dichotoma. The cp genome of C. dichotoma is 154,110 bp long with the GC content of 38.09% and consists of four subregions: a large single-copy (LSC) region of 84,915 bp, a small single-copy (SSC) region of 17,783 bp and a pair of inverted repeats (IRs) of 25,706 bp each. The cp genome of C. dichotoma encodes a total of 114 unique genes, comprising 80 protein-coding genes, 30 tRNA genes, and four rRNA genes. Phylogenetic trees based on the coding sequences strongly support the position of C. dichotoma within the genus Callicarpa, confirming the previously reported monophyly of the genus.

9.
J Mater Sci Mater Med ; 33(10): 72, 2022 Oct 04.
Article in English | MEDLINE | ID: mdl-36195780

ABSTRACT

Hepatocellular carcinoma is a common type of cancer associated with a high mortality rate. Among several bioactive compounds, Murrayafoline A (MuA) has been proved as a bio substance that exhibits great potentials in treating liver cancer. In order to overcome the high cytotoxicity and low solubility of MuA, a delivery system based on nanocarriers is necessary to deliver MuA towards the desired target. In the present study, 18ß-glycyrrhetinic acid (GA), which is known as a ligand for liver targeting, was used to construct the cholesterol-poly (ethylene glycol)-glycyrrhetinic acid (GA-PEG-Chol) conjugate and liposome for MuA administration. The compound was then examined for therapeutic efficacy and safety in HUVEC and HepG2 cells in 2D and 3D cell cultures. Results have shown that MuA-loaded liposomes had IC50 value of 2 µM in HepG2 and had the cytosolic absorption of 8.83 ± 0.97 ng/105 cells, while The IC50 value of MuA-loaded liposomes in HUVEC cell lines was 15 µM and the the cytosolic absorption was recorded as 3.62 ± 0.61 cells. The drug test on the 3D cancer sphere platform of the HepG2 cancer sphere showed that MuA-loaded GA liposomes had the highest efficacy at a concentration of 100 µg/mL. In short, these results suggest that MuA-loaded GA liposomes have the potential for maintenance drug delivery and liver targeting.


Subject(s)
Carcinoma, Hepatocellular , Glycyrrhetinic Acid , Liver Neoplasms , Alkaloids , Carbazoles , Carcinoma, Hepatocellular/drug therapy , Cholesterol , Glycyrrhetinic Acid/therapeutic use , Hep G2 Cells , Humans , Ligands , Liposomes , Liver Neoplasms/drug therapy
10.
Phys Chem Chem Phys ; 24(41): 25611-25619, 2022 Oct 27.
Article in English | MEDLINE | ID: mdl-36254777

ABSTRACT

Spinel LiMn2O4 (LMO) is a well-known cathode material for lithium-ion batteries. In order to elucidate the molecular mechanism of the solid electrolyte interface (SEI) formation and the effect of an additive, vinylene carbonate (VC), we systematically studied the spontaneous and electrochemical reactions of solvents and a salt (LiPF6) in electrolytes with LMO in the absence and presence of VC. X-ray photoelectron spectroscopy (XPS) results of the LMO surfaces after soaking in the electrolyte solutions showed that the carbonate solvents as well as VC spontaneously decomposed on the LMO surfaces to form new compounds, such as alcohols, ethers, and carboxylates. The ratio of the produced LiF to MnF2 was similar for both with and without VC. Considering these spontaneously formed initial SEI components, we then investigated the variation of the SEI compositions during the initial electrochemical process until 3.8 V vs. Li+/Li. The role of the additive was studied and found that the electrochemical reaction of VC produced more organic compounds and led to an increase in the LiF/MnF2 ratio of the SEI layer. Based on the hard and soft acid and base theory, we proposed the mechanisms of the SEI formation via spontaneous and electrochemical reactions on the LMO thin film cathode with and without VC.

11.
PLoS Pathog ; 18(7): e1010681, 2022 07.
Article in English | MEDLINE | ID: mdl-35797411

ABSTRACT

During hematogenously disseminated candidiasis, blood borne fungi must invade the endothelial cells that line the blood vessels to infect the deep tissues. Although Candida albicans, which forms hyphae, readily invades endothelial cells, other medically important species of Candida are poorly invasive in standard in vitro assays and have low virulence in immunocompetent mouse models of disseminated infection. Here, we show that Candida glabrata, Candida tropicalis, Candida parapsilosis, and Candida krusei can bind to vitronectin and high molecular weight kininogen present in human serum. Acting as bridging molecules, vitronectin and kininogen bind to αv integrins and the globular C1q receptor (gC1qR), inducing human endothelial cells to endocytose the fungus. This mechanism of endothelial cell invasion is poorly supported by mouse endothelial cells but can be restored when mouse endothelial cells are engineered to express human gC1qR or αv integrin. Overall, these data indicate that bridging molecule-mediated endocytosis is a common pathogenic strategy used by many medically important Candida spp. to invade human vascular endothelial cells.


Subject(s)
Candidiasis , Endothelial Cells , Animals , Candida , Candida albicans , Candidiasis/microbiology , Endothelial Cells/microbiology , Humans , Mice , Vitronectin
12.
Biosens Bioelectron ; 197: 113732, 2022 Feb 01.
Article in English | MEDLINE | ID: mdl-34741959

ABSTRACT

CRISPR diagnostics (CRISPR-Dx) offer a wide range of enhancements compared to traditional nanobiosensors by taking advantage of the excellent trans-cleavage activity of the CRISPR/Cas systems. However, the single-stranded DNA/RNA reporters of the current CRISPR-Dx suffer from poor stability and limited sensitivity, which make their application in complex biological environments difficult. In comparison, nanomaterials, especially metal nanoparticles, exhibits robust stability and desirable optical and electrocatalytical properties, which make them ideal as reporter molecules. Therefore, biosensing research is moving towards the use of the trans-cleavage activity of CRISPR/Cas effectors on metal nanoparticles and apply the new phenomenon to develop novel nanobiosensors to target various targets such as viral infections, genetic mutations and tumor biomarkers, by using different sensing methods, including, but not limited to fluorescence, luminescence resonance, colorimetric and electrochemical signal readout. In this review, we explore some of the most recent advances in the field of CRISPR-powered nanotechnological biosensors. Demonstrating high accuracy, sensitivity, selectivity and versatility, nanobiosensors along with CRISPR/Cas technology offer tremendous potential for next-generation diagnostics of multiple targets, especially at the point of care and without any target amplification.


Subject(s)
Biosensing Techniques , Metal Nanoparticles , CRISPR-Cas Systems/genetics , DNA/genetics , DNA, Single-Stranded
13.
mBio ; 12(6): e0271621, 2021 12 21.
Article in English | MEDLINE | ID: mdl-34724825

ABSTRACT

During oropharyngeal candidiasis, Candida albicans activates the epidermal growth factor receptor (EGFR), which induces oral epithelial cells to endocytose the fungus and synthesize proinflammatory mediators. To elucidate EGFR signaling pathways that are stimulated by C. albicans, we used proteomics to identify 1,214 proteins that were associated with EGFR in C. albicans-infected cells. Seven of these proteins were selected for additional study. Among these proteins, WW domain-binding protein 2, Toll-interacting protein, interferon-induced transmembrane protein 3 (IFITM3), and the globular C1q receptor (gC1qR) were found to associate with EGFR in viable oral epithelial cells. Each of these proteins was required for maximal endocytosis of C. albicans, and all regulated fungus-induced production of interleukin-1ß (IL-1ß) and/or IL-8, either positively or negatively. gC1qR was found to function as a key coreceptor with EGFR. Interacting with the C. albicans Als3 invasin, gC1qR was required for the fungus to induce autophosphorylation of both EGFR and the ephrin type A receptor 2. The combination of gC1qR and EGFR was necessary for maximal endocytosis of C. albicans and secretion of IL-1ß, IL-8, and granulocyte-macrophage colony-stimulating factor (GM-CSF) by human oral epithelial cells. In mouse oral epithelial cells, inhibition of gC1qR failed to block C. albicans-induced phosphorylation, and knockdown of IFITM3 did not inhibit C. albicans endocytosis, indicating that gC1qR and IFITM3 function differently in mouse versus human oral epithelial cells. Thus, this work provides an atlas of proteins that associate with EGFR and identifies several that play a central role in the response of human oral epithelial cells to C. albicans infection. IMPORTANCE Oral epithelial cells play a key role in the pathogenesis of oropharyngeal candidiasis. In addition to being target host cells for C. albicans adherence and invasion, they secrete proinflammatory cytokines and chemokines that recruit T cells and activated phagocytes to foci of infection. It is known that C. albicans activates EGFR on oral epithelial cells, which induces these cells to endocytose the organism and stimulates them to secrete proinflammatory mediators. To elucidate the EGFR signaling pathways that govern these responses, we analyzed the epithelial cell proteins that associate with EGFR in C. albicans-infected epithelial cells. We identified four proteins that physically associate with EGFR and that regulate different aspects of the epithelial response to C. albicans. One of these is gC1qR, which is required for C. albicans to activate EGFR, induce endocytosis, and stimulate the secretion of proinflammatory mediators, indicating that gC1qR functions as a key coreceptor with EGFR.


Subject(s)
Candida albicans/physiology , Candidiasis, Oral/metabolism , ErbB Receptors/metabolism , Membrane Glycoproteins/metabolism , Receptors, Complement/metabolism , Animals , Candidiasis, Oral/genetics , Candidiasis, Oral/microbiology , Epithelial Cells/metabolism , Epithelial Cells/microbiology , ErbB Receptors/genetics , Humans , Membrane Glycoproteins/genetics , Mice , Mice, Inbred BALB C , NIH 3T3 Cells , Protein Binding , Receptors, Complement/genetics , Signal Transduction
14.
Food Chem ; 355: 129409, 2021 Sep 01.
Article in English | MEDLINE | ID: mdl-33799257

ABSTRACT

An untargeted lipidomic profiling approach based on ultra - performance liquid chromatography - time-of-flight tandem mass spectrometry (UPLC-TOF-MS/MS) was successfully used to study the origin of commercial Pinot noir wines. The total wine lipids were extracted using a modified Bligh-Dyer method. In all wine samples, the total lipids were less than 0.1% (w/w) of wine. The wines analyzed consisted of 222 lipids from 11 different classes. 48 commercial Pinot noir wine samples were collected from producers in Burgundy, California, Oregon, and New Zealand. Lipidomic data was studied using advanced multivariate analysis methods, random forest, k-nearest neighbor (k-NN), and linear discriminant analysis. The overall classification accuracy was 97.5% for random forest and 90% for k-NN. Wine lipids showed a strong potential for classifying wines by origin, with the top 58 lipids contributing to the discrimination. This information could potentially be used for further study of the impacts of lipids on wine characteristics and authenticity.


Subject(s)
Lipidomics/methods , Lipids/analysis , Wine/analysis , Chromatography, High Pressure Liquid , Discriminant Analysis , Multivariate Analysis , New Zealand , Oregon , Tandem Mass Spectrometry
15.
PLoS Pathog ; 17(3): e1009235, 2021 03.
Article in English | MEDLINE | ID: mdl-33780518

ABSTRACT

To gain a better understanding of the transcriptional response of Aspergillus fumigatus during invasive pulmonary infection, we used a NanoString nCounter to assess the transcript levels of 467 A. fumigatus genes during growth in the lungs of immunosuppressed mice. These genes included ones known to respond to diverse environmental conditions and those encoding most transcription factors in the A. fumigatus genome. We found that invasive growth in vivo induces a unique transcriptional profile as the organism responds to nutrient limitation and attack by host phagocytes. This in vivo transcriptional response is largely mimicked by in vitro growth in Aspergillus minimal medium that is deficient in nitrogen, iron, and/or zinc. From the transcriptional profiling data, we selected 9 transcription factor genes that were either highly expressed or strongly up-regulated during in vivo growth. Deletion mutants were constructed for each of these genes and assessed for virulence in mice. Two transcription factor genes were found to be required for maximal virulence. One was rlmA, which is required for the organism to achieve maximal fungal burden in the lung. The other was sltA, which regulates of the expression of multiple secondary metabolite gene clusters and mycotoxin genes independently of laeA. Using deletion and overexpression mutants, we determined that the attenuated virulence of the ΔsltA mutant is due in part to decreased expression aspf1, which specifies a ribotoxin, but is not mediated by reduced expression of the fumigaclavine gene cluster or the fumagillin-pseruotin supercluster. Thus, in vivo transcriptional profiling focused on transcription factors genes provides a facile approach to identifying novel virulence regulators.


Subject(s)
Aspergillus fumigatus/genetics , Gene Expression Regulation, Fungal/genetics , Lung/virology , Transcription Factors/metabolism , Animals , Aspergillosis/microbiology , Aspergillus fumigatus/pathogenicity , Fungal Proteins/metabolism , Gene Expression Profiling/methods , Iron/metabolism , Lung/metabolism , Mice , Virulence/genetics
16.
PLoS Pathog ; 17(1): e1009221, 2021 01.
Article in English | MEDLINE | ID: mdl-33471869

ABSTRACT

During oropharyngeal candidiasis (OPC), Candida albicans invades and damages oral epithelial cells, which respond by producing proinflammatory mediators that recruit phagocytes to foci of infection. The ephrin type-A receptor 2 (EphA2) detects ß-glucan and plays a central role in stimulating epithelial cells to release proinflammatory mediators during OPC. The epidermal growth factor receptor (EGFR) also interacts with C. albicans and is known to be activated by the Als3 adhesin/invasin and the candidalysin pore-forming toxin. Here, we investigated the interactions among EphA2, EGFR, Als3 and candidalysin during OPC. We found that EGFR and EphA2 constitutively associate with each other as part of a heteromeric physical complex and are mutually dependent for C. albicans-induced activation. Als3-mediated endocytosis of a C. albicans hypha leads to the formation of an endocytic vacuole where candidalysin accumulates at high concentration. Thus, Als3 potentiates targeting of candidalysin, and both Als3 and candidalysin are required for C. albicans to cause maximal damage to oral epithelial cells, sustain activation of EphA2 and EGFR, and stimulate pro-inflammatory cytokine and chemokine secretion. In the mouse model of OPC, C. albicans-induced production of CXCL1/KC and CCL20 is dependent on the presence of candidalysin and EGFR, but independent of Als3. The production of IL-1α and IL-17A also requires candidalysin but is independent of Als3 and EGFR. The production of TNFα requires Als1, Als3, and candidalysin. Collectively, these results delineate the complex interplay among host cell receptors EphA2 and EGFR and C. albicans virulence factors Als1, Als3 and candidalysin during the induction of OPC and the resulting oral inflammatory response.


Subject(s)
Candida albicans/physiology , Candidiasis, Oral/pathology , Ephrin-A2/metabolism , Epithelial Cells/pathology , Oropharynx/pathology , Virulence Factors/metabolism , Animals , Candidiasis, Oral/genetics , Candidiasis, Oral/metabolism , Candidiasis, Oral/microbiology , Cytokines/metabolism , Disease Models, Animal , Ephrin-A2/genetics , Epithelial Cells/metabolism , Epithelial Cells/microbiology , ErbB Receptors/genetics , ErbB Receptors/metabolism , Humans , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Oropharynx/metabolism , Oropharynx/microbiology , Receptor, EphA2 , Virulence Factors/genetics
17.
Methods Mol Biol ; 2260: 27-36, 2021.
Article in English | MEDLINE | ID: mdl-33405029

ABSTRACT

Receptors on endothelial and epithelial cells often recognize molecules that are expressed by fungi, and only a limited number of these receptors have been identified to date. Here, we describe a method for identifying novel host cell receptors for fungi that uses intact organisms to precipitate biotin-labelled host cell membrane proteins, which are then detected by immunoblotting with an anti-biotin antibody. Presented here is the method to use for identification of membrane proteins that bind to C. albicans.


Subject(s)
Blotting, Western , Candida albicans/metabolism , Endothelial Cells/metabolism , Epithelial Cells/metabolism , Fungal Proteins/metabolism , Receptors, Cell Surface/isolation & purification , Animals , Biotinylation , Cells, Cultured , Centrifugation , Endothelial Cells/microbiology , Epithelial Cells/microbiology , Host-Pathogen Interactions , Humans , Protein Binding
18.
Foods ; 9(6)2020 Jun 18.
Article in English | MEDLINE | ID: mdl-32570784

ABSTRACT

Malolactic fermentation (MLF) is an important process in wine production due to the resulting reduction in acidity. MLF is typically induced by the addition of Oenococcus oeni after the completion of alcoholic fermentation (AF), but can occur concurrent with AF by co-inoculation of O. oeni with Saccharomyces cerevisiae. This study investigated the effect of MLF inoculation timing and temperature (15 °C and 21 °C) and the presence of the non-Saccharomyces yeast Torulaspora delbrueckii on Chardonnay wine aroma and mouthfeel. Aroma composition was measured using headspace solid-phase microextraction-gas chromatography mass spectrometry (HS-SPME-GCMS). Mouthfeel attributes of the wines produced were assessed by a winemaker panel, using Napping® and Ultra-flash profiling. Significant differences in aroma composition and mouthfeel perception were found based on MLF timing and inoculation conditions, as well as between temperatures. Temperature had a greater impact on the aroma composition for sequential inoculations, while there were little differences based on the temperature of concurrent fermentations. Treatment type and temperature also affected the chemical composition of finished wines. Mouthfeel was impacted, although not as strongly as aroma composition. These findings demonstrate the usefulness of various MLF practices to influence the sensory qualities of a Chardonnay wine.

19.
Asian Pac J Cancer Prev ; 21(4): 1135-1142, 2020 Apr 01.
Article in English | MEDLINE | ID: mdl-32334482

ABSTRACT

BACKGROUND: HER2 is the target of the therapeutic agents which are used to treat HER2-positive breast cancer. Reports have shown that the HER2 oncogene expression and its association with clinicopathological factors remain unclear in breast cancer (BC) patients.  This study aimed to determine the correlation between HER2 expression and clinicalpathological characteristics of breast cancer in Vietnamese women. METHODS: Between June 2016 and August 2018, paraffin-embedded specimens from 237 patients with primary invasive breast carcinoma in Hue University Hospital and Hue Center Hospital, Hue city, Vietnam were examined for pathological features. The gene expression of HER2, ER, PR and Ki-67 were determined by immunohistochemistry (IHC). The gene amplification of Her2 was assessed by using Dual color in situ hybridization (DISH). RESULTS: The most frequent histological type was invasive carcinoma of no special type (NST) with 77.35%, the highest percentage of patients with Grade II was detected (59.36%), tumor size > 2 cm accounted for 71.31% of cases, Lymph node metastases were available in 57.86% cases. Most patients were diagnosed at stage II (59.18%). The majority of patients were classified as moderate Nottingham prognostic index (54.9%). Estrogen receptor and Progesterone receptor were positive in 53.16% and 50.63%, respectively. 76.37% of cases were in high expression group of Ki-67 (≥14%). HER2 IHC 2+, 3+ were accounted for 28.69% and HER2 gene amplification was detected in 31% cases. HER2 gene amplification and/or overexpression was significantly associated with cell proliferation index Ki67. Furthermore, HER2 gene expression tended to be more frequently found in tumors with large tumor size, high grade, high stage and high Nottingham prognostic index and confirmed their prognostic independent role. CONCLUSIONS: Our data indicated that HER2 gene expression was significantly correlated with cell proliferation index Ki67, but not significantly associated with another clinicopathological factors in breast cancer of Vietnamese women.
.


Subject(s)
Biomarkers, Tumor/metabolism , Breast Neoplasms/pathology , Gene Amplification , Receptor, ErbB-2/metabolism , Adult , Biomarkers, Tumor/genetics , Breast Neoplasms/epidemiology , Breast Neoplasms/metabolism , Cross-Sectional Studies , Female , Follow-Up Studies , Humans , Lymphatic Metastasis , Middle Aged , Neoplasm Invasiveness , Prognosis , Receptor, ErbB-2/genetics , Vietnam/epidemiology
20.
Cell Rep ; 28(2): 423-433.e5, 2019 07 09.
Article in English | MEDLINE | ID: mdl-31291578

ABSTRACT

During oropharyngeal candidiasis (OPC), Candida albicans proliferates and invades the superficial oral epithelium. Ephrin type-A receptor 2 (EphA2) functions as an oral epithelial cell ß-glucan receptor that triggers the production of proinflammatory mediators in response to fungal infection. Because EphA2 is also expressed by neutrophils, we investigated its role in neutrophil candidacidal activity during OPC. We found that EphA2 on stromal cells is required for the accumulation of phagocytes in the oral mucosa of mice with OPC. EphA2 on neutrophils is also central to host defense against OPC. The interaction of neutrophil EphA2 with serum-opsonized C. albicans yeast activates the MEK-ERK signaling pathway, leading to NADPH subunit p47phox site-specific phospho-priming. This priming increases intracellular reactive oxygen species production and enhances fungal killing. Thus, in neutrophils, EphA2 serves as a receptor for ß-glucans that augments Fcγ receptor-mediated antifungal activity and controls early fungal proliferation during OPC.


Subject(s)
Antifungal Agents/metabolism , Candida albicans/pathogenicity , Mouth Mucosa/pathology , Mycoses/genetics , Neutrophils/metabolism , Receptor, EphA2/metabolism , Humans
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