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1.
Nat Immunol ; 22(11): 1382-1390, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34663978

RESUMO

Intergenerational inheritance of immune traits linked to epigenetic modifications has been demonstrated in plants and invertebrates. Here we provide evidence for transmission of trained immunity across generations to murine progeny that survived a sublethal systemic infection with Candida albicans or a zymosan challenge. The progeny of trained mice exhibited cellular, developmental, transcriptional and epigenetic changes associated with the bone marrow-resident myeloid effector and progenitor cell compartment. Moreover, the progeny of trained mice showed enhanced responsiveness to endotoxin challenge, alongside improved protection against systemic heterologous Escherichia coli and Listeria monocytogenes infections. Sperm DNA of parental male mice intravenously infected with the fungus C. albicans showed DNA methylation differences linked to immune gene loci. These results provide evidence for inheritance of trained immunity in mammals, enhancing protection against infections.


Assuntos
Candida albicans/imunologia , Candidíase/imunologia , Infecções por Escherichia coli/imunologia , Escherichia coli/imunologia , Hereditariedade , Imunidade Inata/genética , Listeria monocytogenes/imunologia , Listeriose/imunologia , Células Mieloides/imunologia , Animais , Candida albicans/patogenicidade , Candidíase/genética , Candidíase/metabolismo , Candidíase/microbiologia , Células Cultivadas , Metilação de DNA , Modelos Animais de Doenças , Epigênese Genética , Escherichia coli/patogenicidade , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Interações Hospedeiro-Patógeno , Listeria monocytogenes/patogenicidade , Listeriose/genética , Listeriose/metabolismo , Listeriose/microbiologia , Masculino , Camundongos Transgênicos , Células Mieloides/metabolismo , Células Mieloides/microbiologia , Espermatozoides/imunologia , Espermatozoides/metabolismo , Transcrição Genética
2.
Nat Commun ; 12(1): 6235, 2021 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-34716343

RESUMO

The fungal pathogen Candida albicans can form biofilms that protect it from drugs and the immune system. The biofilm cells release extracellular vesicles (EVs) that promote extracellular matrix formation and resistance to antifungal drugs. Here, we define functions for numerous EV cargo proteins in biofilm matrix assembly and drug resistance, as well as in fungal cell adhesion and dissemination. We use a machine-learning analysis of cargo proteomic data from mutants with EV production defects to identify 63 candidate gene products for which we construct mutant and complemented strains for study. Among these, 17 mutants display reduced biofilm matrix accumulation and antifungal drug resistance. An additional subset of 8 cargo mutants exhibit defects in adhesion and/or dispersion. Representative cargo proteins are shown to function as EV cargo through the ability of exogenous wild-type EVs to complement mutant phenotypic defects. Most functionally assigned cargo proteins have roles in two or more of the biofilm phases. Our results support that EVs provide community coordination throughout biofilm development in C. albicans.


Assuntos
Biofilmes/crescimento & desenvolvimento , Candida albicans/fisiologia , Farmacorresistência Fúngica/fisiologia , Vesículas Extracelulares/metabolismo , Proteínas Fúngicas/metabolismo , Animais , Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida albicans/citologia , Candida albicans/efeitos dos fármacos , Candida albicans/patogenicidade , Candidíase/microbiologia , Adesão Celular/efeitos dos fármacos , Cateteres Venosos Centrais/microbiologia , Farmacorresistência Fúngica/efeitos dos fármacos , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Matriz Extracelular/química , Vesículas Extracelulares/química , Feminino , Proteínas Fúngicas/genética , Mutação , Ratos
3.
PLoS Pathog ; 17(9): e1009884, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34506615

RESUMO

Vulvovaginal candidiasis (VVC), caused primarily by the human fungal pathogen Candida albicans, results in significant quality-of-life issues for women worldwide. Candidalysin, a toxin derived from a polypeptide (Ece1p) encoded by the ECE1 gene, plays a crucial role in driving immunopathology at the vaginal mucosa. This study aimed to determine if expression and/or processing of Ece1p differs across C. albicans isolates and whether this partly underlies differential pathogenicity observed clinically. Using a targeted sequencing approach, we determined that isolate 529L harbors a similarly expressed, yet distinct Ece1p isoform variant that encodes for a predicted functional candidalysin; this isoform was conserved amongst a collection of clinical isolates. Expression of the ECE1 open reading frame (ORF) from 529L in an SC5314-derived ece1Δ/Δ strain resulted in significantly reduced vaginopathogenicity as compared to an isogenic control expressing a wild-type (WT) ECE1 allele. However, in vitro challenge of vaginal epithelial cells with synthetic candidalysin demonstrated similar toxigenic activity amongst SC5314 and 529L isoforms. Creation of an isogenic panel of chimeric strains harboring swapped Ece1p peptides or HiBiT tags revealed reduced secretion with the ORF from 529L that was associated with reduced virulence. A genetic survey of 78 clinical isolates demonstrated a conserved pattern between Ece1p P2 and P3 sequences, suggesting that substrate specificity around Kex2p-mediated KR cleavage sites involved in protein processing may contribute to differential pathogenicity amongst clinical isolates. Therefore, we present a new mechanism for attenuation of C. albicans virulence at the ECE1 locus.


Assuntos
Candida albicans/genética , Candidíase Vulvovaginal/microbiologia , Proteínas Fúngicas/genética , Alelos , Animais , Candida albicans/patogenicidade , Feminino , Variação Genética , Humanos , Camundongos , Virulência
4.
Molecules ; 26(16)2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34443525

RESUMO

The epidemiology of yeast infections and resistance to available antifungal drugs are rapidly increasing, and non-albicans Candida species and rare yeast species are increasingly emerging as major opportunistic pathogens. In order to identify new strategies to counter the threat of antimicrobial resistant microorganisms, essential oils (EOs) have become an important potential in the treatment of fungal infections. EOs and their bioactive pure compounds have been found to exhibit a wide range of remarkable biological activities. We investigated the in vitro antifungal activity of nine commercial EOs such as Thymus vulgaris (thyme red), Origanum vulgare (oregano), Lavandula vera (lavender), Pinus sylvestris (pine), Foeniculum vulgare (fennel), Melissa officinalis (lemon balm), Salvia officinalis (sage), Eugenia caryophyllata (clove) and Pelargonium asperum (geranium), and some of their main components (α-pinene, carvacrol, citronellal, eugenol, γ-terpinene, linalool, linalylacetate, terpinen-4-ol, thymol) against non-albicans Candida strains and uncommon yeasts. The EOs were analyzed by GC-MS, and their antifungal properties were evaluated by minimum inhibitory concentration and minimum fungicidal concentration parameters, in accordance with CLSI guidelines, with some modifications for EOs. Pine exhibited strong antifungal activity against the selected non-albicans Candida isolates and uncommon yeasts. In addition, lemon balm EOs and α-pinene exhibited strong antifungal activity against the selected non-albicans Candida yeasts. Thymol inhibited the growth of all uncommon yeasts. These data showed a promising potential application of EOs as natural adjuvant for management of infections by emerging non-albicans Candida species and uncommon pathogenic yeasts.


Assuntos
Antifúngicos/química , Candida/efeitos dos fármacos , Óleos Voláteis/farmacologia , Óleos Vegetais/farmacologia , Antifúngicos/farmacologia , Candida/patogenicidade , Candida albicans/efeitos dos fármacos , Candida albicans/patogenicidade , Candidíase/tratamento farmacológico , Candidíase/microbiologia , Farmacorresistência Fúngica/efeitos dos fármacos , Foeniculum/química , Humanos , Lavandula/química , Melissa/química , Testes de Sensibilidade Microbiana , Óleos Voláteis/química , Origanum/química , Pinus sylvestris/química , Óleos Vegetais/química , Salvia officinalis/química , Syzygium/química , Thymus (Planta)/química
5.
Sci Rep ; 11(1): 16929, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34413406

RESUMO

Patients receiving lipid emulsions are at increased risk of contracting catheter-related bloodstream infections (CRBSIs) in the clinic. More than 15% of CRBSIs are polymicrobial. The objective of this study was to explore the effects of lipid emulsions on the formation of Escherichia coli (E. coli)-Candida albicans (C. albicans) mixed-species biofilms (BFs) on polyvinyl chloride (PVC) surfaces and the underlying mechanism. Mixed-species BFs were produced by coculturing E. coli and C. albicans with PVC in various concentrations of lipid emulsions. Crystal violet staining and XTT assays were performed to test the mixed-species BF biomass and the viability of microbes in the BFs. The microstructures of the BFs were observed by an approach that combined confocal laser scanning microscopy, fluorescence in situ hybridization, and scanning electron microscopy. The study found that lipid emulsions could promote the formation of E. coli-C. albicans mixed-species BFs, especially with 10% lipid emulsions. The mechanism by which lipid emulsions promote mixed-species BF formation may involve significant upregulation of the expression of the flhDC, iha, HTA1, and HWP1 genes, which are associated with bacterial motility, adhesion, and BF formation. The results derived from this study necessitate strict aseptic precautions when handling lipid emulsions and avoiding the use of high concentrations of lipid emulsions for as long as possible.


Assuntos
Biofilmes , Candida albicans , Emulsões/farmacologia , Escherichia coli , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida albicans/efeitos dos fármacos , Candida albicans/patogenicidade , Escherichia coli/efeitos dos fármacos , Escherichia coli/patogenicidade , Cloreto de Polivinila/química
6.
Nature ; 596(7870): 114-118, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34262174

RESUMO

Pathogenic fungi reside in the intestinal microbiota but rarely cause disease. Little is known about the interactions between fungi and the immune system that promote commensalism. Here we investigate the role of adaptive immunity in promoting mutual interactions between fungi and host. We find that potentially pathogenic Candida species induce and are targeted by intestinal immunoglobulin A (IgA) responses. Focused studies on Candida albicans reveal that the pathogenic hyphal morphotype, which is specialized for adhesion and invasion, is preferentially targeted and suppressed by intestinal IgA responses. IgA from mice and humans directly targets hyphal-enriched cell-surface adhesins. Although typically required for pathogenesis, C. albicans hyphae are less fit for gut colonization1,2 and we show that immune selection against hyphae improves the competitive fitness of C. albicans. C. albicans exacerbates intestinal colitis3 and we demonstrate that hyphae and an IgA-targeted adhesin exacerbate intestinal damage. Finally, using a clinically relevant vaccine to induce an adhesin-specific immune response protects mice from C. albicans-associated damage during colitis. Together, our findings show that adaptive immunity suppresses harmful fungal effectors, with benefits to both C. albicans and its host. Thus, IgA uniquely uncouples colonization from pathogenesis in commensal fungi to promote homeostasis.


Assuntos
Imunidade Adaptativa , Candida albicans/imunologia , Candida albicans/fisiologia , Interações Hospedeiro-Patógeno/imunologia , Simbiose/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Antígenos de Fungos/imunologia , Candida albicans/patogenicidade , Colite/imunologia , Colite/microbiologia , Colite/patologia , Feminino , Vacinas Fúngicas/imunologia , Microbioma Gastrointestinal/imunologia , Humanos , Hifas/imunologia , Imunoglobulina A/imunologia , Masculino , Camundongos , Pessoa de Meia-Idade , Adulto Jovem
7.
Int J Mol Sci ; 22(9)2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-34068595

RESUMO

Systemic inflammation, from gut translocation of organismal molecules, might worsen uremic complications in acute kidney injury (AKI). The monitoring of gut permeability integrity and/or organismal molecules in AKI might be clinically beneficial. Due to the less prominence of Candida albicans in human intestine compared with mouse gut, C. albicans were orally administered in bilateral nephrectomy (BiN) mice. Gut dysbiosis, using microbiome analysis, and gut permeability defect (gut leakage), which was determined by fluorescein isothiocyanate-dextran and intestinal tight-junction immunofluorescent staining, in mice with BiN-Candida was more severe than BiN without Candida. Additionally, profound gut leakage in BiN-Candida also resulted in gut translocation of lipopolysaccharide (LPS) and (1→3)-ß-D-glucan (BG), the organismal components from gut contents, that induced more severe systemic inflammation than BiN without Candida. The co-presentation of LPS and BG in mouse serum enhanced inflammatory responses. As such, LPS with Whole Glucan Particle (WGP, a representative BG) induced more severe macrophage responses than LPS alone as determined by supernatant cytokines and gene expression of downstream signals (NFκB, Malt-1 and Syk). Meanwhile, WGP alone did not induced the responses. In parallel, WGP (with or without LPS), but not LPS alone, accelerated macrophage ATP production (extracellular flux analysis) through the upregulation of genes in mitochondria and glycolysis pathway (using RNA sequencing analysis), without the induction of cell activities. These data indicated a WGP pre-conditioning effect on cell energy augmentation. In conclusion, Candida in BiN mice accelerated gut translocation of BG that augmented cell energy status and enhanced pro-inflammatory macrophage responses. Hence, gut fungi and BG were associated with the enhanced systemic inflammation in acute uremia.


Assuntos
Injúria Renal Aguda/metabolismo , Candida albicans/metabolismo , Inflamação/sangue , Proteoglicanas/sangue , Injúria Renal Aguda/genética , Injúria Renal Aguda/microbiologia , Animais , Candida/metabolismo , Candida albicans/patogenicidade , Disbiose/sangue , Metabolismo Energético , Humanos , Inflamação/microbiologia , Inflamação/patologia , Inflamação/cirurgia , Lipopolissacarídeos/sangue , Macrófagos/metabolismo , Macrófagos/microbiologia , Macrófagos/patologia , Camundongos , Microbiota/genética , Nefrectomia/efeitos adversos
8.
Nat Commun ; 12(1): 3899, 2021 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-34162849

RESUMO

The ability of the fungal pathogen Candida albicans to undergo a yeast-to-hypha transition is believed to be a key virulence factor, as filaments mediate tissue damage. Here, we show that virulence is not necessarily reduced in filament-deficient strains, and the results depend on the infection model used. We generate a filament-deficient strain by deletion or repression of EED1 (known to be required for maintenance of hyphal growth). Consistent with previous studies, the strain is attenuated in damaging epithelial cells and macrophages in vitro and in a mouse model of intraperitoneal infection. However, in a mouse model of systemic infection, the strain is as virulent as the wild type when mice are challenged with intermediate infectious doses, and even more virulent when using low infectious doses. Retained virulence is associated with rapid yeast proliferation, likely the result of metabolic adaptation and improved fitness, leading to high organ fungal loads. Analyses of cytokine responses in vitro and in vivo, as well as systemic infections in immunosuppressed mice, suggest that differences in immunopathology contribute to some extent to retained virulence of the filament-deficient mutant. Our findings challenge the long-standing hypothesis that hyphae are essential for pathogenesis of systemic candidiasis by C. albicans.


Assuntos
Candida albicans/metabolismo , Candidíase/metabolismo , Proteínas Fúngicas/metabolismo , Hifas/metabolismo , Animais , Candida albicans/genética , Candida albicans/patogenicidade , Candidíase/microbiologia , Divisão Celular/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Humanos , Hifas/genética , Hifas/crescimento & desenvolvimento , Macrófagos/metabolismo , Camundongos Endogâmicos BALB C , Mutação , Neutrófilos/metabolismo , Virulência/genética
9.
Biomed Res Int ; 2021: 5598907, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34136569

RESUMO

Background: Vulvovaginal candidiasis caused by Candida species is a prevalent fungal infection among women. It is believed that the pathogenesis of Candida species is linked with the production of biofilm which is considered a virulence factor for this organism. The aim of this study was molecular identification, antifungal susceptibility, biomass quantification of biofilm, and detection of virulence markers of Candida species. Methods: We investigated the molecular identification of 70 vaginal isolates of Candida species, antifungal resistance to amphotericin B, fluconazole, itraconazole, and voriconazole according to CLSI M27-A3 and M27-S4, biofilm formation, and frequency analysis of biofilm-related ALS1, ALS3, and HWP1 genes. Results: Our findings showed that the most common yeast isolated from vaginal discharge was C. albicans (67%), followed by the non-Candida albicans species (33%). All C. albicans complex isolates were confirmed as C. albicans by HWP-PCR, and all isolates of the C. glabrata complex were revealed to be C. glabrata sensu stricto using the multiplex PCR method. FLC resistance was observed in 23.4% of C. albicans and 7.7% of C. glabrata. The resistance rate to ITC was found in 10.6% of C. albicans. The frequency of ALS1, ALS3, and HWP1 genes among Candida species was 67.1%, 80%, and 81.4%, respectively. Biofilm formation was observed in 54.3% of Candida species, and the highest frequency detected as a virulence factor was for the ALS3 gene (97.3%) in biofilm-forming species. Discussion. Our results showed the importance of molecular epidemiology studies, investigating antifungal susceptibility profiles, and understanding the role of biofilm-related virulence markers in the pathogenesis of Candida strains.


Assuntos
Antifúngicos/química , Biofilmes , Candida albicans/patogenicidade , Candidíase Vulvovaginal/microbiologia , Vagina/microbiologia , Adulto , Anfotericina B/farmacologia , Biomassa , Candida glabrata/efeitos dos fármacos , Farmacorresistência Fúngica/efeitos dos fármacos , Feminino , Fluconazol/farmacologia , Humanos , Itraconazol/farmacologia , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Pessoa de Meia-Idade , Polimorfismo de Fragmento de Restrição , Virulência , Voriconazol/farmacologia , Adulto Jovem
10.
Res Microbiol ; 172(4-5): 103849, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34089837

RESUMO

Co-infection with other microorganisms can promote the Candida albicans to be invasive. In this study, Escherichia coli and C. albicans were co-isolated from the women with candidiasis symptoms. The in vitro effects of E. coli on C. albicans hypha development, biofilm formation, antibiotic susceptibility, dispersion from the biofilm, expression of Als3, Hwp1, and Tup1 genes, and pathogenesis in Galleria mellonella were investigated. Electron microscopic images revealed that hypha induction was markedly increased in the bacteria-fungi co-culture. Biofilm formation was increased 2.2 fold in the presence of E. coli. The minimum inhibitory concentration of nystatin against Candida was increased from (µg mL-1) 25 to 50 in the dual biofilm. Candida dissemination was increased up to 2.7 fold from the mixed fungi/bacteria biofilm. The expression of ALS3 and HWP1 genes was increased (5.9 and 2.0 fold, respectively) while the TUP1 gene expression was decreased (0.4 fold) when C. albicans was incubated with E. coli. The simultaneous injection of C. albicans and E. coli to the insect larvae increased Galleria mortality up to 40%. This study demonstrated the effects of E. coli to promote fungi virulence factors, which suggest polymicrobial interaction should be considered during treatment of fungal infections.


Assuntos
Biofilmes/crescimento & desenvolvimento , Candida albicans/patogenicidade , Candidíase Vulvovaginal/microbiologia , Coinfecção/microbiologia , Escherichia coli/fisiologia , Interações Microbianas , Fatores de Virulência , Animais , Candida albicans/genética , Feminino , Humanos , Hifas/genética , Hifas/crescimento & desenvolvimento , Larva/microbiologia , Mariposas/microbiologia
11.
Bioengineered ; 12(1): 2420-2431, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34167447

RESUMO

Oral candidiasis is one of the most common types of fungal infection caused by Candida albicans (C. albicans). The present study aims to investigate the antifungal effects of phloretin (a dihydrochalcone flavonoid) against the C. albicans pathogenicity. In this work, we treated C. albicans SC5314 with 37.28, 74.55, or 149.10 µg/mL (equivalent to 0.5×, 1× or 2× MIC) phloretin in vitro. Besides, we established a mice model of oral candidiasis by a sublingual infection of C. albicans suspension (1 × 107 colony-forming unit/mL), and mice were treated with phloretin (3.73 or 7.46 mg/mL, which were equivalent to 50× or 100× MIC) twice a day starting on day one post-infection. The results showed that the MIC of phloretin against C. albicans was 74.55 µg/mL. Phloretin exerted antifungal activity by inhibiting the biofilm formation and suppressing the yeast-to-hyphae transition upon the downregulation of hypha-associated genes including enhanced adherence to polystyrene 1, the extent of cell elongation gene 1, hyphal wall protein 1 gene, and agglutinin-like sequence gene 3. Next, phloretin repressed the secretion of proteases and phospholipases via reducing the expression of protease-encoding genes secreted aspartyl proteases (SAP)1 and SAP2, as well as phospholipase B1. Subsequently, the in vivo antifungal activity of phloretin was testified by the reverse of the enhanced lesion severity, inflammatory infiltration, and the increased colony-forming unit counts caused by C. albicans of tongue tissues in oral candidiasis mice. In conclusion, phloretin suppressed the pathogenicity and virulence factors against C. albicans both in vivo and in vitro.


Assuntos
Candida albicans/patogenicidade , Floretina/farmacologia , Fatores de Virulência/antagonistas & inibidores , Animais , Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida albicans/efeitos dos fármacos , Candidíase/tratamento farmacológico , Candidíase/microbiologia , Modelos Animais de Doenças , Feminino , Hifas/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Boca/microbiologia , Boca/patologia , Peptídeo Hidrolases/metabolismo , Floretina/química , Floretina/uso terapêutico , Fosfolipases/metabolismo , Fatores de Virulência/metabolismo
12.
mBio ; 12(3): e0053121, 2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34154403

RESUMO

Albumin is abundant in serum but is also excreted at mucosal surfaces and enters tissues when inflammation increases vascular permeability. Host-associated opportunistic pathogens encounter albumin during commensalism and when causing infections. Considering the ubiquitous presence of albumin, we investigated its role in the pathogenesis of infections with the model human fungal pathogen, Candida albicans. Albumin was introduced in various in vitro models that mimic different stages of systemic or mucosal candidiasis, where it reduced the ability of C. albicans to damage host cells. The amphipathic toxin candidalysin mediates necrotic host cell damage induced by C. albicans. Using cellular and biophysical assays, we determined that albumin functions by neutralizing candidalysin through hydrophobic interactions. We discovered that albumin, similarly, can neutralize a variety of fungal (α-amanitin), bacterial (streptolysin O and staurosporin), and insect (melittin) hydrophobic toxins. These data suggest albumin as a defense mechanism against toxins, which can play a role in the pathogenesis of microbial infections. IMPORTANCE Albumin is the most abundant serum protein in humans. During inflammation, serum albumin levels decrease drastically, and low albumin levels are associated with poor patient outcome. Thus, albumin may have specific functions during infection. Here, we describe the ability of albumin to neutralize hydrophobic microbial toxins. We show that albumin can protect against damage induced by the pathogenic yeast C. albicans by neutralizing its cytolytic toxin candidalysin. These findings suggest that albumin is a toxin-neutralizing protein that may play a role during infections with toxin-producing microorganisms.


Assuntos
Albuminas/metabolismo , Candida albicans/patogenicidade , Proteínas Fúngicas/metabolismo , Interações Hospedeiro-Patógeno , Membrana Mucosa/microbiologia , Candidíase/microbiologia , Linhagem Celular , Células Cultivadas , Feminino , Proteínas Fúngicas/biossíntese , Células HT29 , Humanos , Interações Hidrofóbicas e Hidrofílicas , Vagina/citologia , Fatores de Virulência
13.
PLoS One ; 16(6): e0252555, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34061886

RESUMO

C. albicans is a commensal organism present in the human microbiome of more than 60% of the healthy population. Transition from commensalism to invasive candidiasis may occur after a local or a general failure of host's immune system. This transition to a more virulent phenotype may reside either on the capacity to form hyphae or on an acquired resistance to antifungal drugs. Indeed, overexpression of genes coding drug efflux pumps or adhesins, cell wall proteins facilitating the contact between the fungus and the host, usually marks the virulence profile of invasive Candida spp. In this paper, we compare virulence of two clinical isolates of C. albicans with that of laboratory-induced resistant strains by challenging G. mellonella larvae with these pathogens along with monitoring transcriptional profiles of drug efflux pumps genes CDR1, CDR2, MDR1 and the adhesin genes ALS1 and HWP1. Although both clinical isolates were found resistant to both fluconazole and micafungin they were found less virulent than laboratory-induced resistant strains. An unexpected behavior emerged for the former clinical isolate in which three genes, CDR1, CDR2 and HWP1, usually correlated with virulence, although hyperexpressed, conferred a less aggressive phenotype. On the contrary, in the other isolate, we observed a decreased expression of CDR1, CDR2 and HWP1as well as of MDR1 and ALS1 that may be consistent with the less aggressive performance observed in this strain. These altered gene expressions might directly influence Candida virulence or they might be an epiphenomenon of a vaster rearrangement occurred in these strains during the challenge with the host's environment. An in-deepth comprehension of this scenario could be crucial for developing interventions able to counteract C. albicans invasiveness and lethality.


Assuntos
Candida albicans/genética , Candida albicans/patogenicidade , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Expressão Gênica , Glicoproteínas de Membrana/genética , Proteínas de Membrana Transportadoras/genética , Animais , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Candida albicans/isolamento & purificação , Candidíase/microbiologia , Farmacorresistência Fúngica/efeitos dos fármacos , Farmacorresistência Fúngica/genética , Feminino , Fluconazol/farmacologia , Humanos , Hifas/genética , Larva/microbiologia , Lepidópteros/microbiologia , Micafungina/farmacologia , Testes de Sensibilidade Microbiana , Fenótipo , Virulência/genética
14.
J Vis Exp ; (171)2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-34057445

RESUMO

While pathogens can be deadly to humans, many of them cause a range of infection types with non-lethal phenotypes. Candida albicans, an opportunistic fungal pathogen of humans, is the fourth most common cause of nosocomial infections which results in ~40% mortality. However, other C. albicans infections are less severe and rarely lethal and include vulvovaginal candidiasis, impacting ~75% of women, as well as oropharyngeal candidiasis, predominantly impacting infants, AIDS patients and cancer patients. While murine models are most frequently used to study C. albicans pathogenesis, these models predominantly assess host survival and are costly, time consuming, and limited in replication. Therefore, several mini-model systems, including Drosophila melanogaster, Danio rerio, Galleria mellonella, and Caenorhabditis elegans, have been developed to study C. albicans. These mini-models are well-suited for screening mutant libraries or diverse genetic backgrounds of C. albicans. Here we describe two approaches to study C. albicans infection using C. elegans. The first is a fecundity assay which measures host reproduction and monitors survival of individual hosts. The second is a lineage expansion assay which measures how C. albicans infection affects host population growth over multiple generations. Together, these assays provide a simple, cost-effective way to quickly assess C. albicans virulence.


Assuntos
Caenorhabditis elegans , Candida albicans , Candidíase , Animais , Caenorhabditis elegans/microbiologia , Candida albicans/isolamento & purificação , Candida albicans/patogenicidade , Modelos Animais de Doenças , Humanos , Camundongos , Fenótipo , Virulência
16.
Nat Commun ; 12(1): 2560, 2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-33963193

RESUMO

The commensal fungus Candida albicans often causes life-threatening infections in patients who are immunocompromised with high mortality. A prominent but poorly understood risk factor for the C. albicans commensal‒pathogen transition is the use of broad-spectrum antibiotics. Here, we report that ß-lactam antibiotics cause bacteria to release significant quantities of peptidoglycan fragments that potently induce the invasive hyphal growth of C. albicans. We identify several active peptidoglycan subunits, including tracheal cytotoxin, a molecule produced by many Gram-negative bacteria, and fragments purified from the cell wall of Gram-positive Staphylococcus aureus. Feeding mice with ß-lactam antibiotics causes a peptidoglycan storm that transforms the gut from a niche usually restraining C. albicans in the commensal state to promoting invasive growth, leading to systemic dissemination. Our findings reveal a mechanism underlying a significant risk factor for C. albicans infection, which could inform clinicians regarding future antibiotic selection to minimize this deadly disease incidence.


Assuntos
Candida albicans/patogenicidade , Candidíase/microbiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Peptidoglicano/toxicidade , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , beta-Lactamas/efeitos adversos , Animais , Antibacterianos/efeitos adversos , Candida albicans/crescimento & desenvolvimento , Candidíase/complicações , Candidíase/tratamento farmacológico , Candidíase/patologia , Parede Celular/química , Parede Celular/efeitos dos fármacos , Cromatografia Líquida , Feminino , Bactérias Gram-Negativas/química , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/metabolismo , Humanos , Hifas/crescimento & desenvolvimento , Hifas/patogenicidade , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos BALB C , Peptidoglicano/química , Infecções Estafilocócicas/complicações , Staphylococcus aureus/química , Staphylococcus aureus/metabolismo
17.
FEMS Yeast Res ; 21(4)2021 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-34021562

RESUMO

Candida albicans typically resides in the human gastrointestinal tract and mucosal membranes as a commensal organism. To adapt and cope with the host immune system, it has evolved a variety of mechanisms of adaptation such as stress-induced mutagenesis and epigenetic regulation. Niche-specific patterns of gene expression also allow the fungus to fine-tune its response to specific microenvironments in the host and switch from harmless commensal to invasive pathogen. Proteome plasticity produced by CUG ambiguity, on the other hand is emerging as a new layer of complexity in C. albicans adaptation, pathogenesis, and drug resistance. Such proteome plasticity is the result of a genetic code alteration where the leucine CUG codon is translated mainly as serine (97%), but maintains some level of leucine (3%) assignment. In this review, we dissect the link between C. albicans non-standard CUG translation, proteome plasticity, host adaptation and pathogenesis. We discuss published work showing how this pathogen uses the fidelity of protein synthesis to spawn novel virulence traits.


Assuntos
Candida albicans/genética , Candida albicans/patogenicidade , Biossíntese de Proteínas , Virulência/genética , Adaptação Fisiológica , Códon , Farmacorresistência Fúngica , Epigênese Genética , Proteoma
18.
Sci Rep ; 11(1): 10802, 2021 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-34031498

RESUMO

Early childhood caries (ECC) recurrence occurs in approximately 40% of treated cases within one year. The association of Streptococcus mutans and Candida albicans with the onset of ECC is well known. Also, S. mutans strains harboring collagen-binding proteins (Cbps) avidly bind to collagen-rich dentin and are linked to increased caries risk. Here, we investigated the presence of Cbp+ S. mutans and C. albicans in saliva and dental plaque of children with varying caries statuses, and their salivary microbiome. In this cross-sectional study, 143 children who were caries-free (n = 73), treated for ECC with no signs of recurrence after 6 months (n = 45), or treated for ECC and experiencing recurrence within 6 months following treatment (n = 25) were enrolled. Co-infection with C. albicans and S. mutans, especially Cbp+ S. mutans, was strongly associated with caries recurrence. Subjects of the recurrence group infected with Cbp+ S. mutans showed a greater burden of Candida spp. and of Mutans streptococci in dentin than those infected with Cbp- strains. Salivary microbiome analysis revealed that Streptococcus parasanguinis was overrepresented in the caries recurrence group. Our findings indicate that Cbp+ S. mutans and C. albicans are intimately associated with caries recurrence, contributing to the establishment of recalcitrant biofilms.


Assuntos
Proteínas de Bactérias/metabolismo , Candida albicans/patogenicidade , Coinfecção/microbiologia , Cárie Dentária/microbiologia , Streptococcus mutans/patogenicidade , Candida albicans/isolamento & purificação , Candida albicans/metabolismo , Pré-Escolar , Estudos Transversais , Cárie Dentária/metabolismo , Suscetibilidade à Cárie Dentária , Dentina/metabolismo , Feminino , Humanos , Masculino , Recidiva , Saliva/microbiologia , Streptococcus/isolamento & purificação , Streptococcus mutans/isolamento & purificação , Streptococcus mutans/metabolismo
19.
Fungal Genet Biol ; 153: 103575, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34033880

RESUMO

Hospital infections caused by the opportunistic fungus Candida albicans are increasingly common and life threatening. The first line of defense consists of administering antifungal drugs such as azoles including fluconazole that prevent ergosterol biosynthesis. C. albicans is rapidly developing resistance towards antifungal drugs through various mechanisms including mutations in ERG11 which is a gene involved in the ergosterol biosynthesis pathway. These mutations prevent the binding of the drug and inactivate ergosterol synthesis. Alternatively, upregulation of cell membrane ergosterol content generates resistance by countering the effect of the drug. In this study we sequenced the ERG11 gene in 6 fluconazole sensitive and 8 fluconazole resistant C. albicans isolates recovered from clinical settings in Lebanon and quantified the ergosterol content of their plasma membranes to identify mechanisms linked to fluconazole resistance. A number of pathogenicity attributes were also analyzed to determine any correlation with fluconazole resistance. Our results revealed an increase in ergosterol content in the fluconazole resistant isolates. In addition, we identified both novel and previously reported amino acid substitutions in ERG11 as well as frameshift mutations that might contribute to resistance. The fluconazole resistant isolates did not exhibit an increased virulence potential in a mouse model of systemic infection and showed decreased in vitro potential to form biofilms. No discrepancy between drug resistant and sensitive isolates to cell surface disrupting agents was observed. This approach is the first of its kind to be carried out in Lebanon to identify possible mechanisms and phenotypes of drug resistant C. albicans isolates.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Candida albicans/patogenicidade , Candidíase/microbiologia , Fluconazol/farmacologia , Genes Fúngicos , Substituição de Aminoácidos , Animais , Biofilmes/crescimento & desenvolvimento , Candida albicans/genética , Candida albicans/crescimento & desenvolvimento , Parede Celular/ultraestrutura , Quitina/análise , Infecção Hospitalar/microbiologia , Farmacorresistência Fúngica , Ergosterol/metabolismo , Feminino , Mutação da Fase de Leitura , Proteínas Fúngicas/genética , Humanos , Líbano , Camundongos , Virulência
20.
J Biol Chem ; 296: 100630, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33823154

RESUMO

Unchecked inflammation can result in severe diseases with high mortality, such as macrophage activation syndrome (MAS). MAS and associated cytokine storms have been observed in COVID-19 patients exhibiting systemic hyperinflammation. Interleukin-18 (IL-18), a proinflammatory cytokine belonging to the IL-1 family, is elevated in both MAS and COVID-19 patients, and its level is known to correlate with the severity of COVID-19 symptoms. IL-18 binds its specific receptor IL-1 receptor 5 (IL-1R5, also known as IL-18 receptor alpha chain), leading to the recruitment of the coreceptor, IL-1 receptor 7 (IL-1R7, also known as IL-18 receptor beta chain). This heterotrimeric complex then initiates downstream signaling, resulting in systemic and local inflammation. Here, we developed a novel humanized monoclonal anti-IL-1R7 antibody to specifically block the activity of IL-18 and its inflammatory signaling. We characterized the function of this antibody in human cell lines, in freshly obtained peripheral blood mononuclear cells (PBMCs) and in human whole blood cultures. We found that the anti-IL-1R7 antibody significantly suppressed IL-18-mediated NFκB activation, reduced IL-18-stimulated IFNγ and IL-6 production in human cell lines, and reduced IL-18-induced IFNγ, IL-6, and TNFα production in PBMCs. Moreover, the anti-IL-1R7 antibody significantly inhibited LPS- and Candida albicans-induced IFNγ production in PBMCs, as well as LPS-induced IFNγ production in whole blood cultures. Our data suggest that blocking IL-1R7 could represent a potential therapeutic strategy to specifically modulate IL-18 signaling and may warrant further investigation into its clinical potential for treating IL-18-mediated diseases, including MAS and COVID-19.


Assuntos
Anti-Inflamatórios/farmacologia , Anticorpos Monoclonais/farmacologia , Anticorpos Neutralizantes/farmacologia , Fatores Imunológicos/farmacologia , Interleucina-18/genética , Receptores de Interleucina-18/genética , Anti-Inflamatórios/metabolismo , Anticorpos Monoclonais/biossíntese , Anticorpos Neutralizantes/biossíntese , COVID-19/tratamento farmacológico , Candida albicans/crescimento & desenvolvimento , Candida albicans/patogenicidade , Regulação da Expressão Gênica , Células HEK293 , Humanos , Fatores Imunológicos/biossíntese , Inflamação , Interferon gama/genética , Interferon gama/imunologia , Interleucina-18/imunologia , Interleucina-6/genética , Interleucina-6/imunologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/microbiologia , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Síndrome de Ativação Macrofágica/tratamento farmacológico , NF-kappa B/genética , NF-kappa B/imunologia , Cultura Primária de Células , Receptores de Interleucina-18/antagonistas & inibidores , Receptores de Interleucina-18/imunologia , SARS-CoV-2/imunologia , SARS-CoV-2/patogenicidade , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
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