Genome-wide transcriptional profiling of human PBMCs stimulated with Candida albicans and non-fungal inflammatory stimuli
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ABSTRACT: Candida albicans is the most common human fungal pathogen causing mucosal and systemic infections, but human anti-fungal immunity remains poorly defined. Expression profiling of Candida-stimulated human peripheral blood mononuclear cells (PBMCs) provides new insights into Candida-specific host defense mechanisms in humans. Total RNA was extracted from PBMCs from healthy human volunteers. PBMCs were stimulated with heat-killed Candida albicans (10^6/ml), non-fungal inflammatory stimuli or RPMI control for 4 or 24 hours. A large number of biological replicates (>20) were included per stimulation condition and duration.
Project description:Candida albicans is the most common human fungal pathogen causing mucosal and systemic infections, but human anti-fungal immunity remains poorly defined. Expression profiling of Candida-stimulated human peripheral blood mononuclear cells (PBMCs) provides new insights into Candida-specific host defense mechanisms in humans.
Project description:Host gene expression responses can be used to determine the etiology of acute infection. PBMCs were stimulated with bacterial, viral, and fungal stimuli and then analyzed for differential gene expression utilizing microarrays to derive pathogen class-specific gene expression classifiers of infection. Discovery Cohort: In vitro human PBMC challenges were performed with bacteria (gram postive and gram negative), viruses (4 strains of influenza), and fungi (Cryptococcus and Candida)
Project description:Host gene expression responses can be used to determine the etiology of acute infection. PBMCs were stimulated with bacterial, viral, and fungal stimuli and then analyzed for differential gene expression utilizing microarrays to derive pathogen class-specific gene expression classifiers of infection. Validation Cohort: peripheral blood samples of human patients with acute viral, bacterial, or fungal infections
Project description:Dendritic cells from three healthy human donors were cultured in the presence or absence of either Aspergillus fumigatus, Saccharomyces cerevisiae, Candida albicans or Candida parapsilosis. Each of the four fungi were also cultured in the absence of human cells. RNA-sequencing was used to evaluate differences in the transcriptomes of human cells challenged and unchallenged with each fungal pathogen, as well as in those of each fungus challenged and unchallenged by cells from the human immune system.
Project description:Candida auris has been globally recognized as a multidrug-resistant human fungal pathogen that contributes for the worldwide occurrence of nosocomial outbreaks. It has been reported that C. auris was able to avoid neutrophil attack, suggestive of an impaired innate immune response. Whether C. auris evades the innate immune recognition of BMDM (bone marrow derived macrophage) remains poorly understood, and as for well-known Candida species -C. albicans, it can trigger immune response. To determine whether occurs difference between immune response stimulated by C. auris or C. albicans, we performed mRNA-seq of BMDM stimulated by C. auris or C. albicans.
Project description:The cell wall provides a major physical interface between fungal pathogens and their mammalian host. This extracellular armour is critical for fungal cell homeostasis and survival. Yet essential cell wall moieties, such as β-1,3-glucan, are recognised as pathogen-associated molecular patterns (PAMPs) that activate immune-mediated clearance mechanisms. We have reported that the opportunistic human fungal pathogen, Candida albicans, masks β-1,3-glucan following exposure to lactate, hypoxia or iron depletion. However, the precise mechanism(s) by which C. albicans masks β-1,3-glucan have remained obscure. Here, we performed proteomic analysis of supernatants harvested from C. albicans cells grown in hypoxia or lactate compared to glucose-grown controls to identify mechanisms driving β-1,3-glucan masking.
Project description:The cell wall provides a major physical interface between fungal pathogens and their mammalian host. This extracellular armour is critical for fungal cell homeostasis and survival. Yet essential cell wall moieties, such as β-1,3-glucan, are recognised as pathogen-associated molecular patterns (PAMPs) that activate immune-mediated clearance mechanisms. We have reported that the opportunistic human fungal pathogen, Candida albicans, masks β-1,3-glucan following exposure to lactate, hypoxia or iron depletion. However, the precise mechanism(s) by which C. albicans masks β-1,3-glucan have remained obscure. Here, we performed proteomic analysis of cell walls from C. albicans cells grown in hypoxia or lactate compared to glucose-grown controls to identify mechanisms driving β-1,3-glucan masking.
Project description:Lysine acetylation is critical in regulating important biological processes in many organisms, yet little is known about acetylome evolution and its contribution to phenotypic diversity. Here, we compare the acetylomes of baker’s yeast and the three deadliest human fungal pathogens, Cryptococcus neoformans, Candida albicans, and Aspergillus fumigatus. Using mass spectrometry enriched for acetylated peptides together with public data from Saccharomyces cerevisiae, we show that fungal acetylomes are characterized by dramatic evolutionary dynamics and limited conservation in core biological processes. Notably, the levels of protein acetylation in pathogenic fungi correlate with their pathogenicity. Using gene knockouts and pathogenity assays in mice, we identify deacetylases with critical roles in virulence and protein translation elongation. Finally, through mutational analysis of deactylation motifs we find evidence of positive selection at specific acetylation motifs in fungal pathogens. These results shed new light on the pathogenicity regulation mechanisms underlying the evolution of fungal acetylomes.
Project description:Candida auris has emerged as a significant healthcare-associated pathogen, posing a serious challenge due to its multidrug-resistant nature. Given the pre-existing constraints in the discovery and provision of new antifungals, there is thus an urgent imperative to design effective strategies to tackle this pressing global concern. Here, we screened a chemical library and identified phenyl-carbohydrazide derivatives with potent activity against both C. auris and the most prevalent human fungal pathogen, C. albicans. SPB00525 (N'-(2,6-Dichlorophenyl)-5-nitro-2-furohydrazide) exhibited potent activity against different strains that were resistant to standard antifungals. Using drug-induced haploinsufficient profiling, transcriptomics and metabolomic analysis, we uncovered that Ole1, a ∆(9) fatty acid desaturase, is most likely the target of SPB00525. We also found that another SPB00525 analog, HTS06170 (N'-(2,6-Dichlorophenyl)-4-methyl-1,2,3-thiadiazole-5-carbohydrazide) had a superior antifungal activity against both C. auris and C. albicans. Both SPB00525 and HTS06170 act as antivirulence agents and inhibited the invasive hyphal growth and biofilm formation of C. albicans. SPB00525 and HTS06170 attenuated fungal damage to human enterocytes and ameliorate survival of Galleria mellonella larvae used as a model of systemic candidiasis. These data, suggest that inhibiting ∆(9) fatty acid desaturase activity represents a potential therapeutic approach for treating fungal infection caused by the superbug C. auris and the most prevalent human fungal pathogen, C. albicans.
Project description:Phenotypic plasticity, the ability to switch between different morphological types, plays critical roles in environmental adaptation, leading to infections, and allowing for sexual reproduction in pathogenic Candida species. Candida tropicalis, which is both an emerging human fungal pathogen and an environmental fungus, can switch between two heritable cell types termed white and opaque. In this study, we report the discovery of a novel phenotype in C. tropicalis, named the gray phenotype. Similar to Candida albicans and Candida dubliniensis, white, gray, and opaque cell types of C. tropicalis also form a tristable switching system, where gray cells are relatively small and elongated. In C. tropicalis, gray cells exhibit intermediate levels of mating competency and virulence in a mouse systemic infection model compared to the white and opaque cell types, express a set of cell type-enriched genes, and exhibit both common and species-specific biological features. The key regulators of white-opaque transitions, Wor1 and Efg1, are not required for the gray phenotype. A comparative study of the gray phenotypes in C. tropicalis, C. albicans, and C. dubliniensis provides clues to explain the species differences in terms of virulence, ecological niches, and prevalence among these three species.