Project description:Although dermatophytes are the most common agents of superficial mycoses in humans and animals, the molecular basis of the pathogenicity of these fungi is largely unknown. In vitro digestion of keratin by dermatophytes is associated with the secretion of multiple proteases, which are assumed to be responsible for their particular specialization to colonize and degrade keratinized host structures during infection. To address this hypothesis a guinea pig infection model was established for the zoophilic dermatophyte Arthroderma benhamiae which causes highly inflammatory cutaneous infections in humans and rodents. Microarray analysis revealed a distinct in vivo protease gene expression profile in the fungal cells, which is surprisingly different from the pattern elicited during in vitro growth on keratin. Instead of the major in vitro expressed proteases others were activated specifically during infection. These enzymes are therefore suggested to fulfill important functions that are not exclusively associated with the degradation of keratin. As the most upregulated in vivo specific A. benhamiae sequence we discovered the gene encoding the serine protease subtilisin 6, which is a known major allergen in the related dermatophyte Trichophyton rubrum and putatively linked to host inflammation. In addition, our approach identified other candidate pathogenicity related factors in A. benhamiae, such as genes encoding key enzymes of the glyoxylate cycle and an opsin-related protein. This first broad transcriptional profiling approach during dermatophyte infection gives new molecular insights into pathogenicity associated mechanisms that make these microorganisms the most successful etiologic agents of superficial mycoses. Keywords: Two-condition experiment, strong proteolytic activity in the supernatant versus no proteolytic activity or infected tissue versus no proteolytic activity Three independently prepared A. benhamiae replicates grown in each of the three media, Sabouraud, soy and keratin-soy medium (designated SabA/B/C, soyA/B/C and keratin-soyA/B/C) were used. ARN from skin samples and fungus together of Guinea Pig infected with A. benhamieae were prepared. Pairwise transcriptional comparisons, i.e. soy versus Sabouraud, keratin-soy versus Sabouraud and Guinea Pig infected versus Sabouraud were done. The total number of slides in this study was 18.
Project description:Although dermatophytes are the most common agents of superficial mycoses in humans and animals, the molecular basis of the pathogenicity of these fungi is largely unknown. In vitro digestion of keratin by dermatophytes is associated with the secretion of multiple proteases, which are assumed to be responsible for their particular specialization to colonize and degrade keratinized host structures during infection. To address this hypothesis a guinea pig infection model was established for the zoophilic dermatophyte Arthroderma benhamiae which causes highly inflammatory cutaneous infections in humans and rodents. Microarray analysis revealed a distinct in vivo protease gene expression profile in the fungal cells, which is surprisingly different from the pattern elicited during in vitro growth on keratin. Instead of the major in vitro expressed proteases others were activated specifically during infection. These enzymes are therefore suggested to fulfill important functions that are not exclusively associated with the degradation of keratin. As the most upregulated in vivo specific A. benhamiae sequence we discovered the gene encoding the serine protease subtilisin 6, which is a known major allergen in the related dermatophyte Trichophyton rubrum and putatively linked to host inflammation. In addition, our approach identified other candidate pathogenicity related factors in A. benhamiae, such as genes encoding key enzymes of the glyoxylate cycle and an opsin-related protein. This first broad transcriptional profiling approach during dermatophyte infection gives new molecular insights into pathogenicity associated mechanisms that make these microorganisms the most successful etiologic agents of superficial mycoses. Keywords: Two-condition experiment, strong proteolytic activity in the supernatant versus no proteolytic activity or infected tissue versus no proteolytic activity
Project description:Dermatophytes are highly specialized filamentous fungi which cause the majority of superficial mycoses in humans and animals. The high secreted proteolytic activity of these microorganisms during growth on proteins is assumed to be linked with their particular ability to exclusively infect keratinized host structures such as skin stratum corneum, hair and nails. Individual secreted dermatophyte proteases were recently described and linked with the in vitro digestion of keratin. However, the overall adaptation and transcriptional response of dermatophytes during protein degradation is largely unknown. To address this question, we constructed a cDNA microarray for the human pathogenic dermatophyte Trichophyton rubrum, which is based on transcripts of the fungus grown on proteins. Gene expression profiling during growth of T. rubrum on soy and keratin displayed the activation of a large set of genes encoding endo- and exoproteases. In addition, other specifically induced factors with potential implication in protein utilization were identified, including heat shock proteins, transporters, metabolic enzymes, transcription factors and hypothetical proteins with unknown function. This broad-scale transcriptional analysis of dermatophytes during growth on proteins reveals new putative pathogenicity related host adaptation mechanism of these human pathogenic fungi. Keywords: Two-condition experiment, strong proteolytic activity in the supernatant versus no proteolytic activity Three independently prepared T. rubrum replicates grown in each of the three media, Sabouraud, soy and keratin-soy medium (designated SabA/B/C, soyA/B/C and keratin-soyA/B/C) were used. Pairwise transcriptional comparisons, i.e. soy versus Sabouraud, keratin-soy versus Sabouraud and keratin-soy versus soy were done. The total number of slides in this study was 9.
Project description:Dermatophytes are highly specialized filamentous fungi which cause the majority of superficial mycoses in humans and animals. The high secreted proteolytic activity of these microorganisms during growth on proteins is assumed to be linked with their particular ability to exclusively infect keratinized host structures such as skin stratum corneum, hair and nails. Individual secreted dermatophyte proteases were recently described and linked with the in vitro digestion of keratin. However, the overall adaptation and transcriptional response of dermatophytes during protein degradation is largely unknown. To address this question, we constructed a cDNA microarray for the human pathogenic dermatophyte Trichophyton rubrum, which is based on transcripts of the fungus grown on proteins. Gene expression profiling during growth of T. rubrum on soy and keratin displayed the activation of a large set of genes encoding endo- and exoproteases. In addition, other specifically induced factors with potential implication in protein utilization were identified, including heat shock proteins, transporters, metabolic enzymes, transcription factors and hypothetical proteins with unknown function. This broad-scale transcriptional analysis of dermatophytes during growth on proteins reveals new putative pathogenicity related host adaptation mechanism of these human pathogenic fungi. Keywords: Two-condition experiment, strong proteolytic activity in the supernatant versus no proteolytic activity
Project description:Purpose: The dermatophyte Trichophyton rubrum is an anthropophilic filamentous fungus that infects keratinized tissues and is the most common etiologic agent isolated in cases of human dermatophytoses. To better understand the molecular effects of stress responses and fungal adaptability, we evaluated the effects of acriflavine, a cytoxic drug, on T. rubrum transcriptome in a time-course assay using high-throughput RNA-seq technology. Results: RNA-seq generated approximately 200 million short reads that were mapped to the Broad Institute’s Dermatophyte Comparative Database before differential gene expression analysis. A subset of 490 genes modulated in response to stress caused T. rubrum exposure to acriflavine were identified. These genes are involved in various cellular processes such as oxidation-reduction reactions, transmembrane transport, metal ion binding, and pathogenicity. The genes involved in pathogenicity were down-regulated, suggesting that this drug interferes with virulence factors that allow the establishment and maintenance of host infection. Conclusion: The results obtained in this large-scale analysis provide insights into the molecular events underlying the stress responses of T. rubrum Acriflavine.