Project description:The filamentous fungus Aspergillus terreus is known to produce both industrially and pharmaceutically important secondary metabolites. The objective of this study is to investigate the effect of exogenously added butyrolactone I (BI) on the submerged culture of A. terreus, especially on the possible regulation of the secondary metabolism on the transcriptional level. In order to elucidate the presumed regulative role of butyrolactone I, a large-scale microarray gene expression study was designed and conducted with an industrially utilised A. terreus strain MUCL38669. A. terreus MUCL38669 was cultured in secondary metabolism inducing submerged conditions for nine days, where butyrolactone I was added at the beginning of the growth phase (at 24 hours p.i.), in the middle of the growth phase (at 96 hours p.i.) or in the late growth phase (at 120 hours p.i.), in addition to the control culture where no exogenous butyrolactone I was added. To obtain comprehensive gene expression profiles over the whole culture time, samples were taken at six time points: 24 hours, 48 hours, 96 hours, 120 hours, 144 hours and 216 hours post inoculation.
Project description:Aspergillus terreus is an emerging fungal pathogen in immunocompromised patients. Due to intrinsic resistance of AmB against A. terreus and acquiring resistance to azoles, alternative antifungal strategy needs investigation. Thus, we explored the activity of phytochemicals such as Shikonin, gallic acid, coumaric acid and quercetin against A. terreus. Amongst these, shikonin showed significant inhibition at MIC50;2 µg/ml, considered for proteome profiling.
Project description:Aspergillus terreus has been described as an allergenic fungus in addition to causing infection to both human beings and plants. However, the allergens in this fungus are still unknown. The identification of allergens is essential to develop diagnostic and therapeutic avenues. Employing a proteomic approach, sixteen allergens were identified based on two-dimensional immuno-blotting with A. terreus susceptible patient sera. Amongst them, triosephosphate isomerase (Asp t 36), one of the dominant immunoglobulin E (IgE)-reactive proteins, was purified under native conditions. To characterize Asp t 36, the gene was cloned and expressed in E. coli. Phylogenetic analysis showed it to be highly conserved with close similarity to Dermatophagoides farinae. Four immuno-dominant epitopes were identified using synthetic peptides and mapped on the tertiary structure of Asp t 36. Among these, two were found to create a continuous surface patch on the 3D structure rendering it to be an IgE binding hotspot. Asp t 36 showed similar secondary structure and temperature sensitivity with other reported triosephosphate isomerase allergens. In-vivo studies using the murine model demonstrated rAsp t 36 able to stimulate airway inflammation, such as an influx of eosinophils, goblet cell hyperplasia, elevated serum immunoglobulins and induction of Th2 cytokines. Collectively, our results reveal the immunogenic property of Asp t 36, a major allergen from A. terreus for the first time in any fungi. This allergen could serve as a potent candidate for investigating component resolved diagnosis and immunotherapy.
