title: Identification of inhibitors of yeast-to-hyphae transition in Candida albicans by a reporter screening assay.
abstract: Candida albicans is one of the most common opportunistic fungal pathogens, causing life-threatening disease in immunocompromised patients. As it is not primarily a pathogen, but can exist in a commensal state, we aimed at the identification of new anti-infective compounds which do not eradicate the fungus, but primarily disable a virulence determinant. The yeast–hyphae-dimorphism of C. albicans is considered a major contributor to fungal disease, as mutants locked into either yeast or hyphal state have been shown to be less virulent in the mouse-model. We devised a high-throughput screening procedure which allows us to find inhibitors of the induction of hyphae. Hyphae-formation was induced by nitrogen starvation at 37 °C and neutral pH in a reporter strain, which couples promoter activity of the hyphae-specific HWP1 to β-galactosidase expression. In a pilot screening of 720 novel synthetic compounds, we identified substances which inhibited the outgrowth of germ tubes. They belonged to chemical classes not yet known for antimycotic properties, namely methyl aryl-oxazoline carboxylates, dihydrobenzo[d]isoxazolones and thiazolo[4,5-e]benzoisoxazoles. In conclusion we developed a novel screening assay, which addresses the morphological switch from the yeast form of C. albicans to its hyphal form and identified novel chemical structures with activity against C. albicans.
authors.affiliation: Department of Biological Systems Analysis, Helmholtz Centre for Infection Research, Inhoffenstr. 7, 38124 Braunschweig, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Heintz-Buschart
authors.forename: Holger
authors.initials: H
authors.lastname: Eickhoff
authors.forename: Erwin
authors.initials: E
authors.lastname: Hohn
authors.forename: Ursula
authors.initials: U
authors.lastname: Bilitewski
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development* / Q000472:pathogenicity; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D005656:Fungal Proteins / Q000235:genetics; D017930:Genes, Reporter; D057166:High-Throughput Screening Assays; D006801:Humans; D025301:Hyphae / Q000187:drug effects / Q000254:growth & development; D008562:Membrane Glycoproteins / Q000235:genetics; D008826:Microbial Sensitivity Tests; D011401:Promoter Regions, Genetic / Q000235:genetics; D015203:Reproducibility of Results; D001616:beta-Galactosidase / Q000032:analysis / Q000235:genetics / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; D005656:Fungal Proteins; C118102:HWP1 protein, Candida albicans; D008562:Membrane Glycoproteins; D001616:beta-Galactosidase