title: Use of the Porcine Intestinal Epithelium (PIE)-Assay to analyze early stages of colonization by the human fungal pathogen Candida albicans.
abstract: Virulence of C. albicans strains can be tested using a mouse model of haematogenously disseminated Candida cells. Initial steps of host-pathogen contact such as adhesion and colonization are not taken into account due to the injection of Candida cells into the blood stream. Here we describe an assay, based on the ex vivo usage of porcine intestinal epithelium (PIE), that is useful to monitor the early stages of a C. albicans infection. The ability of C. albicans to undergo morphogenetic switching between yeast and hyphal stages is thought to contribute to its virulence. We found that hyphal formation was required to allow cells to colonize the PIE. The non-filamentous mutant strains efg1/cph1 which lacks two of the central transcription factors that are required to promote hyphal growth and wal1 that carries a deletion of the C. albicans homolog of the human Wiskott-Aldrich Syndrome Protein and is deficient in endocytosis showed only weak adherence. Furthermore, the wal1 mutant was found to be reduced in virulence using the mouse tail vein injection assay. We also analyzed the colonization properties of a variety of other mutant strains carrying deletions of either secreted aspartyl proteinase (SAP)-family genes or amino acid permease encoding genes (GAP1, SSY1, and PUT4). Interestingly, the nag5 strain which lacks an N-acetylglucosamine kinase showed enhanced filamentation and invasive growth as well as increased resistance against farnesol.
authors.affiliation: Leibniz Institute for Natural Products Research and Infection Biology - Hans-Knöll Institute - Junior Research Group: Fungal Pathogens, Jena, Germany. juergen.wendland@crc.dk
authors.forename: Jürgen
authors.initials: J
authors.lastname: Wendland
authors.forename: Daniela
authors.initials: D
authors.lastname: Hellwig
authors.forename: Andrea
authors.initials: A
authors.lastname: Walther
authors.forename: Stefan
authors.initials: S
authors.lastname: Sickinger
authors.forename: Yona
authors.initials: Y
authors.lastname: Shadkchan
authors.forename: Ronny
authors.initials: R
authors.lastname: Martin
authors.forename: Janine
authors.initials: J
authors.lastname: Bauer
authors.forename: Nir
authors.initials: N
authors.lastname: Osherov
authors.forename: Alexander
authors.initials: A
authors.lastname: Tretiakov
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Saluz
mesh_terms: D026905:Amino Acid Transport Systems / Q000235:genetics / Q000502:physiology; D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000235:genetics / Q000502:physiology; D002176:Candida albicans / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D002177:Candidiasis / Q000382:microbiology*; D002448:Cell Adhesion / Q000502:physiology*; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D005204:Farnesol / Q000494:pharmacology; D005260:Female; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000382:microbiology* / Q000502:physiology; D051379:Mice; D008856:Microscopy, Fluorescence; D016254:Mutagenesis, Insertional; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000502:physiology; D016019:Survival Analysis; D013552:Swine; D014774:Virulence
chemical_list: D026905:Amino Acid Transport Systems; D004271:DNA, Fungal; D005204:Farnesol; D017853:Phosphotransferases (Alcohol Group Acceptor); C018716:N-acetylglucosamine kinase; D016282:Aspartic Acid Endopeptidases