title: An in vitro evaluation of Candida tropicalis infectivity using human cell monolayers.
abstract: The aim of this study was to investigate the interaction of Candida tropicalis with three different human cell lines: TCC-SUP (epithelial cells from urinary bladder), HeLa (epithelial cells from cervical carcinoma) and Caco-2 (epithelial cells from colorectal adenocarcinoma). In particular we sought to assess the degree of cell damage and activity reduction induced by C. tropicalis adhesion and the role of secreted aspartyl proteinase (SAP) gene expression in this process. Two C. tropicalis strains were used: the reference strain ATCC 750 and a clinical isolate from urine (U69). The ability of C. tropicalis to adhere to a confluent layer of human cells was determined using an adaptation of the crystal violet staining method; cell damage and cell activity inhibition induced by the adhesion of C. tropicalis were assessed by measuring lactate dehydrogenase and tetrazolium salt (MTS) reduction, respectively. C. tropicalis SAP gene expression was determined by real-time PCR. Both C. tropicalis strains were able to adhere to the different human cells, although in a strain- and cell-line-dependent manner. Concerning the cellular response to C. tropicalis, the highest inhibition of cell activity was obtained for Caco-2, followed by TCC-SUP and HeLa cells. The highest percentage of cell damage (around 14 %) was observed for TCC-SUP cells in contact with the U69 isolate and for Caco-2 in contact with the reference strain. Real-time PCR analysis revealed a wide range of expression profiles of SAP genes for both C. tropicalis strains in contact with the different types of epithelial cells. SAPT3 was the gene expressed at the highest level for both C. tropicalis strains in contact with the three human epithelial cell lines. The results highlight that the response of human cells to C. tropicalis adhesion, as well as production of SAPs, is dependent on both the strain and the epithelial cell line.
authors.affiliation: Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Melyssa
authors.initials: M
authors.lastname: Negri
authors.affiliation: Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Cláudia
authors.initials: C
authors.lastname: Botelho
authors.affiliation: Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Sónia
authors.initials: S
authors.lastname: Silva
authors.affiliation: Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Luís Miguel Reis Henriques
authors.initials: LMRH
authors.lastname: Lopes
authors.affiliation: Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Mariana
authors.initials: M
authors.lastname: Henriques
authors.affiliation: Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Azeredo
authors.affiliation: Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Rosário
authors.initials: R
authors.lastname: Oliveira
mesh_terms: D000369:Aged, 80 and over; D016282:Aspartic Acid Endopeptidases / Q000096:biosynthesis; D018441:Biofilms / Q000254:growth & development; D041022:Candida tropicalis / Q000302:isolation & purification / Q000472:pathogenicity*; D002448:Cell Adhesion; D018929:Cell Culture Techniques / Q000379:methods; D002460:Cell Line; D002470:Cell Survival; D003584:Cytological Techniques / Q000379:methods; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D009172:Mycology / Q000379:methods; D009246:NADH Tetrazolium Reductase / Q000378:metabolism; D014556:Urine / Q000382:microbiology
chemical_list: D007770:L-Lactate Dehydrogenase; D009246:NADH Tetrazolium Reductase; D016282:Aspartic Acid Endopeptidases; C086390:SAP1 protein, Candida albicans