Oral epithelium-Candida glabrata interactions in vitro

Background: Oropharyngeal candidiasis is a common opportunistic infection and Candida glabrata is the second or third most frequently isolated species from oropharyngeal candidiasis lesions, after Candida albicans. The aim of this study was to study the cytokine-inducing and cell-damaging potential of C. glabrata in oral epithelial cells and compare this to C. albicans. Methods: Oral epithelial cell lines and primary gingival epithelial cells were cocultured with C. glabrata strains GDH2269 and 94-11 or C. albicans strains SC5314 and ATCC28366. Supernatants were analysed for the presence of interleukin-1 alpha (IL-1 alpha), IL-8 and granulocyte-macrophage colony-stimulating factor (GM-CSF) by enzyme-linked immunosorbent assay. The cytotoxity of different strains was determined using the CytoTox-96 assay. Results: Compared to C. albicans, C. glabrata induced different proinflammatory cytokine responses in oral epithelial cells; a high level of GM-CSF induction was only detected in C. glabrata-infected cells and not in C. albicans-infected cells, regardless of the origin of these cells (cell lines or primary cells) or the strain used. Like C. albicans, C. glabrata induced an IL-1 alpha response by oral epithelial cells, but this response was both strain-dependent and epithelial cell origin-dependent. Unlike C. albicans, C. glabrata failed to induce a strong IL-8 response in any of the cell systems studied. Finally, in these studies C. glabrata showed lower cytotoxicity than C. albicans. Conclusions: C. glabrata is less cytotoxic than C. albicans and induces different proinflammatory cytokine responses in oral epithelial cells.