Potential Role for a Carbohydrate Moiety in Anti-CandidaActivity of Human Oral Epithelial Cells

Authors:
Open Access
Publisher website
Google Scholar
Abstract
Candida albicansis both a commensal and a pathogen at the oral mucosa. Although an intricate network of host defense mechanisms are expected for protection against oropharyngeal candidiasis, anti-Candidahost defense mechanisms at the oral mucosa are poorly understood. Our laboratory recently showed that primary epithelial cells from human oral mucosa, as well as an oral epithelial cell line, inhibit the growth of blastoconidia and/or hyphal phases of severalCandidaspecies in vitro with a requirement for cell contact and with no demonstrable role for soluble factors. In the present study, we show that oral epithelial cell-mediated anti-Candidaactivity is resistant to gamma-irradiation and is not mediated by phagocytosis, nitric oxide, hydrogen peroxide, and superoxide oxidative inhibitory pathways or by nonoxidative components such as soluble defensin and calprotectin peptides. In contrast, epithelial cell-mediated anti-Candidaactivity was sensitive to heat, paraformaldehyde fixation, and detergents, but these treatments were accompanied by a significant loss in epithelial cell viability. Treatments that removed existing membrane protein or lipid moieties in the presence or absence of protein synthesis inhibitors had no effect on epithelial cell inhibitory activity. In contrast, the epithelial cell-mediated anti-Candidaactivity was abrogated after treatment of the epithelial cells with periodic acid, suggesting a role for carbohydrates. Adherence ofC. albicansto oral epithelial cells was unaffected, indicating that the carbohydrate moiety is exclusively associated with the growth inhibition activity. Subsequent studies that evaluated specific membrane carbohydrate moieties, however, showed no role for sulfated polysaccharides, sialic acid residues, or glucose- and mannose-containing carbohydrates. These results suggest that oral epithelial cell-mediated anti-Candidaactivity occurs exclusively with viable epithelial cells through contact withC. albicansby an as-yet-undefined carbohydrate moiety.

This publication has 65 references indexed in Scilit: