IL‐1α, IL‐1ra and IL‐8 are differentially induced by Candida in experimental oral candidiasis

Abstract

To investigate the expression of interleukin-1alpha (IL-1alpha), IL-1ra and IL-8 by the oral epithelium challenged by various Candida species. In vitro candidiasis was induced by C. albicans wild type SC5314, its EFG1, CPH1 and secretory aspartyl proteinase (SAP) mutants and, ATCC isolates of C. albicans, C. tropicalis and C. dubliniensis using a reconstituted human oral epithelium (RHOE) model. IL-1alpha, IL-1ra and IL-8 levels in culture media were quantified by an enzyme-linked immunosorbent assay at 12, 24 and 48 h. Fungal invasion and IL-1ra expression in RHOE were detected by periodic acid-Schiff staining and immunohistochemistry. Overall, the invasive Candida induced relatively higher levels of IL-1alpha, IL-1ra and IL-8 in the culture media than the noninvasive isolates. IL-1alpha and IL-1ra levels induced by Candida with hyphal invasion were significantly higher (P < 0.05) than those induced by the isolates without hyphal invasion at 12, 24 and 48 h. Candida albicans SC5314 induced IL-1ra expression in RHOE at 12 and 24 h but not at 48 h consistent with its hyphal invasion; while the noninvasive mutants and non-albicans Candida induced IL-1ra expression at 48 h. The cytokine expression profiles in experimental oral candidiasis may be associated with the invasive potential of Candida.