Find in Library

<b>AIM:</b> To explore the immunomodulatory effects of curdlan on innate immune responses against <i>Aspergillus fumigatus</i> (<i>A. fumigatus</i>) in cultured human corneal epithelial cells (HCECs), and whether C-type lectin receptor Dectin-1 mediates the immunomodulatory effects of curdlan.<b>METHODS:</b>The HCECs were stimulated by curdlan in different concentrations (50, 100, 200, 400 μg/mL) for various time. Then HCECs pretreated with or without laminarin (Dectin-1 blocker, 0.3 mg/mL) and curdlan were stimulated by <i>A. fumigatus</i> hyphae. The mRNA and protein production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were determined by real-timequantitative polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The protein level of Dectin-1 was measured by Western blot.<b>RESULTS:</b> Curdlan stimulated mRNA expression of TNF-α and IL-6 in a dose and time dependent manner in HCECs. Curdlan pretreatment before <i>A. fumigatus</i> hyphae stimulation significantly enhanced the expression of TNF-α and IL-6 at mRNA and protein levels compared with <i>A. fumigatus</i> hyphae stimulation group (<i>P</i>&lt;0.05). Both curdlan and <i>A. fumigatus</i> hyphae up-regulated Dectin-1 protein expression in HCECs, and Dectin-1 expression was elevated to 1.5- to 2-fold by curdlan pretreatment followed hyphaestimulation. The Dectin-1 blocker laminarin suppressed the mRNA expression and protein production of TNF-α and IL-6 induced by curdlan and hyphae (<i>P</i>&lt;0.05).<b>CONCLUSION:</b>These findings demonstrated that curdlan pretreatment enhanced the inflammatory response induced by <i>A. fumigatus </i>hyphae in HCECs. Dectin-1 is essential for the immunomodulatory effects of curdlan. Curdlan may have high clinical application values in fungal keratitis treatment.