Dectin-1 agonist curdlan modulates innate immunity to Aspergillus fumigatus in human corneal epithelial cells

• Published in: International journal of ophthalmology Vol. 8; no. 4; pp. 690 - 696
• Main Authors: Zhu, Cheng-Cheng, Zhao, Gui-Qiu, Lin, Jing, Hu, Li-Ting, Xu, Qiang, Peng, Xu-Dong, Wang, Xue, Qiu, Sheng
• Format: Journal Article
• Language: English
• Published: China International Journal of Ophthalmology Press 18.08.2015; Press of International Journal of Ophthalmology (IJO PRESS)
• Subjects: Aspergillus; Aspergillus fumigatus; Basic Research; corneal; corneal epithelium; curdlan; Dectin-1; epithelium; fumigatus; immunity; innate; innate immunity; curdlan; Dectin-1; innate immunity; Aspergillus fumigatus; corneal epithelium
• ISSN: 2222-3959; 2227-4898
• DOI: 10.3980/j.issn.2222-3959.2015.04.09

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