title: Fungus induces the release of IL-8 in human corneal epithelial cells, via Dectin-1-mediated protein kinase C pathways.
abstract: OBJECTIVE
  To identify whether Aspergillus fumigatus (A. fumigatus) hyphae antigens induced the release of interleukin-8 (IL-8) in anti-fungal innate immunity of cultured human corneal epithelial cells (HCECs) and determine the involvement of intracellular signalling pathways.
  
  
  METHODS
  HCECs were treated with A. fumigatus hyphae antigens with different concentrations and time. The cytoplasmic calcium of HCECs were assessed by fluorescence imaging. Western blot was used to detect the expression of Ca(2+)-dependent protein kinase C (PKC). The IL-8 levels were determined by specific human IL-8 enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase polymerase chain reaction (RT-PCR). Using a series of pharmacological inhibitors, we examined the upstream signalling pathway responsible for IL-8 expression in response to A. fumigatus hyphae antigens.
  
  
  RESULTS
  Cells exposed to A. fumigatus hyphae antigens showed higher level of IL-8 mRNA expression and protein production. We demonstrated here that stimulation of HCECs with A. fumigatus hyphae triggers an intracellular Ca(2+) flux and results in the activation of Ca(2+)-dependent PKC (α, βI and βII) which can be attenuated by pre-treatment of cells with laminarin, suggesting that Dectin-1 signals pathway induced cytoplasmic calcium and influence the activation of PKC in HCECs. Inhibitors of Ca(2+)-dependent PKC (Ro-31-8220 and Go6976) significantly abolished hyphae-induced expression of IL-8.
  
  
  CONCLUSIONS
  Our findings suggest that A. fumigatus hyphae-induced IL-8 expression was regulated by the activation of Dectin-1-mediated Ca(2+)-dependent PKC in HCECs.
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
authors.forename: Xu-Dong
authors.initials: XD
authors.lastname: Peng
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
authors.forename: Gui-Qiu
authors.initials: GQ
authors.lastname: Zhao
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Lin
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Jiang
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
authors.forename: Cheng-Cheng
authors.initials: CC
authors.lastname: Zhu
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
authors.forename: Jian-Qiu
authors.initials: JQ
authors.lastname: Qu
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Cong
authors.affiliation: Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
keywords: Aspergillus fumigatus; Ca2+; Dectin-1; corneal epithelium; interleukin-8; protein kinase C