The role of Dectin-1/Raf-1 signal cascade in innate immune of human corneal epithelial cells againstAspergillus fumigatusinfection.
OBJECTIVE
To investigate the expression of the v-raf-1 murine leukemia viral oncogene homolog 1 (Raf-1) and its role in the innate immune response of human corneal epithelial cells (HCECs) infected byAspergillus fumigatus.


METHODS
HCECs were culturedin vitro. They were randomly divided into 4 groups, including control group,Aspergillus fumigatusgroup, GW5074 (an inhibitor of Raf-1) group and Laminarin [an inhibitor of Dendriti-cell-associated C-type lectin 1 (Dectin-1)] group. The protein expression level of total Raf-1 and p-Raf-1was measured by Western blot. The expression of IL-6 and IL-8 mRNA in each group was detected by real-time polymerase chain reaction.


RESULTS
InAspergillus fumigatusgroup, total Raf-1 protein levels in HCECs remained unchanged at 5, 15, 30 and 45min after infection, while p-Raf-1 expression was significantly enhanced at 30min after infection compared with control group. However, the expression of p-Raf-1 was apparently declined after treated with GW5074 or Laminarin compared withAspergillus fumigatusgroup. The expression levels of IL-6, IL-8 mRNA were significantly increased after stimulation with fumigatus compared with control group. Pre-treated with GW5074 significantly inhibitedAspergillus fumigatus-induced upregulation of IL-8 and IL-6.


CONCLUSIONS
Aspergillus fumigatusstimulation can elevate the expression of p-Raf-1 in HCECsin vitro. Dectin-1/Raf-1 signal pathway may play a role on regulating the expression of inflammatory cytokines, including IL-6 and IL-8.
Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
Gui-Qiu
GQ
Zhao
Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
Jing
J
Lin
Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
Li-Ting
LT
Hu
Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
Xiao-Ni
XN
Yin
Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
Qian
Q
Wang
Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
Qiang
Q
Xu
Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao 266003, Shandong Province, China.
Hui
H
Li
Aspergillus fumigatus; Dectin-1/Raf-1 signal pathway; human corneal epithelial cells; innate immune