The Relationship Of Dectin-1and TLR2in Innate Immunity Of Human Corneal Epithelial Cells

Objective:To investigate the relationship of dendritic cell-associated C-type lectin-1(Dectin-1), Toll-like receptor2(TLR2), and relative chemotactic factors in the Telomease-immortalized human corneal epithelial (THCE) cells after exposure to aspergillus fumigatus (Af) hyphae.Methods:The normal THCE cells were investigated as controls. Experimental groups included Af hyphae stimulations group and receptors block group. Af hyphae stimulations group was THCE cells cultured in vitro with Af hyphae. THCE cells were respectively pretreated with laminarin (a Dectin-1inhibitor) and TLR2neutralizing antibody for30minutes, after then, were added the Af hyphae, these were the receptors block groups. After THCE cells were cultured in vitro with Af hyphae, laminarin+Af hyphae and anti-TLR2+Af hyphae for4,8,16and24hours, We harvested THCE cells. The expression of Dectin-1, TLR2, CXCL1and CXCL8mRNA were detected at4,8, and16hours by Real-time PCR. The protein expression of Dectin-1and TLR2were analyzed at8,16, and24hours by Western-blot.Results:Our data indicate that the mRNA expression of Dectin-1, TLR2, CXCL1and CXCL8was increased after being stimulated with Af hyphae. They were increased in a time-depended manner, and reached the peak at8hours. The protein of Dectin-1and TLR2were in the same trend as mRNA. Western-blot of Dectin-1and TLR2showed positive expression and gradually increased till16hours, and then the expression began to decline. While pretreated with laminarin and TLR2neutralizing antibody, the expression of Dectin-1, TLR2, CXCL1and CXCL8all decreased dramatically at the peak point.Conclusion:Our findings suggest that Dectin-1and TLR2interact on each other after treated with inactive Af hyphae in the THCE cells, and they contribute to the innate immune responses by induction of chemotactic factors, such as CXCL1and CXCL8.