Aspergillus fumigatus antigens activate immortalized human corneal epithelial cells via toll-like receptors 2 and 4

Purpose: To evaluate the role of toll-like receptors (TLR) 2 and 4 in host responses to Aspergillus fumigatus by use of cultured telomerase-immortalized human corneal epithelial cells (HCECs). Methods: HCECs were stimulated with inactive antigens from A. fumigatus. The expression of TLR2 and TLR4, phosphorylation of I kappa B-alpha (pI kappa B-alpha), and release of interleukin (IL)-1 beta and IL-6 was measured with and without inhibitors to TLR2 and TLR4,. Results: Exposure of HCECs to A. fumigatus antigens resulted in up-regulation of TLR2 and TLR4, activation of pI kappa B, and release of IL-1 beta and IL-6 in HCECs, effects that could be inhibited by treatment with TLR2 and TLR4 antibodies. Conclusions: TLR2 and TLR4-nuclear factor-kappa B signaling pathways in corneal epithelium play important roles in inflammatory responses against A. fumigatus antigens.