Aspergillus fumigatus Antigens Activate Immortalized Human Corneal Epithelial Cells via Toll-Like Receptors 2 and 4

Abstract

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 Iκ B-α (pIκ B-α), and release of interleukin (IL)-1β 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 pIκ B, and release of IL-1β and IL-6 in HCECs, effects that could be inhibited by treatment with TLR2 and TLR4 antibodies. Conclusions: TLR2 and TLR4-nuclear factor-κ B signaling pathways in corneal epithelium play important roles in inflammatory responses against A. fumigatus antigens.

KEYWORDS:

• Aspergillus fumigatus
• cytokines
• keratitis
• NF-κ B
• toll-like receptors