Open AccessInnate responses of corneal epithelial cells against Aspergillus fumigatus challenge
Author(s) -
Guo Hui,
Wu Xinyi
Publication year - 2009
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.2009.00551.x
Subject(s) - tlr2 , aspergillus fumigatus , tlr4 , innate immune system , biology , toll like receptor , microbiology and biotechnology , immunology , lipopolysaccharide , zymosan , pattern recognition receptor , proinflammatory cytokine , immune system , inflammation , in vitro , biochemistry
Toll‐like receptors (TLRs) are key components of the innate immune system that detects microbial infection and triggers host defensive responses. To determine the roles of TLR2 and TLR4 in corneal epithelial cells in mediating innate responses against Aspergillus fumigatus , telomerase‐immortalized human corneal epithelial cells (THCE) were challenged by TLR2 ligand zymosan, TLR4 ligand lipopolysaccharide and A. fumigatus hyphae, respectively. Culture media were collected at different time points and enzyme‐linked immunosorbent assay was performed to detect the levels of inflammatory cytokines interleukin‐1β (IL‐1β) and IL‐6. We found that THCE responded to the challenge of TLR2 or TLR4 ligand by expressing and secreting inflammatory cytokines into the culture media. And exposure of THCE to A. fumigatus hyphae resulted in the upregulation of IL‐1β and IL‐6. Treatment with TLR2‐ or TLR4‐siRNA plasmid reduced TLR2 or TLR4 expression level in THCE when compared with controls, and caused a significant decrease in A. fumigatus ‐induced IL‐1β and IL‐6 production. Our results suggested that THCE can respond to TLR2 and TLR4 ligand challenge by secreting IL‐1β and IL‐6. They recognize A. fumigatus hyphae via TLR2 and TLR4 and initiate innate immune responses. Corneal epithelial cells play a role in innate defense against fungal infection through the mediation of inflammatory cytokines production.