Abstract
Purpose: :
Recent evidence indicates that gamma delta T cells regulate dermal wound healing and inflammation associated with injuries. The current study analyzes gamma delta T cells in the context of corneal epithelial injury.
Methods: :
A standardized corneal epithelial wound was performed in wild–type and TCR gamma chain deficient mice (TCRγ–/–). Parameters of the inflammatory response and re–epithelialization were analyzed over an observation period of 96 h using corneal whole mount techniques.
Results: :
A bimodal distribution of GL3+ gamma delta T cell infiltration to corneal epithelium and stroma was noted in wild–type mice. The first peak appeared at 6 hours after wounding. However, a second, more pronounced peak occurred at 24 hours. Two peaks of neutrophil emigration occurred in wild–type mice at 12 hours and 30 hours and followed those of GL3+ cells by 6 hours and 24 hours. In contrast to wild–type mice, neutrophil emigration in the TCRγ–/– mice was reduced by 70 % and 85 % at two peaks, respectively (p<0.001). In addition, epithelial wound closure was delayed by 12 hours and epithelial cell division was significantly depressed.
Conclusions: :
These results indicate that gamma delta T cells migrate into the cornea after epithelial injury and that they contribute to both the acute inflammatory response and re–epithelialization.
Keywords: cornea: epithelium • wound healing • inflammation