| PURPOSE: In this study, the contributions of γδ T cells to wound healing process, including neutrophil emigration, platelet accumulation, proliferation, and re- epithelialization after central epithelial wound were investigated.
METHODS: Re-epithelialization, neutrophil influx, and platelet accumulation were assessed in C57BL/6 mice after removal of a 2-mm diameter area of central corneal epithelium that did not directly injure the limbal vessels or the avascular stroma of the cornea. Comparisons were made between wild-type (WT) mice and mice with targeted deletions of genes for T cell receptor (TCR) δ chain, LFA-1, CD54, or mice with antibody-induced γδ T cell depletion.
RESULTS: In the present study T cells in the limbal epithelium were found to predominantly express the γδ TCR. Corneal abrasion in wild type, CD11a-/- and P-sel-/- mice increased the numbers of γδ T cells in the limbal and peripheral corneal epithelium and in the corneal stroma adjacent to the limbal blood vessels. ICAM-1-/- mice exhibited a reduction in γδ T cell accumulation. TCRδ-/- mice exhibited reduced inflammation and delayed epithelial wound healing as evidenced by delayed wound closure, reduced epithelial cell division, reduced neutrophil infiltration, and reduced epithelial cell density at 96 hours after wounding. TCRδ-/- mice also exhibited >60% reduction in platelet localization in the limbus despite similar platelet counts and platelet function assessed with an in vivo thrombosis model.
CONCLUSIONS: γδ T cells are necessary for efficient inflammation and epithelial wound healing following corneal abrasion. |
