γδ T cell depletion does not affect fungal keratitis
Reviewed by Graham Wallace

Fungal keratitis (FK) is a blinding condition prevalent in agricultural areas of countries such as India and China. The fungus enters the cornea and induces an inflammatory response which leads to tissue damage. Neutrophils are the earliest infiltrating immune cells that enter the cornea in response to chemokines released by corneal cells. Another population of immune cells γδ T cells, are known to be involved in recruitment of neutrophils, however, their function in FK is not understood. In this paper FK was induced by delivery of Fusarium solani to a scarified cornea, in wild-type and γδ T cells depleted mice. The results show that γδ T cells increased in the cornea at 36 and 72 hours after induction of FK, following migration from the limbal region. Depletion of γδ T cells led to increase and decreased expression of multiple cytokines. However, depletion did not affect the number of neutrophils or fungal hyphae in the affected corneas, nor influence the course of disease. These results show that while γδ T cells can influence the levels of many cytokines, this did not have an effect on neutrophil migration into the site. It will be of interest to dissect further the source and kinetics of cytokine production in the cornea and correlate with neutrophil infiltration. If γδ T cells migration is a later event then any effects may be greater in resolution of disease rather than onset.

γδ T cells regulate the expression of cytokines but not the manifestation of fungal keratitis.
He S, Zhang H, Liu S, et al.
EXPERIMENTAL EYE RESEARCH
2105;135:93-101.