The Dry Eye Zone

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Abstract: Pinning down those T cells...

Invest Ophthalmol Vis Sci. 2009 Apr 1.
Characterization of Effector T cells in Dry Eye Disease.

El Annan J, Chauhan SK, Ecoiffier T, Zhang Q, Saban DR, Dana R.
Harvard Dept. Ophthalmology, Schepens Eye Research Inst., Boston, Massachusetts, United States.

Purpose: Dry eye disease (DED) is associated with ocular surface inflammation that is thought to be primarily mediated by CD4 T cells. The purpose of this study was to investigate whether this T cell mediated immune response is generated in the lymphoid compartment, and to characterize the functional phenotype of the T cells activated in DED.

Methods: DED was induced in female C57BL/6 mice by exposure to a desiccating environment in the controlled environment chamber (CEC) and to systemic scopolamine. T cells from regional draining lymph nodes (LN) of DED mice and normal mice were analyzed for surface activation markers (CD69 and CD154), chemokine and cytokine receptors, and for their proliferation potential.

Results: Draining LN of DE mice showed increased frequencies of CD69 and CD154 expressing T cells with higher proliferative capacity. In addition, these LN T cells primarily showed a Th-1 phenotype, expressing significantly higher levels of IFN-gamma and IL-12Rbeta2 but not IL-4R. Similarly, the LN of DE mice showed significantly increased frequencies of T cells expressing CXCR3 and CCR5, but not CCR4, suggesting a bias toward a Th-1 phenotype.

Conclusions: Our data demonstrate that a Th-1 type immune response is induced in the regional LN of DE mice. The identification of specific cytokine/chemokine receptors overexpressed by these T cells may signify potential novel targets/strategies for the treatment of DED.