Strain-related cytokine profiles on the murine ocular surface in response to desiccating stress.

PURPOSE

To evaluate the effects of desiccating ocular surface stress on levels of inflammatory cytokines in the corneal epithelium, conjunctiva, and tear fluid of BALB/c and C57BL/6 mice.

METHODS

Experimental dry eye (EDE) was created in BALB/c and C57BL/6 mice by cholinergic blockade and exposure to a desiccating environment. Real-time polymerase chain reaction was performed to measure levels of cytokine transcripts. A multiplex immunobead assay was used to measure concentrations of these cytokines in tears.

RESULTS

Experimental dryness significantly increased the expression of interleukin (IL)-1alpha, IL-6, and tumor necrosis factor (TNF)-alpha transcripts in the corneal epithelium and conjunctiva of C57BL/6 mice. Strain-specific changes in tear cytokine profiles were observed. C57BL/6 mice had significantly greater tear concentrations of IL-1alpha and TNF-alpha and the Th-1 cytokines IL-2, IL-12, and interferon-gamma in response to desiccating stress than BALB/c mice. The Th-2 cytokines IL-4 and IL-10 were significantly greater in BALB/c tears.

CONCLUSIONS

This study indicates that desiccating stress increases levels of certain cytokines in the corneal epithelium and conjunctiva in a strain-dependent fashion and that C57BL/6 mice had greater levels of Th-1 cytokines in their tears, whereas BALB/c mice had a greater increase in Th-2 cytokines.