Abstract
Purpose: :
To characterize the chemokine receptor expression by corneal CD11b+ cells in dry eye disease (DED).
Methods: :
Dry eye was induced by exposing mice to a controlled environment chamber and administering daily scopolamine injections. The expression of different chemokine receptors (CCR) on CD11b+ cells in the cornea was evaluated using confocal microscopy. Flow cytometric analysis on the draining lymph nodes (LN) was performed to investigate the expression of CCR7 and MHC class II by CD11b+ cells.
Results: :
The majority of CD11b+ cells in the normal cornea were CCR5+ and almost 40% were CCR1+; however CCR2 and CCR7 were both minimally expressed in the normal cornea. Following the induction of DED, the majority of CD11b+ cells expressed CCR7. Flow cytometric analysis of draining LN demonstrated a significant increase in the proportion of mature MHC Class II+CD11b+ cells compared with normal mice. Furthermore, triple color analysis confirmed a significant increase in the proportion of MHC Class II+ CCR7+ CD11b+ cells in DED.
Conclusions: :
Our data shows up-regulation of CCR7 expression by corneal CD11b+ cells and increased frequencies of mature CCR7+CD11b+ cells in the draining LN of dry eye mice. These findings suggest that CCR7 could be critical in trafficking of corneal CD11b+ to the draining LN in DED where they prime naïve T cells to generate autoimmune responses.
Keywords: cornea: tears/tear film/dry eye