The morphology, distribution and quantitation of dendritic (Langerhans) cells (LC) was determined by analysis of
ADPase stained epithelial flat mounts from 6-8 week young adult (resistant) and 24 month old (susceptible) aged mice before and after experimental
infection with P. aeruginosa topically applied to the scarified cornea. The contralateral eye (controls) was also scarified and
phosphate buffered saline applied similarly. This study has examined the changes in
ADPase positive cell populations of the conjunctival limbal epithelium and corneal epithelium of naturally resistant mice (Swiss-Webster and CD2F1) following corneal
infection with Pseudomonas aeruginosa at two different ages, young adult (8 week old) and aged (24 month old). The young adult mice recover from their
infection and restore corneal clarity while the aged mice have extensive ocular destruction and corneal
scarring. Conjunctival limbal dendritic cell numbers in young adult mice were found to be significantly increased at day seven post
infection and then returned to baseline levels. In contrast, conjunctival limbal dendritic cell numbers in aged mice were found to increase slowly and to peak at fourteen days after
infection. Other differences between the two ages (young adult and aged) included an initial increase in dendritic cells five hours post
infection in the young adult groups and an initial decrease at five hours in the aged groups of mice.