Purpose: To examine dendritic cells from human conjunctiva and to characterize their surface markers immunologically.
Methods: Conjunctival cells were isolated by conjunctival impression cytology from 150 patients: controls (65 patients, 126 eyes) or with various chronic inflammatory conditions (85 patients, 160 eyes); and by conjunctival biopsies from 25 patients: controls (10 patients) or treated topically for primary open angle glaucoma (15 patients). Immunostaining was performed using antibodies to investigate expression of 21 different membrane markers relevant to immunologic functions of dendritic cells.
Results: Conjunctival dendritic cells exhibited surface markers both in normal and inflammatory conditions: class II antigens HLA-DR and HLA-DQ, CD1a, vimentin, CD11a and CD18 (LFA-1), CD22, CD45RO and CD50. Some markers were more occasionally found CD4, CD11b, CD29, CD32, CD45RA and CD54, others being almost totally absent. Conjunctival inflammation induced the migration of dendritic cells from the stroma to the epithelium and thus increased their density.
Conclusion: We conclude that conjunctival dendritic cells show common immunophenotypic features with those of other nonlymphoid tissues. Thus, conjunctival dendritic cells may be important in the immune regulation of the anterior segment.