A comparison of conjunctival and nonocular dendritic cells utilizing new monoclonal antibodies.

Langerhans cells belong to the dendritic cell family. Their presence in the conjunctiva and cornea has been demonstrated by means of various membrane and cytoplasmic markers. Utilizing OKT6, a monoclonal antibody that specifically binds to Langerhans cells in conjunction with la histocompatibility antigens (HLA-DR), and a new panel of monoclonal antibodies, we compared the population density and characteristic phenotypes of Langerhans cells in normal conjunctiva with those in normal epidermis. A greater density of Langerhans cells was noted in epidermis in comparison with conjunctiva. Various areas of the conjunctiva and cornea were mapped for Langerhans cell distribution. The T6/la ratio of Langerhans cells in conjunctiva was notably different from that in skin. Utilizing the Prolm2 marker, we identified non-Langerhans dendritic cells in the substantia propria and in the basilar epithelium of the conjunctiva, antigen-processing cells probably identical to the interdigitating dendritic cells of lymph nodes.