[The local immune system of ocular surface]

Local immunity on the ocular surface was observed in guinea pigs immunized with horseradish peroxidase (HRP) by determining the activity of a specific antibody in local sites of the conjunctiva by the enzyme-antigen method, which enables a specific antibody to be stained. In addition, immunohistochemical study of the localization of IgA was performed by the enzyme-labelled antibody method. The enzyme-antigen method revealed a number of positive cells in the subconjunctival tissue and the parafollicular area of conjunctival-associated lymphoid tissue. These cells were identified as plasma cells by electron microscopy. The mirror section technique revealed that the cells positive for the enzyme-antigen method were consistent with anti-IgA-positive cells at many sites. Thus the distribution of plasma cells secreting IgA-specific antibody responsible for local immunity on the ocular surface was observed immunohistochemically. The results suggest that immunocytes in the conjunctival-associated lymphoid tissue differentiate and mature into specific antibody-producing plasma cells.