The fine structure of epithelial cells in normal and pathological buccal mucosa. IV. Interactions between epithelial cells, lymphocytes, and macrophages.

In oral lichen planus two types of lymphocytes were found in the lamina propria in the basal and suprabasal layers. The T-cell is identified by the absence of rough-surfaced endoplasmic reticulum in contrast to its extensive development in the B-cell of which various types were identified including plasma cells. Interaction was noted between macrophages, lymphocytes, and epithelial cells. The variability noted in T-cells may arise from sensitization related to phagocytosis of degenerate epithelial cells by macrophages which transfer the immunological information to lymphocytes.