Expression of CDw29 and CD45R antigens on epithelial cells in oral lichen planus

The CD45R and CDw29 antigens are expressed on naive and primed helper T cell populations which serve suppressor-inducer or helper-inducer functions, respectively. These antigens may also be expressed on epithelial cell subpopulations. In the present study, monoclonal antibodies reacting with T lymphocytes and Langerhans cells (LC) were used to characterize the expression of CD45R and CDw29 antigens in oral lichen planus. CDw29 was expressed by LC and lymphocytic cells whereas keratinocyte reactivity varied from negative through to full thickness staining. Expression of CD45R was confined to intraepithelial cells with either lymphocytic or dendritic morphology. A relatively constant ratio of CD1a + LC to CD45R + cells (2:1) was seen. These results demonstrate the existence of intraepithelial cells expressing antigens which are functionally important in T cell responses and which may provide local immunoregulatory influences.