Immunohistochemical Study of CD1a-labeled Langerhans Cells and Anti-tumor Immune Cells in Oral Verrucous Carcinomas.

Abstract

To clarify the possible role of Langerhans cells (LCs) in oral verrucous carcinoma (OVC), LCs and anti-tumor immune cells in OVCs were immunohistochemically investigated with the use of anti-CD1a, 3, 4, 8, 68, and 79α antibodies. In OVCs, mucosa adjacent to OVCs, and normal oral mucosa, most intraepithelial CD1a-positive LCs were located in parabasal regions. Subepithelial LCs were scatteredly throughout the lamina propria. The densities of intraepithelial and subepithelial CD1a-positive LCs in OVCs were significantly higher than those in adjacent mucosa or normal oral mucosa. The density of CD1a-positive LCs in T3 stage OVCs was slightly lower than those in T1 and T2 stage OVCs. The majority of infiltrating CD3-, CD4-, and CD8-positive T lymphocytes, CD79α-positive B lymphocytes, and CD68-positive macrophages were observed in subepithelial portions of OVCs, but scattered CD3-, CD4-, and CD8-positive T lymphocytes were observed in intraepithelial portions of OVCs. CD8-positive T lymphocytes were more numerous than CD4-positive T lymphocytes in subepithelial portions of OVCs. In mucosa adjacent to OVCs and in normal oral mucosa, infiltration by CD3-, CD4-, and CD8-positive T lymphocytes, CD79α-positive B lymphocytes, and CD68-positive macrophages was minimal in both intraepithelial and subepithelial regions. LCs were slightly more numerous in CD8-positive T-cell dominant OVCs than in CD4-positive T-cell dominant OVCs. These results suggest that CD1a-positive LCs are related to CD8-positive T lymphocytes and that CD1a-positive LCs play a role in the anti-tumor immune response in OVCs.