Demonstration of Langerhans Cells (Lcs) in the Intra-Follicular and Inter-Follicular Regions of the Human Palatine Tonsil Ultrastructural and Immunohistochemical Study

Abstract

Dendritic cells (DCs) and macrophages function to capture and process antigen and present it to T lymphocytes, a critical step in early immune response. The dendritic Langerhans cells (LCs) belong to the system of antigen presenting cells and play a role in cutaneous immune responses. In our previous studies, we have ultrastructurally demonstrated the presence of LCs in the crypt epithelium and surface epithelium of the human palatine tonsil. In the present study our aim was to demonstrate the LCs in the intra-follicular and inter-follicular area of human palatine tonsil by conventional electron microscopy and immunocytochemistry. Here we report the presence of CD1a positive Langerhans Cells (LCs) in the intra-follicular and inter-follicular areas of the human palatine tonsil and confirm their presence ultrastructurally by demonstrating typical Birbeck granules (BGs) in their cytoplasm. Identification of LCs in the intra-follicular and inter-follicular areas of the palatine tonsil supports the migratory nature of the LCs. Apposition between the Langerhans cells and lymphocytes in the intra-follicular area further strengthens the function of Langerhans cells as antigen presenting cells in initiating immune responses in human palatine tonsil.