Demonstration of T200 on human Langerhans cell surface membranes

We have demonstrated the presence of the glycoprotein T200 on the surface of human epidermal Langerhans and indeterminate cells by immunoelectron microscopy with the use of a monoclonal antibody. No other epidermal cells were positive. The presence of T200 on Langerhans cells confirms their hematopoietic origin because T200 is limited to hematopoietic cells and neoplasms. Although the function of T200 is not known, antibodies directed against T200 have been previously shown to inhibit accessory cell and natural killer cell activities. While the existence of a possible relationship between Langerhans cells and natural killer cells is unclear, Langerhans cells are important in cutaneous accessory cell functions; therefore. T200 may be important in understanding the biology of Langerhans cells and their relationship to other cells in the immune response.