Early antitumor activity of oral Langerhans cells is compromised by a carcinogen

Abstract

SignificanceOral cancer is often diagnosed at late stages, resulting in a poor prognosis of this disease. Understanding early carcinogenic events taking place during the development of oral cancer is, therefore, an important unmet clinical need. This study identifies an early anticancer protective role of oral Langerhans cells (LCs), the principal mononuclear phagocyte involved in immunosurveillance of the oral epithelium. Continuous exposure to the carcinogen 4NQO hampers the local differentiation of LCs, while other mononuclear phagocytes and T cells with immunosuppressive characteristics populate the epithelium, leading to the development of oral cancer. These findings reveal an initial step by which immunosurveillance is compromised by a carcinogen, which could facilitate novel diagnostic approaches to better detection of oral cancer.