Regulation of tumor immunity: the role of NKT cells

Background: Tumor immunosurveillance is a part of the dynamic process of interaction between abnormal cells and the host immune system. Tumor immunosurveillance is actively and continuously regulated in both positive and negative ways. Natural killer T (NKT) cells are cells that have been shown to play a role in both positive and negative regulation of tumor immunosurveillance. Recent studies suggest that NKT cells are a heterogeneous cell population with multiple subsets with distinct functions. Objective: This review discusses the functions of those NKT cell subsets in regulating tumor immunity and potential interactions or counter-regulation among the NKT cell subsets. Method: Selected literature is reviewed. Conclusion: Manipulation of the balance among those subsets may provide new modes of intervention for tumor immunotherapy.