Innate Immune Receptors in the Regulation of Tumor Immunity

Innate immune receptors, also called pattern recognition receptors (PRRs), have gained much attention for their ability to evoke innate immune responses and regulate adaptive immunity. While the recent advent of immunotherapy for the treatment of cancer has primarily focused on harnessing the adaptive immune responses, signal-transducing innate receptors have come under extensive investigation in the context of regulating antitumor immune responses. Indeed, while these innate receptor classes are well known for the critical roles they play in the recognition of invading pathogens, a mounting body of evidence indicates that they also have the capacity to recognize ligands that are expressed by live or dead cancer cells. Although generally beneficial to the host’s innate responses against pathogens, these receptors appear to manifest either beneficial or harmful role in the host’s immune responses to cancers. Here, we summarize our current knowledge of the role of signal-transducing innate immune receptors in the regulation of cancer progression. We believe that a better understanding of these receptor functions may contribute to the development of effective strategies for cancer immunotherapies.