The Immune Response to Glioblastoma: Overview and Focus on Checkpoint Blockade

Cancer immunotherapy has become a promising therapeutic modality in many tumor types. Recent evidence supports the idea that immune-based therapies may also be effective in treating central nervous system (CNS) malignancies. In order to design better immunotherapeutic approaches, however, it is first necessary to understand how the immune system interplays with cancer. Furthermore, with regard to CNS malignancies, a deeper understanding of how the immune system surveys the CNS adds an additional layer of complexity. This chapter will provide a basic overview of the immune system as a foundation to focus specifically on CNS immunosurveillance, particularly as it relates to detection of intracranial tumors. Lastly, we will review the current understanding of mechanisms employed by brain tumors to evade immune detection, with a focus on immune checkpoint pathways.