Immune Responses to Tumours in the CNS

After a brief introduction to the most frequent tumours of the central nervous system (CNS), the inflammatory responses in different CNS tumours will be described from a traditional neuropathologist's perspective. Subsequently, immunobiological aspects of immune responses to CNS tumours will be covered, including the nature and role of different immune cells and molecules involved in these processes. In the last part of this chapter, we summarize characteristics of different immunotherapeutic approaches for CNS tumours as well as present some results obtained in this field so far. Of note, by far the most frequently investigated CNS tumours with regard to immunobiological and immunotherapeutic aspects are the diffuse gliomas, especially their most malignant and most frequent representative (i.e. glioblastoma). Even for glioblastomas, however, knowledge about the exact extent, composition and 'dynamics' of immune responses in and around the tumours is still far from complete. Also, immunotherapeutic approaches for CNS tumours are not yet standard care. Hopefully, further elucidation of the pathobiology of immune responses to CNS tumours will ultimately lead to therapeutic strategies that do not just inhibit tumour growth but also effectively 'search and destroy' tumour cells, especially in tumours that to date are incurable because of their relentless proliferation and migration into the CNS tissue.