Immune surveillance of the normal human CNS takes place in dependence of the locoregional blood-brain barrier configuration and is mainly performed by CD3(+)/CD8(+) lymphocytes.

Despite the blood-brain barrier (BBB) the human CNS is continuously screened by blood-derived immunological cells. In certain brain areas the local BBB configuration grants passage of large molecules, whereas others are better shielded. We investigated whether these regional BBB compositions are paralleled by differences in the degree of cellular immunosurveillance by investigating tissue from 23 normal human brains for several CD markers, FoxP3, granzyme B, and perforin.

Immune cell infiltration of intrinsic and metastatic intracranial tumours.

Background: Immune escape is one prerequisite for the formation of neoplasms that is reflected by the pattern of immune cell infiltration. Abundant monocytic infiltration without apparent phagocytic activity is well known in human gliomas, while other types of human intracranial tumours have not yet been investigated.

Materials And Methods: We analysed LCA-positive lymphocytes and CD68-positive macrophages/microglia by immunohistochemistry in 67 intracranial neoplasms: 18 glioblastomas (GBM), 14 primitive neuroectodermal tumours and medulloblastomas (PNET), metastases of 9 adenocarcinomas and of 8 malignant melanomas, and 18 benign meningiomas.