ABSTRACT
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. Our results provide evidence that immunosurveillance is associated with locoregional BBB configuration and is mainly performed by CD3(+)/CD8(+)/granzyme B(-)/perforin(-) lymphocytes.
Subject(s)
Blood-Brain Barrier/immunology , CD8-Positive T-Lymphocytes/immunology , Central Nervous System/blood supply , Central Nervous System/immunology , Adult , Age Factors , Aged , Blood-Brain Barrier/cytology , CD3 Complex/metabolism , CD8 Antigens/metabolism , CD8-Positive T-Lymphocytes/metabolism , Central Nervous System/cytology , Female , Humans , Immunohistochemistry , Immunophenotyping , Male , Middle Aged , Sex Factors , Young AdultABSTRACT
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. RESULTS: Levels of monocytic infiltration in GBM and adenocarcinomas were higher than in PNET and meningiomas. Lymphocytes were rare in all tested tumours. No differences were found between all malignant neoplasms and benign meningiomas and between primary intracranial and metastatic tumours. CONCLUSION: Malignancy or primary intracranial origin seem not to be major determinants of immune cell infiltration. Different patterns of cytokine production may explain the differences in single tumour entities.
