Immunohistochemical identification of T-lymphocytes in the central nervous system of patients with multiple sclerosis and subacute sclerosing panencephalitis.

T-lymphocytes were identified in frozen brain sections derived from patients with chronic inflammatory disorders of the CNS by using a specific heteroantiserum and the unlabelled antibody enzyme method. Clusters of T-cells were found in post-mortem material of cases with multiple sclerosis (MS) and subacute sclerosing penencephalitis (SSPE). The results suggest that T-lymphocytes are involved in the pathogenesis of both MS and SSPE

Immunohistochemical analysis of CDX2 expression in normal choroid plexus epithelium and choroid plexus tumors

Background: The Wnt and BMP signaling pathways are involved in the morphogenesis of both gastrointestinal and choroid plexus epithelium. In the intestine, Wnt signaling represses the expression of the tumor suppressor gene CDX2 via SOX9, a transcription factor, which is also expressed in the choroid plexus. Recently, an inverse correlation between CDX2 expression and tumor grade, tumor stage and lymph node metastasis in colorectal adenocarcinomas has been reported. Besides intestinal tissues, expression of CDX2 has also been reported in various other epithelial tissues and carcinomas. To date, no data exist on expression of CDX2 in normal and neoplastic choroid plexus epithelium. Aim: To investigate CDX2 expression in normal and neoplastic choroid plexus. Materials and Methods: Paraffin-embedded samples from 60 normal choroid plexus, including 23 fetal tissue samples and from 65 choroid plexus tumors (47 choroid plexus papillomas WHO grade I, 16 atypical choroid plexus papillomas and 2 choroid plexus carcinomas WHO grade III) were examined by immunohistochemistry. Samples from normal choroid plexus were collected from 45 autopsy cases and from 15 neurosurgical specimens. Results: Normal and neoplastic choroid plexus lacked CDX2 expression. Conclusion: In our series, immunohistochemistry shows no evidence for a role of CDX2 in development or differentiation of normal choroid plexus from the 9th gestational week until adulthood. Since choroid plexus tumors reliably lack CDX2 immunoreactivity, this marker may be helpful in distinguishing cerebral metastases from CDX2-positive adenocarcinomas and choroid plexus neoplasms

Expression of integrins αvβ3 and αvβ5 and their ligands in primary and secondary central nervous system neoplasms

Aims: To study the expression of integrins αvβ3 and αvβ5 and their ligands in tumour, stroma and endothelial cells from human glioblastoma and CNS metastases from breast, lung and skin tumours. Methods and results: Integrin and integrin ligand expression was quantified in frozen tumour surgical specimens (15 glioblastomas and breast carcinoma metastases as well as 16 lung carcinoma and melanoma metastases) using immunohistochemistry. Gene expression profiles were evaluated in glioblastomas (n=424) and in normal brain (n=11). Overall, αvβ3 expression was more common than αvβ5 except in tumours derived from lung. αvβ3 expression was most frequent in glioblastomas and melanoma metastases. Most lung-derived tumours expressed αvβ5 but expression was less frequent in other tumours; about 20% of breast-derived tumours strongly expressed αvβ5. Melanoma-derived tumours did not express αvβ5. Expression of integrin ligands vitronectin, fibrinogen, fibronectin and osteopontin was variable between tumours, although most tumours expressed the ligands to some extent. Marked αvβ3, but not αvβ5, expression was common in stroma of CNS metastases. In blood vessels, αvβ3 expression was more frequent than αvβ5 and more pronounced in CNS metastases than in glioblastomas. Integrin ligand expression occurred in blood vessels in most tumours. In glioblastomas, mRNA expression of αvβ3, αvβ5, osteopontin and fibronectin were significantly upregulated over normal brain. Conclusions: Overall, we report distinct and heterogeneous patterns of integrin expression in primary and secondary brain tumours that may be relevant to the future development of integrin-targeting therapeutic approaches to brain tumours

De novo expression of the hemoglobin scavenger receptor CD163 by activated microglia is not associated with hemorrhages in human brain lesions

The main function of CD163 (hemoglobin scavenger receptor) is to bind the hemoglobinhaptoglobin complex, thereby mediating extravasal hemolysis. However, CD163 also has an antiinflammatory function. After CD163-mediated endocytosis, hemoglobin is catabolized further by hemeoxygenase 1 (HO-1). Previously, we found expression of HO-1 to be restricted to microglia/ macrophages at sites of hemorrhages in human traumatic and ischemic brain lesions. We now investigated if CD163 expression is also correlated with hemorrhages in brain lesions. Methods. Autopsy brain tissue from 44 cases with hemorrhagic brain lesions (32 traumatic brain injuries/TBI, 12 intracerebral bleedings/ICB), 56 nonhemorrhagic brain lesions (30 ischemias, 26 hypoxias) and 6 control brains were investigated. The post injury survival times ranged from a few minutes to 60 months. Results. In controls, single perivascular monocytes expressed CD163, but only single CD163+ microglia were found in 3/6 cases. CD163+ cells in the parenchyma (activated microglia/macrophages) increased significantly within 24 hours after trauma and ischemia and within 1-7 days following ICB or hypoxia. Overall, significantly lower and higher levels of parenchymal CD163+ cells occurred in hypoxia and ischemia, respectively. Perivascular CD163+ cells also increased significantly in all pathological conditions. In areas remote from circumscribed brain lesions (TBI, ICB, ischemia), significant changes were only found in ICB and ischemia. Conclusions. De novo expression of CD163 by activated microglia/macrophages and CD163+ infiltrating monocytes are neither restricted to nor predominant in hemorrhagic brain lesions. Thus, the antiinflammatory function of CD163 probably predominates, both in hemorrhagic and non-hemorrhagic brain lesions and points to possible immunomodulatory treatment strategies targeting CD16