B. Boccardi

T-cell tumour necrosis factor-α receptor binding in demented patients

Abstract Dementia of Alzheimer type (DAT) is a neurodegenerative disease of the central nervous system (CNS), in which an unbalanced cytokine network may lead to an altered immunoregulation. Tumour necrosis factor (TNF)-α is a cytokine with manifold effects on the neuroimmune system. Specific TNF-α receptors have been found on human peripheral blood lymphocytes. The aim of the present study has been to assay TNF-α binding on T cells from DAT patients and healthy sex- and age-matched controls. We found that T lymphocytes from demented patients bear significantly more p60 and p80 TNF-α receptors than those from controls (Bmax: 705, 29 vs 131, 6 (mean, SEM) receptors/cell). Such TNF-α binding sites, of the same type in DAT patients and healthy subjects (Kd: 67.6, 5.0 vs 70.7, 5.6 (mean, SEM) pM), are functional, since they are able to mediate in vitro NF-κB activation. These results are discussed in terms of DAT pathogenesis. Since it has been reported that activated T cells have more TNF-α receptors than resting cells, an increased number of lymphocyte TNF-α receptors might indicate a systemic immune activation in DAT patients as compared with healthy controls.

T-lymphocyte tumor necrosis factor-α receptor binding in patients with Parkinson's disease

Abstract Parkinsons disease (PD) is a neurodegenerative disease of the central nervous system (CNS), in which the cytokine network may be deranged, leading to an altered immunoregulation. Tumor necrosis factor(TNF)-α, a cytokine with pleiotropic neuroimmune effects, has specific receptors on human lymphocytes, as well as on other cell types, even in the CNS. The aim of the present study was to assay TNF-α binding on peripheral blood T cells from PD patients, as compared with healthy subjects. We found on T lymphocytes from parkinsonian patients significantly more TNF-α receptors than on those from controls (Bmax: 637±23 vs. 131±6 (mean±S.E.M.) receptors/cell). Such TNF-α binding sites are of the same type in patients and healthy subjects (Kd: 66.8±5.1 vs. 70.7±5.6 (mean±S.E.M.) pM). These results are discussed in terms of PD immunopathogenesis, since it has been reported that activated T lymphocytes have increased amounts of TNF-α receptors.