title: [The immunology of aging: immunoregulatory role of lipoproteins].
abstract: This report deals with immunoregulation by lipoproteins and with age-related changes in immune function. It was investigated whether a diminished immune response during ageing could be caused by a disturbed interaction of lipoproteins with cells of the immune system. The aim of these investigations was to show whether changes in the immune response in the elderly were really age-related, or attributable to other factors (i.e. medication, life style) not related to ageing per se. Therefore, admission criteria for blood donors to take part in these studies of the ageing human immune system were set up by using the Senieur protocol (EURAGE). An immunoregulatory influence of lipoproteins from different density fractions-Low Density Lipoproteins (LDL), High Density Lipoproteins (HDL) and Very Low Density Lipoproteins (VLDL) on the in vitro mitogen response of human peripheral blood lymphocytes (PBL) was shown. Lymphocytes can take up lipoproteins by receptor-mediated (specific binding) and non receptor-mediated (receptor-independent exchange) mechanisms. In this context a HDL-binding site/receptor was demonstrated and characterised here for the first time on human T-cells. Furthermore, interactions of lipoproteins with lymphocytes were investigated in the elderly and compared with young control groups. The increased LDL uptake during ageing was found to correlate with an increased HDL uptake. The age-related diminished immune response correlated with a decrease in plasma membrane fluidity of human PBL, but not with an enhanced lipoprotein uptake. The Senieur protocol in this present form, used for classifying blood donors, had no influence on distribution and statistical processing of the obtained sets of data, indicating that this protocol needs further modifications.
authors.affiliation: Institut für Allgemeine und Experimentelle Pathologie Universität Innsbruck.
authors.forename: L A
authors.initials: LA
authors.lastname: Huber
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000276:immunology*; D005260:Female; D006801:Humans; D007108:Immune Tolerance; D008074:Lipoproteins / Q000502:physiology*; D008075:Lipoproteins, HDL / Q000502:physiology; D008077:Lipoproteins, LDL / Q000502:physiology; D008213:Lymphocyte Activation; D008297:Male; D008560:Membrane Fluidity; D008875:Middle Aged; D011956:Receptors, Cell Surface / Q000502:physiology*; D018110:Receptors, Lipoprotein; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D008074:Lipoproteins; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D011956:Receptors, Cell Surface; D018110:Receptors, Lipoprotein
vernacular_title: Immunologie des Alterns: Die immunoregulatorische Rolle von Lipoproteinen.