Differences in dexamethasone-sensitivity between lymphocytes from patients with Alzheimer's disease and patients with multi-infarct dementia

Peripheral blood mononuclear cells (PBMC) from 40 consecutive patients entering a screening program on cognitive impairment were studied in vitro with respect to their sensitivity to dexamethasone (DEX). Phytohemagglutinin-induced proliferation by PBMC from patients with senile dementia of the Alzheimer type (SDAT) was less sensitive to the...

Correlation between the antibody response to influenza vaccine and helper T cell subsets in healthy ageing

To investigate the effects of the altered composition of the helper T cell compartment in ageing on the humoral response to influenza vaccine, we investigated correlations between helper T cell subsets and anti-influenza antibody responses in 23 JUNIEUR healthy young and 41 SENIEUR healthy elderly subjects. Naive helper T cell numbers (CD4...

Regulation of T cell activation by glucocorticoids in healthy donors and patients with cognitive disorders

Differential sensitivity of human naive and memory CD4+ T cells for dexamethasone

Human CD45RA+ ('naive') and CD45RO+ ('memory') CD4+ T cells were compared with respect to their sensitivity to dexamethasone (DEX). In three different activation pathways, i.e. (i) immobilized anti-CD3, (ii) immobilized anti-CD3 plus soluble anti-CD28 and (iii) soluble anti-CD2 plus soluble anti-CD28, naive CD4+ T cells appeared more sensitive...

Abrogation of the suppressive effects of dexamethasone by PKC activation or CD28 triggering

The suppressive effect of the glucocorticoid dexamethasone (DEX) on purified CD4+ T cells was found to depend on the activation pathway. In contrast to anti-CD3- or PHA-induced T cell proliferation, the alternative pathway of T cell activation, i.e., through anti-CD2 and anti-CD28, appeared largely resistant to DEX. By titrating anti-CD28 or the...

Age-related increase in the fraction of CD27-CD4+ T cells and IL-4 production as a feature of CD4+ T cell differentiation in vivo

Age-related changes in immune reactivity: The influence of intrinsic defects and of a changed composition of the CD4+ T cell compartment

Aging is accompanied by a decline in immune reactivity which to a major extent can be attributed to changes at the level of the regulatory CD4+ T cells. In addition to evidence pointing to intrinsic defects, resulting in improper responsiveness of lymphocytes, it is likely that many age-related phenomena can be explained by a changed composition...