Age-associated deficiency in activation-induced up-regulation of telomerase activity in CD4+ T cells

Whole Blood Analysis of Phagocytosis, Apoptosis, Cytokine Production, and Leukocyte Subsets in Healthy Older Men and Women: The ZENITH Study

Few studies to date have examined age-related changes in markers of immune status in healthy older individuals. The immune status of 93 healthy individuals aged 55-70 years was assessed by two- and three-color flow cytometry and biochemical analysis. There were significant age effects (p <or=.05) on monocyte phagocytic activity and cluster of differentiation (CD) 3/human leukocyte antigen-D-related (HLA-DR) late-activated T lymphocytes (% expression). There was a significant (p <or= 0.1) Age x Sex interaction in absolute counts (x 10(9)/L) of CD3/CD8 total cytotoxic T lymphocytes (CTL), the CD4 T- helper to CD8 CTL ratio, the CD3/CD4/CD45RA naïve T helper to CD3/CD4/CD45RO memory T helper lymphocyte ratio, and interleukin (IL)-1beta (% expression) by activated monocytes. The study shows that alterations in markers of immune status occur between 55 and 70 years, and provides reference values for the lymphocyte measures in healthy men and postmenopausal women in this age group. The study further highlights the need for sex-specific reference ranges for such markers.

Telomerase activity in peripheral blood mononuclear cells from senile patients with pneumonia

To investigate the changes of the activity of telomerase in peripheral blood mononuclear cells (PBMCs) from senile patients with pneumonia, the telomerase activity was examined before and after the stimulation of phytohemagglutinin-M (PHA-M) in PBMCs from 10 control subjects (group A), 12 non-senile patients with pneumonia (group B) and 9 senile patients with pneumonia (group C). Also observed was the proliferative response of these PBMCs to PHA-M. The results showed that, both with or without the stimulation of PHA-M, the values of telomerase activity in PBMCs from group C patients (A values: pre-stimulation, 0.43 +/- 0.04; post-stimulation, 0.63 +/- 0. 03) were significantly lower than those in PBMCs from both group A patients (A values: pre-stimulation, 0.65 +/- 0.05; post-stimulation, 1.26 +/- 0.13; P<0.001, respectively) and group B patients (A values: pre-stimulation, 0.63 +/- 0.03; post-stimulation, 0.93 +/- 0.03; P<0.05, respectively). The results of MTT test showed that the proliferative activity of PBMCs in group C patients (A value: 0.35 +/- 0.03) was also significantly lower than that in group A patients (A value: 0. 55 +/- 0.04; P<0.05) and group B patients (A value: 0.46 +/- 0.03; P<0.05). These results indicate that the telomerase activity decreases in senile patients with pneumonia, which may be one of the mechanisms for the weakened immune function in those patients.