Flow cytometry data analysis of the immune system in human aging

Abstract

Chronological aging is often accompanied with increase in acute or chronic co-morbidities. Immunosenescence, the aging of the immune system, was proposed to influence the susceptibility towards diseases in the elderly and chronic latent infections by herpes viruses such as Cytomegalovirus and Epstein-Barr virus are responsible for immunosenescence. Aged immune T-lymphocytes are characterized by the loss of CD28 and the gain of CD57 markers. In addition, another phenomenon known as inflammaging, a low-grade chronic pro-inflammatory state, often accompanies immunosenescence. We show in this study a shift in the T-lymphocyte subsets towards a more CD57+ phenotype in the elderly, and that Herpes Simplex virus 2 and Helicobacter pylori can also influence the shift. Both pro- and anti-inflammatory cytokines (IFN-γ, IL-6, IL-10, TGF-β1 and CRP) are also shown to increase in the elderly as compared to the young, and that immunosenescence and inflammaging appear to occur independently. Further analyses of the physiological parameters, such as blood pressure, with levels of cytokines were also done to determine the probable influence of the elevated levels of cytokines. Gaining knowledge of the presence of such correlations aims to discover possible markers that can reflect the immunosenescence and also the natural aging process.