Function, Oxidative, and Inflammatory Stress Parameters in Immune Cells as Predictive Markers of Lifespan throughout Aging

According to the oxidative-inflammatory theory of aging, there is a link between the function, the oxidative-inflammatory stress state of immune cells, and longevity. However, it is unknown which immune cell parameters can predict lifespan and if there would be any changes in this prediction, depending on the age of the subject. Therefore, a longitudinal study in mice was performed analysing immune function (chemotaxis of macrophages and lymphocytes, phagocytosis of macrophages, natural killer (NK) activity, and lymphoproliferation capacity), antioxidant (catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) activities as well as reduced glutathione (GSH) concentrations), oxidant (oxidized glutathione (GSSG), superoxide anion, and malondialdehyde (MDA) concentrations), and inflammation-related markers (basal release of IL-1β, IL-6, TNF-α, and IL-10) in peritoneal leukocytes from mice at the adult, mature, old, very old, and long-lived ages (40, 56, 72, 96, and 120±4 weeks of age, respectively). The results reveal that some of the investigated parameters are determinants of longevity at the adult age (lymphoproliferative capacity, lymphocyte chemotaxis, macrophage chemotaxis and phagocytosis, GPx activity, and GSH, MDA, IL-6, TNF-α, and IL-10 concentrations), and therefore, they could be proposed as markers of the rate of aging. However, other parameters are predictive of extreme longevity only at the very old age (NK activity, CAT and GR activities, and IL-6 and IL-1β concentrations), and as such, they could reflect some of the adaptive mechanisms underlying the achievement of high longevity. Nevertheless, although preliminary, the results of the present study provide a new perspective on the use of function, redox, and inflammatory parameters in immune cells as prognostic tools in aging research and represent a novel benchmark for future work aimed at prediction of lifespan.