Markers of immunosenescence and oxidative stress in healthy adults

Abstract

This thesis investigated markers of oxidative stress and immunosenescence in healthy adults. The results presented represent several novel findings which support the notion that oxidative stress and infection with micro-organisms shape our biology and can accelerate aspects of ageing. Acute exercise of high intensity was shown to cause alterations in the cellular composition of blood, which was most pronounced in lymphocyte sub-populations important for immunosurveillance. This exercise also resulted in increased markers of oxidative stress in lymphocytes, and resulted in a whole body oxidative stress, which was more pronounced and prolonged, following ultra-endurance exercise. Studies also showed that infection with a highly prevalent and asymptomatic herpes virus, Cytomegalovirus (CMV), shapes our immune biology in two significant ways. First, CMV amplified the magnitude and kinetics of lymphocyte responses to exercise, which could potentially facilitate immune surveillance, or aggravate inflammatory processes. Second, CMV was seen to drive the development of an ‘Immune Risk Profile’ in young adults, characterised by increased inflammatory activity and smaller responses to vaccination. These outcomes are associated with frailty, cognitive decline, and mortality in the elderly.