B CELL CHANGES IN AGING

The aging of the immune system is a gradual and dynamic process that modifies some immunological functions. These changes are known as “immunosenescence” that have a great impact on immune performance in late life, contributing to the decreased ability of the elderly people to respond to emerging pathogens and to the decreased responsiveness to vaccinations. It is known that the adaptive immune functions are affected in the aged. In particular, with aging, the acquired compartment of the immune system shows significant modifications in both T and B cell branches. Thus, the adaptive immune response of elderly people is qualitatively and quantitatively reduced when compared to that observed in young people. Lifelong and chronic antigenic load are the major driving forces of this process that is associated with a general increase in the production of pro-inflammatory cytokines and other inflammatory molecules that render elderly people prone to frailty and susceptible to major age-related diseases, such as Alzheimer’s disease (AD). On the other hand, centenarians represent an example of successful aging because they have delayed diseases that normally cause mortality in the general population. The aim of this thesis is to study changes in immune system with age, also focusing on people genetically advantaged for healthy ageing (Centenarian Offspring) or unsuccessfully aged patients (Alzheimer’s Disease), paying attention principally on the naïve/memory B cell compartments. The presented data suggest that the study of naïve/memory B and T cell compartments may be relevant in the evaluation of biological ageing of the immune system.