Innate Immune System Modulation During Aging: Contributions of Macrophages and Dendritic Cells

Cumulative evidence indicates that aging exerts significant effects on the immune system, with a rise in the frequency and severity of infections, and a diminished protection occurring after vaccination. Age-related changes in the adaptive immune response have been well established but the alterations taking place in the innate immune response and its regulation by immune modulators are not well understood. This review examines the current knowledge about the way aging affects the function of several cells of the innate immune system. In particular, this review will focus on dendritic cells and macrophages and their contributions to the changes in the immune system during aging. Furthermore, this review will analyse how the response to Toll-like receptors is affected during aging. The recognition of defects in cells of the innate immune system of aged individuals and the understanding of their consequences will help in the development of better therapeutic strategies for the elderly.