Aging and Immune Dysfunction

The number of people over the age of 65 is increasing, a trend that will continue in the foreseeable future. A considerable volume of evidence exists to support the contention that immune system function deteriorates as human beings age. The decline in immune function, frequently called immunosenescence, is often attributed to thymic involution and the associated impairments in T-cell function. More recent evidence points to the decline in antigen naive cells and the accumulation of regulatory T cells (Treg or suppressor T cells), which appears to coincide with aging. Innate immunity also appears to decline with age, with impaired dendritic cell and macrophage function. These cells are responsible for presenting antigen to the adaptive arm of the immune system. B-cell function, and the associated antibody ...