Immunosenescence

Immunosenescence is the gradual deterioration of the immune system, brought on by natural age advancement. It affects both innate and adaptive immunity, including changes in lymphocyte production, immune cell function, and inflammatory regulation. Immunosenescence involves both the host's capacity to respond to infections and the development of long-term immune memory. Age-associated immune deficiency is found in both long- and short-lived species as a function of their age relative to life expectancy rather than elapsed time.

Immunosenescence has been studied in animal models, including mice, marsupials, and monkeys. In humans, it is associated with increased rates of morbidity and mortality in older adults. Along with anergy and T-cell exhaustion, immunosenescence is among the major dysfunctional states of the immune system. Strategies to reverse immunosenescence and the mechanisms underlying immune system aging remain active areas of research.

Immunosenescence is not a random, deteriorative phenomenon. It instead appears to reflect an evolutionary pattern in reverse where there is a gradual loss of features that had been optimized for effective immunity earlier in life. Many of the parameters affected by immunosenescence are thought to be under genetic control.