Aging T Cells May Promote Pathological Changes in Tissue Structure

The immune system is complex and undertakes many activities in the body beyond mounting a defense against pathogens. Immune cells are involved in many of the normal processes of tissue maintenance. Even where there is no direct involvement, the secreted signals produced by inflammatory immune cells produce changes in the behavior of other cell populations. Thus we should not be surprised to find it possible to draw connections between the state of the immune system and the structural properties of tissue that arise from the behavior of the cells making up that tissue. This is one of many reasons why change and dysfunction in the immune system is an important component of aging, and one that should be addressed as a part of any broad attempt to produce rejuvenation.

It is well known that during the aging process, the immune system changes, that is, the disorder and decline of immune system function. In the aging state, the immune system usually shows a relatively continuous state of low activation. When stimulated by the outside world, its dynamic response becomes weaker and the amplitude is reduced, and this combination of chronic inflammatory state and reduced effective defense ability is often referred to as immune aging.

Studies have found that immune aging is associated with increased morbidity and mortality in the elderly. With the increase of age, T cells with aging phenotypes will continue to accumulate, further promoting immune aging, resulting in a decrease in immune function and an increase in pro-inflammatory function.

It has been found that aging T cells may promote pathological changes in the tissue structure of various systems of the human body through a variety of mechanisms, thereby leading to related diseases and fundamentally affecting the health of the elderly. First, aging T cells continue to produce cytokines that directly promote inflammation. Secondly, aging T cells may not be able to perform the function of monitoring aging, so that they cannot clear the irreversibly damaged cells that become senescent cells. In addition, aging T cells can lead to the loss of autoimmune tolerance and secrete cytotoxic substances that directly damage tissues. Finally, aging T cells can also indirectly participate in various changes by regulating intestinal homeostasis.