What is the Origin of Immune System Senescence?

Immune System Senescence is a term established in immunology and gerontology to describe the functional erosion of immune surveillance with advancing age. This process is closely linked to changes in the thymic microenvironment and systemic hormonal shifts, such as declining sex steroids. Recognizing this decline informs strategies to maintain T-cell competency and responsiveness to new antigens.

What is the Mechanism of Immune System Senescence?

Senescence involves the accumulation of exhausted, non-proliferative immune cells (senescent T-cells) and reduced output from primary lymphoid organs like the thymus, which is sensitive to thymic involution influenced by sex steroids. This reduces the diversity of the T-cell repertoire necessary to mount novel immune responses. The mechanism results in a state of immunodeficiency coupled with chronic low-grade inflammation (inflammaging).

Immune System Senescence

Meaning

Immune System Senescence refers to the gradual, age-associated decline in the functional capacity of the adaptive and innate immune responses, often exacerbated by chronic inflammation or thymic involution. This decline compromises pathogen defense and increases susceptibility to neoplasia, linked to altered steroid hormone milieu. Thymic output reduction impacts T-cell repertoire diversity, a key component of immunological surveillance. Recognizing this senescence is vital for proactive health management in older populations.