T-cell aging in rheumatoid arthritis.

Area of Science:

• Immunology
• Gerontology
• Rheumatology

Background:

• Immune system function declines with age, increasing susceptibility to infections, cancer, and chronic inflammation.
• Rheumatoid arthritis (RA) accelerates the aging process of the immune system, known as immunosenescence.
• Individuals over 50 face higher risks of infections, cancer, chronic inflammation, and immune-mediated tissue damage.

Purpose of the Study:

• To review the fundamental changes in the immune system with aging.
• To understand the accelerated immunosenescence in rheumatoid arthritis (RA).
• To explore the molecular mechanisms of T-cell aging and its implications.

Main Methods:

• Review of current literature on immunosenescence and T-cell aging.
• Analysis of molecular mechanisms contributing to T-cell senescence.
• Examination of the senescence-associated secretory phenotype (SASP).

Main Results:

• Premature T-cell senescence is implicated in RA and chronic HIV infection, contributing to morbidity and mortality.
• Senescent T-cells exhibit a 'senescence-associated secretory phenotype' (SASP) that promotes chronic inflammation.
• Molecular defects in T-cell aging include reduced diversity, impaired kinase/phosphatase balance, DNA repair issues, and telomere shortening.

Conclusions:

• Senescent T-cells, through gain- and loss-of-function, impair immunity and drive chronic inflammation, characteristic of RA.
• Understanding the genetic programs in T-cell signaling and DNA repair is crucial for identifying molecular defects in T-cell aging.