The Aged Immune System Fails to Clear Senescent Cells

Cells become senescent constantly throughout life, in response to damage, stress, or reaching the Hayflick limit on replication. A senescent cell ceases to replicate, grows in size, and begins to secrete a potent mix of pro-inflammatory signals. In youth, the immune system efficiently clears senescent cells. Clearance falters in later life, however, and this failure of the immune system to keep up…