Scientists from Massachusetts General Hospital have discovered that immune cells that fight cytomegalovirus can help “clear” the skin of old cells. Research published in the journal cell.
Senescent or senescent cells are cells that can no longer divide and function normally but do not die. Their buildup over the years can contribute to chronic inflammation, which increases the risk of cancer and other diseases.
In a new study, scientists discovered that virus-fighting immune cells can detect and destroy aging cells in the skin. Biologists analyzed skin samples from young and old. As expected, they found more senescent cells in the older samples. However, the number of senescent cells did not increase as people got older, suggesting some sort of inhibitory mechanism is at work.
Experiments have shown that the increase in the number of senescent cells is retained by immune CD4+ T cells. The more it was found in the tissues of the aged, the lower the content of aged skin cells (fibroblasts). The researchers found that aging skin cells secrete more cytomegalovirus antigens than younger cells. This makes them immune targets and activates T cells.
Most people are infected with cytomegalovirus. The scientists’ discovery may mean that the human immune system has evolved to destroy senescent cells affected by cytomegalovirus.
Scientists believe that the immune response to cytomegalovirus could be used to treat skin cancer, fibrosis and degenerative skin diseases in the elderly.