Immune cells deliver packages of telomeres to T cells, helping them retain their virus-fighting function over time, research suggests
When a foreign invader such as a virus enters the body, T cells rapidly divide, and their numbers skyrocket. Previously, scientists knew that T cells employ telomerase, an enzyme that extends telomeres, to combat telomere loss during this rapid division, which over time can lead to shortened telomeres and eventual senescence. But telomerase isn’t sufficient to prevent T cell senescence, sending scientists searching for another key mechanism responsible for guarding against T cell aging.
Like all of the cells in our body, immune cells age Over time, they become less and less able to fight infection, cancer, and disease.Previously, researchers thought the process of cells growing old and feeble, known as cellular senescence, was an inevitable consequence of routine infection and time. But a study published in September in Nature Cell Biology suggests that an interaction between T cells and antigen presenting cells (APCs) early in the immune response to viruses may determine how fast T cells decline.
Telomeres are long, repeating sequences of DNA that bookend chromosomes and protect their ends from fraying. As cells age, their telomeres get shorter and shorter with each cell division until eventually, they can no longer divide. The new study finds that after infection, APCs, the cells that initially kickstart T cells’ immune response by presenting them with a foreign antigen, chop off and deliver their telomeres to T cells, the white blood cells that fight viruses. This action extended the receiving T cells’ telomeres up to 30 times more than telomerase would. The researchers found that when APCSs deliver their telomeres to T cells, the latter shift into stem cell-like configuration, which delays their senescence. The researchers also found that this interaction boosts long-term immunity in mice, suggesting that this finding could pave the way for more efficient vaccination.
https://www.the-scientist.com/news-opinion/t-cells-ward-off-aging-with-help-from-their-friends-70505
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