from patients with rheumatoid arthritis are worn out and prematurely aged, because their telomeres are not replenished, according to scientists at Emory University
School of Medicine.
They say that the T cells have a hard time turning on enzyme telomerase, which rejuvenates telomeres and helps prevent the loss of genetic information.
“What we see in rheumatoid arthritis is an aged and more restricted T-cell repertoire,” says Cornelia Weyand, M.D., Ph.D., senior author of the study. “This biases the immune system toward autoimmunity.”
The researchers found that T cells from patients with rheumatoid arthritis make 40% less telomerase enzyme when stimulated. The cells came from 69 patients, 92% of them female. The average age of the patients was 50, and they were compared with cells from healthy people with similar demographics.
When investigators shut off a gene encoding part of the enzyme, it made normal T cells vulnerable to programmed cell death. Transferring telomerase into patients' T cells, on the other hand, kept them from dying.
The investigators thus suggest that restoring defective telomerase to T cells could reset the immune system in rheumatoid arthritis.
The results are published online this week in Proceedings of the National Academy of Sciences.