French researchers have used a protein called receptor activator of NF-κB ligand (RANKL) to revive the structure and function of the thymus in old mice. The thymus sits in front of the heart and is where T cells mature; its age-related decline is associated with cancer, infections and autoimmune conditions, according to a Dec. 4 release about the results.
The findings were published in Science Translational Medicine on Dec. 4.
The researchers, led by immunologist Magali Irla, Ph.D., of the French National Institute of Health and Medical Research (INSERM), studied the thymi of eight-week, six-month and one-year-old mice and noticed that RANKL levels declined as the rodents aged. Treating the elderly mice with RANKL restored their levels of thymic epithelial cells, which are important for T cell development.
Treated mice also had reduced tumor growth when injected with melanoma cells, and they produced more T cells in response to being immunized against an egg white protein, a common test of immune system strength.
RANKL treatment also led to a boon of thymic endothelial and epithelial cells in human cells grown in the lab, which means the compound could be translated to human studies, the authors suggest in the release.
RANKL is a cytokine that binds to the receptor activator of NF-κB (RANK) and has been implicated in numerous diseases, including osteoporosis and other bone diseases.