Deciphering Novel Communication Patterns in T Regulatory Cells From Very Old Adults

Regulatory T cells (Tregs) are important in maintaining tolerance and are key players in immunity. In aging, increased Treg function along with low-grade inflammation has been reported. This dichotomy of enhanced Treg function along with inflammation highlights the importance of understanding Treg biology and communication patterns in the very old. In this proof-of-concept study, we demonstrate that aged Tregs (85 years) do not significantly communicate with CD4⁺ and CD8⁺ T effectors when compared with healthy < 66-year-olds. Of note was the enhanced communication of aged Tregs with CD3⁺CD8⁺CD56⁺CD161^- NK-like T-cell populations, which are important in antitumor and chronic viral diseases in older individuals. We found that in turn this population of killer-like T cells showed diminished cytotoxic characteristics, and killer receptor expression. Taken together, our proof-of-concept study delineates the biology of Tregs and identifies previously undefined communication patterns in the very old.