A mechanism tries to stop our T cells from causing autoimmune disorders, and it’s like a tight handshake that kills overly aggressive T cells.

A person reaches out for a handshake; the other person takes their hand with two hands and tugs then dies as a consequence. That’s a rough description of newly discovered cellular mechanisms that eliminate T cells that may cause autoimmune disorders.

Although the mechanisms are intertwined with biochemical processes, they also work mechanically, grasping, tugging and clamping, say researchers at the Georgia Institute of Technology, who, for a new study in the journal Nature Immunology, measured responses to physical force acting upon these elimination mechanisms.

The mechanisms’ purpose is to make dangerously aggressive developing immune cells called thymocytes kill themselves to keep them from attacking the body, while sparing healthy thymocytes as they mature into T cells. Understanding these selection mechanisms, which ensure T cells aggressively pursue hordes of infectors and cancers but not damage healthy human tissue, could someday lead to new immune-regulating therapies.