LinkResearchers have found a chemical messenger that frees some white blood cells from the body's normal constraints, allowing the cells to act like renegades that could damage nerves in the central nervous system.

The work, published in the Journal of Immunology, helps explain one of the fundamental mysteries of multiple sclerosis ( MS ).

It was discovered that a chemical messenger, found at high levels in MS patients, allows some immune cells known as T-effector cells to evade normal regulation.
Instead, the cells bypass their usual gatekeepers and could become active in the body's tissues, including the brain and spinal cord.

Researchers believe that during multiple sclerosis, renegade T-effector cells damage the myelin coating that covers nerve cells, causing the disease's symptoms. While another subset of white blood cells called T-regulatory cells normally control the activation of T-effector cells, investigators found that the chemical messenger interleukin-12 ( IL12 ) allows some cells to sidestep that regulation and run amok.