Inflammation Can Hijack Brain Repair Cells to Ramp Up Immune Attacks in MS, Researchers Report
September 4, 2019
- Johns Hopkins researchers and collaborators have traced abnormal activity of immature brain cells called “OPCs,” which normally spring into action to repair nerve-insulating myelin after it is damaged by immune system attacks in MS.
- The team reports that under inflammatory conditions such as what occurs in MS, the OPCs can be hijacked to act as immune helpers that can ramp up damage to myelin and suppress myelin repair.
- Understanding this new finding may lead to new ways to protect the nervous system and resume normal repair mechanisms in people with MS.
- The team, funded in part by the National MS Society, published its findings on August 29, 2019 in Nature Communications: volume 10, Article number: 3887 (2019).
Multiple sclerosis involves immune system attacks on the myelin sheath that supports and protects nerve fibers and facilitates nerve signaling in the brain and spinal cord. The brain has natural capacity to repair myelin, and this is facilitated by resident immature cells (oligodendrocyte precursor cells – OPCs) that normally spring into action when damage occurs, maturing into myelin-making cells capable of restoring lost myelin. This process can stall in MS, leaving the underlying nerve fibers vulnerable to damage and loss.
Researchers at Johns Hopkins University, including Drs. Leslie Kirby and Peter Calabresi, and other collaborators conducted a series of studies aimed at determining why myelin repair can be stalled in MS. They found that in a mouse model, inflammatory factors such as immune messenger chemicals and immune cells can inhibit OPCs from maturing into myelin-making cells. Under these inflammatory conditions, OPCs were also co-opted to become immune helpers (antigen-presenting cells) that could ramp up immune-mediated damage to myelin. The team also confirmed that in MS brain lesions in postmortem MS tissues, OPCs showed similar signs of being co-opted.
This study offers new insights into mechanisms that may underlie the inadequate myelin repair that occurs in MS, and opens up new possibilities for finding ways to reduce ongoing inflammation and restore myelin.
The team, funded in part by the National MS Society, published its findings on August 29, 2019 in Nature Communications
: volume 10, Article number: 3887 (2019)
. The open-access paper can be read by anyone.
About research on nervous system repair
Multiple sclerosis is an unpredictable disease of the central nervous system. Currently there is no cure. Symptoms vary from person to person and may include disabling fatigue, mobility challenges, cognitive changes, and vision issues. An estimated 1 million people live with MS in the United States. Early diagnosis and treatment are critical to minimize disability. Significant progress is being made to achieve a world free of MS.