New subset of monocytes offers hope for MS treatment

A new mouse model study has suggested targeting a subset of monocytes, a type of immune cell, might be a better way to treat multiple sclerosis (MS) than targeting all of the immune system’s cells, which is currently done in MS therapy.

Monocytes are immune cells which start out in the blood and then infiltrate tissue, and fight off threats by engulfing them. They destroy parts of the central nervous system in people with MS.

At the moment, MS therapies that dampen immune reactions against myelin put people at risk of infection. But scientists at the Max Delbruck Centre for Molecular Medicine in Germany found that by depleting a newly identified subset of monocytes they could reduce signs of MS without affecting the body’s ability to fight off infection.

The two subsets identified are called Saa3+ and Cxcl10+ and they exhibit pro-inflammatory and disease-causing genetic ability. The researchers think that these monocytes could have a huge roll in MS – they suspect they might be the immune cells that open up the blood-brain barrier for other immune cells to enter the central nervous system, and activate other immune cells involved in the condition.

The scientists say that if what they are hypothesising is true, future MS treatment could deactivate the Cxcl10+ monocytes rather than targeting the T or B cells of the immune system.

The research team believes that Cxcl10+ monocytes may have an even bigger role than anticipated, being the immune cells that open up the blood-brain-barrier to help other immune cells enter the CNS, and then recruiting and activating other immune players in the disease.

“If that is the case, in the future most forms of MS could be treated by specifically deactivating the Cxcl10+ monocytes instead of targeting the T- or B-cells of the immune system,” said Mildner. “This would protect the body’s immune memory and prevent many side effects of current MS therapies.”