treatment to stop the disease and protect the immune system

Multiple sclerosis is an autoimmune disease in which the immune system turns against the body. For the moment, the treatments are aimed at lowering the reactions of the immune system, which is risky given the serious side effects that this entails, particularly with the onset of infections or even tumors. Researchers from Jefferson University (United States) have found a way to prevent the immune system from attacking the body and thus to stop the progression of multiple sclerosis. The results of their study were published on November 4, 2020 in the journal Scientific translational medicine.

When multiple sclerosis develops in humans, it attacks the electrical insulation around the axon of neurons, the myelin sheath. This sheath allows you not to lose the electrical impulse that passes from one neuron to another, which affects the speed of information exchange. The focus of current research is to find a way to preserve these sheaths and stop the attack produced by the immune system.

Antigens present in extracellular vesicles

“There are many possible immune-activating antigens in the myelin sheath, but the biggest obstacle is that we don’t know which component of myelin triggers the immune response in patients with multiple sclerosis.says Abdolmohamad Rostami, director of the neurology department at Jefferson University. Previous studies have used single myelin antigens or combinations of antigens to prevent autoimmunity in animal models, but have had limited success in humans.. “

To better understand, the researchers went to analyze oligodendrocytes, the cells responsible for making the myelin sheath in the central nervous system. When he grew up in vitro, oligodendrocytes produce extracellular vesicles, which contain all myelin antigens. Hence, it seems easier to stop an autoimmune attack thanks to the antigens present in these vesicles. “The advantage of these extracellular vesicles is that they give us the ability to treat the disease in an antigen-specific way, without having to know the exact identity of the target antigen.“, Emphasizes Abdolmohamad Rostami.

A curbed disease and a preserved immune system

These extracellular vesicles were injected into three mice with multiple sclerosis in the early or late stages of the disease. When administered before the disease develops, the extracellular vesicles have a prophylactic effect, which prevents the mice from suffering from paralysis or reduced mobility. If extracellular vesicles are injected after the onset of multiple sclerosis, the severity of the disease is significantly reduced. Furthermore, this method does not attack the myelin sheath and leaves the immune system intact, which is not weakened.

“The antigens involved in the autoimmune response can differ among MS patients and even change over time in an individual patient. The fact that our approach has been effective in several experimental models shows that it could act as a universal therapy “, details Abdolmohamad Rostami. He pursues: “This is a huge advantage of our antigen-specific method over current therapies, which destroy the immune system. This is what makes ours so innovative.“

The extracellular vesicles themselves could be isolated in humans. Like mice, they also have more myelin antigens in them, which could therefore provide the same therapeutic effect as the tested rodents. Abdolmohamad Rostami and his team are now looking to patent their approach, which could be a breakthrough in the treatment of multiple sclerosis.