In an experiment, some researchers claim to have been able to stop multiple sclerosis in mice with the help of nanoparticles. The size of the particles used are estimated to be about 200 times smaller in comparison to a human hair. The material those particles are made of is similar to what is used to create dissolving stitches.
Researchers have found that they could find a way to teach the body not to attack its own tissues by attaching specific proteins to the particle. In a situation where this new technique should work with a human species, the hope is one day, it could be used not only for treating multiple sclerosis but also other diseases like diabetes type 1 or rheumatoid arthritis.
The study which was funded by grants was published in the journal Nature Biotechnology.
How to reverse an autoimmune attack
The human brain is made of nerve fibers. Those nerve fibers are coated with a material referred to as myelin that acts as a protective cover just like the insulation around electric wires. The myelin insulation allows the nerve fibers to properly carry nerve impulses. When a person is diagnosed with multiple sclerosis, it means that the person’s own immune system is attacking the myelin covering it nerve fibers.
Over time, as the myelin sheet starts wearing off, the person suffering from MS will start facing problems like the inability to properly coordinate its muscles, pain, vision problems and numbness. The most popular form of MS that affect most people is the relapsing-remitting form (80%). This form is characterized by the fact that the symptoms appear for sometimes and disappear for another period of time, then come back again. The mice used for this experiment was having exactly this type of MS.
Reaserchers were asking themselves if there was a way to stop the wearing off of the myelin by relying on the body’s own “garbage disposal system”. Since one of the immune system role is to get rid of dead cells, the scientists had the idea of taking advantage of that to prevent the attacks of the myelin. As dead cells pass through the spleen, it is the role of other cells called macrophages to gobble them up. As macrophages take care of dead cells they also let other part of the immune system know that those cells are not harmful. The macrophages do that by sending signals.
An immunologist in the Feinberg School of Medicine, Stephen D. Miller, PhD, came up with the idea that if there was a way to hijack this garbage disposal system one could prevent the body to recognize its own cells as threats. Miller has already tried something to induced this type of selective immune protection in the human species. According to him the results showed no side effects, no re-triggering of the disease and there was a decrease of the immune response from the patient. That said the immune response the patient had for other infections remained strong. With this finding there is a possibilty to treat patients with MS without having to give them drugs that completely suppress their immune system. Which is the case in the current autoimmune disease treatment.
How nanoparticles are used
First, Miller requested assistance from Lonnie Shea, PhD who is biomedical engineer, to help create a tiny particle that could carry myelin proteins. Together they decided on poly(lactide-co-glycolide), or PLG. So in an experiment, they diffused a myelin protein coated PLG into mice that had a disease comparable to multiple sclerosis. They were able to stop the progression of the disease over time using that technique.
The exciting news about it is that there are different kinds of proteins that could be coated into the nanoparticles used in the experiment. That way those same nanoparticles could be used to treat other diseases. The technology has not been tested in humans yet. Miller said there was the need to conduct more trials on animals first. If all goes well he hopes in 2 years they might be ready to try some tests on humans.
