Researchers have developed what’s being hailed as a “breakthrough” in the treatment of multiple sclerosis, a crippling autoimmune disease that attacks the outer sheath of nerve cells, eventually disabling many of those with the neurological condition. The new treatment involves sweeping away immune system cells responsible for MS.
In multiple sclerosis, immune system white blood cells, called T cells, become misdirected, attacking the protective myelin sheath on the outside of nerve cells. In healthy individuals, T cells or leukocytes are responsible for destroying tumor cells or those infected with a virus.
Myelin speeds the transmission of nerve impulses from the brain and spinal cord to limbs and the optic nerves, which also are insulated with myelin.
When the myelin is destroyed, motor neuronal impulses are blocked, resulting in severe disability and blindness in many people with multiple sclerosis. Worldwide, an estimated 2.5 million people are affected by MS.
U.S. and German researchers have developed a therapy that stops the autoimmune attack against myelin in its tracks without impairing the normal function of the immune system, according to Stephan Miller, a microbiologist and immunologist at Northwestern University in Evanston, Illinois.
Miller says the experimental treatment targets T cells in the brain that are responsible for the disease. The therapy, Miller says, has a different mode of action from current MS treatments, which suppress the immune system.
“They will not only try to down-regulate the autoimmune response that’s actually causing the disease, but will also make patients in the long run susceptible to everyday infections and increased rates of cancer," said Miller.
The novel MS treatment involves taking billions of T cells from a patient and engineering them to carry myelin antigens. The approach is similar to the way a vaccine works.
Antigens are harmless proteins from a virus or bacterium that do not cause illness but stimulate the immune system to recognize and destroy disease-causing microbes so a person exposed later to an infection doesn’t become ill.
Nine MS patients in Hamburg, Germany were treated with the myelin antigens. Miller says their immune systems considered the engineered T cells to be foreign, disabling and killing the harmful leukocytes
“The dead and dying cells to which the antigens are attached get uptaken by cells in the immune system that ends up tricking the immune system into believing that these antigens are no longer dangerous, and will actually turn off the immune response against the antigens rather than turning it on," he said.
The therapy swept away the dead T cells. The experimental treatment reset the patients’ immune systems, halting the leukocytes' attack on the nerve sheaths and reducing the assault on the myelin by 50 to 75 percent.
While not a cure for MS, Miller believes it’s a step in the right direction.
An article on a promising, new treatment for multiple sclerosis is published in the journal Science Translational Medicine.