RNA vaccines are also in use against Kovid-19. Researchers are now showing that such a vaccine may strengthen autoimmune diseases such as multiple sclerosis in the future. A widespread application of technology is also possible.
RNA vaccines protect against the infectious disease Kovid-19 and are also tested against cancer. Researchers led by Mainz Doctor and Biontech founder Ugur Sahin are now showing that such active ingredients can also help with autoimmune diseases such as multiple sclerosis (MS). In one sample, the researchers write in the journal Science, they significantly improved symptoms of MS-like illness in mice.
An independent expert speaks of very exciting figures, but urges caution. “You never know if it would work so well for humans,” says Ralph Gould, president of the Medical Advisory Board of the German Multiple Sclerosis Society (DMSG).
Sahin said that at present the compatibility of this approach is being tested and preparations are being made so that it can be researched in humans. Clinical trials can begin in about two to three years “if everything goes according to plan”. In addition, RNA vaccines are being tested for uses other than cancer, including chronic inflammatory diseases such as arthritis.
In December, BNet 162B2, produced by Biotech against Kovid-19, was the first RNA vaccine to ever be approved. This vaccine contains the genetic material of the pathogen, which the body then uses to make a viral protein. The aim is to activate the immune system so that in the event of infection, it produces antibodies to inhibit the Sars-CoV-2 virus.
Multiple sclerosis (MS) vaccines have a different purpose, in which the immune system damages the myelin that coat the nerve fibers. Here, a vaccine must ensure that myelin is accepted by the body’s own defense and does not produce any invading immune cells or antibodies. In Germany, damage to the myelin sheath leads to paralytic motor problems, affecting more than 250,000 people.
We were looking for a therapeutic approach that mimics the natural mechanism of immune tolerance, ”the researchers wrote, who mostly work at Mainz University Hospital. At the same time, the immune system should not be attenuated by RNA vaccination – for example, when protecting against pathogens.
The RNA vaccine includes the blueprint (RNA) for myelin oligodendrocyte glycoprotein (MOG) content – a part of the myelin sheath that is targeted by violent autoimmune responses in MS. The vaccine is designed so that the protein is tolerated by the immune system. “With the RNA therapy approach, we induce the formation of immune cells that have a protective effect so that tissue is not attacked,” Stein explained.
The Mainz team tested therapeutic effects in mice with experimental autoimmune encephalomyelitis (EAE). The disease, similar to multiple sclerosis, is based on inflammatory processes against components of myelin. Vaccination increased the inflammatory response in mice and prevented the disease from growing. At the same time, pathogens, like components of the flu virus, continued to react to the immune system.
The ability of mice to produce a protective immune response and neutralize antibodies was unaffected. “
In another step, the researchers showed that immunization did not trigger additional immune cells against myelin. This is important because it is the so-called biodysor effect, in which the myelin sheath is slowly attacked by other immune cells in a cascade, playing a key role in multiple sclerosis. Overall, the results, according to the researchers, lay the foundation for the method’s subsequent clinical application in autoimmune diseases.
DMSG experts consider this transfer of gold humans as an important sticking point. “The study proves that vaccination works excellently in mice,” says the director of the neurological clinic at Ruhr University in Bochum. “But it is not easily transferable to humans.”
Repeatedly, active ingredients that show promise in animal experiments have failed in humans. On one hand, it is due to the fact that the human immune system is very complex. Humans, on the other hand, are much more complex than the closely described strains of mice that are used in studies, says Gould.
Sahin is well aware of this problem. The method is now to be tested on various human immune cells in the laboratory, he says. Each person may have a different type of multiple sclerosis, he said, each with a specific pattern of autoimmunity. In the current study, researchers were able to use a single antigen to induce tolerance in the immune system to all myelin tissue in mice, he said.