Researchers discovered an encouraging novel vaccine variant that does not suppress the immune system in laboratory tests. This discovery shows the potential to effectively reverse autoimmune diseases like arthritis, multiple sclerosis, Type 1 diabetes, and Crohn's disease.

A typical vaccine instructs the human immune system to recognize a virus or bacteria as an adversary that it should combat. Currently, doctors commonly treat autoimmune diseases with drugs that broadly suppress the immune system.

Revolutionary Inverse Vaccine

The inverse vaccine, featured in the journal Nature Biomedical Engineering, capitalizes on the natural process by which the liver tags molecules from broken-down cells with "do not attack" flags. This prevents autoimmune reactions to cells that naturally undergo cell death. "In the past, we showed that we could use this approach to prevent autoimmunity," said lead author Jeffrey Hubbell, Professor in Tissue Engineering from the varsity's Pritzker School of Molecular Engineering (PME).

"But what is so exciting about this work is that we have shown that we can treat diseases like multiple sclerosis after there is already ongoing inflammation, which is more useful in a real-world context," he added. "The human body has a mechanism for ensuring that immune reactions don't occur in response to every damaged cell in the body -- a phenomenon known as peripheral immune tolerance and carried out in the liver. The team discovered in recent years that tagging molecules with a sugar known as N-acetylgalactosamine (pGal) could mimic this process, sending the molecules to the liver where tolerance to them develops."

"The idea is that we can attach any molecule we want to pGal and it will teach the immune system to tolerate it," explained Hubbell."Rather than rev up immunity as with a vaccine, we can tamp it down in a very specific way with an inverse vaccine." In the new study, researchers concentrated on a multiple-sclerosis-like disease characterized by the immune system attacking myelin, resulting in weakness, numbness, vision loss, and eventually mobility issues and paralysis.

The researchers linked myelin proteins to pGal and investigated the impact of the new inverse vaccine. They discovered that the immune system stopped attacking myelin, allowing nerves to function normally again and reversing disease symptoms in animals. The scientists demonstrated that the same approach effectively reduced other ongoing immune reactions in a series of other experiments.

"These treatments can be very effective, but you're also blocking the immune responses necessary to fight off infections and so there are a lot of side effects," said Hubbell. "If we could treat patients with an inverse vaccine instead, it could be much more specific and lead to fewer side effects."