University of California, Irvine researchers have found that a sugar supplement may help treat the overactive immune cells that are responsible for autoimmune diseases, such as multiple sclerosis (MS) and type 1 diabetes, and stop them attacking the body's tissues.
Lead researcher Michael Demetriou says that their finding is based on a study of N-acetylglucosamine (GlcNAc)—a compound similar to glucosamine, a dietary supplement taken by people with osteoarthritis that is known to have some immunosuppressive effects.
Autoimmune diseases are triggered when receptors on the outside of immune cells called T-helper 1 (Th1) cells start binding "self" antigens rather than pieces of foreign invaders. Anything that decreases the amount of binding should suppress the autoimmune response.
The researchers found that naturally occurring GlcNAc molecules attach to T-cell receptors and these GlcNAc "branches" form a lattice on the cell surface that prevents the receptors from clustering near where the antigens are located. They say that less clustering means less antigen binding, and less activation of Th1 cells, reducing the autoimmune reaction.
During the study, Mice given oral GlcNAc supplements were seen to have twice as much GlcNAc branching on their T-cell receptors as untreated mice. It was also found that T-cells engineered to cause the mouse equivalent of MS failed to do so if they had been incubated in GlcNAc first.
A daily oral dose of GlcNAc also prevented type 1 diabetes in mice genetically engineered to develop the disease.
"T-cells engineered to cause the mouse equivalent of multiple sclerosis failed to do so if they had been incubated in GlcNAc. I'm astounded by their outcomes," the New Scientist quoted Nick Giannoukakis, a pathologist at the University of Pittsburgh School of Medicine in Pennsylvania, as saying.
The researchers, however, warn that still there is need for evidence that glucosamine can reverse symptoms in animals with autoimmune diseases, rather than just preventing them from occurring in the first place. They say that more research is needed to prove the safety of glucosamine and GlcNAc supplements in humans with autoimmune disease.