Italian researchers discover a possible onset mechanism for Multiple Sclerosis

I just read an interesting article on how bacterium might be a trigger for the onset of Multiple Sclerosis. One theory regarding the cause of MS is that it is an autoimmune triggered. A recent study in mice found that a harmless bacterium made to look like a nerve cell allows T-cells to modify to the point where they can repeatedly break into the central nervous system. Normally, T-cells can not do this. However, in mice where this modified bacterium has been introduced, the T-cells modify in the inflammatory response. These modified T-cells persist well after the bacterium has been killed and continue to cause inflammation in the central nervous system.

I think it's interesting to see how other immune disorders operate as there may be analogs in Crohn's.

Here's an excerpt:

This is the hypothesis that the researchers coming from the Institutes of General Pathology, Microbiology and Anatomy of the Catholic University of Rome have been testing with their two-year long work. To demonstrate the viability of this idea, scientists have fooled the mouse immune system, modifying subtly a bacterium of the common family of mycobacteria (the same family to which also the bacterium causing tuberculosis belongs) to make it look like to myelin, the protein coating nerve cells. This modified mycobacterium is completely innocuous. As all external agents, though, it is capable to trigger the reaction of the T-cells of the immune systems. They intervene to destroy it. Since they are innocuous bacteria, although very common in the environment, and since they induce an immune reaction, they are the ideal bacteria scientists can use to study the environmental factor contributing, together with the genetic factor, to cause multiple sclerosis.

"Normally, T-cells cannot penetrate into the Central Nervous System", adds Rea, "because the hematoencephalic barrier prevents them from doing so. But the bacterium modifies the characteristics of the T-cells and allows them to overcome the barrier. In 15 days the bacterium disappears completely from the body".

Yet these T-cells can now enter into the brain. This way, they begin to attack the myelin of the nerve cells, and here is how the immune disease breaks out.

"We basically demonstrate – explains Rea – that in an animal model it is possible to be infected with something not carrying any disease, and later on develop a purely autoimmune disease".

Pretty interesting.