May 10, 2019
Little is known about why the immune system turns on its own cells in autoimmune conditions, but scientists at Institut Pasteur say they have discovered a piece of the puzzle to what causes the inflammation associated with multiple sclerosis.
Multiple sclerosis is a demyelinating autoimmune disease that attacks the nervous system. With MS, the central nervous system (brain, optic nerve, and spinal cord) become inflamed, damaging the myelin sheath, or the insulation and protective covering of the nerve cells.
Scientists at Institut Pasteur in Paris, France, report they've found that human endogenous retroviruses (HERVs) – also known as ancient viruses or fossil viruses – are involved in the central nervous system’s defensive response in multiple sclerosis.
These ancient viral sequences have evolved into our DNA, and while they mostly lie dormant, the scientists say these viral sequences resurface in MS patients. That the emergence of these sequences caused several pro-inflammatory genes to become active, according to the researchers.
Christian Muchardt, Head of the Epigenetic Regulation Unit at the Institut Pasteur commented that this new discovery may be valuable in finding new ways of helping patients manage and live with MS.
In people with MS, inflammation damages the myelin sheaths insulating the nerve cells, resulting in messages from the brain having a harder time getting to their final destinations. This demyelination process causes a breakdown in communication between the body and the brain.
Symptoms of MS include trouble with coordination or balance, thinking and memory problems, and muscle weakness. When the disease is advanced enough a person diagnosed with the condition can lose the ability to write, speak, and even walk.