Multiple sclerosis (MS) is an autoimmune disease, that is, in which the immune system mistakenly attacks the body itself, destroying in the case of multiple sclerosis, the myelin layer that surrounds and protects neurons. It is a disease for which there is no cure and suffered by around 2.3 million people worldwide.
Now, new research could change this scenario diametrically, since a team of researchers from the University of Florida in Gainesville (USA) has managed, through genetic immunotherapy, to prevent and reverse multiple sclerosis in a group of rodents. The intention was to develop a genetic strategy that would provide long-term protection for myelin.
His approach was to use an adeno-associated virus vector (very similar to that of colds) and manipulate it to deliver the MOG protein – myelin oligodendrocyte glycoprotein – to the liver cells of mice with multiple sclerosis. This triggered the activity of MOG-specific regulatory T cells, which suppresses the destructive activity of autoreactive effector T cells, which are those that react against the body itself and trigger the immune response.
The experts revealed how this new technique allowed them to target and suppress destructive immune cells that, as we have seen, play a key role in the development of multiple sclerosis. This therapy reduced the clinical symptoms of the disease and, when combined with an immunosuppressive drug, also produced complete remission of the disease in mice with end-stage multiple sclerosis.
Thus, when testing the gene therapy technique in mouse models at high risk of multiple sclerosis, it prevented rodents from developing clinical symptoms of the disease over the course of 7 months and reversed a series of symptoms in mice that had already developed MS. , including neurological problems and paralysis of the hind legs.
The researchers note that their immunotherapy strategy alone was not able to reverse the late stage of multiple sclerosis, but when combined with a short dose of the immunosuppressive medication rapamycin, it led to complete remission in almost all of the mice with stage disease. late. Specifically , it reversed the severe paralysis and avoided any MS symptoms for 100 days.
“I had spent almost a decade studying the mechanisms of immune tolerance induced by gene therapy, so I was confident that gene immunotherapy would be effective, especially in preventing disease. However, my team and I were surprised and impressed by how well it was. It was effective in reversing pre-existing disease and restoring mobility in mice that were essentially paralyzed, “explains Brad Hoffman, leader of the work.
Would it be valid for human beings?
It goes without saying that the safety and efficacy of this technique need to be evaluated in human trials, and there are also a number of important limitations that must be overcome.
“Although gene immunotherapy was very effective in mice, it is important to remember that the mouse model of MS is less complex than that of human disease,” says Hoffman.
Despite these hurdles, the scientists hope their findings will pave the way for an effective strategy to prevent and reverse multiple sclerosis in humans.
Referencia: Molecular Therapy, Keeler et al.: “Gene Therapy Induced Antigen-Specific Tregs Inhibits Neuro-inflammation and Reverses Disease in a Mouse Model of Multiple Sclerosis” http://www.cell.com/molecular-therapy-family/molecular-therapy/fulltext/S1525-0016(17)30413-6 , DOI: 10.1016/j.ymthe.2017.09.001
