How does Epstein-Barr virus trigger MS in some people?
Original story from Karolinska Institutet (Stockholm, Sweden).
The immune system’s reaction to the common Epstein-Barr virus (EBV) can ultimately damage the brain and contribute to multiple sclerosis (MS).
This is shown by new research from Karolinska Institutet (Stockholm, Sweden), published in Cell. The study provides new insight into the long-suspected link between EBV and MS.
MS is a chronic inflammatory disease in which the immune system attacks the central nervous system and causes nerve damage. It has long been known that everyone who develops MS has had an infection with the EBV – a common virus that often infects young people, sometimes causing glandular fever but often without any obvious symptoms. Exactly how this virus contributes to MS has long been unclear.
The new study shows that when the immune system fights EBV, certain T cells – which normally attack the virus – can also react to a protein in the brain called Anoctamin-2 (ANO2). This phenomenon is called molecular mimicry – immune cells mistaking the body’s own proteins for those of the virus.
The researchers found that these cross-reactive T cells are significantly more common in people with MS than in healthy controls. The study builds on previous research showing that misdirected antibodies after EBV infection may play a role.
Uncovering the role of mitochondrial dysfunction in multiple sclerosis
How mitochondrial dysfunction impacts nerve damage, Purkinje cell loss and motor impairments in multiple sclerosis has been identified, providing promise for targeted treatments.
“Our results provide mechanistic evidence that immune responses to EBV can directly damage the brain in MS. It is a complex neurological disease, and it may be that the molecular mechanisms vary between patients,” explained the study’s first author, Olivia Thomas, assistant professor at the Department of Clinical Neuroscience at Karolinska Institutet.
The study is based on analyses of blood samples from people with MS compared with healthy controls. The researchers were able to isolate T cells that react to both the EBV protein EBNA1 and ANO2 from people with MS. In addition, experiments in a mouse model showed that these cells can exacerbate MS-like symptoms and cause damage to the brain.
According to the researchers, the results may help explain why some people develop MS after an EBV infection while others do not.
“The discovery opens up new treatments that target these cross-reactive immune cells. Since several EBV vaccines and antiviral drugs are now being tested in clinical trials, the results may be of great importance for future preventive and therapeutic efforts,” added Tomas Olsson, who led the study together with Andre Ortlieb Guerreiro-Cacais at the same institution.
This article has been republished from the following materials. Material may have been edited for length and house style. For further information, please contact the cited source. Our press release publishing policy can be accessed here.