Nature Immunology pp 940 - 943

Multiple sclerosis (MS) is associated with the genes, DRB1 and DRB5, but it is not known why these are MS risk factors. In Nature Immunology, scientists show that both DRB1 and DRB5 influence susceptibility to MS because they are structurally equivalent, which can potentially confuse the immune system during infection and trigger the immune system to attack the body.

Yvonne Jones and her team from Oxford University showed that a T cell clone taken from an MS patient could recognize both Epstein Barr Virus (EBV) and myelin, a component of the nervous system. EBV is presented to the T cells by DRB5 whereas myelin is presented by DRB1. Structural analysis of the DRB5-EBV complex revealed a remarkable degree of structural similarity to the DRB1-myelin complex in the region important for T cell recognition. Therefore, a virus infection such as EBV could trigger MS in genetically susceptible individuals because the T cells induced by the virus also cross-react with tissues from the nervous system.