Infection with a virus related to Epstein-Barr dysregulates the immune system of monkeys

19 July 2016

BPRC - 1. Infection with a virus related to Epstein-Barr dysregulates the immune system of monkeys

Infection with Epstein Barr Virus (EBV) is a major risk factor for the development of multiple sclerosis (MS). However, it is not clear why this is the case. Using monkey models, BPRC researchers claim to have found a possible explanation for this association.

In the normal situation, the immune system focuses on the elimination of pathogens such as viruses, bacteria and parasites. In MS, however, the immune system attacks components of the own body, in particular the insulating (myelin) layer that surrounds nerve fibers, causing impairment of nerve function. The onset of MS and the mechanisms that underlie the chronic disease course are difficult to study in patients. To enable this kind of studies, researchers at the BPRC use monkey models for MS.

The BPRC researchers have studied the effect of an infection with a lymphocryptovirus (LCV) related to EBV, on the immune system of monkeys. LCV infect B-cells, a white blood cell component belonging to the immune system. Non-infected B-cells were shown to take up endogenous proteins, in this case a protein that is present in myelin, and destroy it to prevent the activation of other immune cells (T-cells). This prohibits the immune attack on the own body. B-cells infected with LCV, however, only partially degraded endogenous proteins, therebye displaying them to the immune system. Against a particular genetic background of the monkey other cells of the immune system will respond and attack the own body, in this case the nerves.

This mechanism may explain the association between EBV and MS: B-cells typically have a protective effect in MS, but this effect is abolished by infection with EBV. This work is described in the Journal of Immunology