MS: There May Be
More to the Story

Dan, MS Advocate
Dan, MS Advocate
Dan, MS Advocate

Epstein-Barr Virus and Its Role in MS

If you or a loved one has multiple sclerosis (MS), you probably know that MS is a disease of the central nervous system, which includes the brain, the spinal cord, and the optic nerves. While we don’t know exactly what causes MS, there is evidence that the Epstein-Barr virus (EBV) may play a key role.

~2.8 million<sup>1</sup>
~2.8 million1 people worldwide have
been diagnosed with MS
~2.8 million<sup>1</sup>
Up to 100%
of all people with MS are EBV positive

There are many different risk factors associated with MS. The interplay between environmental (smoking, vitamin D, and EBV) and genetic factors (family history, genes) determines a person’s overall risk of getting MS. While all these factors can play a role, being EBV positive (EBV+) is the only risk factor that may be required for the development of MS.

Illustration of a scale with a large EBV+ box on the left side and three smaller boxes on the right side that contain: Smoking, Low vitamin D, and Genes.

1 Atlas of MS, MS International Federation

At Atara, we’re investigating therapies that target EBV-infected cells in progressive forms of MS.
SEE MS CLINICAL STUDIES

The Players in MS

It is believed that MS is caused by the interaction of several different types of immune cells and proteins. These are some of the players that may be involved in the MS disease process:
EBV
EBV
B CELL
B CELL
EBV-INFECTED<br> B CELL
EBV-INFECTED
B CELL
T CELL
T CELL Kills EBV-infected
B cells
AUTOIMMUNE T CELL
AUTOIMMUNE T CELL Targets myelin in the body
ANTIBODY
ANTIBODY Identifies and binds foreign substances as part of an immune response
MYELIN
MYELIN Protective layer that insulates nerves

MS: A Destructive Cascade

In MS, damage to nerves occurs throughout the central nervous system (CNS), which includes the brain, the spinal cord, and the optic nerves. The damage to myelin throughout the CNS causes the debilitating symptoms of MS.

Although it is not clear exactly how EBV may be involved in the development of MS, research suggests that people with MS are unable to properly control the number of EBV-infected B cells in their bodies. This may allow the infected B cells to accumulate in the brain, where they interact with and instruct other immune cells called T cells to attack myelin.

Additionally, these EBV-infected B cells produce antibodies, some of which may also attack myelin.

1

Under normal conditions, T cells bind to EBV-infected B cells.

Illustration of T cells binding to EBV-infected B cells outside of the brain.
2

T cells then destroy EBV-infected B cells, keeping their numbers in check.

T cells binding to EBV-infected B cells
3

In MS, the immune system doesn't function properly, which may allow EBV-infected B cells to accumulate and enter the brain.

MS damaged central nervous system
4a

Inside the brain, EBV-infected B cells may instruct T cells to attack myelin.

MS damaged central nervous system
4b

EBV-infected B cells also produce antibodies, some of which may attack myelin.

Myelin, antibody, ebv-infected-b-cell
5

Together, this autoimmune response may cause the destruction of myelin, leading to the symptoms of MS.

Myelin, autoimmune, t-cell antibody

Resources

Here, you’ll find links to MS-related organizations and support groups.