Discovery of immune cells that protect against multiple sclerosis offers hope for new treatment

In multiple sclerosis, the immune system attacks nerves in the brain and spinal cord, causing movement problems, muscle weakness and loss of vision. Immune cells called dendritic cells, which were previously thought to contribute to the onset and development of multiple sclerosis, actually protect against the disease in a mouse model, according to a study published by Cell Press in the August issue of the journal Immunity. These new insights change our fundamental understanding of the origins of multiple sclerosis and could lead to the development of more effective treatments for the disease.

"By transfusing dendritic cells into the blood, it may be possible to reduce autoimmunity," says senior study author Ari Waisman of University Medical Center of Johannes Gutenberg University Mainz. "Beyond multiple sclerosis, I can easily imagine that this approach could be applied to other , such as and psoriasis."

In an animal model of multiple sclerosis known as experimental autoimmune encephalomyelitis (EAE), called trigger the disease after being activated by other immune cells called antigen-presenting cells (APCs). Dendritic cells are APCs capable of activating T cells, but it was not known whether dendritic cells are the APCs that induce EAE.

In the new study, Waisman and his team used genetic methods to deplete dendritic cells in mice. Unexpectedly, these mice were still susceptible to EAE and developed worse autoimmune responses and disease clinical scores, suggesting that dendritic cells are not required to induce EAE and other APCs stimulate T cells to trigger the disease. The researchers also found that dendritic cells reduce the responsiveness of T cells and lower susceptibility to EAE by increasing the expression of PD-1 receptors on T cells.

"Removing dendritic cells tips the balance toward T cell-mediated autoimmunity," says study author Nir Yogev of University Medical Center of Johannes Gutenberg University Mainz. "Our findings suggest that dendritic cells keep immunity under check, so transferring dendritic cells to patients with multiple sclerosis could cure defects in T cells and serve as an effective intervention for the disease."

More information: Yogev et al.: "Dendritic Cells Ameliorate Autoimmunity in the CNS by Controlling the Homeostasis of PD-1 Receptor+ Regulatory T Cells."
dx.doi.org/10.1016/j.immuni.2012.05.025

Related Stories

Skin sentry cells promote distinct immune responses

Jul 21, 2011

A new study reveals that just as different soldiers in the field have different jobs, subsets of a type of immune cell that polices the barriers of the body can promote unique and opposite immune responses against the same ...

When helper cells aren't helpful

May 24, 2010

Current research suggests that T helper-type 1 (Th1) cells, previously thought to mediate autoimmunity, may actual inhibit the development of experimental immune encephalomyelitis (EAE), a mouse model of multiple sclerosis ...

How excess alcohol depresses immune function

Aug 16, 2011

Alcoholism suppresses the immune system, resulting in a high risk of serious, and even life-threatening infections. A new study shows that this effect stems largely from alcohol’s toxicity to immune system cells called ...

New origin found for a critical immune response

Mar 01, 2009

An immune system response that is critical to the first stages of fighting off viruses and harmful bacteria comes from an entirely different direction than most scientists had thought, according to a finding by researchers ...

Dendritic cells ensure immune tolerance

Mar 16, 2009

Dendritic cells are essential to the body's immune defenses. Now, Ludwig-Maximilians-Universitaet Muenchen (Germany) researchers show that they also have to protect the body from itself: They help to identify any immune cells ...

Recommended for you

For an immune cell, microgravity mimics aging

Apr 22, 2014

(Medical Xpress)—Telling someone to "act your age" is another way of asking him or her to behave better. Age, however, does not always bring improvements. Certain cells of the immune system tend to misbehave ...

User comments