Vaccine Against Multiple Sclerosis? Mouse Experiment Yields Promising Results

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http://www.sciencedaily.com/releases/2008/12/081201105851.htm

Vaccine Against Multiple Sclerosis? Mouse Experiment Yields Promising

Results

ScienceDaily (Dec. 3, 2008) — Some 80,000 people in Germany suffer from

multiple sclerosis – their immune system attacks and destroys healthy nerve

tissue. Researchers at the Heidelberg University Hospital and the German

Cancer Research Center in Heidelberg have succeeded in vaccinating mice with

specially treated, autologous immune cells and preventing them from

developing encephalitis, which is similar to multiple sclerosis in humans.

A protein of the nervous system, that is the target of the harmful immune

reaction in multiple sclerosis, was placed on the surface of the cells; the

cells were treated with an agent that suppresses immune defense.

The Heidelberg researchers have published their results, initially online,

in the Proceedings of the National Academy of Sciences USA.

The team around Professor Dr. Terness is working in the Department of

Transplantation Immunology (Director: Professor Dr. Gerhard Opelz) of the

Institute of Immunology at the Heidelberg University Hospital. Professor

Terness and his colleagues work primarily on developing methods to prevent

rejection of donor organs without impairing the immune system.

Vaccine developed from transplant research

“The vaccine against multiple sclerosis works on the same principle,”

explains Professor Terness. “We have to teach the immune system not to fight

the donor organ, or in this case its own nerve cells, as a foreign body.”

In the course of their research on organ rejection, the scientists

successfully treated immune cells (known as dendritic cells) of a donor

animal with the chemotherapeutic agent mitomycin and injected them into the

organ recipient before transplantation – the modified cells were not

attacked. The immune system of the transplant recipient subsequently

accepted the tissue of the donor animal as well. The results were published

in “Transplantation” in 2007.

Treated cells suppress the immune response

Subsequently, Professor Terness’s team used this procedure to suppress the

harmful immune response in multiple sclerosis – in cooperation with Dr.

Thilo Oelert from the Department of Molecular Immunology at the German

Cancer Research Center they loaded immune cells from mice with a self

protein from the nervous system, treated them with mitomycin, and reinjected

them into the animals. Afterwards, experimental autoimmune encephalitis –

the equivalent of multiple sclerosis in humans – could no longer be induced

in these mice; they were resistant.

“The treated cells express the target protein and simultaneously suppress

the immune response. In this manner, the immune cells become accustomed to

the protein and do not attack it later, even without the inhibitor,”

explains Professor Terness.

The researchers now want to study whether this method is also effective for

treating already-existing multiple sclerosis. They will use animal

experiments to study whether the vaccine with treated autologous cells has

not only a preventive effect, but a therapeutic effect as well.

Journal reference:

Terness, Thilo Oelert, Ehser, Jing Jing Chuang, Imad Lahdou,

Christian Kleist, Florian Velten, Günter J. Hämmerling, Bernd Arnold and Gerhard

Opelz. Mitomycin C-treated dendritic cells inactivate autoreactive T cells:

Toward the development of a tolerogenic vaccine in autoimmune diseases. Proc

Natl Acad Sci USA, 2008; DOI: 10.1073/pnas.0807185105