Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Regulatory immune cell diversity tempers autoimmunity in rheumatoid arthritis

09.05.2012
Untangling the root cause of rheumatoid arthritis has been a difficult task for immunologists, as decades of research has pointed to multiple culprits in our immune system, with contradictory lines of evidence.
Now, researchers at The Wistar Institute announce that it takes a diverse array of regulatory T cells (a specialized subset of white blood cells) to prevent the immune system from generating the tissue-specific inflammation that is a hallmark of the disease. Regulatory T cell diversity, the researchers say, provides a cumulative protective effect against rheumatoid arthritis. When that diversity is not present, it allows the immune system to attack joints.

The Wistar scientists presented their findings, developed in a mouse model of rheumatoid arthritis, in the May 1 issue of the Journal of Immunology. Defining the immune mechanisms involved in rheumatoid arthritis could point to new therapies for the disease.

“Our results show, surprisingly, that suppressing the immune response against a single target will not shut down the inflammatory response that causes rheumatoid arthritis,” said Andrew J. Caton, Ph.D., senior author and professor in The Wistar Institute Cancer Center’s Tumor Microenvironment and Metastasis program. “Instead, an array of inflammation-stimulating antigens may be involved in causing the disease, since our study shows that an array of regulatory T cells is required to temper the immune system’s attack on joints.”

Rheumatoid arthritis (RA) is an autoimmune disorder that occurs as the immune system attacks the synovium, the membrane that lines all the joints of the body. It is a common disorder that causes uncontrolled inflammation—resulting in pain and swelling—around the joints. It is thought that approximately one percent of the adult population, worldwide, suffers from rheumatoid arthritis. RA has shown to be exacerbated by drinking and smoking, and the disease can lead to an overall increased risk of death.

While the exact cause of RA is unknown, the Caton laboratory and others have shown that a variety of white blood cells called regulatory T cells (or Tregs) are a necessary component to either restrain (or encourage) the immune system’s inflammatory response. Tregs are activated as molecules on their surface membranes called T cell receptors interact with “friendly” or “self” molecules—a way for the immune system to recognize friend from foe. Mismanagement of these Tregs, which normally serve to restrain the immune system from over-reacting to healthy tissue, could then lead to runaway inflammation.

In this study, the researchers sought to examine how T cell receptors affect the ability of Tregs to suppress arthritis in a mouse that had been bred to express a “self” molecule that drives arthritis. They showed that an array of Tregs given to the mice effectively stops arthritis. Unexpectedly, however, Tregs that are specific for the surrogate “self” molecule do not prevent arthritis.

“We find that the Treg responsible for recognition of the disease-initiating self antigen are sufficient for stopping arthritis, but a diverse repertoire of Tregs are very effective,” Caton said. “All of these Tregs, together, influence other components of the immune system which serves to slow down the inflammatory process that causes RA.”

According to Caton, their findings also point to a possible answer of why the immune system targets the membranes that line joints. Tregs influence other types of T cells to produce a substance known as IL-17, and these cells often travel through the body’s lymphatic system where they then drain out into the joints.

“The big unanswered question of RA is ‘why are joints targeted?’” Caton said. “Of all the tissues in the body, of all the places our immune system could attack, this question remains.”

“One idea is that the immune system isn’t deliberately attacking joints in patients with rheumatoid arthritis,” Caton said, “but the joint inflammation is a side effect of the natural tendency of these cells to accumulate in these areas of the body.”

Funding for this project was provided by the National Institutes of Health’s National Institute for Allergy and Infectious Disease and National Cancer Institute, and a grant from Sibley Memorial Hospital.

The lead author of this study is Soyoung Oh, Ph.D., a postdoctoral fellow in the Caton laboratory, and co-authors include Caton laboratory members Malinda Aitken, Donald M. Simons, Ph.D, Alissa Basehoar, Victoria Garcia, and Elizabeth Kropf.

The Wistar Institute is an international leader in biomedical research with special expertise in cancer research and vaccine development. Founded in 1892 as the first independent nonprofit biomedical research institute in the country, Wistar has long held the prestigious Cancer Center designation from the National Cancer Institute. The Institute works actively to ensure that research advances move from the laboratory to the clinic as quickly as possible. The Wistar Institute: Today’s Discoveries – Tomorrow’s Cures.

Greg Lester | EurekAlert!
Further information:
http://www.wistar.org

More articles from Health and Medicine:

nachricht Organ-on-a-chip mimics heart's biomechanical properties
23.02.2017 | Vanderbilt University

nachricht Researchers identify cause of hereditary skeletal muscle disorder
22.02.2017 | Klinikum der Universität München

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>