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 Serious children’s infections also spreading in Switzerland
26.07.2017 | Universitätsspital Bern

nachricht New vaccine production could improve flu shot accuracy
25.07.2017 | Duke University

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: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

CCNY physicists master unexplored electron property

26.07.2017 | Physics and Astronomy

Molecular microscopy illuminates molecular motor motion

26.07.2017 | Life Sciences

Large-Mouthed Fish Was Top Predator After Mass Extinction

26.07.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>