Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers identify T cell that relieves asthma in mice

27.09.2004


For the second time in two years, scientists at the Stanford University School of Medicine have discovered a new type of regulatory T cell that reduces asthma and airway inflammation in mice, bolstering the theory that a deficiency of such cells is a prime cause of the breathing disorder as well as allergies.



The team’s research not only provides a detailed profile of these newfound cells but also sheds light on how such cells are related to other T cells and suggests that there exists a spectrum of regulatory T cells, known as Tregs, to be identified and studied. "It’s likely that Tregs aren’t functioning or developing properly in people who suffer from asthma and allergies," said Dale Umetsu, MD, PhD, professor of pediatrics who led the research team. "This new understanding of the fine characteristics of regulatory T cells brings us closer to developing therapies that will provide cures for allergies, asthma, and perhaps a number of other diseases involving immune dysregulation," added Umetsu, who is also chief of the division of allergy and immunology at Lucile Packard Children’s Hospital at Stanford.

Humans have a variety of T cells - including regulatory (Tregs), helper (Th) and natural killer (NKTs) - and there are different types within each of those categories. But all of them play a critical role in how, ideally, the human immune system responds when invaded by viruses, bacteria and allergens: the cells fight the enemies - the viruses and bacteria - and ignore the innocuous visitors - the allergens. The problem for allergy and asthma sufferers is that the body responds to allergens as if they were reviled foes, engaging in a full-out battle that inflames airways and impedes breathing.


In hopes of preventing such reactions, the Stanford researchers have been studying the Tregs, which appear to act as the immune system’s peacekeepers, signaling to other T cells when to hold off from attacking an intruder. Two years ago, they identified one type of Treg cell that could reduce airway inflammation and asthma in mice. And now, in a study published in the Sept. 26 online version of Nature Immunology, they have identified another type of regulatory T cell that produced the same result: the airways of mice that received injections of the cells were not inflamed despite confrontation with allergens.

The team’s findings also show that all of the Tregs share important features that might explain how they exert a calming influence on their battle-hungry brethren. Before now, researchers had identified two broad categories of Tregs - natural and adaptive. Natural Tregs are produced in the thymus, are always present in predictable quantities and appear to be important in the prevention of autoimmune disease. Adaptive regulatory T cells, the type studied by Umetsu and his colleagues, develop in response to incoming invaders and have been thought be to quite distinct from natural Tregs.

But Umetsu and his colleagues found that both the adaptive and natural Tregs depend on a gene called Foxp3. When this gene doesn’t function properly in humans, they lack natural Tregs and develop an autoimmune disorder called IPEX Syndrome, which includes severe allergies among its symptoms. By identifying this gene in the adaptive Tregs, the researchers add credence to the idea that nonfunctional or inadequate Tregs lead to allergies.

The researchers also found that the two adaptive Tregs share certain characteristics. Both appear to communicate their peacekeeping message using the same language: they produce a chemical called IL-10 and signal their desires through the same pipeline, known as the ICOS-ICOSL regulatory pathway.

But the two types of Tregs exhibit intriguing differences. Umetsu said each appears to be associated with a different helper T cell (Th cell). Each Treg has a gene turned on that is also turned on in the corresponding Th cell, and each Treg appears to be produced in greater numbers when its corresponding Th cell responds to an intruder. Although an excess of one of the Th cells is associated with autoimmune diseases such as multiple sclerosis and type 1-diabetes, and an excess of the other is linked to allergies and asthma, both Th cells cause inflammation. In turn, the two Treg cells have the opposite effect. "Both can help reduce airway inflammation," said Umetsu. "We have now found several subtypes of regulatory T cells," he added, "and we are proposing how these are all interrelated. We believe this study provides a scaffold for future studies of regulatory T cells."

Umetsu’s Stanford collaborators include Philippe Stock, MD, PhD; Omid Akbari, PhD; Rosemarie DeKruyff, PhD, professor of pediatrics; and Gerald Berry, MD, associate professor of pathology.

Katharine Miller | EurekAlert!
Further information:
http://www.stanford.edu

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>