Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New immune cell found to be a key to inflammatory diseases

04.10.2005


The molecular roots of inflammatory and autoimmune diseases such as asthma, arthritis, and multiple sclerosis (MS) have been discovered by a team of researchers led by The University of Texas M. D. Anderson Cancer Center. They say their findings may point to ways to effectively treat these diseases - if not stop them before they start.



In a lead article in the November issue of Nature Immunology (released online on Oct. 2), the scientists report finding a novel type of "T helper" cell they say is the culprit for initiating chronic inflammation and autoimmunity in a variety of body tissues. This newly described T cell - which they call inflammatory TH cells (or THi) - produces interleukin 17 (IL-17), a potent cytokine that researchers have already linked to an immune system gone awry.

"We suspected that IL-17 is a player in autoimmune and inflammatory diseases, but we didn’t understand where IL-17 came from before this finding," says the study’s lead investigator, Chen Dong, Ph.D., an associate professor in the Department of Immunology.


"Now we have discovered the source of IL-17 and also have solidly demonstrated that these are the crucial cells that regulate tissue inflammation in autoimmune disease and asthma," he says. "These findings suggest that shutting down the activity of these THi cells might stop chronic inflammatory diseases from developing in the first place."

He adds that while such drugs are years away from development and clinical trials, agents that block IL-17 could represent an effective treatment, based on these results.

Dong and four other M. D. Anderson researchers collaborated with scientists from the University of Washington, the Institute for Systems Biology in Seattle and Johns Hopkins School of Medicine.

While the findings have no immediate relevance to the field of oncology, it is known that cancer can arise from inflammatory processes. Further understanding of how the immune system functions, and how it can go awry, is important, Dong says.

T cells are white blood cells that play a variety of roles in the immune system, including the identification of foreign molecules in the body, such as bacteria and viruses, and the activation and deactivation of other immune cells.

T helper cells are specific T cells that have receptors that recognize and bind to fragments (known as antigens) of the invaders that already have been displayed on the surface of other immune system cells. (These T helper cells are also called CD4 T cells since they express CD4 molecules.) Once the antigen has been bound, these T helper cells become activated, and they morph into "effector" cells which then boost an immune response by secreting "cytokine" molecules such as interleukins and interferons.

Before this study, two such different types of effector T helper cells had been known - type I (TH1), linked to the body’s response to microbial infection, and type 2 (TH2), which plays a crucial function in production of B cell antibodies and also is associated with development of allergies.

Although TH1 and TH2 are known to produce powerful cytokines - such as interferon-gamma (IFN-g) and allergy-associated interleukin 4 (IL-4), respectively - they are not inflammatory or associated with production of IL-17, which sets off an errant immune response that results in tissue inflammation.

Researchers could not understand the origins of such an inflammatory response in body tissues. The only clue they had was that excess IL-17 molecules are found in arthritic joints, in lungs swollen by asthma and in brain cells that lead to nerve degeneration and the onset of MS. "But we didn’t know which T cells were responsible for secreting IL-17," Dong says. To find out where IL-17 came from, the researchers designed a series of cell culture studies and mouse experiments. In brief, they "educated" T helper cells to become IL-17 producing cells. They found that IL-17 is triggered by a unique set of signals that now define this new "lineage" of T helper cells. "They are completely different from TH1 and TH2 effector cells," says Dong. They then used a mouse model of MS and demonstrated that they could stop development of the disease with an antibody agent that blocked IL-17. Finally, they developed a transgenic mouse model of asthma and found that, by producing excessive IL-17 in the lung, they were able to produce asthmalike symptoms.

Dong says the researchers hypothesize that these newly discovered THi cells travel to selected body tissues and release IL-17. This action, in turn, stimulates expression of "chemokines," which results in a rush of inflammatory cells into the tissue. Thus a chronic inflammatory reaction is set up, he says.

The scientists don’t know what initially sets off activation of the newly discovered T helper cell in diseases such as arthritis and asthma, Dong says. "We don’t know why these dangerous helper T cells are activated in the patients, but we now know how they function, and that should take us a long way to understanding and treating these and other inflammatory and autoimmune diseases."

Nancy Jensen | EurekAlert!
Further information:
http://www.mdanderson.org

More articles from Life Sciences:

nachricht During HIV infection, antibody can block B cells from fighting pathogens
14.08.2018 | NIH/National Institute of Allergy and Infectious Diseases

nachricht First study on physical properties of giant cancer cells may inform new treatments
14.08.2018 | Brown University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

'Building up' stretchable electronics to be as multipurpose as your smartphone

14.08.2018 | Information Technology

During HIV infection, antibody can block B cells from fighting pathogens

14.08.2018 | Life Sciences

First study on physical properties of giant cancer cells may inform new treatments

14.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>