Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers define link between eosinophils and asthma

17.09.2004


Mayo Clinic researchers have used a comparative genomic strategy to demonstrate a causative link between eosinophils, a rare type of white blood cell, and asthma. Their research shows that the presence of these unique blood cells is absolutely required for the development of asthma. The details of this animal-based study appear in the Sept. 17, 2004, issue of Science, the journal of the American Association for the Advancement of Science (AAAS).



For more than a century, scientists have known that eosinophils are often the dominant inflammatory cells present in the lungs of asthma patients, but the importance of these white blood cells has been poorly understood with some studies even discounting a role for these cells. This new study demonstrates that eosinophils are required for the mucus accumulation and the lung dysfunction associated with asthma.

Using the tools of genomics, Mayo Clinic researchers have engineered a mouse that is specifically devoid of eosinophils, but otherwise has a full complement of blood-derived cells. Disease symptoms in these transgenic mice were dramatically reduced, and in some cases completely eliminated, following exposure to an allergen that in normal animals leads to asthma.


The development of a unique and novel transgenic mouse model without eosinophils now permits a definitive assessment of a number of human diseases besides asthma that have been linked to this white blood cell, including allergic diseases, parasite infections and cancer.

"Demonstrating that the eosinophil, a rare and often ignored cell, is a central mediator in the inflammation associated with asthma is a very important finding," says James J. Lee, Ph.D., director, Special Animal Services Laboratory at Mayo Clinic in Scottsdale, Ariz. "The outcomes of this study suggest the possibility of developing novel therapies and pharmaceuticals to treat and/or prevent asthma."

The Study

Researchers at Mayo Clinic Scottsdale created genetically-engineered transgenic mice that selectively express a toxic "suicide" gene, diphtheria toxin A, in bone marrow stem cells that go on to become circulating eosinophils in the blood. As a result of the selective expression of this toxin, unique marrow stem cells are eliminated and eosinophils never appear in circulation. The resulting mice have a normal complement of all red and white blood cell types except they are uniquely devoid of eosinophils.

Lung disease studies were conducted by comparing the responses of these transgenic mice without eosinophils relative to normal animals that contain eosinophils following exposure to an airborne allergen that provoked symptoms characteristic of asthma.

Significance of the Discovery

This study clearly shows that eosinophil activities are important contributing factors leading to symptoms classically defined as hallmark features of asthma. Future medical genomics studies will seek to confirm these findings in asthma patients and to further define the role of eosinophils in human disease, thereby widening the understanding of the principle causes of asthma and leading to targeted therapeutic approaches previously dismissed or overlooked. Because no known human patients or naturally occurring mutations in the mouse have been reported to be deficient of eosinophils without other additional consequences, this transgenic mouse model represents an important opportunity to define unambiguously the specific role of eosinophils in many diseases.

Participants in the Study

In addition to Dr. James J. Lee, others involved in the research include Dawn Dimina; MiMi P. Macias, PhD; Sergei I. Ochkur, PhD; Michael P. McGarry, PhD; Katie R. O’Neill, PhD; Cheryl Protheroe; Ralph Pero; Thanh Nguyen, M.D.; Stephania A. Cormier, PhD; Elizabeth Lenkiewicz; Dana Colbert; Lisa Rinaldi; Steven J. Ackerman, PhD; Charles G. Irvin, PhD; and Nancy A. Lee, PhD.

Support

The research was supported by grants from the Mayo Foundation, the American Heart Association, and the National Institutes of Health.

Bob Nellis | EurekAlert!
Further information:
http://www.mayo.edu

More articles from Life Sciences:

nachricht Complete skin regeneration system of fish unraveled
24.04.2018 | Tokyo Institute of Technology

nachricht Scientists generate an atlas of the human genome using stem cells
24.04.2018 | The Hebrew University of Jerusalem

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Quantum Technology for Advanced Imaging – QUILT

24.04.2018 | Information Technology

AWI researchers measure a record concentration of microplastic in arctic sea ice

24.04.2018 | Earth Sciences

Complete skin regeneration system of fish unraveled

24.04.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>