Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists show how shifts in temperature prime immune response

09.05.2011
Researchers at The Scripps Research Institute have found a temperature-sensing protein within immune cells that, when tripped, allows calcium to pour in and activate an immune response. This process can occur as temperature rises, such as during a fever, or when it falls—such as when immune cells are "called" from the body's warm interior to a site of injury on cooler skin.

The study, recently published online ahead of print by Nature Chemical Biology, is the first to find such a sensor in immune cells—specifically, in the T lymphocytes that play a central role in activation of killer immune cells. The protein, STIM1, previously known as an endoplasmic reticulum (ER) calcium sensor, had been thought to be important in immune function, and now the scientists show it is also a temperature sensor.

"Temperature has a profound effect on all biological processes including immune responses, but surprisingly little is known about molecules in immune cells that sense temperature sifts," said the study's principal investigator, Scripps Research Professor Ardem Patapoutian. "Here we show that STIM1 senses temperature and has a profound impact on immune cells."

This is the second family of thermosensation molecules that the Patapoutian laboratory has uncovered. The team has isolated and characterized three of six members of the transient receptor potential (TRP) family of ion channels—the so-called thermoTRPs. "These proteins translate temperature, which is a physical stimulus, into a chemical signal—ions flowing into cells," said Patapoutian.

"ThermoTRPs mainly function in specialized sensory neurons that relay environmental temperature information to the brain."

In this study, the researchers turned to immune cells to look for temperature sensors. "Immune cells can experience dramatic temperature changes under either normal or pathophysiological conditions," said first author Bailong Xiao, a research associate in the Patapoutian laboratory. "The temperature drops significantly when, say, immune cells move from the 37 degree Celsius temperature of the spleen to skin, where it is normally 33 degrees. During fever, core body temperature can rise to 41 degrees." Scientists have discussed for decades whether fever is beneficial to the immune system. The researchers believe that identification of a molecular sensor of temperature within immune cells provides a novel avenue to address such questions mechanistically.

The research team, which included Bertrand Coste and Jayanti Mathur, also of the Patapoutian lab, found that STIM1 can be activated by heat with a high degree of temperature sensitivity. Both STIM1 and a plasma membrane pore-forming protein known as Orai1 have recently been identified as essential components of the so-called the calcium release activated calcium (CRAC) channel. But STIM1 had not been known to be heat sensitive until this research, according to Xiao.

The process goes like this: STIM1 proteins are located on the ER, which is the organelle that stores calcium inside the cell. When a sudden change in temperature occurs, STIM1 proteins cluster together and translocate close to the plasma membrane. There, these clusters then can activate Orai1, which leads to the opening of the channel pore and an influx of calcium to activate the cell. Calcium is essential for a number of cellular functions, and, in immune cells, a sustained influx of calcium into these cells activates gene expression and cell proliferation. It turns the immune cell "on," Xiao said.

The function of STIM1 and Orai1 had already been known to be critical to immune function, Xiao said. Mutations in genes encoding either of the proteins lead to development of severe combined immunodeficiency (SCID), the so-called "bubble boy" disease characterized by a complete absence of immunity.

Given the relatively wide expression pattern of STIM1, the researchers suggest that STIM1 may also function as a temperature sensor in other tissues in addition to immune system, including skin, brain, skeletal muscle, and even in blood platelets, all of which could experience moderate but significant temperature changes. For example, temperature-induced STIM1-mediated calcium influx may help muscle cells remodel after exercise, Xiao explained. "We know that calcium is very important for skeletal muscle physiology and remodeling. Temperature can rise in skeletal muscles when they are exercised."

The same principle may be working in blood platelets, where STIM1 is also found and plays important roles, he said. When platelets move to the skin surface to repair a cut, the change in temperature may activate STIM1, which can contribute to platelet activation, resulting in formation of a clot, Xiao said.

While sensing temperature is essential for survival and efficient metabolism, it is not clear yet if and how these findings can be clinically translated, said Patapoutian. "It is too early to make predictions on the implications of these findings, but STIM1 and Orai1 are of interest to the pharmaceutical industry given their role in immunodeficiency."

The study was funded by grants from the National Institutes of Health and the Novartis Research Foundation. For more information on the study, see http://www.nature.com/nchembio/journal/vaop/ncurrent/abs/nchembio.558.html .

About The Scripps Research Institute

The Scripps Research Institute is one of the world's largest independent, non-profit biomedical research organizations. Scripps Research is internationally recognized for its discoveries in immunology, molecular and cellular biology, chemistry, neuroscience, and vaccine development, as well as for its insights into autoimmune, cardiovascular, and infectious disease. Headquartered in La Jolla, California, the institute also includes a campus in Jupiter, Florida, where scientists focus on drug discovery and technology development in addition to basic biomedical science. Scripps Research currently employs about 3,000 scientists, staff, postdoctoral fellows, and graduate students on its two campuses. The institute's graduate program, which awards Ph.D. degrees in biology and chemistry, is ranked among the top ten such programs in the nation.

Mika Ono | EurekAlert!
Further information:
http://www.scripps.edu

More articles from Life Sciences:

nachricht Individual Receptors Caught at Work
19.10.2017 | Julius-Maximilians-Universität Würzburg

nachricht Rapid environmental change makes species more vulnerable to extinction
19.10.2017 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Electrode materials from the microwave oven

19.10.2017 | Materials Sciences

New material for digital memories of the future

19.10.2017 | Materials Sciences

Physics boosts artificial intelligence methods

19.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>