LA JOLLA, CA May 6, 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 fallssuch 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 cellsspecifically, 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 channelsthe so-called thermoTRPs. "These proteins translate temperature, which is a physical stimulus, into a chemical signalions 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
|Contact: Mika Ono|
Scripps Research Institute