Featured Research

from universities, journals, and other organizations

Immune system release valve: Scientists reveal a new mechanism for keeping inflammation in check

Date:
May 26, 2011
Source:
Weizmann Institute of Science
Summary:
Scientists have discovered a mechanism that controls inflammation similarly to a steam-engine valve: just when the inflammatory mechanism that protects cells against viruses reaches its peak of activity, the molecular "steam-release valve" interferes, restoring this mechanism to its resting state, ready for re-activation.

The molecular machines that defend our body against infection don't huff and puff, but some of them apparently operate on the same principle as a steam engine. Weizmann Institute scientists have discovered a mechanism that controls inflammation similarly to a steam-engine valve: Just when the inflammatory mechanism that protects cells against viruses reaches its peak of activity, the molecular "steam-release valve" interferes, restoring this mechanism to its resting state, ready for re-activation. This finding might shed new light on such inflammatory disorders as rheumatoid arthritis or inflammatory bowel disease, and point the way to developing effective therapies.

Related Articles


How does the cellular "steam-release valve" work? The scientists have discovered that its crucial component is the enzyme called caspase-8. When the cell is invaded by a virus, caspase-8 joins a large molecular complex that forms in order to send out an inflammatory signal. However, this same signal, once triggered, makes sure that the inflammatory response will eventually be shut down. The mechanism can be likened to the peak of the steam cycle when the valve opens, releasing steam and restoring the engine to its initial position. In the case of the cell, the inflammatory signal prompts caspase-8 to destroy a protein called RIP1 -- a crucial signal amplifier -- after RIP1 has reached a state in which it can produce maximal amplification. The inflammatory cycle is thus completed: The signaling mechanism, precisely after reaching its peak activity level, returns to its neutral state, ready to enter yet another inflammatory cycle in case the cell is still under viral attack.

Until recently, caspase-8, discovered by study leader Prof. David Wallach of Weizmann's Biological Chemistry Department some 15 years ago, was known to prevent inflammation in only one way -- by causing damaged cells to self-destruct in a process called apoptosis. In the course of this process, the contents of the dying cells are prevented from spreading around and triggering inflammation. The present study, reported recently in Immunity, reveals an entirely new mechanism by which caspase-8 can control inflammation more directly. The research was performed in Wallach's lab by Dr. Akhil Rajput, Dr. Andrew Kovalenko, Dr. Konstantin Bogdanov, Seung-Hoon Yang, Dr. Tae-Bong Kang, Dr. Jin-Chul Kim and Dr. Jianfang Du.

The study results might be relevant for various types of inflammation -- not only that caused by viruses -- and can thus provide important insights into inflammatory disorders. Since such disorders may occur when the inflammatory response fails to be shut down properly, it's possible that caspase-8 malfunction and the resulting excessive activity of the RIP1 "signal amplifier" might be involved. And if this is indeed the case, a new treatment approach could aim at blocking RIP1, thereby fighting inflammation in a precise and selective manner.

Prof. David Wallach's research is supported by the M.D. Moross Institute for Cancer Research; and the Leona M. and Harry B. Helmsley Charitable Trust. Prof. Wallach is the incumbent of the Joseph and Bessie Feinberg Professorial Chair.


Story Source:

The above story is based on materials provided by Weizmann Institute of Science. Note: Materials may be edited for content and length.


Journal Reference:

  1. Akhil Rajput, Andrew Kovalenko, Konstantin Bogdanov, Seung-Hoon Yang, Tae-Bong Kang, Jin-Chul Kim, Jianfang Du, David Wallach. RIG-I RNA Helicase Activation of IRF3 Transcription Factor Is Negatively Regulated by Caspase-8-Mediated Cleavage of the RIP1 Protein. Immunity, 2011; 34 (3): 340 DOI: 10.1016/j.immuni.2010.12.018

Cite This Page:

Weizmann Institute of Science. "Immune system release valve: Scientists reveal a new mechanism for keeping inflammation in check." ScienceDaily. ScienceDaily, 26 May 2011. <www.sciencedaily.com/releases/2011/05/110525110153.htm>.
Weizmann Institute of Science. (2011, May 26). Immune system release valve: Scientists reveal a new mechanism for keeping inflammation in check. ScienceDaily. Retrieved November 22, 2014 from www.sciencedaily.com/releases/2011/05/110525110153.htm
Weizmann Institute of Science. "Immune system release valve: Scientists reveal a new mechanism for keeping inflammation in check." ScienceDaily. www.sciencedaily.com/releases/2011/05/110525110153.htm (accessed November 22, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Saturday, November 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

WFP: Ebola Risks Heightened Among Women Throughout Africa

WFP: Ebola Risks Heightened Among Women Throughout Africa

AFP (Nov. 21, 2014) Having children has always been a frightening prospect in Sierra Leone, the world's most dangerous place to give birth, but Ebola has presented an alarming new threat for expectant mothers. Duration: 00:37 Video provided by AFP
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. Video provided by Newsy
Powered by NewsLook.com
Milestone Birthdays Can Bring Existential Crisis, Study Says

Milestone Birthdays Can Bring Existential Crisis, Study Says

Newsy (Nov. 21, 2014) Researchers find that as people approach new decades in their lives they make bigger life decisions. Video provided by Newsy
Powered by NewsLook.com
Ebola: Life Without School in Guinea

Ebola: Life Without School in Guinea

AFP (Nov. 21, 2014) Following the closure of schools and universities in Guinea because of the Ebola virus, students look for temporary work or gather in makeshift classrooms to catch up on their syllabus. Duration: 02:14 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins